An expandable fastener for orthopaedic applications

Abstract

An expandable fastener for orthopaedic applications is disclosed. In one form, the expandable fastener is arranged for fastening when positioned in a bore hole in bone, and comprises a body operable coaxial with an axis of the expandable fastener. The fastener further comprises an expansion member having at least one expansion portion moveable between a contracted configuration and an expanded configuration such that, in use, the or each expansion portion moves outwardly from the axis of the body towards the bone surrounding the bore hole when moving towards the expanded configuration. An actuator is provided that is arranged movable along the axis. A coupling arrangement is also provided that is configured operable for coupling the expansion member with the actuator for enabling operation of the or each expansion portion toward / or from the contracted / expanded configurations via the actuator. In one form, the coupling arrangement is configured so as to directly couple the expansion member with the actuator so that the actuator captively supports or retains the expansion member so that relative movement between the actuator and the expansion member along the axis is substantially restrained.

Description

[0001] AN EXPANDABLE FASTENER FOR ORTHOPAEDIC APPLICATIONS

[0002] Field of the Invention

[0003] The present disclosure relates to an expandable fastener for orthopaedic applications.

[0004] Related applications

[0005] The present application claims priority to Australian provisional patent application No. 2023901768 filed 5 June 2023, the content of which is incorporated herein by reference in its entirety.

[0006] Background of the Invention

[0007] Expandable fasteners have been used for orthopaedic applications in order to increase fixation strength and decrease the risk of failures. Such expandable fasteners are inserted into holes in bone in which they expand and secure broken portions of the bone.

[0008] Expandable fasteners of this type can also be used for applications in which they interface with, or are coupled to, another device such as plates and rods. For example, expandable fasteners are used when securing portions of the femur when the femur neck is fractured and may also be used for securing femur nails in the femur.

[0009] After the bone has healed, the expandable fasteners are usually removed from the bore holes in order to avoid leaving a foreign body inside the human body. However, fasteners, and especially expandable fasteners, present hollows and asperities, into which bone may grow, preventing the ability to remove the fasteners. Removal of the fasteners requires contracting the fasteners from an expanded configuration to a contracted configuration.

[0010] However, ingrowth of bone often makes it impossible to contract the fasteners, which can result in complications.

[0011] The present applicant’s US patent no. 10,729,480 (the disclosure of which is incorporated herein by reference in its entirety) discloses an expandable fastener arranged to reduce ingrowth of bone and facilitate removal of the fastener. Challenges can be faced when seeking to apply principles having advantageous utility and on which high performing expandable fasteners operate to a scale (miniaturisation) appropriate for use in intricate / complex surgeries, such as for example, spinal surgeries. It is against this general background that the embodiments described herein have been developed.

[0012] Summary of the Invention

[0013] In a first aspect of the present invention there is provided an expandable fastener for orthopaedic applications, the expandable fastener being arranged for fastening when positioned in a bore hole in bone, the expandable fastener comprising: a body having an axis; an expansion member comprising at least one expansion portion moveable between a contracted configuration and an expanded configuration such that, in use, the or each expansion portion moves outwardly from the axis of the body towards the bone surrounding the bore hole when moving towards the expanded configuration; an actuator or actuable means movable along the axis of the body; and a coupling arrangement operable for coupling the expansion member with the actuator for enabling operation of the or each expansion portion toward / or from the contracted / expanded configurations via the actuator, the coupling arrangement configured so as to directly couple the expansion member with the actuator such that relative movement between the actuator and the expansion member along the axis is substantially restrained.

[0014] In a second aspect, there is provided an expandable fastener for orthopaedic applications, the expandable fastener being arranged for fastening when positioned in a bore hole in bone, the expandable fastener comprising: a body operable coaxial with an axis of the expandable fastener; an expansion member comprising at least one expansion portion moveable between a contracted configuration and an expanded configuration such that, in use, the or each expansion portion moves outwardly from the axis towards the bone surrounding the bore hole when moving towards the expanded configuration; an actuator or actuable means movable along or relative to the axis; and a coupling arrangement operable for coupling the expansion member with the actuator for enabling operation of the or each expansion portion toward / or from the contracted / expanded configurations via the actuator, the coupling arrangement configured so as to directly couple the expansion member with the actuator so as to captively support or retain the expansion member with the actuator so that, in use, relative movement between the actuator and the expansion member along the axis is substantially restrained.

[0015] Embodiments of the aspects described above, and those described below, may comprise any of the following features either individually or in combination.

[0016] In an embodiment, the coupling arrangement is configured so as to directly couple the expansion member with the actuator so as to captively support or retain the expansion member with the actuator so that relative movement between the actuator and the expansion member along the axis is substantially restrained while allowing or facilitating relative movement between the expansion member and the actuator about the axis.

[0017] In an embodiment, the coupling arrangement is configured so as to directly couple the expansion member with the actuator so that the actuator captively supports or retains the expansion member so that relative movement between the actuator and the expansion member along the axis is substantially restrained.

[0018] In an embodiment, the coupling arrangement is configured so as to directly couple the expansion member with the actuator so that the actuator captively supports or retains the expansion member so that relative movement between the actuator and the expansion member along the axis is substantially restrained while allowing or facilitating relative movement between the expansion member and the actuator about the axis.

[0019] In one embodiment, the fastener body comprises an interior region having a first passage substantially concentric with the fastener body’s axis and configured for accommodating movement of the actuator or actuable means (hereinafter, actuator) there along, the first passage configured so as to extend between a first opening formed at or near a first end of the fastener body and a slot formed in the body and spaced from the fastener body’s first end, which slot opens to one or more regions (for example, exterior region(s)) of the fastener body and shaped for accommodating the expansion member such that when the or each expansion portion are in the contracted configuration a profile of the expansion member does not extend beyond that of the fastener body.

[0020] In one example, the actuator comprises a first end projecting outward or proud of the first opening of the fastener body, and at or near which a force is applied for causing the actuator to move along the first passage along the axis, the direction of movement of the actuator along the first passage corresponding with the operation of the expansion member due to the operation of the coupling arrangement such that when the applied force moves the actuator in a direction inward of the first passage, the or each expansion portion move outward via a respective slot opening region in the fastener body toward the expanded configuration (or away from the contracted configuration); when the applied force moves the actuator in a direction outward of the first passage along the axis, the or each expansion portion move toward the contracted configuration (or away from the expanded configuration).

[0021] The coupling arrangement is configured so as to couple the expansion member with the actuator so that the expansion member is responsive to movement of the actuator by seeking to follow movement of the actuator. The coupling arrangement coupling the expansion member with the actuator may be enabled by way of any of the following: a mechanical fastener (such as, for example, a rivet or like fastener), a form of ‘snap-fit’ coupling, a form of a friction weld process, a form of a swaging process.

[0022] In one form, the actuator comprises a second end at or near which couples directly with the expansion member by way of the coupling arrangement formed on an alignment of the actuator’s second end relative to the expansion member within the interior region of the fastener body, and a portion of or associated with the actuator at or near its second end and a portion of or associated with the expansion member being caused to interact so as to form an engagement therebetween operable for restraining relative movement between the actuator and the expansion member along the axis. In one form, the engagement between the actuator and the expansion member is a captive engagement.

[0023] Advantageously, in the context of the challenge(s) involved in miniaturising componentry for functional utility, the need for, for example, a coupling relying on a threaded engagement is avoided thereby improving, at the least, structural performance of the relevant components of the fastener as well as improving manufacturing efficiencies (eg. time / cost) of the fastener.

[0024] In one embodiment, the expansion member comprises one or more expansion portions connected by way of a connecting portion disposed therebetween, the interior region of the fastener body comprises a second passage opening to the fastener body’s slot and extends to a second opening formed at or near a second end of the body distal of its first end, the second passage being configured for use in, on the alignment of the actuator’s second end with the expansion member when positioned within the fastener body’s slot in which the actuator’s second end is passed through an aperture provided in the connecting portion enabling same to be in seated relation with the actuator inward of its second end, directing application of a force to or toward the actuator’s second end sufficient for plastically displacing or deforming a portion of material at or near the actuator’s second end so as to bear against a portion of the connecting portion for holding the expansion member against the actuator so as to restrain relative movement between the actuator and the expansion member along the axis. In this manner, the coupling arrangement is analogous to a swaging process in that plastic deformation (bending / shaping) is used to directly couple the expansion member with the actuator.

[0025] In one form, the second end of the actuator comprises a recess generally concentric with the fastener body’s axis whereby application of a force via the second passage causes material of the actuator adjacent the recess to plastically displace or deform about adjacent or corresponding portions of the connecting portion thereby placing the expansion member in captive engagement with the actuator.

[0026] In one embodiment, the expandable fastener is operable with an apparatus or tool assembly (hereinafter, deployment tool) configured for use in deploying the expansion portion(s) of the expansion member to or toward the expanded configuration on or following positioning of the expandable fastener at a desired location in the bore hole in the bone.

[0027] In one embodiment, the deployment tool is configured operable in a mode operation in which the fastener body can be driven or screwed into the bore hole in the bone, and in another mode of operation in which the or each expansion portion of the expansion member are caused to be moved to or toward the expanded configuration on or following positioning of the expandable fastener at the desired location in the bore hole in the bone.

[0028] In one embodiment, the expandable fastener is operable with the deployment tool via a connector (hereinafter, tulip connector) which is arranged to be carried, in a substantially articulable manner, by a head portion of the fastener’s body at or near its first end.

[0029] In one form, the tulip connector is of generally annular or tubular form having a first end configured so as to be placeable in articulable engagement (by way of, for example, a ballsocket like joint) with the head portion of the fastener body, and a second end, oppositely disposed from the first end, configured to be placeable in fixed relation with the deployment tool (by way of, for example, a threaded engagement). In this manner, the deployment tool is operably associable (or otherwise connectable) with the fastener body via the tulip connector so as to confer, at least in part, stability to the expandable fastener during deployment of the expansion portion(s) while also allowing for a degree of articulation between the fastener body and the deployment tool.

[0030] In one embodiment, the deployment tool comprises a driving element arranged in operable association with a driven member for causing movement of the driven member for providing a force for transfer to the actuator for, via the coupling arrangement, causing movement of the or each expansion portion to or toward the expanded configuration.

[0031] In one embodiment, the deployment tool comprises an actuable portion configured so as to carry the driven member and driving element, wherein the actuable portion comprises a passage along which the driven member moves on actuation of the driving element. In one embodiment, the deployment tool comprises a piston arranged operable between the driven member and the actuator, the piston configured so as to be responsive to operation of the driven member for transferring a force received from the driven member to the actuator on actuation of the driving element. In one form, the driven member is arranged with the driving element so that a movement of the driving element (for example, a generally linear movement of the driving element actuated by a user) facilitates linear movement of the driven member toward the piston. In another form, the driven member is arranged in threaded engagement with the driving element so that rotation of the driving element actuated or caused by a user facilitates linear movement of the driven element toward the piston.

[0032] In one embodiment, the deployment tool comprises a guide member configured operable for accommodating and guiding movement of the piston, the guide member configured at or near a first end for keyed engagement with the head portion of the fastener body enabling rotational movement of the guide member to be transferred to the fastener’s body operable for driving said body into the bore hole in the bone, and / or, the guide member configured at or near a second end for operable association with the actuable portion for enabling the piston to be acted upon by the driven member. In this manner, the deployment tool is capable of being used to perform two functions: (i) enable the piston to receive a force actuated by way of the actuable portion for transfer to the actuator, and (ii) enable screwing or driving of the fastener body into the bore hole in the bone by way of the actuable portion or the guide sleeve.

[0033] In one embodiment, the deployment tool comprises a support member configured for providing a passage for accommodating operation (for example, movement) of the guide member during use, the support member configured at one end for engaging with the tulip connector in a manner enabling the deployment tool to be placed in fixed relation therewith (by way of, for example, a threaded engagement) for conferring concentric support to the guide member for (i) maintaining guidance of the piston and / or (ii) driving of the fastener body into the bore hole in the bone (which may be irrespective of any articulation between the fastener body and the deployment tool occurring). In one embodiment, a portion of the first end of the actuator is substantially rounded or spherical shaped (eg. so as to provide a rounded or spherical contact face) so that a force applied thereto (for example, to the actuator by the piston of the deployment tool / assembly) is operable (for example, so that the applied force is substantially normal to the rounded or spherical contact face so as to be better directed toward the fastener’s body’s axis) for causing the actuator to move substantially along the fastener body’s axis (or within / along the first passage of the fastener body) irrespective of any articulation between the fastener body and a direction the force is applied (for example, due to an orientation of the deployment tool relative to the fastener body) occurring during use or otherwise.

[0034] Advantageously, embodiments of the deployment tool described herein enable simplified application or use within existing implant surgery workflows.

[0035] In one embodiment, the expandable fastener is operable with an apparatus or tool assembly (hereinafter, removal tool) configured for use in moving the or each expansion portion from the expanded configuration to or toward the contracted configuration for removal of the expandable fastener from the bore hole in the bone.

[0036] In one embodiment, the removal tool comprises an extraction member configured operable for engaging the actuator (for example, at or near its first end), the extraction member arranged so as to be operably responsive to actuation of an actuable portion of the removal tool (in one form, for example, by way of a portion of the extraction member being in threaded engagement with a portion of the actuable portion) for causing the extraction member to move the actuator in a direction outward of the fastener body’s first passage along the axis so as to cause the or each expansion portion to move away from the expanded configuration to or toward the contracted configuration.

[0037] In one form, the actuator is configured at or near its first end so as to be engageable with or by a portion of the removal tool (for example, the extraction member) in a manner enabling the actuator to follow movement of said portion (eg. the extraction member) for moving the actuator in a direction outward of the first passage of the expandable fastener’s body. In one form, the actuator is provided with one or more recesses spaced from its first end and configured for receiving respective projecting portions of one or more engagement arms which extend from the extraction member. In one form, the actuator is provided with one or more grooves (which could be generally annular about the actuator, and / or of finite length or continuous in form / profile) spaced from its first end and configured for receiving one or more of the projecting portions of one or more engagement arms.

[0038] In one embodiment, the actuable portion of the removal tool comprises a passage for accommodating operation of the extraction member, the extraction member being moveable within the passage by way of a portion of the extraction member being placed in operable association or engagement with a portion of the actuable portion, which engagement, on movement of the actuable portion, operates to cause the extraction member, when engaged with the actuator of the expandable fastener, to move the actuator in a direction outward of the first passage of the expandable fastener’s body thereby causing, via the coupling arrangement, the or each expansion portion to be moved to or toward the contracted configuration.

[0039] In one embodiment, a portion of the actuable portion of the removal tool is configured so as to, when in use (for example, on engagement with the tulip connector), cooperate with the extraction member for preventing the engagement arm(s) from splaying apart and disrupting their respective engagement with the actuator. Such engagement may be configured of a captured or captive configuration.

