Implant for fusing at least two bone components and method for fusing bone components with the implant

Abstract

An implant for fusing at least two bone components and a method of using the implant. The implant has a body with a first anchoring portion and a second anchoring portion. The first anchoring portion has a stem that is configured to be guided into a first bone component and is further configured to cooperate with at least a first fastener that can be used to fix the stem relative to the first bone component in an operative position. The second anchoring portion is configured to cover at least a second bone component at a placement location where bone has been strategically removed and is further configured to cooperate with at least a second fastener that can be used to fix a portion of the second anchoring portion to the second bone component when the second anchoring portion is in the operative position.

Description

Technical Field

[0001] The present invention relates to medical implants, and more particularly, to implants for fusing separated bone / bone components. The present invention also relates to a method of using the implant to effect fusion of bone components. Background Art

[0002] Arthritis results in limited movement, pain, and dysfunction, and can affect any joint in the human body. One option for treating pain is arthrodesis, which involves roughening the bone surfaces and applying some type of fixation to hold the separated bone components rigidly juxtaposed until they heal as a single mass. Although successful fusion eliminates relative movement between the bone components / bone at the joint, the process can very effectively address most, if not all, arthritis pain.

[0003] The present invention herein can be applied to any joint in the body where one of the bones has a tubular portion. For purposes of illustration, the wrist will be used throughout the document to describe the prior art and the present invention, but it is provided only by way of example and should not imply any anatomical limitations.

[0004] The wrist contains multiple small bones, making it difficult to individually fix these bones and provide adequate screw fixation. In addition, there are multiple tendons in the wrist that are closely juxtaposed to the bones in the area. Implants can irritate or damage these structures, resulting in stiffness, pain, inflammation, and even rupture. The wrist is a highly mobile joint and is subjected to strong forces that create significant bending loads due to pulling on the tendons that cross the joint.

[0005] Generally, when performing arthrodesis or fusion, there are four main types of contemporary implants used to provide fixation: external fixation; cross plates; intramedullary nails; and circular cups.

[0006] External fixation fixes the joint with an external rod that is fixed to a cluster of one or more pins placed in the bone on either side of the joint. This method is generally not preferred for a variety of reasons, including possible infection, tendon irritation, inability to rigidly fix the bone between the pin clusters, pain, nonunion, etc.

[0007] A spanning plate is an internal implant that is screwed into the bone on either side of a joint and sometimes into an intermediate bone within the joint. The most commonly accepted plates for wrist fusion span from the radius in the forearm to one of the metacarpal bones in the hand. This type of plate deviates from the central neutral axis of the bone, putting them at further mechanical disadvantage. They need to be rather thick to resist normal torques and bending moments, resulting in bulky surface implants that can often cause soft tissue irritation, prominence of the surface, and even tendon rupture. Due to the curved shape of the bone surface as it extends from the distal radius through the carpal bones, these plates are typically formed with complex curved shapes to maintain juxtaposition of the hardware with the bone along the length of the plate. Often these shapes do not fit precisely to the specific anatomy and can be prominent or require extensive modification of the bone surface. Since the plates are fixed to the metacarpal bones, which are narrow bones, the screw holes in the bone can cause secondary fractures and result in morbidity and secondary surgery. Additionally, fixation to the metacarpal bones causes the plates to span the carpometacarpal joints, which are not typically damaged and do not require fusion. These plates cannot include fixation in the intermediate carpal bones or are ineffective for including fixation in the intermediate carpal bones because some are located outside the lateral boundary of the plate. With this type of implant, it is nearly impossible to ensure that the screw holes will optimally lie beneath each of the carpal bones involved in the fusion. The heavy surface plates can cause stress shielding and disuse osteoporosis, which can lead to fracture at either end of the plate. Finally, these plates can be prominent and cause cosmetic problems.

[0008] An alternative to spanning plate fixation is a non - spanning plate. This device is similar to a spanning plate but does not cross the carpometacarpal joint, thus avoiding the problems associated with metacarpal fixation. Instead, the plate widens at its distal end and screws are placed in several of the carpal bones. However, this type of plate design still has other drawbacks associated with spanning plates, including: fixation deviating from the central neutral axis of the bone; the need for sufficient plate volume and thickness to overcome bending loads, surface prominence, and soft tissue irritation; and tendon problems. However, in addition to this, it introduces other problems.

[0009] Because this design does not extend to the metacarpals, it has only a limited lever arm at the distal lever of its fusion mass and for this reason it bears a greater load than the transplate. Most designs provide a flared widening at the distal end to allow screws to be used in multiple planes to lever multiple carpal bones. However, the screw holes may not align with the optimal levering sites on the carpal bones. This implant still requires the surgeon to perform a cumbersome debridement of both the joint surface and the superficial bone surface to provide a rich raw bone bed to promote fusion. These plates are applied to the bone surface and have a degree of surface protrusion which may still cause soft tissue irritation. Finally, most of these plates still require complex curvatures to match the surface of the bone, or require the surgeon to effectively become a skilled carpenter and precisely cut from a flat channel to match the plate profile so that the plate can be recessed within the bone.

