Orthopaedic nozzle

Abstract

A nozzle is disclosed for an orthopaedic paste delivery system. The nozzle extends from an inlet at a proximal end to an outlet at a distal end. The nozzle comprises a hub (at the proximal end) having a connection interface for engaging a complementary interface on a delivery system. A conduit extends through the nozzle from the proximal to the distal end. A dispensing tip is at the distal end. The nozzle also comprises an alignment collar rotatable relative to the hub to adjust the angular orientation of the dispensing tip independently of the connection interface.

Description

[0001] Orthopaedic Nozzle

[0002] Field of Invention

[0003] The present invention generally relates to a nozzle for orthopaedic paste delivery systems. Embodiments may also relate to an orthopaedic delivery system including a nozzle.

[0004] Background

[0005] Orthopaedic pastes include bone cement, bone substitute, and filler materials. The most common bone cement is polymethyl methacrylate ("PM MA"), which is typically provided as a powder co-polymer (for example a polymethylmethacrylate powder) and a liquid monomer (for example methylmethacrylate monomer). It will be appreciated that one or both of the powder component and the liquid component may also include additional substances - these may, for example, include additives such as one or more of: stabilisers, initiators, accelerators, radio-opacifiers, and antibiotics.

[0006] During orthopaedic procedures pastes are usually prepared (for example mixing components of a multi-part paste which react and subsequently cure) and delivered using a delivery system. The delivery system may include a syringe which is typically used with a delivery gun. The syringe may incorporate a mixing apparatus. The mixing apparatus is usually arranged to allow the paste to be mixed under a vacuum to enable consistent and homogenised results with minimum porosity. A variety of such devices are commercially available - for example, the Applicant's own HIVAC (RTM) range of products. The delivery system may include at least one nozzle which is attached to the syringe (typically after mixing and before dispensing the paste). It may be appreciated that the specific form and configuration of the nozzle may be selectable depending upon the procedure that is being carried out, with the surgeon attaching an appropriate nozzle to ensure the orthopaedic paste can be delivered to the required surgical location in a controlled and accurate manner. Dedicated nozzles may be provided for different procedures and may, for example, vary in one or more of length, curvature, rigidity, and tip profile.

[0007] Embodiments of the invention seek to provide alternative and / or improved delivery systems and nozzles therefor. In particular, embodiments seek to provide devices which offer improved user ergonomics by allowing a nozzle to be conveniently oriented relative to a delivery gun.

[0008] Summary of Invention

[0009] In accordance with an aspect of the invention, there is provided a nozzle for an orthopaedic paste delivery system. The nozzle extends from an inlet at a proximal end to an outlet at a distal end. The nozzle comprises a hub (at the proximal end) having a connection interface for engaging a complementary interface on a delivery system. A conduit extends through the nozzle from the proximal to the distal end. A dispensing tip is at the distal end. The nozzle also comprises an alignment collar rotatable relative to the hub to adjust the angular orientation of the dispensing tip independently of the connection interface.

[0010] The Applicant has identified that the provision of a rotationally alignable nozzle is advantageous to the ergonomics of an orthopaedic delivery system. In particular, in the Applicants have recognised that a conventional delivery system provides the user with no ability to select or control the alignment of the nozzle relative to the portion of the delivery system which is gripped by the user (specifically the handle and trigger of a delivery gun). In such conventional systems there are at least two separate screw interfaces - firstly between the nozzle and syringe and secondly between the syringe and the delivery gun. The combined tolerances of two separate screw interfaces make it difficult or impossible to provide a precise angular alignment between the nozzle and the handle of the delivery gun.

[0011] The connection interface may be a screw thread, for example a female screw thread.

[0012] The connection interface may be configured to engage a male screw thread on a boss or outlet of an orthopaedic paste delivery system. In some embodiments the nozzle may further comprise an intermediate hub body which is disposed between the hub and the delivery system. The intermediate hub body may comprise a first connection interface at a first end for connection to the delivery system and a second connection interface at a second end for connection to the hub connection interface.