[0040] The skilled reader will appreciate that the engagement (eg. captured / captive) between the actuator and the extraction member may be enabled by other forms of ‘snap-fit’ connection. Alternatively, the engagement between the actuator and the extraction member may be enabled by way of a form of a collet chuck associated with the extraction member that attaches to the actuator by way of a friction-based association / engagement. Advantageously, engagement between the actuator and the removal tool seeks to avoid reliance on any form of threaded connection thereby simplifying manufacturing processes, enhancing structural capacity of the actuator and the extraction member which features assist in enabling miniaturisation of the expandable fastener.

[0041] The expansion member may comprise any number of expansion portions. In one specific embodiment, the expansion member comprises first and second expansion portions connected by way of the connecting portion disposed therebetween.

[0042] The or each expansion portion may be shaped so as to increase their respective effective length for seeking to increase the scope of its respective effective elastic range between the contracted and expanded configurations. In this manner, advantageously, the profile shape of each expansion portion may serve to enable an increase in the allowable thickness of the relevant expansion portion while still maintaining the same desired elastic range of articulation or flexing.

[0043] Multiple expansion portions may be spaced regularly or irregularly about an axis concentric with the aperture of the connecting portion of the expansion member.

[0044] The expansion portion may be configured of generally planar form and shaped so as to extend away from the connecting portion so as to define a respective distal end.

[0045] The expansion portion may extend away from the connecting portion and return toward the axis concentric with the aperture of the connecting portion in a curved or curvilinear manner, before extending substantially parallel with said axis to a respective distal end of the relevant expansion portion, the curved shape / form operating to, at least in part, increase an effective length of the expansion portion which, advantageously, increases its elastic range or flexing of movement between the contracted / expanded configurations. As such, the allowable thickness of the expansion portions can be increased while maintaining the same scope of elastic range. In this regard, dimensionally thin expansion portions are difficult to manufacture and more likely to fail. Other shapes may confer similar characteristics, such as for example, profile shapes or wavy forms or profile shapes in which defining edges are angled outwards or away from the axis.

[0046] The or each expansion portion may comprise an open slot of generally elongate form which opens adjacent the connecting portion. In such embodiments, a portion of an edge defining the opening of the open slot may serve as a stop against which another (in one form, generally opposing) portion of the edge defining the open slot may bear for providing or conferring stabilising support to the relevant expansion portion when experiencing articulation or flexing on experiencing load when in or moving toward or away from the expanded configuration.

[0047] In one embodiment, the tulip connector is configured so that, when the or each expansion portion are in the expanded configuration, the actuator can be prevented from moving in a direction outward of the fastener body’s passage by way of a locking nut or locking cap being arranged in threaded engagement with the tulip connector and being brought to bear against the actuator, either directly or indirectly, such as for example, via a stop member (for example, spinal rod) arranged in abutting relation between / intermediate the first end of the actuator and the locking nut or cap. In this manner the actuator is prevented from any inadvertent movement in a direction outward of the fastener body’s first passage which could cause, via the coupling arrangement, movement of the expansion portion(s) to or toward the contracted configuration.

[0048] In an embodiment, the body is configured operable with the actuator. In an embodiment, the actuator and the body are threadedly engaged by way of respectively carried or hosted threaded portions or regions which operate so as to enable or facilitate movement of the actuator along the axis in response to the actuator being caused to be rotated in a direction about the axis for operating the expansion member to any of the retracted or expanded configurations.

[0049] In an embodiment, a region of an interior wall of the first passage is configured so as to carry a thread operable with a thread carried by a region of an exterior wall of the actuator thereby enabling threaded engagement of the actuator and body. In an embodiment, the actuator has a body, which body comprises a passage extending therethrough coaxial with the axis, the passage opening respectively at first and second opposing ends of the body of the actuator, the first end opening being up hole and the second end opening of the passage being downhole relative to an in-use orientation of the expandable fastener.

[0050] In an embodiment, the first end comprises a region adjacent the first end opening configured so as to receive or key with a driving tool or instrument for use in driving the actuator about the axis.

[0051] In an embodiment, the expansion member comprises a proximal end region providing an annular or collar shaped portion from which the or each expansion portion(s) of the expansion member extend away from.

[0052] In an embodiment, the annular shaped portion of the proximal end region of the expansion member is configured so as to be receivable within the passage via the second end opening of the body of the actuator so as to be positioned coaxial with the axis.

[0053] In an embodiment, the or each expansion portion are configured having respective exterior surfaces of rounded or semicircular form or profile extending outward from the annular shaped portion of the proximal end region of the expansion member, the rounding or semicircular form or profile presenting exterior of the expansion member so as increase a surface area of the exterior for increasing prospective engagement with bone structure (of the wall of the bore hole).

[0054] In an embodiment, the expansion member is formed from any suitable elastically deformable material operable within its elastic range throughout expansion to the expanded configuration as described herein so that it can return to mostly it's unexpanded state of configuration when not subject to load.

[0055] In an embodiment, the annular shaped portion of the proximal end region of the expansion member comprises an annular lip portion provided at or near an end of the annular shaped portion of the proximal end region of the expansion member.

[0056] In an embodiment, the coupling arrangement is provided or configured by way of a portion of the passage of the body of the actuator configured so as to comprise an annular shaped recess formed within an interior wall of said portion of the passage, and which annular recess is configured or shaped so as to be receivable of the annular lip portion of the expansion member so that the annular lip portion is captively supported or retained by the annular recess so that relative movement between the actuator and the expansion member along the axis is substantially restrained while allowing or facilitating relative movement between the expansion member and the actuator about the axis.

[0057] In an embodiment, the engagement between the annular recess formed within the interior wall of said portion of the passage and annular lip portion of the expansion member is configured so as to key the actuator and the expansion member along the axis.

[0058] In an embodiment, the engagement between the annular recess formed within the interior wall of said portion of the passage and annular lip portion of the expansion member is configured so as to not key the actuator and the expansion member about the axis.

[0059] In an embodiment, the body is configured operable coaxial relative the axis, said body having a proximal end region shaped so as to be operable within the passage of the body of the actuator, the body having a distal end region configured for engagement with bone when in use. In an embodiment, a tip of the proximal end region is configured so as to receive or key with a driving tool or instrument for use in driving the body about the axis.

[0060] In an embodiment, the proximal end region of the body of the expandable fastener is receivable through a hollow of the annular shaped portion of the expansion member in assembly of the body with the passage of the body of the actuator so that the expansion member is operable between the actuator and the body.

[0061] In an embodiment, the or each expansion portions of the expansion member extend from the annular shaped portion of the expansion member and cover over or about respective portions of an exterior of the body when in the retracted configuration, said covered portions of the body being offset or spaced from the distal end region of the body so as to expose a portion thereof for engaging bone when in use.

[0062] In an embodiment, respective portions of the passage of the actuator and the proximal end region of the body are arranged in threaded engagement with each other for enabling or facilitating the actuator to, on operation thereof, drive movement of the expansion member along the axis when the body is caused to be stationary relative to the axis during use.

[0063] In an embodiment, an exterior surface of a proximal region of the actuator comprises a first male thread portion, and an exterior of the distal end region of the body adjacent its distal end comprises a second male thread, and wherein respective pitches of one or both of the first, second male threads is substantially the same as a pitch of the threaded engagement between the actuator and the proximal end region of the body.

[0064] In an embodiment, substantial consistency in the pitches of the first and the second male threads and the pitch of the threaded engagement between the actuator and the proximal end region of the body enables or facilitates driving of the expandable fastener to a desired target position in the bore hole and subsequent movement of the expansion member to the expanded configuration by way of rotation of the actuator about the axis in the same direction of rotation.

[0065] In an embodiment, movement of the actuator along the axis for moving the expansion member to the expanded configuration substantially commences on the body becoming or being caused to become stationary relative to the axis.

[0066] In an embodiment, driving of the expandable fastener to the desired target position in the bore hole and subsequent movement of the expansion member to the expanded configuration by way of rotation of the actuator about the axis in the same direction of rotation is a substantially single stage / step or continuous operation. In a third aspect of the present invention there is provided an apparatus for use with an embodiment of an expandable fastener arranged in accordance with the expandable fastener of the first aspect, the apparatus configured operable for enabling selective application of a force to the actuator of the expandable fastener so as to move the or each expansion portion of the expansion member of the expandable fastener to or toward the expanded configuration (for example, for seeking to secure the expandable fastener at a position in a bore hole formed in a region of bone). The apparatus of the present aspect may be configured substantially in accordance with the deployment tool of the first aspect.

[0067] In a fourth aspect of the present invention there is provided an apparatus for use with an embodiment of an expandable fastener arranged in accordance with the expandable fastener of the first aspect, the apparatus configured operable for enabling selective application of a force to the actuator of the expandable fastener so as to move the or each expansion portion of the expansion member of the expandable fastener from the expanded configuration to or toward the contracted configuration (for example, for removing the expandable fastener from a position in a bore hole formed in a region of bone). The apparatus of the present aspect may be configured substantially in accordance with the removal tool of the first aspect.

[0068] In another aspect of the present invention there is provided an expandable fastening system for orthopaedic applications, the expandable fastening system comprising: an expandable fastener arranged substantially in accordance with any embodiment of the expandable fastener of the first aspect; and or a first apparatus or tool assembly configured operable for use in operating the actuator of the expandable fastener for selectively moving the or each expansion portion of the expansion member or the expandable fastener to or toward the expanded configuration; and or a second apparatus or tool assembly configured operable for use in operating the actuator of the expandable fastener for selectively moving the or each expansion portion of said expansion member to or toward the contracted configuration. The first apparatus or tool assembly of the present aspect may be configured substantially in accordance with the deployment tool of the third aspect, and / or the second apparatus or tool assembly of the present aspect may be configured substantially in accordance with the removal tool of the fourth aspect.

[0069] In a further aspect, there is provided a method for forming an expandable fastener, the method comprising: providing or forming a body having an axis, providing or forming an expansion member comprising at least one expansion portion moveable between a contracted configuration and an expanded configuration such that, in use, the or each expansion portion moves outwardly from the axis of the body towards the bone surrounding the bore hole when moving towards the expanded configuration; providing or forming an actuator, the actuator being movable along the axis of the body; and coupling the expansion member with the actuator so as to directly couple the expansion member with the actuator such that relative movement between the actuator and the expansion member along the axis is substantially restrained thereby enabling operation of the or each expansion portion toward / or from the contracted / expanded configurations via the actuator.

[0070] According to a further aspect, there is provided a method for operating an expandable fastener arranged in accordance with the first or second aspects implanted in a bore hole in a bone, the method comprising: providing an apparatus or tool arranged in accordance with the third aspect, associating the apparatus or tool with the expandable fastener, and operating the apparatus or tool for enabling selective application of a force to the actuator of the expandable fastener so as to move the or each expansion portion of the expansion member to or toward the expanded configuration for securing the expandable fastener in the bore hole.

[0071] In one embodiment, the method comprises securing the actuator so as to confirm the or each expansion portion of the expansion member in the expanded configuration.

[0072] According to a further aspect, there is provided a method for use in removing an expandable fastener arranged in accordance with the first or second aspects from a bore hole in a bone when in the expanded configuration, the method comprising: providing an apparatus or tool arranged in accordance with the fourth aspect, associating the apparatus or tool with the expandable fastener, and operating the apparatus or tool for enabling selective application of a force to the actuator of the expandable fastener so as to move the or each expansion portion of the expansion member to or toward the contracted configuration for removing the expandable fastener from the bore hole in the bone.

[0073] An embodiment provides a method of using any embodiment of an expandable fastener described herein. An embodiment provides a method of inserting any embodiment of an expandable fastener into a bore hole of bone. An embodiment provides a method of removing any embodiment of an expandable fastener into a bore hole of bone.

[0074] Various aspects described herein can be practiced alone or combination with one or more of the other aspects, as will be readily appreciated by the skilled reader. The various aspects can optionally be provided in combination with one or more of the optional features described in relation to the other aspects. Furthermore, optional features described in relation to one example (or embodiment) can optionally be combined alone or together with other features in different examples or embodiments.

[0075] For the purposes of summarising the various aspects, certain aspects, advantages and novel features have been described herein above. It is to be understood, however, that not necessarily all such advantages may be achieved in accordance with any particular embodiment or carried out in a manner that achieves or optimises one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

[0076] It is to be understood that each document, reference, patent application or patent cited in this text is expressly incorporated herein in their entirety by reference, which means that it should be read and considered by the reader as part of this text. That the document, reference, patent application, or patent cited in this text is not repeated herein is merely for reasons of conciseness.

[0077] Furthermore, in this specification, where a literary work, act or item of knowledge (or combinations thereof), is discussed, such reference is not an acknowledgment or admission that any of the information referred to formed part of the common general knowledge as at the priority date of the application. Such information is included only for the purposes of providing context for facilitating an understanding of the inventive concept / principles and the various forms or embodiments in which those inventive concept / principles is / are exemplified.

[0078] The invention will be more fully understood from the following description of specific embodiments of the invention. The description is provided with reference to the accompanying drawings.

[0079] Brief Description of the Drawings

[0080] Figure 1 is a perspective view of one embodiment of an expandable fastener arranged in accordance with the present invention.

[0081] Figure 2 is an elevation view of the embodiment of the expandable fastener shown in

[0082] Figure 1.

[0083] Figure 3 is an end view of the embodiment of the expandable fastener shown in Figure 1.

[0084] Figure 4 is a cross section view of the embodiment of the expandable fastener shown in Figure 2 (showing the expansion member assembled in position). Figure 5 shows a sequence of steps (a) to (d) relating to one embodiment of a method used in the assembly of the embodiment of the expandable fastener shown in Figures 1 to 4.

[0085] Figure 6 shows a sequence of steps (a) to (c) relating to one embodiment of a method used to couple the expansion member to the actuator of the embodiment of the expandable fastener shown in Figures 1 to 4 (each of steps (a) to (c) showing a close view of the region identified in Figure 5(d) where the coupling between the expansion member and the actuator occurs for the embodiment considered).

[0086] Figure 7 shows a perspective view of one embodiment of an apparatus or tool used with the embodiment of the expandable fastener shown in Figures 1 to 4.

[0087] Figure 8 shows an elevation view of the embodiment of the apparatus or tool shown in Figure 7.

[0088] Figure 9 shows a cross section view of the embodiment of the apparatus or tool shown in Figure 8.

[0089] Figure 10 shows a sequence of steps (a) to (e) relating to one embodiment of a method used with the embodiment of the apparatus or tool shown in Figures 7 to 9 (for operating the expansion portions of the expansion member to or toward the expanded configuration).

[0090] Figure 11 shows a sequence of steps (a) to (b) relating to one embodiment of a method used with the embodiment of the apparatus or tool shown in Figures 7 to 9 (for disconnecting the apparatus or tool from the expandable fastener).

[0091] Figure 12 shows a perspective view of the embodiment of the expandable fastener shown in Figures 1 to 4 when in a condition in which the expansion portion(s) of the expansion member are secured in the expanded configuration. Figure 13 shows an elevation view of that shown in Figure 12.

[0092] Figure 14 shows an end view of that shown in Figure 12.