[0010] Another implant option for wrist fusion is an intramedullary device that extends from the intramedullary canal of the distal radius, through the carpal bones, and into the intramedullary canal of one of the metacarpals. Although this concept has the theoretical advantage of removing the hardware from the bone surface and placing the implant closer to the central neutral axis of the bone, it introduces a number of other problems that severely limit its acceptance in clinical applications.

[0011] First, the canals in the metacarpals are very narrow, restricting both the size of the implant and the size of the interlocking screws used to secure the implant, both of which increase the risk of implant failure. Adding screws to this narrow intramedullary nail further weakens it. Second, due to the anatomy, it is not possible to place a single intramedullary nail across the wrist. Since the wrist is typically fused in the range of 0° to 30° of extension, implanting a nail in this position requires two parts that are joined together after separate intramedullary components are implanted on either side of the joint. The joining mechanism is cumbersome, adds a small intermediate component that further weakens the device, is difficult to apply, may fail due to insufficient strength, and adds additional volume between the bones the surgeon is trying to fuse. Third, once the wrist is fused, these implants are almost impossible to remove without extensive bone destruction. If the wrist becomes infected and removal is required, the surgeon is faced with cutting through the bone canals to remove the implant. The surgical techniques for this type of implant are difficult and technically challenging.

[0012] Metal or polyetheretherketone (PEEK) circular or partially circular cups have been successfully used for partial intercarpal fusions that limit the number of carpal bones. Examples include four-corner fusions that fuse the capitate, hamate, lunate, and triquetral bones, scaphoid-trapezium-trapezoid fusions, intercarpal fusions, or radio-scaphoid-lunate fusions that fuse the radius to the scaphoid and lunate bones. These are also done on bones in the foot. In this process, for any fusion, the joint surface is first decorticated. Then a hemispherical curved power reamer is used to create a cup-shaped groove within the surface of the bone. This easily and quickly creates an original vascular bone bed that helps generate a fusion mass of new bone on the joint and that matches at least a portion of the curvature of the cup to improve fixation stability. Additionally, PEEK cups have several other advantages. In terms of stiffness, it is more isotropic with respect to cortical bone, and thus has less stress shielding compared to metal plates. The cup shape design has natural rigidity, thus effectively increasing the resistance to bending loads due to the three-dimensional structural form while allowing for the use of thinner implants. Some designs provide multi-axial locking screws for plate fixation. This allows for direction changes over a range of angles and creates an angular lock on the plate, which increases stiffness and stability. This type of design makes it easier for the surgeon to direct each screw in an optimal direction into the underlying carpal bones. PEEK cups are also radiolucent, thus allowing the surgeon to visualize on an X-ray the accuracy of screw position, implant, and bone position, as well as bone juxtaposition.

[0013] Currently, PEEK cups are mainly used for partial wrist fusions. Due to the high bending loads at the wrist, their use is limited when applied to total wrist fusions or fusions of the proximal carpal row to the radius. Circular cups only span a limited distance, thus providing a shorter lever arm to resist the large bending loads that occur at the wrist. Additionally, if a total wrist fusion is considered, the circular cup would require an overly large diameter. Besides creating a cumbersome, bulky implant that would be difficult to apply, it would physically extend the span of the implant, thus causing interference with the movement of the distal radioulnar joint.

[0014] The medical industry continues to search for alternative implant designs and fusion methods to address one or more of the above problems or drawbacks. SUMMARY OF THE INVENTION

[0015] In one form, the present invention relates to an implant for fusing at least two bone components. The implant has a body with a first anchoring portion and a second anchoring portion. The first anchoring portion has a stem that is configured to be guided into a first bone component when the first anchoring portion is in an operative position. The first anchoring portion is configured to cooperate with at least a first fastener that can be used to fix the stem relative to the first bone component when the first anchoring portion is in its operative position. The second anchoring portion is configured to be fixed to at least a second bone component. The second anchoring portion is configured such that when in the operative position, at least a portion of the second anchoring portion is located within a cavity created in at least the second bone. The second anchoring portion is further configured to cooperate with at least a second fastener that can be used to fix a portion of the second anchoring portion relative to the second bone component, thereby holding the second anchoring portion in its operative position.

[0016] In one form, the stem has an opening therein for cooperating with the first fastener that can be used to fix the stem relative to the first bone component and thereby hold the first anchoring portion in its operative position.

[0017] In one form, the implant is provided in combination with the first fastener, which is configured to extend into the first bone component and the stem opening to fix the stem relative to the first bone component.

[0018] In one form, the second anchoring portion has an opening therein through which the second fastener can extend to be guided into the second bone component, thereby fixing a portion of the second anchoring portion relative to the second bone component.

[0019] In one form, the implant is further provided in combination with the second fastener, which is configured to extend through the opening in the second anchoring portion and into the second bone component to fix a portion of the second anchoring portion relative to the second bone component.