[0013] The nozzle may comprise a body defining at least a portion of the conduit. The body may be integrally formed with the alignment collar. The dispensing tip may be integrally formed at the distal end of the body.

[0014] In embodiments the hub may define a second portion of the conduit. The second portion of the conduit may extend into an interior of the body. A distal end of the second portion of the conduit may sealingly engages an interior surface of the body.

[0015] The body may comprise inner and outer concentric walls defining an annular channel therebetween. The annular channel may be configured to receive the distal end of the second portion. Seating the distal end of the second portion within an annular channel of the body may provide improved sealing between the conduit portions defined by the body and the hub.

[0016] In embodiments the proximal end of the inner concentric wall has an axial end face with a variable axial position around the circumference. For example, the end of the inner concentric wall may have a castellated end profile (which may include a wavey or zig-zag profile). The provision of a non-continuous end profile may assist in assembly of the nozzle components by enabling the inner concentric wall to flex and aid insertion of the distal end of the second portion into the annular channel.

[0017] In embodiments the alignment collar may be axially fixed relative to the hub. A portion of the alignment collar may axially overlap a portion of the hub. The alignment collar may include a portion at its proximal end which concentrically surrounds the hub. The alignment collar may for example comprise a cap which is axially fixed to a portion of the hub. The cap may extend over and be coupled to an external portion of the hub

[0018] The axially overlapping portions may comprising a coupling between the alignment collar and hub. A plurality of couplings may be circumferentially distributed around the nozzle, for example a pair of diametrically opposed couplings. The coupling may comprise an interface configured to axially couple the hub and collar and allow relative rotation thereof without release of the coupling.

[0019] The coupling may comprise a complementary projection and recess. The projection may comprise a radially projecting boss. The recess may comprise a circumferentially extending slot. The slot may axially retain the boss whilst allowing the boss to slide circumferentially along its length to enable relative rotation between the hub and alignment collar. The slot and projection may for example comprise a bayonet interface. Alternatively the projection may simply be positionable within the slot via a (snap-fit) resilient engagement.

[0020] The coupling may have a first configuration in which the alignment collar is rotationally engaged to the hub and a second configuration in which the alignment collar is rotationally disengaged the hub. As such, in the first configuration the alignment collar may be usable (for example gripped by the user) to rotationally attach the hub to the connection interface of a delivery system. In the second configuration the alignment collar may be rotatable relative to the hub (and therefore without effecting the connection to the interface on a delivery system). The hub and alignment collar may be biased into one of the first or second configurations. The bias mayfor example be provided by one or more resilient members, for example spring arms formed as features of the hub or collar plastic moulding.

[0021] In some embodiments the relative position of the hub and collar may move the assembly between the first and second configuration. For example, the configuration could be selected by a manually actuated relative movement. The movement may be against a bias which acts to urge the collar and hub into one of the configurations. For example, a linear movement of the collar relative to the hub may move the coupling into one of the first or second configurations.

[0022] Alternatively, in other embodiments the coupling may automatically be in one of the first or second configurations. For example, the configuration of the coupling may depend upon the relative torque applied between the hub and collar. Such an arrangement may allow the nozzle to be tightened onto the delivery system using the alignment collar and then, once fully tightened, be rotated relative to the delivery system. For example, the coupling may comprise a clutch which allows the collar to overrun the cutch. The coupling may, for example, comprise a rachet. The rachet may have resilient members on one of the hub and collar which engage complementary recesses on the other of the hub and collar. The resilient members may comprise radially projecting splines on one of the hub and collar. The complementary recesses may be formed on an opposed coaxial circumferential surface of the other of the hub and collar.

[0023] In embodiments the hub may comprises an annular member. The annular member may comprise an inner radial surface comprising the connection interface. The annular member may comprise an outer radial surface comprising a coupling interface for engaging a corresponding coupling on the alignment collar.