[0093] Figure 15(a) shows a cross section view of that shown in Figure 13, whereby Figure 15(b) shows that of Figure15(a) but with a degree of articulation between embodiments of the connector and the body of the expandable fastener shown in Figure 1 to 4.

[0094] Figure 16(a) and (b) both show respective perspective views of components of one embodiment of an apparatus or tool used with the embodiment of the expandable fastener shown in Figures 1 to 4 (for use in transitioning the expansion portions to or toward the contracted configuration).

[0095] Figure 17 shows an elevation view of that shown in Figure 16.

[0096] Figure 18 shows a cross section view of that shown in Figures 16 and 17, when both components are assembled together for operational purposes.

[0097] Figure 19 shows a sequence of steps (a) to (e) relating to one embodiment of a method used with the embodiment of the apparatus or tool shown in Figures 16 to 18 (for operating the expansion portions of the expansion member to or toward the contracted configuration).

[0098] Figure 20 shows a sequence of steps (a) to (c) relating to one embodiment of a method used with the embodiment of the apparatus or tool shown in Figures 16 to 18 (for disconnecting the apparatus or tool from the expandable fastener).

[0099] Figure 21 shows the (geometrical) profile of the expansion member when in the contracted configuration.

[0100] Figure 22 shows the (geometrical) profile of the expansion member when in the expanded configuration. Figure 23 shows the expansion member shown in Figures 21 and 22 (a) about to be inserted in the slot during assembly with the fastener body, and (b) in position in the slot.

[0101] Figure 24 shows perspective views of another embodiment of an expandable fastener arranged consistent with the principles of the present disclosure, showing the embodiment in a non-expanded condition, whereby (b) shows a cross-section taken through a plane A1-A2 as indicated in (a).

[0102] Figure 25 shows the embodiment of the expandable fastener shown in Figure 24, when in the expanded condition.

[0103] Figure 26 shows a sequence of steps of operation (a) to (c) of the embodiment shown in Figures 24 and 25 for operating the expansion portions of the expansion member to or toward the expanded configuration.

[0104] Figure 27 shows perspective views of another embodiment of an expandable fastener arranged consistent with the principles of the present disclosure, showing the embodiment in a non-expanded condition, whereby (b) shows a cross-section taken through a plane A1-A2 as indicated in (a).

[0105] Figure 28 shows the embodiment of the expandable fastener shown in Figure 27, when in the expanded condition.

[0106] Figure 29 shows a sequence of steps of operation (a) to (c) of the embodiment shown in Figures 27 and 28 for operating the expansion portions of the expansion member to or toward the expanded configuration; Figure 29(d) shows a close-up cross section of view of the coupling arrangement identified in Figure 29(c).

[0107] Detailed Description of Embodiments

[0108] The words used in the specification are words of description rather than limitation, and it is to be understood that various changes may be made without departing from the spirit and scope of any aspect of the invention. Those skilled in the art will readily appreciate that a wide variety of modifications, alterations, and combinations can be made with respect to the above described embodiments without departing from the spirit and scope of any aspect of the invention, and that such modifications, alterations, and combinations are to be viewed as falling within the ambit of the inventive concept.

[0109] Throughout the specification and the claims that follow, unless the context requires otherwise, the word “comprise” or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

[0110] Furthermore, throughout the specification and the claims that follow, unless the context requires otherwise, the word “include” or variations such as “includes” or “including”, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.

[0111] Embodiments of the present invention generally relate to an expandable fastener arranged operable for fastening when positioned in a bore hole in a region of bone. Embodiments of the expandable fastener described herein may be used for orthopaedic applications to secure stabilisation members used to stabilise fractured bones or to fuse joints. In one example, an expandable fastener formed consistent with the principles of the present disclosure may be arranged for use in a spinal fusion procedure. A person skilled in the art will, however, appreciate that an expandable fastener arranged in accordance with the present disclosure has various further orthopaedic applications.

[0112] Figures 1 to 22 show one embodiment of an expandable fastener (hereinafter, fastener 2) and related apparatus / tool assemblies and processes used in deployment (Figures 7 to 11), locking (Figures 12 to 15), and removal operations (Figures 16 to 20).

[0113] With reference to Figures 1 to 6 and 22, the fastener 2 comprises a body 5 having an axis X. As shown in Figure 4, the fastener body 5 is of screw like form having a head portion 62 at a first end 34 and tapering generally to a second end 50 (which is distal of its first end 34 as shown in Figure 4). The fastener body 5 carries about its exterior surface a first region of male (cortical) thread 5a near the first end 34, transitioning then to a second region of male (cancellous) thread 5b commencing at or near a generally central region of the fastener body 5 and extending to / toward the second end 50. For the example of the fastener 2 shown throughout the Figures, the male thread of the first region 5a is of finer pitch than that of the second region 5b so as to (i) improve cortical fixation in, for example, a pedicle region of bone, as well as (ii) seeking to enhance strength capacity while reducing stress concentration factors that may develop at the shank of the fastener body 5 (the region of the fastener body 5 carrying the first threaded region 5a) where the force is usually found to be the highest.

[0114] The fastener 2 comprises an expansion member 10 comprising first 14, second 16 expansion portions moveable between a contracted configuration (see the configuration of the expansion member 10 shown in Figures 1 to 4) and an expanded configuration (see the configuration of the expansion member 10 shown in Figures 12 to 13). When in use, the first 14, second 16 expansion portions are operable to respectively move outwardly / away from the axis X of the fastener body 5 towards the bone (not shown) surrounding the bore hole (not shown) when moving towards the expanded configuration. The skilled reader will appreciate that any number of expansion portions (14, 16) may be used in forming an expandable fastener consistent with the principles described in the present disclosure.

[0115] The fastener 2 comprises an actuator or actuable means (hereinafter, actuator 20) that is movable along the axis X of the fastener’s body 5. The actuator 20 is of rod like form having first 40 and second 42 ends.

[0116] The fastener 2 further comprises a coupling arrangement 24 configured operable for coupling the expansion member 10 with the actuator 20 for enabling operation of the first 14, second 16 expansion portions toward or from the contracted / expanded configurations via the actuator 20. The coupling arrangement 24 is configured so as to directly couple the expansion member 10 with the actuator 20 such that relative movement between the actuator 20 and the expansion member 10 along the axis X is substantially restrained. In some embodiments, the coupling arrangement 24 may be configured so as to directly couple the expansion member 10 with the actuator 20 such that relative movement between the actuator 20 and the expansion member 10 along the axis X is substantially restrained while allowing or facilitating relative movement between the expansion member 10 and the actuator 20 about the axis X (as with the embodiments of fasteners 2’ and 400 described below).

[0117] The fastener body 5 comprises an interior region having a first passage 30 that is substantially concentric with the fastener body’s axis X and configured for accommodating and guiding movement of the actuator 20 there along. The first passage 30 is configured so as to extend between (thereby joining) a first opening 32 formed at the first end 34 of the fastener body 5 and a slot 36 formed in the body 5 and spaced from the fastener body’s first end 34. The slot 36 comprises an axis Y (as shown in Figures 1 and 4) which runs substantially perpendicular or transverse to the fastener body’s axis X. The slot 36 is shaped for receiving and accommodating the expansion member 10 such that when the first 14, second 16 expansion portions are in the contracted configuration a profile of the expansion member 10 does not extend beyond that of the fastener body 5. As shown in Figures 1 and 4, the slot 36 is configured so as to open to two exterior regions of the fastener body 5 (in this example, two generally oppositely disposed exterior regions of the fastener body 5) through which a respective expansion portion 14, 16 moves so as to extend beyond the profile of the fastener body 5 so as to adopt the expanded configuration in a symmetrical manner about the axis X.

[0118] As seen in Figure 4, the actuator 20 comprises a first end 40 which, when assembled with the fastener body 5 for use, projects outward or proud of the first opening 32 of the fastener body 5 sufficiently so that a force can be applied at or near the first end 40 so as to cause the actuator 20 to move within the first passage 30 along the axis X. The direction of movement of the actuator 20 within the first passage 30 corresponds with or drives the operation of the expansion member 10 due to the operation of the coupling arrangement 24 such that, when a force applied to the actuator’s first end 40 moves the actuator 20 in a direction inward of the first passage 30 toward the second end 50 along the axis X, the first 14, second 16 expansion portions move (via respective slot 36 openings in the fastener body 5) outward of the slot 36 away from the axis X toward the expanded configuration by way of respective edges 14j, 16j (refer Figures 21 to 23) being caused to run against a lower disposed wall portion 36a (refer Figures 21 and 23) which contributes in defining the slot 36. In this manner, running of edges 14j , 16j against the lower disposed wall portion 36a serves to urge / motivate the expansion portions 14, 16 in a direction outward / away from the axis X.

[0119] On the expansion portions 14, 16 being in the expanded configuration, when a force is applied to the actuator’s first end 40 causing movement of the actuator 20 in a direction outward of the first passage 30 away from the second end 50 along the axis X, the first 14, second 16 expansion portions move toward the contracted configuration.

[0120] With brief reference to Figure 23, the expansion portions 14, 16 are generally of planner form and connected to each other at respective ends 14a, 16a by way of a connecting portion 35 which serves to bridge both expansion portions 14, 16. The connecting portion 35 is provided with an aperture 37 extending there through and having an axis D about which the expansion portions 14, 16 are generally symmetrically spaced relative to each other. As seen throughout the figures, each expansion portion 14, 16 extends generally from the connecting portion 35 to its respective distal tip 14c, 16c. The shape of the expansion portions 14, 16 and the relevant advantage(s) it confers is described further below.

[0121] The actuator 20 comprises a second end 42 at or near which couples directly with the expansion member 10 by way of the coupling arrangement 24. In substance, the coupling arrangement 24 is formed on an alignment of the actuator’s second end 42 relative to the expansion member 10 within the interior region of the fastener body 5 so that a portion of the actuator 20 at or near its second end 42 and a portion of the expansion member 10 are caused to interact so as to form an engagement therebetween operable for restraining relative movement between the actuator 20 and the expansion member 10 along the axis X. Advantageously, in the context of the challenge(s) involved in miniaturising componentry for functional utility in complex / intricate surgeries, the need for, for example, a coupling relying on a threaded engagement is avoided thereby improving structural performance of the relevant components of the fastener as well as improving manufacturing efficiencies (eg. time / cost) of the fastener.

[0122] The second end 42 of the actuator 20 comprises a recess 52 (refer to Figure 6(a)) which is generally concentric with the fastener body’s axis X.

[0123] As seen in Figure 4, the interior region of the fastener body 5 comprises a second passage 46 opening to the fastener body’s slot 36 and extending to a second opening 48 formed at the second end 50 of the fastener body 5.

[0124] Reference is now made to Figures 5(a) to 5(d) which show one example of a process used to assemble the expansion member 10 with the slot 36 of the fastener’s body 5 prior to coupling the actuator 20 with the expansion member 10.

[0125] Figure 5(a) shows insertion of the expansion member 10 into the slot 36. In achieving this, the expansion member 10 is manipulated so as to flex or bend sufficiently (by virtue of the shape / profile of the expansion portions 14, 16, as described below) for insertion into one of the exterior openings (the left-hand side opening shown in Figure 5(a)) of the slot 36 so that the expansion member 10 can be accommodated within the general geometry of the slot 36. Specifically, the expansion portions 14, 16 are caused to be splayed apart and one of the portions 14, 16 inserted through one side’s exterior opening of the slot 36, and the expansion member 10 then rotated in the direction shown in Figure 5(a)so that it arrives at the relative positioning in the slot 36 shown in Figure 5(b).

[0126] Figure 5(b) shows the expansion member 10 having been positioned within the fastener body’s slot 36. Figure 5(b) also shows the insertion of the actuator 20 in the fastener body’s first passage 30 in which the actuator’s second end 42 is directed toward the slot 36. In Figure 5(c), the actuator’s second end 42 is shown passed through the aperture 37 provided in the connecting portion 35. The actuator’s second end 42 is dimensioned so that the connecting portion 35 becomes seated in abutting relation with the actuator 20 inward of its second end 42. In this manner, as will be seen in Figures 6 (a) to (c), the abutment between the connecting portion 35 and the actuator 20 inward of its second end 42 results from a stepped profile 47 formed about the exterior surface of the actuator 20 and which operates to seat the connecting portion 35 about the rod-like form of the actuator 20 and inward of its second end 42.

[0127] Figure 5(d) shows a force applying tool T having been inserted into the fastener body’s second passage 46 (via the fastener body’s second opening 48) and moved toward the actuator’s second end 42. Enroute, the force applying tool T physically encounters the expansion portions 14, 16 and, due to the flexible / bendable nature of the shape of the expansion portions 14, 16 (described below), begin to be caused to splay apart from one another - which continues with further advancement of the force applying tool T toward the actuator’s second end 42.

[0128] Reference is now made to Figures 6(a) to 6(c), which follow from that shown in Figure 5(d), illustrating an example process (generally analogous to a swaging process) which establishes one example embodiment of the coupling arrangement 24 between the actuator 20 and the expansion member 10.

[0129] In Figure 6(a) the tool T is advanced from that shown in Figure 5(d) and further physically splays the expansion portions 14, 16 apart thereby procuring direct access to the actuator’s second end 42. In Figure 6(b) the force applying tool T engages the actuator’s second end 42 via the recess 52 and is used to apply sufficient force to the actuator’s second end 42 for plastically displacing portion(s) of material of the actuator 20 adjacent the recess 52 so as to bear against adjacent / corresponding portion(s) of the connecting portion 35 for holding same (and therefore the expansion member 10) against the actuator 20 in a captive / captured like manner so as to restrain relative movement between the actuator 20 and the expansion member 10 along the axis X. As is shown in Figure 6(b), application of the force by the force applying tool T causes material of the actuator 20 peripheral / adjacent the recess 52 to plastically displace / deform about adjacent / corresponding portions of the connecting portion 35 thereby placing the expansion member 10 in captive engagement (between the stepped profile 47 inward of the actuator’s second end 42 and the plastically displaced material) with the actuator 20 thereby confirming the establishment of the coupling arrangement 24. In this exemplification of the coupling arrangement 24, the plastic displacement of the material of the actuator 20 about adjacent portions of the connecting portion 35 is sufficient to generate enough contact friction between respective contacting portions to achieve relative rotational restraint between the expansion member 10 and the actuator 20 about the axis X. However, as will be seen with expandable fasteners 2’, 400 described further below, embodiments of the coupling arrangement (20’ and 424) can be configured so as to allow for relative rotational movement between the expansion member 10 and the actuator 20 about the axis X while providing a captive engagement operating to restrain relative movement of both components along the axis X.

[0130] Once the coupling arrangement 24 is established, the force applying tool T is withdrawn, as shown in Figure 6(c).