[0020] In one form, the body has a single rigid piece defining the first anchoring portion and the second anchoring portion.

[0021] In one form, the body has an elongate shape having a length and a width between a first end and a second end. The stem extends to the first body end and the second anchoring portion is at the second body end.

[0022] In one form, with the second anchoring portion in its operative position, the surface of the second anchoring portion that extends into the cavity has at least a portion that is convex in shape.

[0023] In one form, the second anchoring portion has a cup-shaped surface.

[0024] In one form, the cup-shaped surface has a central axis. The body has an elongated portion that defines a stem. The elongated portion extends away from a part of the second anchoring portion and has a longitudinal centerline. The longitudinal centerline is offset from the central axis.

[0025] In one form, the cup-shaped surface extends to an edge. There are discrete incisions through the edge.

[0026] In one form, at least a part of the second anchoring portion has a cup-shaped wall.

[0027] In one form, the cup-shaped wall has a central axis. A convex outer surface defines a surface on the second anchoring portion that extends into a cavity. The convex outer surface is symmetric about the central axis and tapers axially.

[0028] In one form, the cup-shaped wall has a plurality of openings through which fasteners can be directed at different angles.

[0029] In one form, the cup-shaped wall has discrete receptacles therein for a quantity of bone graft material.

[0030] In one form, the cup-shaped wall has at least a part that is substantially flat. The discrete receptacles are formed in the substantially flat wall portion.

[0031] In one form, the body is made of polyetheretherketone (PEEK).

[0032] In one form, the body is made of a non-PEEK material that is one of a metal and a non-metal.

[0033] In one form, the body has an elongated shape with a length and a width between a first end and a second end. At least a part of the second anchoring portion is cup-shaped. The stem extends away from the cup-shaped part of the second anchoring portion to the first body end. Another part of the body extends away from the cup-shaped part of the second anchoring portion at a location spaced from the location where the stem extends from the cup-shaped part of the second anchoring portion.

[0034] In one form, the another part of the body extends away from the cup-shaped part of the second anchoring portion in a direction away from the first body end.

[0035] In one form, the stem has an elongated shape with a central axis and a flat profile approximated by a reference plane that includes the central axis. The second anchoring portion has a cup-shaped wall that has a substantially flat surface to abut against a second bone member when the second anchoring portion is in its operative position. The flat surface of the cup-shaped wall is angled in two dimensions relative to the reference plane.

[0036] In one form, the second anchoring portion has a surface, at least a portion of which has a convex shape to be guided into a cavity in at least a second bone member so as to be juxtaposed with at least a portion of a surface on the at least second bone member that defines the cavity.

[0037] In one form, at least a portion of the second anchoring portion has a cup-shaped surface with an axis. The convex shape is an arcuate shape that extends at least partially around the axis.

[0038] In one form, the second anchoring portion has a cup-shaped wall with an opening defined therethrough to receive a second fastener.

[0039] In one form, the second anchoring portion has a cup-shaped wall having a bottom wall portion at which a first connector is provided. The implant is further provided in combination with a first support member having a second connector. The first connector and the second connector are configured to be engageable to releasably hold the first support member in an operative position on the implant.

[0040] In one form, the cup-shaped wall has an axis. The first support member is elongate and has a length. When the first support member is in its operative position, the length of the first support member is aligned with the axis of the cup-shaped wall.

[0041] In one form, the implant is provided in combination with a cutting tool that is operative to produce a predetermined cavity shape in at least a second bone member. When the second anchoring portion is in its operative position, at least a portion of a surface of the second anchoring portion that extends into the cavity is juxtaposed with at least a portion of a surface on the at least second bone member that defines the cavity.

[0042] In one form, the cutting tool has a reamer with a shaft that is rotated to cause a cutting surface on the reamer to produce a predetermined cavity shape in at least a second member.

[0043] In one form, the predetermined cavity shape is cup-shaped.

[0044] In one form, the rod has a plurality of openings therein, each opening being adapted to cooperate with a fastener that can be used to secure the rod relative to a first bone member. The implant is further provided in combination with an outer frame guiding assembly that can be releasably attached to the implant. The outer frame guiding assembly has guiding openings to facilitate the controlled formation of a plurality of openings in the first bone member, each opening being alignable with one of the openings in the rod.

[0045] In one form, one of the openings in the rod is elongate.

[0046] In one form, the combination described above is further combined with a support member to provide. The outer frame guiding assembly is configured to facilitate the formation of a first opening among a plurality of openings such that a first support member can be guided into the first opening and into an elongated rod opening at one of its ends to allow the implant to be offset relative to the first support member and thus be located at the opposite end of the one elongated rod opening.

[0047] In one form, the rod has a plurality of openings therein, each opening being adapted to cooperate with a fastener that can be used to fix the rod relative to the first bone member. One of the openings in the rod is elongated.