[0024] In some embodiments the nozzle may comprise a body defining at least a portion of the conduit, and the alignment collar may comprise a bracing member which deforms at least a portion of the body. The body may be integrally formed with the hub. For example, the body and hub may be a single moulding or may be permanently bonded. The body may comprise a flexible cannular. The flexible body, for example cannular, may be fixed relative to the hub but deformable such that its configuration may be altered. The bracing member may provide an exoskeletal support for the body. The bracing member supports and aligns the flexible cannular. The bracing member may at least partially surround the body. The bracing member may, for example define a curvature along its axial length which deforms the body to conform to its shape. As such, rotation of the alignment collar may adjust the direction of the shape formed by the bracing member.

[0025] The bracing member may be formed of a material which has a greater rigidity than the body. The bracing member may at least partially surround the body and may orientate the body relative to the hub. The bracing member may for example be a sleeve. For example, the bracing member may define a curvature along a length of the body, and the body may conform to the shape and alignment of the bracing member. The bracing member may resiliently engage the body. The bracing member may define profile along its axial length and rotation of the bracing member about its axis (and relative to the body and or hub) may adjust the radial direction of the profile (for example the direction towards which the bracing member curves relative to the hub).

[0026] The bracing member may further comprise a tip member which comprises the dispensing tip at the distal end. The tip member may interface with the distal end of the body (for example having a portion which is inserted into the interior of the body) and may be contiguous with the conduit of the nozzle.

[0027] The dispensing tip of embodiment may comprise a shaped outlet. For example, the shaped outlet may have a flat, elongate nozzle (which can be rotationally aligned relative to the body by the alignment hub). In some embodiments the dispensing tip (and at least a portion of the conduit) may be angled away from the axial direction. The nozzle may have a profile along its axial length. Rotation of the alignment collar about its axis, and relative to the hub, may adjusts the radial direction of the profile and / or the radial alignment of the dispensing tip.

[0028] In another aspect of the invention there may be provided an orthopaedic paste delivery system comprising at least one nozzle in accordance with an embodiment. The delivery system may further comprise a syringe, and the syringe may comprise an orthopaedic paste mixing device. The delivery system may further comprise a delivery gun. The syringe and delivery gun may have a screw fit connection interface.

[0029] An orthopaedic nozzle as claimed in any preceding claim wherein the hub comprises an intermediate hub body, the intermediate hub body comprising a first connection interface at a first end for connection to a delivery system and a second connection interface at a second end for connection to the hub connection interface.

[0030] The nozzle of embodiments may be referred to as an orthopaedic nozzle since it is specifically adapted for use during orthopaedic surgical procedures.

[0031] According to an aspect of the invention there is provided a nozzle for an orthopaedic delivery system. The nozzle comprises a hub including a connection interface (for example a female screw thread) for engaging a complementary interface on a delivery system (for example a male screw thread on a boss or outlet). The nozzle further comprises a body defining a conduit extending from the hub to a dispensing tip at the distal end. The nozzle further comprises an alignment collar which is rotatable relative to the hub such that the orientation of at least the dispensing tip of the nozzle may adjusted independently of the connection interface.

[0032] Unless otherwise stated, each of the integers described may be used in combination with any other integer as would be understood by the person skilled in the art. Further, although all aspects of the invention preferably "comprise" the features described in relation to that aspect, it is specifically envisaged that they may "consist" or "consist essentially" of those features outlined in the claims. In addition, all terms, unless specifically defined herein, are intended to be given their commonly understood meaning in the art.