[0131] In the present example, the force applying tool T is a cylindrically shaped tool having a shaped free end (acute shaped end shown in Figure 6(b)) that interacts with the recess 52 to cause the plastic displacement or deformation of portions of material of the actuator’s second end 42 against corresponding portions of the connecting portion 35 of the expansion member 10 for establishing the coupling arrangement 24 described above. Various suitably shaped tools could be used. In this manner, the coupling arrangement 24, in this embodiment, is analogous to a swaging process in that plastic displacement / deformation (bending / shaping) is used to directly couple the expansion member 10 with the actuator 20 (via the connecting portion 35).

[0132] Other ways of establishing a suitable coupling between the actuator 20 and the expansion member 10 are possible. In one form, the coupling between the expansion member 10 and the actuator 20 may be enabled by way of a mechanical fastener such as, for example, a rivet. In another form, the coupling arrangement 24 may be enabled by way of an appropriately configured ‘snap-fit’ coupling. Alternatively, the coupling arrangement 24 may be enabled by way of a friction weld process.

[0133] Advantageously, small scale orthopaedic applications where tolerancing and strength are key design concerns due to challenges in miniaturisation (for example, spinal surgeries), coupling the expansion member 10 and the actuator 20 in accordance with the principles described herein seeks to avoid any need for the expansion member 10 to be needed to be moved down within the first passage 30 of the fastener body 5. As such, various geometries of the contracted profile of the expansion member 10 (for example, the width dimension) can be configured so as to be in the order of the diameter of the fastener body 5. Advantageously, this enables the expanded profile of the expansion member 10 to be increased (or maximised to the extent possible), thereby increasing the holding capacity of the fastener 2 in the bore hole in the bone. Furthermore, any complex manufacturing processes (such as those increasing time and / or cost) can be confined specifically to the expansion member 10 and not all components of the fastener 2 thereby seeking to reduce (as much as possible, to the extent possible) the cost of the components for the complete fastener 2. It can then be possible to use processes like wirecutting and metal 3D printing for only particular parts, therefore helping facilitate a favourable cost efficiency over the production of the complete fastener 2 to be achieved. Moreover, because the expansion member 10 does not have to fit down the first passage 30 enables the passage 30 to be formed having a smaller diameter thereby increasing the overall strength capacity of the fastener body 5.

[0134] In one form, the fastener 2 is operable with an apparatus or tool assembly (hereinafter, deployment tool 58) configured operable for use in deploying the expansion portions 14, 16 to or toward the expanded configuration on or following positioning of the fastener 2 at the desired location in the bore hole in the bone. The deployment tool 58 may form part of a system of components with the fastener 2.

[0135] One example of a suitable deployment tool 58 is shown in Figures 7 to 11. Figures 7 to 9 show the various component parts that form the deployment tool 58: an actuable portion 70, a driving element 76, a driven member 72, a piston 84, a guide member 88, and a support member 94, as will be described below.

[0136] With reference to Figure 10, the fastener 2 is operable with the deployment tool 58 via a connector (hereinafter, tulip connector 60) which is arranged to be carried, in a substantially articulable manner, by the head portion 62 of the fastener body 5. The tulip connector 50 may form part of the system of components with the fastener 2 and / or the deployment tool 58.

[0137] As is shown in Figure 4, the tulip connector 60 is of generally annular or ring like form (of finite length) having a first end 64 configured so as to be placeable in articulable engagement (by way of, for example, a ball-socket like joint) with the head portion 62 of the fastener body 5. The tulip connector 60 further comprises a second end 63 oppositely disposed from the first end 64, and configured with an internal threaded region 63a so that the tulip connector 60 is placeable in fixed relation with the deployment tool 58 (specifically, via a guide sleeve 88 described below) by way of a threaded engagement 59 as shown in Figure 10(c). In this manner, the deployment tool 58 is connectable with the fastener body 5 via the tulip connector 60 so as to confer, at least in part, stability to the fastener 2 during deployment of the expansion portions 14, 16 while also allowing for a degree of articulation between the fastener body 5 and the deployment tool 58 should it occur.

[0138] With reference to Figure 9, the deployment tool 58 comprises an actuable portion 70 configured so as to carry a driven member 72 and driving element 76 (hereinafter, actuating knob 76). The actuable portion 70 comprises a passage 77 along which the driven member 72 moves on actuation of the actuating knob 76. Broadly, in operation of the deployment tool 58, the driven member 72 is responsive to the actuating knob 76 for enabling provision of a force for transfer to the actuator 20 for, via the coupling arrangement 24, causing movement of the expansion portions 14, 16 to or toward the expanded configuration.

[0139] The actuable portion 70 comprises a body 80 having a handle portion 83 (having a shape or profile allowing easy or convenient manual handling of the deployment tool 58 by a user) that is in fixed relation with a socket defining portion 80a that provides a socket recess 80b configured to receive, in keyed engagement, an end of a guide member 88 (described below). The body 80 is formed so as to provide the passage 77 that is concentric about axis Z and that opens to the socket recess 80b. As seen in Figure 9, the driven member 72 is operably engaged by way of a threaded engagement 79 with the actuating knob 76 which enables movement of the driven member 72 within / along the passage 77 formed in the body 80 of the actuable portion 70. The actuating knob 76 is operable (by selective rotational movement by an operator) within a slotted region 78 of the handle portion 83 of the actuable portion 70 so that it can be rotated (either clockwise or counter-clockwise) about the axis Z (as shown in Figures 7 to 11) depending on the direction of axial movement / translation of the driven member 72 along the axis Z needed by an operator of the deployment tool 58. As the skilled reader will appreciate, axial translation or movement of the driven member 72 along the passage 77 results from rotation of the actuating knob 76 about the axis Z due to: (i) the threaded engagement 79, (ii) the body 80 of the actuable portion 70 being held stationary, and (iii) the actuating knob 76 being restrained from itself translating along the axis Z relative to the body 80 - in practice this is achieved by the actuating knob 76 bearing against one of the upper 78a, lower 78b (see Figures 8 and 9) facing surfaces of the slotted region 78 depending on the direction along the axis Z the driven member 72 is needed to be moved (eg. upwards or downwards). As will be described below, rotational restraint is conferred to the body 80 by way of its keyed relationship with the fastener body 5 which is achieved by way of an intermediary guide member 88 (described below) being placed in keyed relation with both the fastener body 5 (via keyed engagement with a recess 93 (shown in Figure 4) of the body 5) and the body 80 (via keyed engagement with the socket recess 80b).

[0140] As shown in Figure 9, the deployment tool 58 comprises a piston 84 arranged and operable intermediate the driven member 72 and the actuator 20. The piston 84 is arranged operable for transferring force received from the driven member 72 to the actuator 20 on actuation of the actuating knob 76. The piston 84 is of rod like form / profile as shown in Figure 9.

[0141] With reference to Figure 9, the deployment tool 58 comprises a guide member (hereinafter, guide sleeve 88) operable for accommodating and guiding movement of the piston 84. The guide sleeve comprises a passage 89 within / along which the piston 84 operates. The guide sleeve 88 is configured at or near a first end 90 with a shaped portion 90a configured for keyed engagement with the recess 93 formed in the head portion 62 of the fastener body 5 thereby enabling the transfer of rotational movement experienced by the guide sleeve 88 to the fastener’s body 5, which transfer of rotational movement is operable for use in driving / screwing the fastener body 5 into the bore hole in the bone. Adjacent the shaped portion 90a along the guide sleeve 88 is a wider dimensioned portion 90b which defines / provides two spaced apart stepped profiles 90c and 90d, as shown in Figures 8 and 9.

[0142] As seen in Figure 9, the guide sleeve 88 is configured at or near a second end 92 for operable association with the actuable portion 70 for enabling the piston 84 to be acted upon by the driven member 72. In this manner, the deployment tool 58 is capable of being used to perform two functions: (i) enable the piston 84 to receive a force actuated by way of the actuable portion 70 for transfer to the actuator 20 by manipulation of the actuating knob 76, and (ii) enable screwing / driving of the fastener body 5 into the bore hole in the bone by way of the actuable portion 70 (specifically, via the handle portion 83) due to a keyed relationship 99 (see Figures 9, 10(d) / (e)) between the body 80 of the actuable portion 70 (via socket recess 80b) with the second end 92 of the guide sleeve 88 (which is shaped so as to key with the socket recess 80b) and the keyed relationship between the shaped portion 90a (of the guide sleeve 88) and the recess 93 of the fastener body 5.

[0143] With reference to Figures 7 to 9, the deployment tool 58 comprises a support member being of tubular form (hereinafter, support tube 94) providing a passage 96 for accommodating operation (for example, axial linear movement) of the guide sleeve 88 during use. The support tube 94 is configured at one end 94a (see Figure 7) for engaging with the tulip connector 60 in a manner enabling the deployment tool 58 to be placed in fixed relation therewith by way of the threaded engagement 59 involving a threaded region 59a of the support tube 94 and a threaded region 63a (as clearly seen in Figure 4) formed at the second end 63 of the tulip connector 60. The support tube 94 further comprises a section 98 configured of wider dimension and including suitable textured / patterned surface 98a (see Figures 7 / 8) for handling purposes. In this manner, concentric support is conferred to the guide sleeve 88 for (i) helping maintain guidance of the piston 84 during its linear / axial movement, and / or (ii) driving / screwing of the fastener body 5 into the bore hole in the bone, and which may be irrespective of any articulation between the fastener body 5 and the deployment tool 58 occurring (due to the articulable nature of the ball / socket type joint attaching the tulip connector 60 with the fastener body 5).

[0144] As shown in Figure 4, a portion of the first end 40 of the actuator 20 is substantially rounded or spherical shaped so that the force applied to the actuator 20 by the piston 84 is operable for causing the actuator 20 to move substantially within the fastener body’s first passage 30 along the fastener’s axis X irrespective of any articulation between the fastener body 5 and the deployment tool 58 (which influences the direction the force is applied) occurring.

[0145] Figure 10(a) shows assembly of the guide sleeve 88 (accommodating the piston 84) with the support tube 94 such that a larger dimensioned portion 92a of the end 92 of the guide sleeve 88 abuts the end 91 of the support tube 94. Figure 10(b) shows engagement of the shaped portion 90a of the guide sleeve 88 within the recess 93 of the fastener body 5 so that both are in keyed relation with one another with step 90c bearing against the exterior periphery of the recess 93. Figure 10(c) shows rotation of the support tube 94 as it is placed in threaded engagement 59 with the end 63 of the tulip connector 60. The threaded engagement 59 is sufficiently advanced so that the distal end of the support tube 94 abuts or bears against a stop 61 held by the tulip connector 60 (refer Figure 4) and the step 90d of the wider dimensioned portion 90b of the guide sleeve 88 thereby securing the guide sleeve 88 in position with the fastener 2. Figure 10(d) shows the actuable portion 70 located in keyed relation 99 with the guide sleeve 88, ready for use in either driving of the fastener 2 into the bore hole, or for use in deploying the expansion portions 14, 16 to the expanded configuration. Figure 10(e) shows, on rotation of the actuating knob 76, the axial movement of the driven member 72 making contact with and driving movement of the piston 84 so as to drive movement of the actuator 20 thereby resulting in, via the coupling arrangement 24, the expansion portions 14, 16 moving to the expanded configuration.

[0146] Other embodiments of the deployment tool 58 may comprise mechanisms that, while resulting in a linear movement of the piston 84 for providing an appropriate force to the actuator 20, are actuated by different movements or motions to that described herein. For example, the driven member 72 may be caused to translate linearly in response to a driving element that is actuated, either directly or indirectly, by a user in a linear manner. As noted, the skilled reader will appreciate that other actuation or triggering motions / movements can be suitably mechanised so as to result in linear movement of the driven member 72.

[0147] Figure 11 shows the disassembly of the deployment tool 58 from the fastener 2, whereby, simply, the support tube 94 is unthreaded from engagement with the tulip connector 60 (Figure 11(a)) and disassociated from the fastener 2 completely in the direction shown so as to arrive that shown in Figure 11(b).

[0148] Advantageously, embodiments of the deployment tool 58 described herein enable simplified application or use within existing implant surgery workflows. Only an additional step of expanding the expansion portions 14, 16 using the deployment tool 58 is needed. This also allows any complicated manufacturing to happen external to the implanted parts (therefore not increasing the per implant cost of goods). Because the deployment tool 58 is reusable this makes things more cost effective.

[0149] In one form, the fastener 2 is operable with an apparatus or tool assembly (hereinafter, removal tool 100) configured operable for use in moving the expansion portions 14, 16 from the expanded configuration to or toward the contracted configuration for removal of the fastener 2 from the bore hole in the bone. One example of a suitable removal tool 100 is shown in Figures 16 to 20. The removal tool 100 may form part of the system of components with the deployment tool 58, the tulip connector 60, and the fastener 2.

[0150] With reference to Figures 16 to 18, the removal tool 100 comprises an extraction member 105 configured operable for engaging the actuator 20 at or near its first end 40. As shown in Figures 16 to 18, the extraction member 105 is of rod-like form / profile.

[0151] The extraction member 105 is arranged so as to be operably responsive to actuation of an actuable portion 110 by way of a threaded portion 112 provided at an end 105a of the extraction member 105 being engageable in threaded engagement 113 (see Figures 16, 17 and 18) with a threaded portion 114 of an end 116 of an interior wall of a passage 118 formed internal of the actuable portion 110. The threaded engagement 113 between the extraction member 105 and the actuable portion 110 is operable for enabling the extraction member 105 to move the actuator 20, when engaged therewith, in a direction outward of the fastener body’s first passage 30 away from the second end 50 along the axis X so as to cause the expansion portions 14, 16 to move away from the expanded configuration toward the contracted configuration. In one form, the actuable portion 110 is manually operable.

[0152] As shown in Figure 4, the actuator 20 is provided with an annular groove 120 spaced from the distal tip of its first end 40. With reference to Figures 18 and 19, the extraction member 105 comprises a body portion 105b from which first 124 and second 128 engagement arms extend so as to define an end region 105c of the extraction member 105. The annular groove 120 is configured for receiving portions 123, 127 which project inward from respective first 124, second 128 engagement arms. As can be seen in the inset drawing in Figure 18, the projecting portions 123, 127 are each carried by respective engagement arms 124, 128 and project towards each other in opposing and spaced relation. Furthermore, as also seen in the inset drawing in Figure 18, a respective side of each of the projecting portions 123, 127 adjacent a distal end 129 of the extraction member 105 comprise a respective ramp like profile 123a, 127a which serves to allow the portions 123, 127 to be pushed (ramped) over / about the actuator’s first end 40 for establishing engagement with the actuator’s annular groove 120. Due to their geometrical form and spacing the engagement arms 124, 128 exhibit a degree of flexibility allowing them to splay apart from each other so as to be push-able / passable about the actuators first end 40 so that the projecting portions 123, 127 can locate suitably within the actuator’s annular groove 120.

[0153] The engagement between the projecting portions 123, 127 with the annular groove 120 is configured so that sufficient friction is created / established therebetween so as to prevent the projecting portions 123, 127 from rotating (about the axis A) within the annular groove 120. The skilled reader will appreciate that various connection / engagement configurations can be devised to establish a keyed relationship or connection between the engagement arms 124, 128 and the actuator 20 (alternative to reliance on a friction-based engagement between both components 20, 105).