[0048] In one form, the rod has a plurality of openings therein, each opening being adapted to cooperate with a fastener that can be used to fix the rod relative to the first bone member. The implant is further provided in combination with an outer frame guiding assembly that is capable of releasably attaching to the implant and has guiding openings to facilitate the controlled formation of a plurality of openings in the first bone member, each opening being alignable with one of the openings in the rod.

[0049] In one form, the combination described above is further combined with a second support member to provide, the second support member being configured to connect to the first bone member.

[0050] In one form, the rod has an elongated opening therein through which the second support member can extend.

[0051] In one form, the combination described above is further combined with a tool for engaging the first support member and the second support member and pressing the first support member and the second support member towards each other to provide.

[0052] In one form, the present invention relates to a method of fusing bone members. The method includes the steps of: obtaining the above implant; guiding the rod into the first bone member to place the first anchoring member in its operative position; fixing the rod in its operative position using at least a first fastener; strategically removing bone from at least a second bone member to define a cavity at the placement position for the second anchoring portion; placing the second anchoring portion in its operative position, wherein at least a portion of the second anchoring portion covers at least one bone at the placement position; and fixing the second anchoring portion in its operative position using at least a second fastener.

[0053] In one form, the first bone member is the radius and the second bone member is a carpal bone.

[0054] In one form, at least the second bone member is a plurality of carpal bones.

[0055] In one form, the step of strategically removing bone includes removing bone using a reamer having a rotating cutting surface.

[0056] In one form, the method further includes the step of placing a bone graft material between the second anchoring portion and the bone at the placement location.

[0057] In one form, the step of strategically removing bone includes removing bone from the first bone member at another placement location. With the second anchoring portion in its operative position, the second anchoring portion covers the another placement location.

[0058] In one form, the first bone member is the tibia and at least the second bone member is a tarsal bone.

[0059] In one form, the first bone member is a metatarsal bone and the second bone member is a tarsal bone.

[0060] In one form, the step of strategically removing bone includes removing bone to define a cavity at the placement location, the cavity having a shape complementary to a portion of the second anchoring portion that covers the placement location.

[0061] In one form, the step of strategically removing bone includes removing bone in a manner that allows a portion of the second anchoring portion that covers the placement location to recess into the cavity at the placement location.

[0062] In one form, the step of using a reamer includes using the reamer such that a rotating cutting surface removes bone from multiple bone members simultaneously.

[0063] In one form, the cavity at the placement location has a tapered shape. The step of placing the second anchoring portion includes guiding a portion of the second anchoring portion into the cavity such that at least one bone surface surrounding the cavity mates with a portion of the second anchoring portion to always guide the second anchoring portion to its operative position.

[0064] In one form, the second anchoring portion has a cup-shaped wall. The step of securing the second anchoring portion includes guiding a plurality of fasteners through the cup-shaped wall and into different bone members.

[0065] In one form, at least two of the plurality of fasteners are guided into different bone members at different angles.

[0066] In one form, the second anchoring portion has discrete incisions therein. The method further includes the step of securing the second anchoring portion in its operative position, wherein the incisions are positioned to avoid implant impingement on the radioulnar joint.

[0067] In one form, the method further includes the steps of: connecting a first support member to the implant; guiding a second support member through an elongate opening in the first anchoring portion and into the first bone member; and applying a force that tends to pull the first and second anchoring portions toward each other, whereby the second support member moves within the elongate opening and the first bone member and at least the second bone member are pushed toward each other into a desired relationship.

[0068] In one form, the step of fixing the rod in its operative position includes guiding a first fastener into the first bone member and the rod after the first bone member and at least a second bone member have been placed in a desired relationship.

[0069] In one form, the method further includes the steps of broaching the first bone member with a broaching tool and, after broaching the first bone member, separating the broaching tool from the first bone member and guiding the rod into the first bone member.

[0070] In one form, the rotary cutting surface is configured to produce a cup-shaped cavity and has a guiding extension.

[0071] In one form, the method further includes the step of forming a guiding hole in at least the second bone member.

[0072] In one form, the method further includes the step of releasably connecting a guide to a second anchoring portion. The step of placing the second anchoring portion in its operative position includes guiding a portion of the guide into the guiding hole to always guide the second anchoring portion to its operative position.

[0073] In one form, the method further includes the step of temporarily fixing the second anchoring portion in its operative position with a temporary fastener before using at least the first fastener.

[0074] In one form, the method further includes the step of stabilizing the first bone member and the second bone member before strategically removing bone from at least the second bone member.

[0075] In one form, the method further includes the step of using the broaching tool as a guide to form a guiding hole in at least the second bone member.