[0033] Whilst the invention has been described above, it extends to any inventive combination of the features set out above or in the following description or drawings. Description of the Drawings

[0034] Embodiments of the invention may be performed in various ways, and embodiments thereof will now be described by way of example only, reference being made to the accompanying drawings, in which:

[0035] Figure 1 shows a three-dimensional view of a typical bone cement delivery apparatus which may be used with embodiments of the invention;

[0036] Figure 2A 2B and 2C, shows a nozzle assembly in accordance with an embodiment of the invention and the components of the nozzle assembly in isolation;

[0037] Figure 3A, 3B and 3C show views of an alternate embodiment of the nozzle of figure 2;

[0038] Figure 4A and 4B shows three dimensional and cross-sectional views of a nozzle assembly in accordance with another embodiment;

[0039] Figure 5 shows a cross-sectional detail of the embodiment of figure 4;

[0040] Figure 6 shows an isolated view of the hub of the embodiment of figures 4 and 5;

[0041] Figure 7 shows a further view of the nozzle of the embodiment of figures 4 to 6;

[0042] Figures 8A to 8C show an alternative variant of the embodiment of figures 4 to 7;

[0043] Figure 9A and 9B shows an external and cross-sectional view of a nozzle in accordance with another embodiment;

[0044] Figure 10A and 10B shows an exploded external and cross-sectional view of the nozzle of figure 9;

[0045] Figure 11A and 11B show a cross-sectional view and detail of the nozzle of figures 9 and 10;

[0046] Figure 12A and 12B show an alternative variant of the embodiment of figures 9 to 11;

[0047] Figure 13 shows a cross-sectional view of a variant of the nozzle of figures 9 and 10; and Figure 14A and 14B show cross sectional view of the components of the nozzle assembly of figure 13 in isolation.

[0048] Detailed Description of Embodiments

[0049] Proximal is used herein to refer to the end of the device (or components thereof) which are close to the user (i.e. the inlet end) and distal is used to refer to the end which is directed away from the user (i.e. the dispensing end). It may be noted that forward and rearward may also be used herein to conveniently refer to the device in its typical in use orientation with the forward direction or features being those facing towards the distal end and the rearward direction or features being those in the reverse direction (i.e. towards the proximal end). However, it will be appreciated that such references are not intended to be limiting, and that the device may take any orientation in use. Likewise, any references to circumferential, radial or axial directions may be interpreted broadly as general geometric terms of orientation relative to the component and, for example, do not exclude that a component may have a non-circular or irregular form. It will be appreciated that the axial direction is generally aligned along the lengthwise direction of the delivery system (and the other directions aligned relative to the axial direction).

[0050] A delivery system 100 for orthopaedic pastes is shown in figure 1. The delivery system 100 may, for example be the one of the Applicant's HIVAC (RTM) range of products. The delivery system comprises a syringe 101 which comprises a cylindrical tubular body in which a two-part paste such as PMMA bone cement can be mixed under vacuum. The skilled person will appreciate that such syringes provide both a mixing and delivery system (i.e. allow the mixing to take place within the same syringe body that is subsequently used for cement delivery). Once the bone cement, or other such paste, is ready the syringe is mounted into a delivery gun 102 with a trigger actuated plunger which moves axially along the syringe 101 to dispense the paste. A nozzle 110 is attached to an interface 120 at the forward end of the syringe 101 and extends to a tip 115. The nozzle has a profile which is determined by the intended use which may include a specific size and shape of the tip 105 of the nozzle 110. In the example of figure 1, the nozzle has a profile which includes a tip which forms a radially flattened and elongated end shape (with the cross-section of the nozzle having transitioned to this profile along its axial length from an initial cylindrical tubular shape). It may be appreciated that the delivery system 100 of figure 1 is a prior art arrangement included for illustrative purposes and, as such, includes a standard nozzle assembly 110. However, it may be appreciated that embodiments of the invention as described below may be used with such a prior art delivery system and that it is generally desirable for improved nozzles to be fully compatible with existing delivery systems. In use, the rearward end of the body of the syringe 101 is screwed into the delivery gun 102 and the cap at the forward end of the syringe (which carries the nozzle interface 120) is screwed to the syringe body. As a result of these interfaces the relative rotational alignment of syringe and its nozzle, when assembled for use in surgery, is not controllable by the user. During a procedure, a surgeon will need to align the tip 115 of nozzle 110 relative to the local geometry of the surgical site whilst using the trigger of the delivery gun 102 to cause extrusion of the cement. The applicant has recognised that this can result in inconvenient ergonomics depending upon the nozzle orientation. As such, embodiments of the invention seek to provide nozzle arrangements which enable the user to select and adjust the relative rotational alignment of the nozzle to provide improved ergonomics during surgical procedures.