[0154] With particular reference to Figure 17(a) the actuable portion 110 is of tubular form having first 140 and second ends 142. A handle portion 144 extends a distance inward from the actuable portion’s first end 140 and configured so as to be easily gripped by a user of the removal tool 100 (handle portion 144 being of a wider diameter than the remainder of the actuable portion 110 and having a suitably textured surface for manual gripping purposes, such as for example a rubberised substrate or surface modification such as a knurl or similar surface texture / pattern).

[0155] The actuable portion 110 comprises a narrow-dimensioned portion 143 (relative to dimensioning of the remainder of the actuable portion) which extends a distance inward from the actuable portion’s second end 142. The narrow-dimensioned portion 143 is configured / dimensioned so as to engage, in a generally snug like manner, within the annular hollow of the tulip connector 60 as part of the removal process (as will be described below). As shown in Figure 19(e), the narrow-dimensioned portion 143 is configured so as to, on insertion into the annular hollow of the tulip connector 60 during a removal mode of operation, cooperate with the geometry of the engagement arms 124, 128 prevent the engagement arms 124, 128 from splaying apart and disrupting their respective engagement of the actuator’s annular groove 120. Furthermore, the dimensioning of the narrow-dimensioned portion 143 driving its depth of insertion within the annular hollow of the tulip connector 60 serves to help provide for a stable engagement between the actuable portion 110 and the tulip connector 60 during use (ie. removal of the actuator 20).

[0156] A region 150 of the actuable portion 110 intermediate its first end 140 and the narrow- dimensioned portion 143 is generally dimensioned (being of wider dimension than narrow- dimensioned portion 143) for ease of handling by a user of the removal tool 100 and to provide sufficient concentric support to the extraction member 105 for operational purposes. As clearly seen in Figure 18, a transition region 145 occurs between region 150 and the narrow-dimensioned portion 143 of the actuable portion 110 as the diameters of the respective portions change. As shown, the transition region 145 is generally ramp like in profile / form, whereby its respective ramped surface, in operation, abuts against the first end 63 of the tulip connector 60.

[0157] With reference to Figures 18 to 20, the passage 118 of the actuable portion 110 accommodates operation (eg. axial / linear movement) of the extraction member 105. The extraction member 105 is arranged so as to be moveable within the passage 118 by way of the threaded portion 112 of the extraction member 105 being placed in threaded engagement 113 with the threaded portion 114 of the passage 118 of the actuable portion 110. Such threaded engagement 113, on movement of the actuable portion 110 about its axis A (refer Figure 17(a)) and with the extraction member 105 experiencing sufficient rotational restraint (about its axis B - refer Figure 17(b)) by the friction created / established by the engagement between the engagement arms 124, 128 (of the extraction member 105) and the annular groove 120 (of the actuator 20), operates to cause the extraction member 105 to move the actuator 20 in a direction outward of the fastener body’s first passage 30 away from the second end 50 thereby causing the expansion portions 14, 16 to be moved to or toward the contracted configuration. As noted above, in one embodiment, the actuator 20 is rotationally restrained due to sufficient friction created / established by the coupling arrangement 24.

[0158] Figure 19 shows one example of the operation of the removal tool 100. Figure 19(a) shows the extraction member 105 being moved into position so that the engagement arms 124, 128 enter the hollow of the tulip connector 60. Figure 19(b) shows an advancement on Figure 19(a) with projecting portions 123, 127 pushed / passed about the actuator’s first end 40 (with the assistance of the ramp like features 123a, 127a) for establishing engagement with the actuator’s annular groove 120. As the skilled reader will appreciate, such a connection between the engagement arms 124, 128 and the actuator 20 as presently described represents a form of ‘snap-fit’ engagement. As noted above, the engagement between the projecting portions 123, 127 with the annular groove 20 is configured so that sufficient friction is created / established therebetween so as to prevent the projecting portions 123, 127 from rotating (about the axis A) within the annular groove 120 so that rotation of the actuable portion 110 onto the threaded portion 112 will not rotate the extraction member 105 - but rather advance the extraction member 105 upwards (as shown in Figure 19) during the removal operation. The skilled reader will appreciate that other connection arrangements that provide the same functionality are possible.

[0159] Figure 19(c) shows the actuable portion 110 assembled with the extraction member 105, and its narrow-dimensioned portion 143 about to be received by the hollow of the tulip connector 60. At Figure 19(d), the actuable portion 110 is advanced sufficiently within the hollow of the tulip connector 60 so that the transition region 145 adjacent the actuable portion’s narrow-dimensioned portion 143 is brought proximal the tulip connector’s second end 63. At this stage, the threaded engagement 113 between the extraction member 105 and the actuable portion 110 begins.

[0160] At Figure 19(e), operation of the removal tool 100 begins. As noted above, for the specific embodiment shown, the coupling arrangement 24 is configured so as to provide a sufficient degree of (contact) friction that operates to restrain relative rotational movement between the expansion member 10 and the actuator 20. As such, rotational restraint provided via the coupling arrangement 24 is transferred to the extraction member 105 via the friction created by the engagement between the projecting portions 123, 127 and the actuator 20 (via the annular groove 120). Accordingly, rotation of the actuable portion 110 causes linear movement of the extraction member 105 in the passage 118 of the actuable portion 110 away from the fastener body 5 via the threaded engagement 113 between the portion 114 of the passage 118 of the actuable portion 110, thereby causing the actuator 20 to be moved in a direction away from the second end 50 outward of the passage 30. At the same time, the actuable portion 110 is physically pushed against the tulip connector 60 such that the transition region 145 at the actuable portion 110 bears against the second end 63 of the tulip connector 60 so as to offer sufficient resistance for preventing the fastener body 5 from being pulled from the bore hole in the bone during the transition of the expansion member 10 from the expanded configuration to the contracted configuration. Figure 20(a) shows manual translation of the removal tool 100 away from its engagement with the tulip connector 60, and the actuable portion 110 is sought to be unthreaded from the extraction member 105 (the actuator 20 continues to transfer rotational restraint to the extraction member 105 enabling its threaded engagement with the actuable portion 110 to operate).

[0161] At Figure 20(b), the actuable portion 110 is disassembled from the extraction member 105, followed by, as shown in Figure 20(c), the extraction member being caused to cease its engagement with the actuator’s annular groove 120.

[0162] The skilled reader will appreciate that the engagement between the actuator 20 and the extraction member 105 (which could be described as a captured or captive based form of engagement) could be enabled by other forms of ‘snap-fit’ connection. Alternatively, the captive / captured engagement between the actuator 20 and the extraction member 105 could be enabled by way of a form of a collet chuck associated with the extraction member 105 that attaches to the actuator 20 by way of a friction-based association.

[0163] Advantageously, engagement between the actuator 20 and the removal tool 100 does not rely on any form of threaded connection; for example, because the actuator 20 is threadless, a male thread on the outside of the actuator 20 or a female thread on its inside is not required. As compared some existing prior art arrangements that rely on threaded engagements, advantages of a threadless connection arrangement can be seen in the general simplification of the relevant manufacturing processes where embodiments of the expandable fasteners are to be produced of small (or miniaturised) sizes. Additionally, a female thread on the internal bore (30) of the fastener body 5, for example, can be avoided thereby enabling the effective diameter of the bore to be decreased and eliminating the stress concentration factor of any thread. Furthermore, avoidance of threaded surfaces (male or female thread components) serves to assist in improving the structural strength of the host part (of the relevant thread component) assisting in enabling miniaturisation of an expandable fastener arranged consistent with the present disclosure.

[0164] Reference is now made to Figure 21 (showing the expansion member 10 in the contracted configuration), Figure 22 (showing the expansion member 10 in the expanded configuration), and Figure 23 (showing the expansion member 10 in a flexed condition about to be inserted in the slot 36 during assembly with the fastener body 5), which show the general operation of the shaped form / profile exhibited by each of the expansion members 14, 16 and the associated advantage conferred generally to the expansion member 10.

[0165] For the embodiment described herein, each expansion portion 14, 16 is shaped so as to benefit from an increase in respective effective length for seeking to increase the scope of their effective elastic range between the contracted and expanded configurations. In this manner, advantageously, the profile shape of the expansion portions 14, 16 operates to enable an increase in the allowable thickness of the relevant expansion portion (and / or the expansion member 10 generally) while still maintaining the same desired elastic range of articulation or flex.

[0166] The expansion portions 14, 16 are configured of generally planar form (as clearly seen in Figures 12, 13, and 14) and shaped so as to extend away from the connecting portion 35 for defining respective distal ends 14c, 16c (refer Figure 23(a)). The expansion portions 14, 16 each extend away (outward of axis D) from the connecting portion 35 (better seen in Figure 23(b)) and return toward the axis X for defining respective curved or curvilinear shaped segments 14b, 16b, before then extending substantially toward their respective distal ends 14c, 16c (refer Figure 23(a)) in a manner substantially parallel with the axis D. The curved shape / form of the respective curved shaped segments 14b, 16b of the expansion portions 14, 16 operates to, at least in part, increase their effective length which, advantageously, increases their respective elastic range of movement / flex between the contracted / expanded configurations. As such, the allowable thickness of the planar form of the expansion portions 14, 16 can be increased while maintaining the same scope of elastic range. In this regard, dimensionally thin expansion portions are difficult to manufacture and more likely to fail. Other profile forms / shapes may confer similar characteristics, such as for example, wavy forms or profile shapes in which defining edges of the relevant profile are angled outwards or away from the expansion portion’s axis D. As shown in each of Figures 21 to 23, the expansion portions 14, 16 comprise respective open slots 14d, 16d of generally elongate form which open (at respective reference numerals 14e, 16e) adjacent respective curved shaped segments 14b, 16b and which define respective extending segments 14f, 16f. The geometry of the open slots 14d, 16d thereby contributes, in part, to the degree of articulation or flex conferred to the respective expansion portions 14, 16, and, consequentially, to the expansion member 10.

[0167] With specific reference to Figure 23(b), respective edge portions 14g, 16g which help define respective slot openings 14e, 16e serve as a form of limit-stop against which respective generally oppositely disposed end portions 14h, 16h (which respectively contribute to defining the slot openings 14e, 16e of the open slots 14d, 16d) of respective extending segments 14f, 16f (and which also help define respective slot openings 14e, 16e) may bear for providing or conferring stabilising support to the relevant expansion portion 14, 16 (on experiencing load as shown in Figure 23(a)) when in or moving toward the expanded configuration.

[0168] Advantageously, shaping of the expansion portions 14, 16 in accordance with the principles described herein may serve to enable an increase in the allowable thickness of the relevant expansion portion 14, 16 while still maintaining the same desired scope of elastic range or articulation / flex of the expansion member 10. Furthermore, the shape of the curved sections 14b and 16b helps reduce sharp corners around bending / flexing sections that can create stress raisers that can create or develop weak points / regions that result in breakage (as well as the ability to provide increased material thickness). The skilled reader will appreciate that comparatively thinner thicknessed expansion portions can provide manufacturing difficulties (for example, if each expansion portion is only, for example, 0.5mm in thickness, then a 0.1 mm tolerance can make them very thin). Additionally, thinner expansion portions 14, 16 are more likely to break during use. Furthermore, in some embodiments, a higher elastic range also allows a larger expansion size and shorter expansion portions 14, 16 (creating a higher expansion angle, ie. departure of the respective expansion portion 14, 16 from the axis D). The skilled reader will appreciate that there are many geometrical profiles that could be developed to achieve this, including, for example, wavy profile shapes or profile shapes which angle outwards of the axis D.

[0169] Once the fastener 2 is positioned in the bore hole in the bone, the tulip connector 60 is configured so that, when the expansion portions 14, 16 are in the expanded configuration, the actuator 20 can be affirmatively secured or locked in position to prevent it from moving in a direction away from the second end 50 outward of the fastener body’s first passage 30. With reference to Figures 12 to 15, this is achieved by way of a locking nut or cap 160 being arranged in threaded engagement with the first end 63 of the tulip connector 60 and being brought to bear against a stop member (hereinafter, spinal rod 162) which is received in a ‘U’ shaped channel 165 formed in the tulip connecter 60 (see Figures 12 and 13). The spinal rod 162 is arranged or locked in abutting relation between / intermediate the actuator’s first end 40 and the locking nut or cap 160, as shown in Figures 12, 13 and 15. In this manner, the actuator 20 is prevented from any inadvertent movement in a direction away from the second end 50 outward of the fastener body’s first passage 30 which could cause, via the coupling arrangement 24, movement of the expansion portions 14, 16 to or toward the contracted configuration.

[0170] As described above, with reference to the force transfer from the piston 84 of the deployment tool 58 to the actuator 20, and with reference to Figures 15(a) and (b), a portion of the first end 40 of the actuator 20 is substantially rounded or spherical shaped. In this manner, a force applied to the actuator 20 by the spinal rod 162 (generated by the threaded advancement of the locking nut or cap 160) can be suitably received by the shaped form of the actuator’s first end 40 so that, to the extent possible, the holding force applied by the spinal rod 162 is suitably directed substantially along the fastener body’s axis X irrespective of any articulation between the fastener body 5 and the tulip connector 60 when the actuator 20 is locked in position (as demonstrated in Figure 15(b) by an articulation angle alpha (a)).

[0171] Figures 24 to 26 show another embodiment of an expandable fastener (hereinafter, fastener 2’) arranged consistent with the principles of the present disclosure. Analogous features retain corresponding reference numerals as for fastener 2’ for ease of explanation.

[0172] The fastener 2’ comprises an axis X relative which body 5’ is coaxial. The body 5’ is of screw like form having a head portion 62’ at a first end 34’ and tapering generally to a second end 50’ (which is distal of its first end 34’ as shown in Figure 24). The body 5’ carries about its exterior surface a first region of male thread 5a’ near the first end 34’, and a second region of male cortical thread 5b’ commencing at or near a generally central region of the body 5’ and extending to / toward the second end 50’. The male thread of the first thread region 5a’ is of substantially the same pitch and depth as that of the second thread region 5b’ so as to increase the inner volume of the body 5’ while also allowing for synchronous operation when driving of the fastener 2’ into the bore and subsequent deployment of the expansion member 10’ (as discussed below). For the embodiment shown, the male threads 5a’, 5b’ are the same, but could be different thread forms as with the fastener 2.

[0173] For example, in an embodiment, the second region 5b’ could be formed providing male cancellous thread (as with the fastener 2). By way of brief explanation, the cortical thread doubles in the number of starts relative to the cancellous thread so as to reduce the thread form size. Moreover, consistency of the threads 5a’, 5b’ also allows for synchronous driving operation of the fastener 2’ such that the movements of the threads do not conflict causing jamming and consequential pull / push forces, as outlined further below. This allows for a generally single stage or continuous operation across the initial driving insertion and expansion member 10’ deployment processes.

[0174] Embodiments could be realised in which either of the first 405a and second 500a threads could be shallower than the other and / or with the same number of starts.