[0076] In one form, when the second anchoring portion is in its operative position, a surface on the second anchoring portion is positioned to be juxtaposed with a surface defining a cavity. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 is a schematic view of an implant for fusing separated bone members according to the present invention;

[0078] Figure 2 shows Figure 1 additional details of the body on the implant in

[0079] Figure 3 shows Figure 1 and Figure 2 additional details of the body in

[0080] Figure 4is as shown Figures 1-3 a side view of a specific exemplary form of the implant schematically shown in;

[0081] Figure 5 is Figure 4 a perspective view of the implant in;

[0082] Figure 6 is Figure 4 and 5 a plan view of the implant in;

[0083] Figure 7 is Figures 4-6 an end view of the implant in conjunction with a schematic view of an associated bone member, with a portion of the implant fixed to the associated bone member by one or more fasteners;

[0084] Figure 8 is as shown Figure 6 a view with a schematic view of a bone member, with another portion of the implant fixed to the bone member using one or more fasteners;

[0085] Figure 9 is a cross-sectional view of the implant taken along line Figure 8 9-9 of;

[0086] Figure 10 is as shown Figures 1-9 a schematic view of a multi-axis opening in the body as shown on the implant in;

[0087] Figure 11 is as shown Figures 4-9 a cross-sectional view of an alternative form of a cup-shaped portion as shown on the implant in;

[0088] Figure 12 is as shown Figure 11 a view showing another alternative form;

[0089] Figure 13 is a view of the human hand and forearm region where wrist fusion is to be performed and a broaching tool is inserted into the intramedullary canal in the radius;

[0090] Figure 14 corresponds to Figure 13 from different perspectives;

[0091] Figure 15 is Figure 13 and 14 a perspective view of the broaching tool depicted in;

[0092] Figure 16 is a schematic view of a cutting tool that can be used to form a cavity to receive a portion of the inventive implant;

[0093] Figure 17 is as shownFigure 16 Perspective view of an exemplary form of a cutting tool schematically shown therein;

[0094] Figure 18 is as shown in Figure 13 a view which shows the insertion of a Kirschner wire (K-wire) to stabilize a bone in the wrist region;

[0095] Figure 19 corresponding to Figure 18 ;

[0096] Figure 20 is as shown in Figure 18 a view in which the cutting tool is operated to create a cavity for receiving a portion of the inventive implant;

[0097] Figure 21 corresponding to Figure 20 ;

[0098] Figure 22 is as shown in Figure 20 a view in which the cutting tool and the Kirschner wire have been removed and the inventive implant has been placed in the operative position and is temporarily held in place by the Kirschner wire;

[0099] Figure 23 corresponding to Figure 22 but from a different perspective;

[0100] Figure 24 is as shown in Figure 22 a view in which a fastener has been guided through a portion of the implant;

[0101] Figure 25 corresponding to Figure 24 but from a different perspective;

[0102] Figure 26 exploded view of an external frame guiding assembly associated with the inventive implant;

[0103] Figure 27 is as shown in Figure 24 a view in which Figure 26 the external frame guiding assembly has been placed in the operative position;

[0104] Figure 28 corresponding to Figure 27 but from a different perspective;

[0105] Figure 29 is as shown in Figure 27 a view in which an anchoring portion in one of the bone members is added;

[0106] Figure 30 corresponding to Figure 30 but from a different perspective;

[0107] Figure 31 is a view corresponding to Figure 29 in which portions of the outer frame guiding assembly are pushed toward each other to move the bone members to be fused into a desired relationship;

[0108] Figure 32 corresponds to Figure 31 , but from a different perspective;

[0109] Figure 33 is a view as in Figure 31 in which additional fasteners have been used to maintain the desired relationship of the fused bone members;

[0110] Figure 34 corresponds to Figure 33 , but from a different perspective;

[0111] Figure 35 is a view as in Figure 33 in which the outer frame guiding assembly has been removed;

[0112] Figure 36 corresponds to Figure 35 , but from a different perspective;

[0113] Figure 37 is a perspective view of the inventive implant as in Figures 4-9 and has a support member associated with an outer frame guiding assembly releasably connected thereto;

[0114] Figure 38 is Figures 4-9 a side view of the inventive implant in which the outer frame guiding assembly is in operative relationship therewith;

[0115] Figure 39 is a schematic view of an alternative use of the inventive implant for fusing the tibia and tarsus; and

[0116] Figure 40 is a schematic view of the inventive implant for fusing the metatarsals and tarsus. DETAILED DESCRIPTION

[0117] Referring initially to Figure 1 , a preferred form of an implant for fusing at least two bones / bone members in accordance with the present invention is shown at 10. The implant 10 includes a body 12 having a first anchoring portion 14 and a second anchoring portion 16, respectively. The first anchoring portion 14 has a stem 18 configured to be guided into a first bone member to place the first anchoring portion 14 in an operative position. The first anchoring portion 14 is further configured to assist with at least a first fastener 20 that can be used to secure the stem 18 relative to the first bone member and thereby hold the first anchoring portion 14 in its operative position.

[0118] The second anchoring portion 16 is configured to cover at least the second bone member when the second anchoring portion 16 is in the operative position and is further configured to cooperate with at least a second fastener 20 that can be used to secure a portion of the second anchoring portion to the second bone member so as to thereby hold the second anchoring portion 16 in its operative position.

[0119] The fasteners 20 for the first anchoring portion 14 and the second anchoring portion 16 can be the same or different and can take any known form.