[0051] A nozzle 10 in accordance with a first embodiment of the invention is shown in figures 2A to 2C. The nozzle 10 comprises a hub 20 which includes a connection interface which allows the nozzle to be attached to a corresponding complementary interface on a delivery system. In this embodiment, the connection interface is in the form of an internal female screw thread and is arranged to connect to a corresponding external male screw thread, which would typically be on an outlet protruding from the front of the syringe. The external surfaces or the hub 20 are moulded with a profile to aid manual gripping when the nozzle is screwed to the syringe. The nozzle 10 defines a conduit 60 (as seen in the cross-sectional views of Figures 3B and 4B) which extends from a proximal end having an inlet 62 at the hub 20 to a distal end having an outlet 64 at its distal tip 35. The nozzle 10 has a body portion 30 which extends axially forwardly from the hub 20. The body portion defines at least a portion of the conduit 60. In the embodiment of figure 2 the body portion 30 is a cannular and is at least partially formed from a flexible material. The nozzle body 30 and hub assembly 20 are shown in isolation in figure 2C. It may be noted that due to the inherent resilience of the body 30, the cannular of the body extends in a substantially straight axial direction when in isolation as shown in figure 2C.

[0052] In accordance with embodiments, the nozzle assembly 10, further comprises an alignment collar 40. In this embodiment the collar 40 is in the form of a bracing member which is shown in isolation in figure 2B and assembled with the nozzle in figure 2A. The bracing member 40 is configured and sized to be positioned over the exterior of the body 30 in use (as shown in figure 2A). The bracing member on an embodiment comprises a pair of engagement portions 42 and 44 and a longitudinal member46 which extends axially with a predetermined curvature (in a radial direction along its axial length) between the engagement sections 42, 44. In the illustrated embodiment the first engagement section is a closed annular sleeve section 42. The second engagement section is a C-shaped retaining section 44. The C-shaped retaining section 44 can help provide a clip-on interface with the body 30 of the nozzle assembly 10 whilst the closed annular section 42 may help ensure the bracing element is not unintentionally removed (although in some embodiments it may still be possible to slide the bracing member off of the nozzle body 30 if required).

[0053] The bracing member 40 is formed from a material which is relatively stiff in comparison to the material of the body 30 (in other words the bracing member has greater rigidity than the body 30). As seen in Figure 2A when the bracing member 40 is assembled over the body 30 of the nozzle 10 it causes the flexible cannular to elastically deform and conform locally to the shape defined by the bracing member and provides an overall curvature to the profile of the nozzle 10. Advantageously, the bracing member 40 can be rotated relative to the body 30 and hub 20 such that the radial direction to which the nozzle curves is adjustable without impacting the (threaded) sealed engagement between the syringe and the nozzle.

[0054] A modified version of the embodiment of figure 2 is shown in figure 3. This embodiment utilises the same overall configuration of an alignment collar which comprises a bracing member 40 which acts an exoskeletal support to define the curvature of a relatively flexible body 30. In the embodiment of figure 3 the member 40 further comprises a tip member 50. The tip member 50 is supported and integrally formed at the distal end of the bracing member 40. The tip member 50 interfaces with the end of the distal end of the flexible body 30 with an insert portion 54 extending into the interior of the body. This ensures that the tip member 50 is contiguous with the conduit 60 of the nozzle. The tip member can define an outlet 52 having a predetermined profile (in this case a flat nozzle outlet) and which is in a fixed alignment relative to the bracing member 40 (and, therefore, relative to the curvature defined by the bracing member). Thus, advantageously, the orientation of the outlet 52 will always remain in the correct relative alignment when the bracing member 40 is used to adjust the direction of the nozzle 10. It may be noted that the tip member 50 may be inserted into the open end of the body 30 and may include a flange for providing a sealing engagement between the conduit of the body and the outlet of the tip.