[0175] The fastener 2’ comprises an expansion member 10’ comprising first 14’, second 16’ expansion portions moveable between a contracted or standby configuration (shown in Figure 24 and 26(a)) and an expanded configuration (as shown in Figures 25 to 26(c)). As with the fastener 2, when the fastener 2’ is in use, the first 14’, second 16’ expansion portions are operable to respectively move outwardly / away from the axis X of the body 5 towards the bone (not shown) surrounding the bore hole (not shown) when moving towards the expanded configuration.

[0176] The fastener 2’ comprises an actuator or actuable means (hereinafter, actuator 20’) configured substantially the same as the actuator 20, that is movable along the axis X of the fastener’s body 5’. As with the actuator 20 fastener 2, the actuator 20’ is of rod like form having first 40’ and second 42’ ends.

[0177] The fastener 2’ further comprises a coupling arrangement 24’ configured substantially the coupling arrangement 20 of the fastener 2. The coupling arrangements 24’ is operable for coupling the expansion member 10’ with the actuator 20’ for enabling operation of the first 14’, second 16’ expansion portions toward or from the contracted / expanded configurations via the actuator 20’. The coupling arrangement 24’ is configured so as to directly couple the expansion member 10’ with the actuator 20’ such that relative movement between the actuator 20’ and the expansion member 10’ along the axis X is substantially restrained while allowing or facilitating relative movement between the expansion member 10’ and the actuator 20’ about the axis X.

[0178] The fastener body 5’ comprises an interior region having a first passage 30’ that is substantially concentric / coaxial with the fastener body’s axis X’ and configured for accommodating and guiding movement of the actuator 20’ there along. The first passage 30’ is configured so as to extend between (thereby joining) a first opening 32’ formed at the first end 34’ of the fastener body 5’ and a slot 36’ formed in the body 5’ and spaced from the fastener body’s first end 34’. The slot 36’ is shaped for receiving and accommodating the expansion member 10’ such that when the first 14’, second 16’ expansion portions are in the contracted configuration a profile of the expansion member 10’ does not extend beyond that of the fastener body 5’. As shown in Figures 24 to 26, the slot 36’ is configured so as to open to two exterior regions of the fastener body 5’ (in this example, two generally oppositely disposed exterior regions of the fastener body 5’) through which a respective expansion portion 14’, 16’ moves so as to extend beyond the profile of the fastener body 5’ so as to adopt the expanded configuration in a symmetrical manner about the axis X. Consistent with the operation of the expansion member 10, the first 14’, second 16’ expansion portions move outward of the slot 36’ away from the axis X toward the expanded configuration by way of respective edges 14j’ , 16j’ (refer Figure 25) being caused to run against a lower disposed wall portion 36a’ (refer Figure 25) which contributes in defining the slot 36’. In this manner, running of edges 14j’, 16j’ against the lower disposed wall portion 36a’ serves to urge / motivate the expansion portions 14’, 16’ in a direction outward / away from the axis X.

[0179] Consistent with the principles of the operation of the fastener 2, the direction of movement of the actuator 20’ within the first passage 30’ corresponds with the operation of the expansion member 10’ due to the operation of the coupling arrangement 24’ such that, when the actuator 20’ is caused to be moved in a direction toward the second end 50’ along the axis X, the first 14’, second 16’ expansion portions move (via respective slot 36’ openings in the fastener body 5’) outward of the slot 36’ away from the axis X toward the expanded configuration in the manner described in relation to the fastener 2.

[0180] However, the means by which movement of the actuator 20’ moves along the axis X for the fastener 2’ is different to that of the fastener 2. Rather than an axial force being applied to the first end 40’ of the actuator 2O’(as is the case for operation of the fastener 5), because the coupling arrangement 24’ allows or facilitates relative movement between the expansion member 10’ and the actuator 20’ about the axis X, a region of threaded engagement between the actuator 20’ and the first passage 30’ of the body 5’ is provided. It will be seen in Figure 24(a) and Figures 26(a)-(c) that the first passage 30’ comprises a region of thread 30t’ provided about a region of the interior wall of the passage 30’. Furthermore, a region of thread 20t’ is provided about a region of the exterior wall of the actuator 20’. It will be understood that both threaded regions 30t’ and 20t’ engage for operation in the usual manner. Accordingly, with the body 5’ stationary due to its engagement with the bone, rotation of the actuator 20’ about the axis X (using an appropriate tool) drives the actuator 20’ in a direction along the axis X which corresponds with the direction of rotation of the actuator 20’ about the axis X. In this manner, rotation of the actuator 20’ in a first direction of rotation causes the actuator 20 to move in a direction toward the second end 50’ along the axis X so as to move the expansion member 10’ into the expanded configuration.

[0181] Similarly, consistent with the principles of the operation of the fastener 2’, on the expansion portions 14’, 16’ being in the expanded configuration, rotation of the actuator 20’ in a second direction of rotation (opposite the first direction of rotation) causes movement of the actuator 20’ in a direction toward the first end 34’ along the axis X away from the second end 50’ causing the first 14’, second 16’ expansion portions to move toward the contracted configuration.

[0182] Figure 26 shows a sequence of steps of operation (a) to (c) of the fastener 2’ shown in Figures 24 and 25 for operating the expansion portions 14’, 16’ of the expansion member 10’ to or toward the expanded configuration. In Figure 26(a) the fastener 2’ is in the standby state with the expansion member 10’ in the contracted configuration; in Figure 26(b) the actuator 20’ is rotated about the axis X so as to cause the actuator 20’ to move in a direction inwards of the passage 30’ (downwards of page) along the axis X so as to cause the expansion member 10’ to move toward the expanded configuration; and in Figure 26(c) sufficient rotation of the actuator 20 has occurred so as to enable the expansion member 10’ to arrive at the fully expanded configuration as shown. It will be appreciated that the reverse rotation of the actuator 20’ about the axis X enables the expansion portion 10’ to move back to the retracted configuration by way of the coupling arrangement 24’ - by the coupling arrangement 24’ being operable for enabling the actuator 20’ to captively support or hold the expansion member 10’ therewith during movement along the axis X - such that relative movement between the actuator 20’ and the expansion member 10’ along the axis X is substantially restrained while allowing or facilitating relative movement between the expansion member 10’ and the actuator 20’ about the axis X.

[0183] Figures 27 to 29 show another embodiment (hereinafter, fastener 400) of an expandable fastener arranged consistent with the present disclosure. As will be described below, the function and operation of the actuator 20, 20’ in the previously described embodiments of the expandable fastener 2, 2’ can also be achieved by way of reconfiguring the coupling arrangement 24, 24’ so that actuation of the expansion member 10, 10’ can be undertaken by way an operation (rotation about the axis X) of a reconfigured body 5 of the fastener 2, 2’ while remaining consistent with the principles of the present disclosure. In this manner, and as will be described below with regard to the fastener 400, the coupling arrangement 24, 24’ can be configured so as to involve respective portions of a reconfigured body (in one form, involving a region of a passage 430 of such reconfigured body 405) and a portion of a reconfigured expansion member 410.

[0184] Fundamentally, the configuration of the fastener 400 is similar to that of the fasteners 2, 2’. With reference to Figures 27 to 29, the fastener 400 comprises an axis X relative which a body 405 is coaxial. As will be described below, the body 405 is reconfigured so as to also serve as a body of the actuator means 420. The body 405 (which will later be referred to as actuator-body 420-405) is of screw like form having a head portion 462 at a first end 434. Spaced from the first end 434 is a proximal region of the body 405 that carries about its exterior surface a first region of male thread 405a. The first threaded region 405a, being disposed in this manner, is positioned to engage what is usually considered to be better quality bone in, for example, a pedicle.

[0185] As will be noted below, and with brief reference to Figure 27(b) and 28(b), the fastener 400 comprises a body 500 having a distal end region 550 and a proximal end region 560. The distal end region 550 carries about its exterior surface a second region of male thread 500a. The proximal end region 560 provides a terminal end portion 540 that is configured to provide a means of engagement allowing the body 500 to be either driven about or held stationary relative to the axis X as circumstances might require during insertion and / or removal of the fastener 400 from a bore hole. In one embodiment, the means of engagement at the terminal end portion 540 of the body 500 could be formed so as to provide a cross-drive or hexalobe (e.g., torx) driver engagement, but the skilled reader will appreciate that a hex form / profile or anything else appropriate that enables keying or spline engagement with the terminal end portion 540 to occur could be applicable.

[0186] The male thread of the first threaded region 405a is of substantially the same pitch as the male thread of the second threaded region 500a but, in the form shown, having a finer thread with more starts. Embodiments could be realised in which either of the first 405a and second 500a male threads could be shallower than the other and / or with the same number of starts. As will be described below, matching of the pitches of the threads 405a, 500a assists in ensuring synchronous operation of the fastener 400 during driving into the bore hole.

[0187] The fastener 400 comprises an expansion member 410 comprising first 414, second 416 expansion portions moveable between a contracted or standby configuration (shown in Figure 27 and 29(a)) and an expanded configuration (as shown in Figures 28 to 29(c)). As with the fasteners 2, 2’, when the fastener 400 is in use, the first 414, second 416 expansion portions are operable to be caused to be respectively moved outwardly / away from the axis X towards the bone (not shown) surrounding the bore hole (not shown) when moving towards the expanded configuration.

[0188] The expansion portions 414, 416 are configured so as to be external as compared the expansion portions 14, 16 of the fasteners 2,2’ so as to engage (to the extent possible) more bone thereby increasing performance of the bone / screw interface in situations when, for example, the fastener 400 is screwed into weaker cancellous bone.

[0189] Like fasteners 2, 2’, the fastener 400 comprises an actuator or actuating means 420. For the configuration of the fastener 400, and unlike with the actuators 20, 20’ of the fastener’s 2, 2’, the actuator means 420 is integrated with the body 405 of the fastener 400. As will be described below, when operating to expand the expansion member 410, the integrated actuator-body 420,405 is arranged so as to be operable with the body 500 so as that the integrated actuator-body 420,405 is movable along the axis X in a direction toward the distal end region 550. Furthermore, the integrated actuator-body 420,405 of the fastener 400 is rotatable about the axis X, which rotation enables movement of the expansion member 410 along the axis X for moving to the expanded configurations as required (the reverse operation causes reverse movement of the expansion member 410). As the actuator means 420 of the fastener 400 is by way of movement of the body 405 (in its integrated form), for ease of reference, hereinafter, the actuating means 420 of the fastener 400 will be referred to as actuator-body 420-405. In this manner, the actuator- body 420-405 is intended to reflect the synergy / integration of the actuator function with the body 405.

[0190] The fastener 400 comprises an interior region having a passage 430 that is substantially concentric / coaxial with the axis X and configured for accommodating and guiding movement of the actuator-body 420-405 there along. The passage 430 is provided within the actuator-body 420-405 and configured so as to extend between a first opening 432 formed at the first end 434 of the actuator-body 420-405 and a second opening 436 formed in the actuator-body 420-405 provided at a second 435 spaced from the body’s first end 434. The second opening 436 is shaped for receiving and accommodating an end region 410a of the expansion member 410, the end region 410a being of annular or collar like form and at which the expansion portions 414, 416 meet. As shown in Figures 27 to 29, the second opening 436 is also configured so as to receive a rod-like portion of the body 500 of the fastener 400.

[0191] The body 500 is shaped at a distal end region 550 in a manner analogous to the second end 50 of the fastener 2, and carries a male thread 500a. substantially similar to thread 5b of the fastener 2. In an embodiment, the male thread 500a may be formed so as to be substantially similar to thread 5b of the fastener 2 for engaging near or into the anterior cortex if desired.

[0192] The body 500 has a proximal end region 560 that is configured of rod-like form coaxial with the axis X and which is receivable within the passage 430 of the body 500 by way of the second opening 436, as shown in Figures 28 and 29. It will be seen that a portion of an exterior wall or surface of the rod-like form of the proximal end region 560 of the body 500 comprises a region of thread. Furthermore, it will be seen that a portion of an interior wall or surface of the passage 430 of the actuator-body 420-405 comprises a region of thread. As described above in relation to the fastener 2’, such threaded regions of the passage 430 and the proximal end region 560 of the body 500 operate to enable or facilitate movement of the actuator-body 420-405 along the axis X so as to move the expansion member 410 between the expanded and retracted configurations. For the present embodiment with the proximal end region 560 of the body 500 inserted into the bore hole in the bone and rendered stationary, movement of the actuator-body 420-405 about the axis X causes the actuator-body 420-405 to move or progress along the axis in the manner shown in Figures 29(a)-(c).

[0193] Consistent with the present disclosure, the fastener 400 further comprises a coupling arrangement 424. The coupling arrangement 424 is operable for coupling the expansion member 410 with the actuator-body 420-405 for enabling operation of the first 414, second 416 expansion portions toward or from the contracted / expanded configurations via operation of the actuator-body 420-405. The coupling arrangement 424 is configured so as to directly couple the expansion member 410 with the actuator-body 420-405 such that relative movement between the actuator-body 420-405 and the expansion member 410 along the axis X is substantially restrained while allowing or facilitating relative movement between the expansion member 410 and the actuator-body 420-405 about the axis X.

[0194] Consistent with the principles of the operation of the fasteners 2, 2’, the actuator-body 420-405 of the fastener 400 comprises a region 440 of the first end 434 configured to operate as a drive engagement means (hereinafter, drive engagement region 440) so as to be receivable of a torque providing tool (for example, using any appropriate torque providing tool or instrument) so as to cause the actuator-body 420-405 to be moved about the axis X. In one embodiment, a hexalobe (e.g., torx) driver engagement is used, but could be a hex or anything else appropriate that enables keying or spline engagement with the drive engagement region 440 to occur. With the body 500 held stationary, the direction of movement of the actuator-body 420-405 along the passage 430 drives the operation of the expansion member 410 due to the operation of the coupling arrangement 424 such that, when the actuator-body 420-405 is rotated about the axis X by the application of torque, the actuator-body 420-405 is moved in a direction toward the distal end region 550 along the axis X. Consequentially, the first 414 and second 416 expansion portions move outward from the axis X toward the expanded configuration in the manner described in relation to the expansion member 10 of the fastener 2. The reverse occurs for moving the expansion member 410 to the retracted configuration. A close up of the configuration of the coupling arrangement 424 of the fastener 400 is shown in Figure 29(d). As can be seen, the coupling arrangement 424 is configured by way of a continuous annular recess 424a formed or provided in the interior wall of the passage 430 of the actuator-body 420-405. The annular recess 424a is shaped having first 424b, second 424c, and third 424d annular wall portions that are positioned adjacent an end of a threaded region 430t provided on the interior wall of the passage 430. The first annular wall portion 424b is angled inclined relative to the axis X as shown; the second annular wall portion 424c is generally parallel relative to the axis X, and the third annular wall portion 424d is oriented so as to be substantially orthogonal or transverse with the axis X.