[0120] The body 12 can be made in multiple parts but in a preferred form has a single rigid piece that defines the first anchoring portion 14 and the second anchoring portion 16.

[0121] As Figure 2 shown, the body 12 has a length between a first end 22 and a second end 24 accordingly. In a preferred form, the rod 18 extends fully to the first body end 22.

[0122] In Figure 3 it, the body 12 including the first anchoring portion 14 and the second anchoring portion 16 is shown in more detail and has optional modifications. In this general form, the second anchoring portion 16 has a cup-shaped portion 26 from which a body portion 28 extends. The body portion 28 and the first anchoring portion 14 typically project from different positions on the cup-shaped portion 26. In Figure 3 the configuration, the second anchoring portion 16 itself can extend fully to the second body end 24. Alternatively, the body portion 28 can extend to one end of the cup-shaped portion 26 and extend to the second body end 24 or extend beyond it so as to define the second body end 24 by itself.

[0123] It should be understood that a plurality of cup-shaped portions 26 can be incorporated into the body 12.

[0124] Figures 1-3 The schematic display of the components in

[0125] is intended to include the components shown in the following specific forms as well as virtually an unlimited number of variations of those components and their mating.

[0125] Now referring to Figures 4-9 , a specific form of the implant 10 will be described. The implant 10 has the body 12 described above, which has a length L between a first end 22 and a second end 24 accordingly and has a main width W.

[0126] The first anchoring portion 14 defines a stem 18 that is configured to be guided into at least a first bone member 30. The stem 18 is elongate in shape and has a plurality of longitudinally spaced openings 32a, 32b, 32c, 32d, each opening for receiving a fastener 20 that can be used to secure the stem 18 relative to the bone member 30 in an operative position. The opening 32c is elongate to permit longitudinal movement of the stem 18 relative to the fastener 20 through which it is guided into the first bone member 30.

[0127] The second anchoring portion 16 is configured to overlie at least a second bone member 34 and has a cup-shaped wall 36 corresponding to the aforementioned cup-shaped portion 26, which has a plurality of openings 38a - 38t, each opening for receiving a fastener 20 that can be used to directly secure a portion of the second anchoring portion 16 to at least one of the second bone members 34, where the second anchoring portion 16 is in an operative position.

[0128] As noted above, the nature of the specific fastener 20 is not critical to the present invention. Generally, a threaded fastener 20 will be guided through or into the openings 32, 38 and will grip the bone to effect fixation.

[0129] As noted above, with reference Figure 3 , the second anchoring portion 16 has a cup-shaped portion 26 generally depicted, which can have a wide range of different shapes. The corresponding cup-shaped wall 36 can be symmetric about a central axis 40, as depicted for the cup-shaped wall in Figures 4-9 , or can have an asymmetric shape.

[0130] As shown, the cup-shaped wall 36 has a cup-shaped concave surface 42 and an opposing cup-shaped convex surface 44. As shown, the surfaces 42, 44 are complementary in shape and the wall 36 has a uniform thickness therebetween. However, this is not required as the shapes of the surfaces 42, 44 can vary significantly.

[0131] At least a portion of the second anchoring portion 16 has such a cup shape. As shown, the cup-shaped wall 36 substantially constitutes all of the second anchoring portion 16.

[0132] In the depicted form, the convex surface 44 extends about the axis 40 and has an axial width AW that tapers between a top edge 46 and a flat bottom wall portion 48. The bottom wall portion actually has a "W" shape as visible in the cross-section of Figure 9 , but is actually flat and will be considered so as the downward-facing surface 50 thereon will rest stably against a flat bone surface.

[0133] The surface 44 is convex when viewed from two different perspectives - as in the cross-section of Figure 9 , and when viewed from an axial perspective.

[0134] The "W" shape forms discrete receptacles 52 in the bottom wall portion 48 to receive bone graft material 54.

[0135] The convex surface 44 is configured to juxtapose the surface against at least one of the second bone members 34 when the second anchoring portion 16 is in its operative position. The bone graft material 54 contacts the cup-shaped wall 36 above the surface defining the receptacle 52 and the bone region over which the bottom wall portion 48 is disposed. The bottom wall surface 50 may abut against at least one of the second bone members 34, but may be spaced above it to accommodate an appropriate volume of bone graft material 54. The bone graft material 54 is not necessary, or may be located at a position other than the bottom wall portion 48, which may allow the bottom wall portion 48 to directly contact at least one of the second bone members 34.

[0136] The receptacles 52 may take many different forms. Additionally, multiple receptacles may be formed at different locations.

[0137] In the depicted form, the first anchoring portion 14 is elongate and has a longitudinal centerline 56. The centerline 56 is offset from the central axis 40 of the cup-shaped wall 36, as Figure 6 most clearly seen in

[0138] In the case where the body portion 28 is provided, it preferably extends away from the cup-shaped wall 36 at a position circumferentially spaced from the position 58 where the first anchoring portion 14 projects away from the cup-shaped wall 36.