[0055] A nozzle 10' in accordance with another embodiment is show in figures 4 to 7. In this embodiment the alignment collar 40' comprises a cap which (as will be explained further below) overlaps and is axially fixed to a portion of the hub 20'. The alignment collar 40' in this embodiment is formed integrally with the body 30 which defines both a portion of the conduit 60 and tip of the nozzle 10.

[0056] The alignment collar 40' extends over and is coupled to at least a portion of the hub 20'. The coupling between the collar 40, and hub 20' has an interface which is configured to axially couple the hub and collar but allow relative rotation thereof without release of the coupling. As best seen in figures 5 and 6, the coupling comprises a pair of diametrically opposed radially outwardly projecting bosses 25 on the hub 20'. The bosses 25 are each retained in a complementary sized circumferentially extending slot 45 in the alignment collar 40'. Optionally, in order to allow the hub 20 and collar 40 to be selectively uncoupled the collar is also provided with axially extending openings 46 which are contiguous with the circumferential slots 45. Thus, it will be appreciated that the slots 45 and openings 46 provide the coupling with a bayonet configuration so that the collar can be passed over the bosses 25 until the correct axial position is achieved. Once in position the rotational alignment between the collar 40 and hub 20 can be adjusted whilst the sides of the bosses 25 and slots 45 provide a retention arrangement which prevents axial movement. If removal of the collar and body 30 is then required, it is possible by aligning the bosses 25 with the openings 46.

[0057] It may be noted that in the embodiment of figure 7, the hub 20' is shown with an optional configuration in which the hub 20' comprises a secondary or intermediate hub body 28. In such an arrangement the interface 22 of the upper part of the hub body may be arranged to interface with corresponding features on the forward end of the lower body 28. The lower body 28 may then include a second interface (i.e. screw thread) for engaging with the syringe. It will be appreciated that any of the embodiments of the invention may use either a single part or two part hub depending, for example, on the particular delivery device which the nozzle is configured for use with (and that the provision of a two part hub may be a simple equivalent to a single part hub).

[0058] Figure 8 shows a variation of the embodiment of figures 4 to 7. In this embodiment the body 30 of the nozzle has a relatively short and straight configuration. However, as the nozzle tip 35 provides a relatively wide and flat elongate dispensing end and it will be appreciated that it is also advantageous to allow a rotational adjustment of such a nozzle (to enable the user to achieve the desired application in surgery). Thus, this embodiment also includes a bayonet type coupling between a circumferential slot 45 and a boss 25. This embodiment also provides a convenient example of the alignment of the boss 25 in the axially openings 46 (in figure 8B) and when assembled with the boss 25 in the slot 45 (in figure 8C).

[0059] Another alternate embodiment is shown in figures 9 to 12. In these embodiments a rachet coupling is provided between the hub 20" and the alignment collar 40". A rachet arrangement enables the coupling to have a first configuration in which the alignment collar is rotationally engaged to the hub and a second configuration in which the alignment collar is rotationally disengaged the hub.

[0060] The rachet arrangement is provided by an annular member 20" of the hub which is enclosed within the alignment collar 40". The annular member has an internal screw thread 22 such that it can be connected to a corresponding thread on the outlet of the syringe. The connection to the syringe could be directly via the thread 22 but may also be indirectly via a secondary hub body 28 as shown in figure 12B and as discussed above. The secondary or intermediate hub body has an internal thread 29 for engaging the thread of the syringe and a threaded boss 27 for engaging the screw thread 22.