[0195] The annular recess 424a receives an annular lip region 415 of the expansion member 410. In the form shown, the annular lip region 415 is shaped so as to substantially complement the form or profile of the annular recess 424a so that it can be received therein and held in captive engagement or support. As can be seen, the respective engagements between (i) the inclined first annular wall portion 424b of the recess 424a and the corresponding annular inclined surface portion of the annular lip region 415, and (ii) the third annular wall portion 424d of the annular recess 424a and the corresponding annular wall portion of the annular lip region 415, in effect, having a stepped form or profile along the axis X, traps the annular lip region 415 within the annular recess 424a thereby directly coupling or keying the expansion member 410 with the actuator-body 420-405 so that the expansion member 410 follows movement of the actuator-body 420-405 along the axis X in both directions. Furthermore, corresponding wall / surfaces of the annular recess 424a and the annular lip region 415 have no such interfering portions circumferentially about the axis X that can cause a keying or spline behaviour thereby enabling the actuator-body 420-405 and the expansion member 410 to be capable of relative movement. In this manner, the direct coupling between the actuator-body 420-405 and the expansion member 410 enables relative movement between the actuator-body 420-405 and the expansion member 410 along the axis X to be substantially restrained (due to keying of the parts in the axis X) while allowing or facilitating relative movement between the expansion member 410 and the actuator-body 420-405 about the axis X (due to no keying of the parts being possible circumferentially about the axis X). In assembly of the fastener 400, the expansion member 410 is formed of a sufficiently resilient material enabling its annular lip region 415 to be sufficiently compressed and inserted into the passage 430 and pushed / positioned therein (via the second opening 436) so that when adjacent the annular recess 424a, the annular lip region 415 expands into the annular recess 415a thereby completing the coupling between the actuator-body 420- 405 and the expansion member 410.

[0196] Once the annular lip region 415 is fitted with the annular recess 424a, the body 500 can then be assembled with the actuator-body 420-405 (i.e. , the proximal region 560 being inserted into the passage 430).

[0197] As noted above, the means by which movement of the actuator-body 420-405 moves along the axis X is due to a threaded engagement between a portion or region of the actuator-body 420-405 and a portion or region of the proximal end of the body 500. It will be seen in Figure 27(b) and Figures 29(a)-(c) that the passage 430 comprises a region of thread 430t is provided about a region of the interior wall of the passage 430 of the actuator-body 420-405. Furthermore, a region of thread 520t is provided about a region of the exterior wall of the rod-like proximal end region 560 of the body 500. It will be understood that both threaded regions 430t and 520t engage for operation in the usual manner. Accordingly, while the body 500 is caused to be stationary in the bore hole (once secured in place), rotation of the actuator-body 420-405 about the axis X (using an appropriate tool) drives the actuator-body 420-405 in a direction along the axis X which corresponds to the direction of rotation of the actuator-body 420-405 about the axis X. In this manner, rotation of the actuator-body 420-405 in a first direction of rotation causes the actuator-body 420-405 to move / progress in a direction toward the distal end region 550 along the axis X so as to move the expansion member 410 into the expanded configuration.

[0198] In an embodiment, the male thread 405a of the actuator-body 420-405 and the male thread 500a of the body 500 may be configured so as to have a pitch that is substantially the same or matched to a pitch of the threads of the engaging threaded regions 430t (at the interior wall of the passage 430 of the actuator-body 420-405) and 520t (at the exterior wall of the rod-like proximal end region 560 of the body 500) enabling threaded engagement between the actuator-body 420-405 and the body 500. It will be understood that the matching of the pitches of the threads (those of male threads 405a, 500a, and those of 430t, 520t) operate to, when in use, reduce or avoid any adverse push / pull forces occurring between the bone during driving of the fastener 400 into the bore hole and the actuation of the operation of the expansion member 410 for deploying the first 414 and second 416 expansion portions. In this manner, rotation of the actuator-body 420-405 into the bore hole can occur without the potential for jamming to occur during insertion and driving of the fastener 400 into the bore hole and deployment of the expansion member 410.

[0199] Consistent with the operation of the expansion members 10, 10’ the first 414, second 416 expansion portions move outward from the body 500 away from the axis X toward the expanded configuration by way of respective edges 414j, 416j being caused to run against a lower disposed annular ramp portion 436a (refer Figures 27(b) and 28(b)) provided with the body 500. In this manner, running of edges 414j , 416j against the lower disposed annular ramp portion 436a’ serves to urge / motivate the expansion portions 414,416 in a direction outward / away from the axis X.

[0200] Having regard to Figures 27 and 28, it is noted that the expansion portions 414, 416 are of a more rounded form / profile than the expansion portions 14,16 of the expansion member 10 (which are more planar in nature). In this regard, the respective exterior / periphery of the expansion portions 414,416 is of a generally circular form / profile configured so that, when in the contracted configuration, both portions 414,416 operate together to substantially surround or cover over / about an exterior of a narrowed portion of the body 500 as shown in Figure 27(a) (the narrowed portion of the body 500 accommodates the respective edges 414j, 416j as shown in Figure 27(b)). The operation or movement of the expansion members 414, 416 is substantially the same in moving over / across the body 500 (via the lower disposed annular ramp portion 436a’) during deployment as for the expansion members 10,10’ by way of, for example, the resilient nature of the material from which the expansion member 410 (and / or the end region 410a at which both expansion portions 414, 416 meet) is formed (e.g., any suitable elastically deformable materials operable within their elastic range throughout the expansion to the expanded configuration as described so that it can return to mostly or substantially its unexpanded state or configuration will find application in this regard). In being configured in this form, as compared the expansion portions 14 / 16,14716’ the broader, semi-circular form / profile of each of the expansion portions 414, 416 presents an increased exterior surface area to the wall of the bore hole for engagement purposes. It will be understood that this increase in surface area offers the expansion member 410 more engagement opportunity with the bore hole wall when expanding downwards / outwards during deployment, leading to increased prospects of a more secure hold with the surrounding bone.

[0201] In addition to the advantages of the increased surface area of the exterior of the sides of the expansion portions 414, 416 in increasing exposure to surrounding / nearby bone structures, their underside regions also find advantage in operating to increase prospective bone engagement around the distal end region 550 of the body 500 as they push down on the bone surrounding the distal end region 550 during deployment to the expanded configuration. As each of the expansion portions 414, 416 run against the lower disposed annular ramp portion 436a as they deploy, they push downwards on the bone surrounding the distal end region 550 forcing or biasing it into engagement with any bone structure that might be at, near, or adjacent the exterior of the distal end region 550 (eg. underneath and / or close by its peripheral extremity). In this manner, as the exterior of the expansion portions 414, 416 engage bone structure and meet reactionary resistance, their respective undersides push against the bone surrounding the distal end region 550 during deployment thereby prejudicing the expansion portions 414, 416 so as to be engageable with any adjacent lying bone structure for further securement of the fastener 400 in the bore hole.

[0202] Similarly, consistent with the principles of the operation of the fastener 2’, on the expansion portions 414, 416 being in the expanded configuration, rotation of the actuatorbody 420-405 in a second direction of rotation causes movement of the actuator-body 420-405 in a direction away from the distal end region 550 of the body 500 along the axis X, causing the first 414, second 416 expansion portions to move toward the contracted configuration.

[0203] Figure 29 shows a sequence of steps of operation (a) to (c) of the fastener 400 shown in Figures 27 and 28 for operating the expansion portions 414, 416 of the expansion member 410 to or toward the expanded configuration. In Figure 29(a) the fastener 400 is in the standby state with the expansion member 410 in the contracted configuration ready for deployment. Driving of the fastener 400 has been by way of the actuator-body 420-405 being rotated about the axis X engaging the thread 405a with the bore hole surrounding.

[0204] In Figure 29(b), the fastener 400 has been driven to a target position in the bore hole, and the expansion member 410 is in the process of deployment. At this stage, the actuatorbody 420-405 is being rotated about the axis X in the same direction of rotation as was used in the driving of the fastener 400 to the target position in the bore hole. Once the body 500 engages the bore hole or is caused to become stationary, continued rotation of the actuator-body 420-405 in the same direction of rotation as was used to drive the fastener 400 to the target position causes the actuator-body 420-405 to move or progress in a direction toward the distal end region 550 of the body 500 (downwards of page) along the axis X. This causes the expansion member 410 to move toward the expanded configuration. As noted above, rotation of the actuator-body 420-405 about the axis X is by way of engagement of an appropriate torque supplying tool or instrument with the drive engagement region 440.

[0205] Accordingly, primary driving of the fastener 400 into the bore hole is by way of the threaded region 405a of the actuator-body 420-405 engaging with the bore hole wall. During this time, the body 500 is not fixed or stationary relative to the axis X or the bore hole, else the actuator-body 420-405 will start to progress along the axis X causing premature opening of the expansion member 410. Such driving of the actuator-body 420- 405 continues until the distal end region 550 of the body 500 engages the bone sufficiently to cause it to become restrained or rendered stationary relative to the axis X or the bore hole. At this time, the actuator-body 420-405 begins to progress toward the distal end region 550 thereby deploying the expansion member 410. This operation is enabled without jamming due to the respective pitches of the male threads 405a, 500a (when engaged with the surrounds of the bore hole) and the threaded engagement of threads 430t / 520t being substantially the same. In this manner, operation of all threaded regions is in sync thereby avoiding the potential for adverse pull / push or jamming forces occurring during insertion and subsequent opening of the expansion member 410. This driving and deployment process is generally continuous allowing a single step operation.

[0206] In the event that the body 500 meets sufficient resistance to restrain its movement relative to the actuator-body 420-405, its terminal end portion 540 can be engaged by an appropriate tool so as to key its movement with the actuator-body 420-405 so that both rotate together during the initial insertion / driving into the bore hole. As noted above, the thread 500a provided with the distal end region 550 of the body 500 is of the same pitch as the other threads (ie. threads 405a, 430t / 520t) of the fastener 400. Similarly, when the thread 500a is engaged with the bone, the consistency of the pitch across all threads (405a, 500a, 430t, 520t) ensures synchronous operation seeking to avoid the potential for adverse pull / push or jamming forces occurring during insertion and subsequent opening of the expansion member 410. In this manner, a more ‘single step’ process (as compared the process of fasteners 2, and 2’) can be progressed where once the distal end region 550 of the further body 500 is in place and its movement secured relative to the axis X, the actuator-body 420-405 can continue so as to progress forwards along the axis X to deploy the expansion portions 414, 416.

[0207] In Figure 29(c) sufficient rotation of the actuator-body 420-405 has occurred so as to enable the expansion member 410 to arrive at the fully expanded configuration as shown. It will be appreciated that the reverse rotation of the actuator-body 420-405 about the axis X enables the expansion portion to retract back to the retracted configuration by way of the coupling arrangement 424 - by the coupling arrangement 424 being operable for enabling the actuator-body 420-405 to captively support or hold the expansion member 410 therewith during movement along the axis X).

[0208] One or more advantages may be realised by way of the expandable fastener 400, which may include: • Providing a more streamlined or ‘single step’ process (as compared the process of fasteners 2, and 2’) where once the distal end region 550 of the further body 500 is in place and restrained rotational relative to the axis X, the actuator-body 420-405 can continue so as to progress forwards along the axis X towards the distal end region 550 to deploy the expansion portions 414, 416.

[0209] • As the deployment of the fastener 400 into the bore hole is done using the proximal region of the actuator-body 420-405, the drive engagement region 440 of the actuator-body 420-405 can be dimensioned or engineered so as to be much larger and therefore stronger. Advantageously, in some embodiments, the drive engagement region (440) can be formed to be the same size as standard pedicle screw drivers that connected to the recess in the expandable fastener 400 head 462.

[0210] • The internal drive provided at the drive engagement region 440 can be used as an access region, if needed to be relied on, to prevent the body 500 from rotating about the axis X during deployment by way of enabling engagement with terminal end portion 540.

[0211] • The annular recess 424a formed or provided in the interior wall of the passage 430 of the actuator-body 420-405 and the annular lip region 415 of the expansion member 410 are ‘snap-fit’ together in preferred embodiments, but could be achieved in other ways as the skilled reader would appreciate. Among various advantages, assembly is made simpler via, in one form, once the annular lip region 415 is fitted with the annular recess 424a, the body 500 is then assembled with the actuator-body 420-405 (i.e. , the proximal region 560 being inserted into the passage 430).

[0212] The skilled reader will appreciate that various methods may be provided that relate to the manufacturing of embodiments of expandable fasteners described herein that are consistent with the present disclosure. One example method of forming an expandable fastener consistent with the present disclosure may follow any appropriate existing manufacturing workflows with any of the following additional operations:

[0213] • forming the slot (36) in a prior formed fastener body (eg. using any suitable machining process / technique); • forming the expansion member (10, 10’, 410) using any appropriate machining process, such as for example, wirecutting, 3D printing or other suitable existing processes / techniques.

[0214] • positioning the expansion member (10, 10’, 410) within the slot (36) (or within the passage 430 of the actuator-body 420-405) by suitable manipulation or flexing of the expansion portions (14, 16, 14716’, 414 / 416). In this manner, any requirement for providing additional clearance for the slot (36) (attracting the risk of reducing strength capacity of the fastener body) for positioning the expansion member (10, 10’, 410) is avoided due to the large degree / scope of flex achievable using the shape profiles applied to the expansion portions (14, 16, 14716’, 414 / 416) as described herein.

[0215] • forming the actuator (20, 20’, or actuator-body 420-405).

[0216] • coupling the actuator (20, 20’, or actuator-body 420-405) with the expansion member (10, 10’, 410) using any of the coupling arrangements described above, for example, coupling arrangement (24, 24’, 424), or other suitable arrangements involving ‘snap-fit’ or friction weld techniques.

[0217] Related methods may also include workflows (for example, clinical procedures) which include procedures that involve implantation of embodiments of expandable fasteners provided / formed consistent with the present disclosure. One example method of implanting an expandable fastener consistent with the present disclosure may follow any existing implantation workflow(s) for driving an expandable fastener into the desired position in the bore hole of the bone, with the additional operation of causing the expansion portions 14, 16 (14’, 16’, 414 / 416) to be moved / deployed to the expanded configuration by way of the deployment tool 58 as described herein by either operation of the actuating knob 76 or by incremental advancement using a linear gripper apparatus or tool assembly configured operable for moving the actuator 20 in a direction toward the second end 50 or inward of the fastener body’s first passage 30.

[0218] Related methods may also include workflows (for example, clinical procedures) which include steps that involve removal of embodiments of expandable fasteners provided / formed consistent with the present disclosure. One example method of removing an expandable fastener consistent with the present disclosure may follow any existing removal workflow with the additional operation of causing the expansion portions 14, 16 (14’, 16’, 414 / 416) to be moved from the expanded configuration to the contracted configuration by way of operation of the removal tool 100 as described herein, or other apparatus or tool assembly configured operable for gripping the actuator 20 for moving same in a direction away from the second end 50 or outward of the fastener body’s first passage 30.

[0219] It will be appreciated that similar workflows and tools / instruments are applicable for use with the embodiments of the fasteners 2’, 400 described herein.