[0139] In most configurations, the body portion 28 projects away from the cup-shaped wall 36 in a direction away from the first end 22 of the body 12. As described above, the body portion 28 may extend completely to the second body end 24. The cup portion 26 may similarly extend completely to the second body end 24, or may be adjacent to or spaced from it.

[0140] In a modified form, optional discrete incisions 59 are formed through the rim 46, as Figure 5 shown by the dashed lines in

[0141] to avoid interference at certain joint sites, as described below.

[0142] The body 12 may be made of any of a variety of different materials. In one form, it is made of metal.

[0143] In a more preferred form, the body 12 is made of a non-metallic material such as polyetheretherketone (PEEK) or other medical-grade plastics. The use of PEEK material helps to form multi-axial openings at various locations on the body 12, as Figure 10 generally identified at 60 in the position where it is desirable to be able to threadedly guide the fastener 20 through each such opening 60 at different angles.

[0144] As described above, the specific "cup shape" of the cup portion 26 for the second anchoring portion 16 can vary significantly. As Figure 11 shown, the cup portion 26' is formed as a hollow section of a sphere having a central axis 40'.

[0145] In Figure 12 a variant is shown where the cup portion 26" has a convex surface 42" that consists of portions with different radii of length when viewed perpendicular to the axis 40".

[0146] These are just examples of the many different forms that the cup portion 26, which constitutes at least a part of the second anchoring portion 16, can take, bearing in mind that it does not need to be symmetric about the corresponding axis 40 and the cup wall 36 does not need to have a uniform thickness.

[0147] In Figures 13-36 a method of fusing bone members on a human wrist is described. This is just one exemplary application of the implant described above.

[0148] The wrist is exposed and the arthritic joint surface is debrided, and the remaining cartilage is removed. The distal end of the radius 64 is exposed and a drill is placed in the central intramedullary canal to determine the longitudinal axis of the radius.

[0149] As Figures 13-15 shown, a broaching tool 66 is used to prepare the radial canal 68 and is inserted centrally from the articular end of the radius 64 into the canal 68. The penetrating portion 70 of the broaching tool 66 preferably matches the profile of the rod 18. In the depicted form, the handle 72 on the broaching tool is offset such that when the broaching tool 66 is fully seated as Figure 13 and 14 shown, it allows for reduction of the joint surface.

[0150] Although not necessary, a preferred method of using the implant 10 is performed with the aid of a cutting tool (generally shown at 74 in Figure 16 ).

[0151] The cutting tool 74 has at least one cutting surface 76 configured such that when the cutting tool 74 is operated, it is capable of creating a cavity having a predetermined shape. The cutting tool 74 is not limited in its construction or manner of operation, so long as it can consistently create a cavity having a predetermined shape.

[0152] In an exemplary form, as Figure 17 shown, the cutting tool 74 is in the form of a reamer having a plurality of cutting surfaces 76. The reamer 74 is rotated about an axis 78 by a suitable driver 80, and as one of its events, the cutting surfaces 76 are capable of progressively removing bone in a symmetric pattern about the axis 78.

[0153] The depicted cutting surfaces 76 are configured to create a cup-shaped cavity. The reamer 74 has a guide extension 82 that axially projects from the cutting surfaces 76.

[0154] The cutting tool / reamer 74 has a footprint diameter D selected based on a particular implant construct and the desired number of bone members to be fused. In the depicted particular wrist application, the implant 10 is configured and sized to permit five carpal bones (scaphoid 84, capitate 86, hamate 88, triquetrum 90, and lunate 92) to fuse with each other and with the radius 64.

[0155] Prior to using the reamer 74, and with the broaching tool in place, as Figure 13 , 14 , 18 and 19 shown, the carpal bones 94 at 94 (specifically including the scaphoid 84, capitate 86, hamate 88, triquetrum 90, and lunate 92) are stabilized relative to the radius 64 by using conventional Kirschner wires 96, which are guided through the bone in the carpal bones 94 and into the radius 64. This ensures that the wrist fuses at a preferred dorsal flexion angle.

[0156] Once the area is stabilized, a guide hole 98 is formed in the carpal bones 94. The broaching tool 66 has a guide opening 100 for a drilling tool 102, and the guide opening 100 is directed at a target location in the area where the second anchoring portion 16 is placed in its operative position. The drilling tool 102 can be manually controlled or can be rotated by a suitable driver 104.

[0157] As Figure 20 and 21 shown, with the area of the carpal bones 94 stabilized by the Kirschner wires 96, the broaching tool 66 is removed, and the cutting tool / reamer 74 is strategically placed on the carpal bone area and the distal end of the radius 64 by guiding the guide extension 82 thereon into the guide hole 98.

[0158] By operating the cutting tool / reamer 74, a desired amount of cortical bone can be removed from the surface to create a cavity 106 in at least the carpal bones 94, as depicted in the radius 64.

[0159] The entire cup-shaped cavity 106 is complementary in shape to the second anchoring portion and, more particularly, to the concave surface 42 and potentially to the surface 50 on the bottom wall portion 48.