[0061] The rachet arrangement of this embodiment is provided by the interface between the opposed external circumferential face of the annular member 20" and the internal circumferential face of the alignment collar 40". The interface comprises complementary splines and recesses. In the illustrated embodiment each surface carries both spline and recess features. The annular member has splines formed by resilient radially projecting members 23 and recesses in the form of grooves 24. The alignment collar has splines formed by radial projections 43 and recesses in the form of a circumferentially distributed array of axially extending recesses 44. When the collar 40 and member 20 are assembled the respective projections 43 and 23 engage the corresponding recesses 44 and 24. When the nozzle arrangement of figures 9 to 12 is screwed onto a fitting (whether of the syringe or an intermediate fitting on a hub body) the rachet coupling between the annular member and the collar 40 will engage (via the splines 23, 43 engaging the recesses 44, 24) and allow the user to rotate the components together. However, when the screw thread 22 is fully attached any further rotational action on collar 40 is unable to continue to rotate the annular member 20. It can be noted from the cross section of figure 11B that when the thread 22 is fully fastened an end surface 26 of the boss 27 of the hub body 28 (or of the syringe boss in the case where no hub body is provided) will sea lingly abut an internal flange 41 of the collar (or a similar sealing surface of the body 30) and delimit further screw thread movement of the internal thread 22.

[0062] Torque applied to the collar after the screw thread is fully engaged will result in disengagement of the coupling between the collar 40 and annular member 20. The splines 23 and 43 will deflect out of their respective recesses 44, 24. Thus, the collar 40 can overrun the member 20 and continue to rotate until it is positioned into a desired orientation. As the collar 40 rotates relative to the member 20 the splines will rachet into position each time they are aligned with a recess. Thus, the collar 40 and member 20 will be retained in the selected alignment when the user removes the torque.

[0063] Whilst the nozzle of figures 9 to 11 is a short flat member and is used for alignment of the tip profile it will also be appreciated that the rachet arrangement of such embodiments may also be applied to any other nozzle configuration which may require rotational alignment. Figure 12 shows an example in which the body 30 is an elongate curved cannular and using the same rachet arrangement as the previous embodiments.

[0064] Figures 13, 14A and 14B show a variant of the embodiment of figures 9 to 11 which is modified to provide improved sealing between the conduit portions formed respectively by the hub 20 and the alignment collar 40. As in the previous embodiment conduit of the nozzle is formed by respective first 60' and second 60" portions defined respectively by the interior of the alignment collar 40 and of the hub 20. As seen in the assembled view of Figure 13, the second portion of the conduit 60" (formed by the hub) extends axially into an interior of the body 30 (which is formed integrally with the alignment collar 40). The conduit portions 60' and 60" must sea lingly engage. To aid sealing the body 30 includes both an outer (exterior) wall 31 and a concentric, axially rearwardly extending, inner wall 37. The space between the inner 37 and outer 31 walls define an annular channel 39. The annular channel receives the distal end 21 of the second conduit portion 60" of the hub 20. To aid insertion of the distal end 21 into the channel 39 (during assembly of the hub 20 and alignment collar 30 / body 30) the rearward axial face 38 of the inner wall 37 is formed with a castellated curved profile. This profile enables an increased degree of flexibility in the inner wall such that it can deflect until the components are correctly aligned.

[0065] Although the invention has been described above with reference to preferred embodiments, it will be appreciated that various changes or modification may be made without departing from the scope of the invention. For example, whilst the embodiments described above utilise a rachet mechanism to provide automatic overrunning disengagement between the collar and member it will be appreciated that other embodiments may be possible in which the user is able to actively select between an engaged and disengaged position. For example, a user may engage or disengage the coupling between a collar and member by a deformation (for example squeezing the collar element to engage) or by manually adjusting the relative axial alignment (for example pressing the collar rearwardly to engage) when the user wishes to rotate the threaded coupling.

[0066] It may be appreciated that embodiment of the invention could be configured with different elements in particular sub-assemblies of the nozzle without altering the functional arrangement of the embodiment. For example, an annular member for providing a coupling and thread could either be initially assembled with the hub 20 or with the collar 40 without the need to modify its essential features. Likewise, a body 30 of the nozzle could be integrally or discretely formed relative to other embodiments without altering the intended function.