[0220] A person skilled in the art will appreciate that various modifications and variations may be made to the present invention within the context of that described herein and shown in the drawings. Such modifications are intended to form part of the inventive concept / principles described in this specification.

[0221] Reference that is being made to patent US 10,729,480 (US’480) does not constitute an admission that US’480 is part of the common general knowledge of a skilled person in Australia or any other country.

Claims

Claims:1 . An expandable fastener for orthopaedic applications, the expandable fastener being arranged for fastening when positioned in a bore hole in bone, the expandable fastener comprising: a body coaxial with an axis of the expandable fastener; an expansion member comprising at least one expansion portion moveable between a contracted configuration and an expanded configuration such that, in use, the or each expansion portion moves outwardly from the axis towards the bone surrounding the bore hole when moving towards the expanded configuration; an actuator movable along the axis; and a coupling arrangement operable for coupling the expansion member with the actuator for enabling operation of the or each expansion portion toward / or from the contracted / expanded configurations via the actuator, the coupling arrangement configured so as to directly couple the expansion member with the actuator so as to captively support or retain the expansion member with the actuator so that relative movement between the actuator and the expansion member along the axis is substantially restrained.

2. The expandable fastener of claim 1 , wherein the coupling arrangement is configured so as to directly couple the expansion member with the actuator so as to captively support or retain the expansion member with the actuator so that relative movement between the actuator and the expansion member along the axis is substantially restrained while allowing or facilitating relative movement between the expansion member and the actuator about the axis.

3. The expandable fastener of claim 1 or claim 2, wherein the fastener body comprises an interior region having a first passage substantially concentric or coaxial with the axis and configured for accommodating movement of the actuator there along, the first passage configured so as to extend between a first opening formed at or near a first end of the fastener body and a slot formed in the body and spaced from the fastener body’s first end, which slot opens to one or more regionsof the fastener body and shaped for accommodating the expansion member such that when the or each expansion portion are in the contracted configuration a profile of the expansion member does not extend beyond that of the fastener body.

4. The expandable fastener of claim 3, wherein the actuator comprises a first end projecting outward or proud of the first opening of the fastener body, and at or near which a force is applied for causing the actuator to move along the first passage along the axis, the direction of movement of the actuator along the first passage corresponding with the operation of the expansion member due to the operation of the coupling arrangement such that when the applied force moves the actuator in a direction inward of the first passage along the axis, the or each expansion portion move outward through a respective slot opening in the fastener body toward the expanded configuration; when the applied force moves the actuator in a direction outward of the first passage along the axis, the or each expansion portion move toward the contracted configuration.

5. The expandable fastener of any one of the preceding claims, wherein the coupling arrangement coupling the expansion member with the actuator is enabled by way of any of the following: a mechanical fastener, a ‘snap-fit’ coupling, a swaging process, a friction weld process.

6. The expandable fastener of claim 4 or claim 5, wherein the actuator comprises a second end at or near which couples directly with the expansion member by way of the coupling arrangement formed on an alignment of the actuator’s second end relative to the expansion member within the interior region of the fastener body, and a portion of or associated with the actuator at or near its second end and a portion of or associated with the expansion member being caused to interact so as to form an engagement therebetween operable for restraining relative movement between the actuator and the expansion member along the axis.

7. The expandable fastener of claim 6, wherein the expansion member comprises more than one expansion portions connected by way of a connecting portiondisposed therebetween, the interior region of the fastener body comprises a second passage opening to the fastener body’s slot and extends to a second opening formed at or near a second end of the body distal of its first end, the second passage being configured for use in, on the alignment of the actuator’s second end with the expansion member when positioned within the fastener body’s slot in which the actuator’s second end is passed through an aperture provided in the connecting portion enabling same to be placed in seated relation with the actuator inward of its second end, directing application of a force to or toward the actuator’s second end sufficient for plastically displacing or deforming a portion of material at or near the actuator’s second end so as to bear against a portion of the connecting portion for holding the expansion member against the actuator so as to restrain relative movement between the actuator and the expansion member along the axis.

8. The expandable fastener of claim 7, wherein the second end of the actuator comprises a recess generally concentric with the fastener body’s axis whereby application of a force via the second passage causes material of the actuator adjacent the recess to plastically displace or deform about adjacent or corresponding portions of the connecting portion thereby placing the expansion member in captive supportive engagement with the actuator.

9. The expandable fastener of any one of claims 4 to 8, wherein a portion of the first end of the actuator is substantially rounded or spherical shaped so that a force applied thereto is operable for causing the actuator to move substantially along the axis irrespective of any articulation between the fastener body and a direction the force is applied occurring during use or otherwise.

10. The expandable fastener of any one of claims 4 to 9, wherein the actuator is configured at or near its first end so as to be engageable with or by a portion of an apparatus or tool assembly configured operable for moving the actuator in a direction outward of the first passage of the fastener body.11 . The expandable fastener of any one of the preceding claims, wherein the or each expansion portion are shaped so as to increase their respective effective length for seeking to increase the scope of its respective effective elastic range between the contracted and expanded configurations.

12. The expandable fastener of claim 11 when dependent on claim 5, wherein the or each expansion portion comprises a respective open slot of generally elongate form which opens adjacent the connecting portion, wherein a portion of an edge defining the opening of the open slot may serve as a stop against which another portion of the edge defining the open slot may bear for providing or conferring stabilising support to the relevant expansion portion when experiencing articulation or flexing on experiencing load when in or moving toward or away from the expanded configuration.

13. An expandable fastener according to any one of the preceding claims, wherein the actuator and the body are threadedly engaged by way of respectively carried or hosted threaded portions or regions which operate so as to enable or facilitate movement of the actuator along the axis in response to the actuator being caused to be rotated in a direction about the axis for operating the expansion member to any of the retracted or expanded configurations.

14. An expandable fastener according to claim 13 when dependent on claim 2, wherein a region of an interior wall of the first passage is configured so as to carry a thread operable with a thread carried by a region of an exterior wall of the actuator thereby enabling threaded engagement of the actuator and body.

15. An expandable fastener according to claim 1 or claim 2, wherein the actuator has a body, which body comprises a passage extending therethrough coaxial with the axis, the passage opening respectively at first and second opposing ends of the body of the actuator, the first end opening being up hole and the second end opening of the passage being downhole relative to an in-use orientation of the expandable fastener.

16. An expandable fastener according to claim 15, wherein the first end comprises a region adjacent the first end opening configured so as to be receive or key with a driving tool or instrument for use in driving the actuator about the axis.

17. An expandable fastener according to claim 16, wherein the expansion member comprises a proximal end region providing an annular or collar shaped portion from which the or each expansion portion(s) of the expansion member extend away from.

18. An expandable fastener according to claim 17, wherein the annular shaped portion of the proximal end region of the expansion member is configured so as to be receivable within the passage via the second end opening of the body of the actuator so as to be positioned coaxial with the axis.

19. An expandable fastener according to claim 18, wherein the annular shaped portion of the proximal end region of the expansion member comprises an annular lip portion provided at or near an end of the annular shaped portion of the proximal end region of the expansion member.

20. An expandable fastener according to claim 19, wherein the coupling arrangement is provided or configured by way of a portion of the passage of the body of the actuator configured so as to comprise an annular recess formed within an interior wall of said portion of the passage, and which annular recess is configured or shaped so as to be receivable of the annular lip portion of the expansion member so that the annular lip portion is captively supported or retained by the annular recess so that relative movement between the actuator and the expansion member along the axis is substantially restrained while allowing or facilitating relative movement between the expansion member and the actuator about the axis.21 . An expandable fastener according to claim 20, wherein the engagement between the annular recess formed within the interior wall of said portion of the passage andannular lip portion of the expansion member is configured so as to key the actuator and the expansion member along the axis.

22. An expandable fastener according to claim 20 or claim 21 , wherein the engagement between the annular recess formed within the interior wall of said portion of the passage and annular lip portion of the expansion member is configured so as to not key the actuator and the expansion member about the axis.

23. An expandable fastener according to any one of claims 15 to 22, wherein the body is configured operable coaxial relative the axis, said body having a proximal end region shaped so as to be operable within the passage of the body of the actuator, said body having a distal end region configured for engagement with bone when in use.

24. An expandable fastener according to claim 23, wherein the proximal end region of the body is receivable through a hollow of the annular shaped portion of the expansion member in assembly of the body with the passage of the body of the actuator so that the expansion member is operable between the actuator and the body.

25. An expandable fastener according to claim 24, wherein end regions of the or each expansion portions of the expansion member extend from the annular shaped portion of the expansion member and cover over or about respective portions of an exterior of the body when in the retracted configuration, said covered portions of the body being offset or spaced from the distal end region of the body so as to expose a portion thereof for engaging bone when in use.

26. An expandable fastener according to claim 25, wherein respective portions of the passage of the actuator and the proximal end region of the body are arranged in threaded engagement with each other for enabling or facilitating the actuator to, on operation thereof, drive movement of the expansion member along the axis when the body is caused to be stationary relative to the axis during use.

27. An expandable fastener according to claim 26, wherein an exterior surface of a proximal region of the actuator comprises a first male thread portion, and an exterior of the distal end region of the body adjacent its distal end comprises a second male thread, and wherein respective pitches of one or both of the first, second male threads is substantially the same as a pitch of the threaded engagement between the actuator and the proximal end region of the body.

28. An expandable fastener according to claim 27, wherein substantial consistency in the pitches of the first and the second male threads and the pitch of the threaded engagement between the actuator and the proximal end region of the body enables or facilitates driving of the expandable fastener to a desired target position in the bore hole and subsequent movement of the expansion member to the expanded configuration by way of rotation of the actuator about the axis in the same direction of rotation.

29. An expandable fastener according to claim 28, wherein movement of the actuator along the axis for moving the expansion member to the expanded configuration substantially commences on the body becoming or being caused to become stationary relative to the axis.

30. An expandable fastener according to claim 29, wherein driving of the expandable fastener to the desired target position in the bore hole and subsequent movement of the expansion member to the expanded configuration by way of rotation of the actuator about the axis in the same direction of rotation is a substantially single stage / step or continuous operation.31 . An apparatus configured operable to be useable with the expandable fastener of any one of claims 1 to 30, the apparatus configured operable for enabling selective application of a force to the actuator of the expandable fastener so as to deploy or move the or each expansion portion of the expansion member of the expandable fastener to or toward the expanded configuration on or following positioning of theexpandable fastener at a desired location in the bore hole in the bone.

32. The apparatus of claim 31 , further configured operable in a mode of operation in which the expandable fastener’s body can be driven or screwed into the bore hole in the bone, and in another mode of operation in which the or each expansion portion of the expansion member of the expandable fastener are caused to be moved to or toward the expanded configuration on or following positioning of the expandable fastener at the desired location in the bore hole in the bone.

33. The apparatus of claim 32, further configured for operable use with the expandable fastener via a connector (hereinafter, tulip connector) which is arranged to be carried, in a substantially articulable manner, by a head portion of the expandable fastener’s body provided at or near its first end, the tulip connector being of generally annular or tubular form having a first end configured so as to be placeable in articulable engagement with the head portion of the expandable fastener’s body, and a second end, oppositely disposed from the first end, configured to be placeable in fixed relation with the apparatus.

34. The apparatus of claim 33, further comprising a driving element arranged in operable association with a driven member for causing movement of the driven member for providing a force for transfer to the actuator of the expandable fastener for, via the coupling arrangement of the expandable fastener, causing movement of the or each expansion portion of the expandable fastener to or toward the expanded configuration.

35. The apparatus of claim 34, further comprising an actuable portion configured so as to carry the driven member and driving element, wherein the actuable portion comprises a passage along which the driven member moves on actuation of the driving element.

36. The apparatus of claim 34 or claim 35, further comprising a piston arranged operable between the driven member and the actuator of the expandable fastener,the piston configured so as to be responsive to operation of the driven member for transferring a force received from the driven member to said actuator on actuation of the driving element.

37. The apparatus of claim 36, further comprising a guide member configured operable for accommodating and guiding movement of the piston, the guide member configured at or near a first end for keyed engagement with the head portion of the expandable fastener’s body enabling rotational movement of the guide member to be transferred to the expandable fastener’s body operable for driving said body into the bore hole in the bone, the guide member configured at or near a second end for operable association with the actuable portion for enabling the piston to be acted upon by the driven member.

38. The apparatus of claim 37, further comprising a support member configured for providing a passage for accommodating operation of the guide member during use, the support member configured at one end for engaging with the tulip connector in a manner enabling the apparatus to be placed in fixed relation therewith for conferring concentric support to the guide member for (i) maintaining guidance of the piston and / or (ii) driving of the fastener body of the expandable fastener into the bore hole in the bone.

39. An apparatus configured operable to be useable with the expandable fastener of any one of claims 1 to 30, the apparatus configured operable for enabling selective application of a force to the actuator of the expandable fastener so as to move the or each expansion portion of the expansion member of the expandable fastener from the expanded configuration to or toward the contracted configuration for removal of the expandable fastener from the bore hole in the bone, the apparatus comprising an extraction member configured operable for engaging said actuator, the extraction member arranged so as to be operably responsive to actuation of an actuable portion of the apparatus for causing the extraction member to move said actuator in a direction outward of the expandable fastener body’s first passage along the axis so as to cause the or each said expansion portion to move awayfrom the expanded configuration to or toward the contracted configuration.

40. The apparatus of claim 39, wherein the actuable portion comprises a passage for accommodating operation of the extraction member, the extraction member being moveable within the passage by way of a portion of the extraction member being placed in operable association with a portion of the actuable portion, which engagement, on movement of the actuable portion, operates to cause the extraction member, when engaged with the actuator of the expandable fastener, to move said actuator in a direction outward of the first passage of the expandable fastener’s body thereby causing, via the coupling arrangement of the expandable fastener, the or each said expansion portion to be moved to or toward the contracted configuration.41 . The apparatus of claim 40, wherein a portion of the actuable portion of the apparatus is configured so as to, when in use, cooperate with the extraction member for preventing the engagement arm(s) from splaying apart and disrupting their respective engagement with said actuator.

42. An expandable fastening system for orthopaedic applications, the expandable fastening system comprising: an expandable fastener arranged substantially in accordance with the expandable fastener of any one of claims 1 to 30; and or a first apparatus or tool assembly for use in operating the actuator of the expandable fastener for selectively moving the or each expansion portion of the expansion member of the expandable fastener to or toward the expanded configuration; and / or a second apparatus or tool assembly configured operable for use in operating said actuator for selectively moving the or each said expansion portion to or toward the contracted configuration.

43. The expandable fastening system of claim 42, wherein the first apparatus or tool assembly is arranged substantially in accordance with an embodiment of theapparatus of any one of claims 31 to 38.

44. The expandable fastening system of claim 42 or claim 43, wherein the second apparatus or tool assembly is arranged substantially in accordance with an embodiment of the apparatus of any one of claims 39 to 41 .

45. A method of using an expandable fastener of any one of claims 1 to 30 or an expandable fastening system of any one of claims 39 to 44.

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