Claims

Claims1. A nozzle for an orthopaedic paste delivery system, the nozzle extending from an inlet at a proximal end to an outlet at a distal end, and comprising: a hub (at the proximal end) having a connection interface for engaging a complementary interface on a delivery system; a conduit extending through the nozzle from the proximal to the distal end; a dispensing tip at the distal end; and an alignment collar rotatable relative to the hub to adjust the angular orientation of the dispensing tip independently of the connection interface.

2. The nozzle as claimed in claim 1, further comprising a body defining at least a portion of the conduit, wherein the body is integrally formed with the alignment collar.

3. The nozzle as claimed in claim 2, wherein the dispensing tip is integrally formed at the distal end of the body.

4. The nozzle as claimed in claim 2 or 3, wherein the hub defines a second portion of the conduit.

5. The nozzle as claimed in claim 4, wherein the second portion of the conduit extends into an interior of the body and wherein a distal end of the second portion sea lingly engages an interior surface of the body.

6. The nozzle as claimed in claim 5, wherein the body comprises inner and outer concentric walls defining an annular channel therebetween for receiving the distal end of the second portion.

7. The nozzle as claimed in claim 6, wherein the proximal end of the inner concentric wall has an axial end face with a variable axial position around the circumference.

8. The nozzle as claimed in any preceding claim, wherein the alignment collar is axially fixed relative to the hub.

9. The nozzle as claimed in claim 8, wherein a portion of the alignment collar axially overlaps a portion of the hub, said portions comprising a coupling between the alignment collar and hub.

10. The nozzle as claimed in claim 9, wherein a plurality of couplings are circumferentially distributed around the nozzle.

11. The nozzle as claimed in claim 9 or 10, wherein the coupling comprises a complementary projection and recess.

12. The nozzle of claim 11, wherein the projection comprises a radially projecting boss and the recess comprises a circumferentially extending slot.

13. The nozzle as claimed claim 9 or 10, wherein the coupling has: a first configuration in which the alignment collar is rotationally engaged to the hub and a second configuration in which the alignment collar is rotationally disengaged the hub.

14. The nozzle as claimed in claim 13, wherein the hub and alignment collar are biased into one of the first or second configurations.

15. The nozzle as claimed in claim 13 or 14, wherein the configuration of the coupling depends upon the relative torque applied between the hub and collar.

16. The nozzle as claimed in claims 13 to 15, wherein the coupling comprises a rachet having resilient members on one of the hub and collar which engage complementary recesses on the other of the hub and collar.

17. The nozzle as claimed in claim 16, wherein the resilient members comprise radially projecting splines on one of the hub and collar and the complementary recesses are formed on an opposed coaxial circumferential surface of the other of the hub and collar.

18. The nozzle as claimed in any preceding claim, wherein the hub comprises an annular member.

19. The nozzle as claimed in claim 18, wherein the annular member comprises an inner radial surface comprising a connection interface and an outer radial surface comprising a coupling interface for engaging a corresponding coupling on the alignment collar.

20. The nozzle as claimed in claim 1, further comprising a body defining at least a portion of the conduit, and wherein the alignment collar comprises a bracing member which deforms at least a portion of the body.

21. The nozzle as claimed in claim 20, wherein the body is integrally formed with the hub.

22. The nozzle as claimed in claim 20 or 21, wherein the body comprises a flexible cannular and wherein the bracing member supports and aligns the flexible cannular.

23. The nozzle as claimed in claims 20 to 22, wherein the bracing member at least partially surrounds the body.

24. The nozzle as claimed in claims 20 to 23, wherein the bracing member further comprises a tip member comprising the dispensing tip at the distal end.

25. The nozzle as claimed in any preceding claim, wherein the dispensing tip comprises a shaped outlet.

26. An orthopaedic paste delivery system comprising at least one nozzle in accordance with any preceding claim and further comprising an orthopaedic paste syringe.21

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