[0160] The cutting path of the cutting tool / reamer 74 is determined by the specific fusion required. It is not necessary to remove cortical bone from the radius 64 for the use of the implant 10. The diameter D (which represents the effective cutting diameter of the cutting surface 76) also determines the number of carpal bones to be treated and the specific area of their placement. The reamer / cutting tool 74 can be simply and conveniently operated to strategically and precisely remove the cortical bone surface to provide a bed for effective fusion.

[0161] As Figure 22 and 23 shown, once the bone treatment is completed with the cutting tool / reamer 74, the bone graft material can be applied within the receiving portion 52 on the cup-shaped wall 36. The rod 18 is inserted into the radial canal 68, and subsequently the cup-shaped wall 36 is pressed into the cavity 106.

[0162] The guiding / insertion rod 108 can be releasably connected to the bottom wall portion 48 and can have a guiding portion 110 that projects beyond the bottom wall portion 48 to be advanced into the guiding hole 98. The guide 108 is grippable to facilitate reorienting the cup-shaped wall 36, where the guiding portion 110 helps align the convex surface 44 with the complementary surface 114 that defines the cavity 106, which is jointly defined by the carpal bones 94 and the radius 64.

[0163] In Figure 22 and 23 shown, the first anchoring portion 14 and the second anchoring portion 16 are respectively shown in their respective operating positions, where the convex surface 44 is juxtaposed with the surface 114 that defines the cavity 106. The surface 50 on the bottom wall portion 48 can similarly be juxtaposed with the bottom surface region 116 that defines the cavity 106.

[0164] When the first anchoring portion 14 and the second anchoring portion 16 are in their respective operating positions, temporary fixation of the implant 10 can be achieved using a small Kirschner wire 118, in which case the Kirschner wire 118 is guided through the opening 120 through the edge 46 of the cup-shaped wall 36 and into the carpal bones 94 and the radius 64.

[0165] As Figure 24 and 25 shown, the implant 10 as Figure 22 and 23For temporary fixation, the hole 122 can be strategically formed into the bone of the carpal bone 94 to receive the fastener 20 guided through the opening 38 in the cup-shaped wall 36.

[0166] Once the fastener 20 is fixed as shown in Figure 24 and 25 the guide / insertion rod 108 is separated from the cup-shaped wall 36.

[0167] Although different arrangements of fasteners are envisioned, a fastener 20 of appropriate size is guided into each of the scaphoid bone 84, capitate bone 86, hamate bone 88, triquetral bone 90, and lunate bone 92, which together define a placement position covered by the cup-shaped wall 36.

[0168] In this embodiment, cortical bone is also removed from the dorsal edge 124 of the radius 64 such that the cup-shaped wall 36 is located at the second placement position 125 where the cup-shaped wall 36 covers the radius 64. Although not required, in this embodiment the radius 64 is reconfigured by a cutting tool / reamer 74. As shown in Figure 25 one of the temporary Kirschner wires 118 is guided into the radius 64.

[0169] As can be seen in Figures 26-30 an external frame guiding assembly 126 can then be used, which includes a first support member 128 and a second support member 130 releasably connected to the cup-shaped wall 36. Alternatively, the guiding assembly 126 can be attached to any other part of the implant body 12. Although the above-mentioned guide 108 and the first support member 128 are shown as different, they can be the same. The first support member 128 includes an elongated sleeve 132 whose length can be aligned with the axis 40 of the cup-shaped wall 36. The anchoring portion 134 has a connecting member 136 which can releasably engage with the connecting member 138 on the cup-shaped wall 36. The connecting members 136, 138 can be threadedly engaged or can be constructed in other ways. With a threaded arrangement and manual clamping using an enlarged head 140, the anchoring portion 134 can be rotated to engage and release the connecting members 136, 138. When the connecting members 136, 138 are engaged, the sleeve 132 and the anchoring portion 134 are fixed with their lengths aligned with the axis 40.

[0170] It should be noted that as schematically shown in Figure 23 the connecting member 138 can also be used to releasably engage with the connecting member 142 on the aforementioned guide / insertion rod 108 to form a releasable connection therewith.

[0171] The sleeve 132 is fixed relative to the elongate guide rod 144, which has openings 32a', 32b", 32c', 32d' that correspond in shape and position to the rod openings 32a, 32b, 32c, 32d, whereby the elongate guide 144 covers the rod 18, with these components being longitudinally aligned and the openings 32a', 32b', 32c', 32d' being aligned with the openings 32a, 32b, 32c, 32d, as Figure 28 most clearly shown in

[0172] The second support member 130 is then guided through the opening 32c' into the radius 64 and through the rod opening 32c. The second support member 130 is configured to be slidable within each of the slots 32c, 32c' in the longitudinal direction of the elongate guide 144 and the rod 18. The second support member 130 is guided into the openings 32c', 32c to be located at or near the edges 146, 146' of the end 22 of the body 12 closest to and the end 148 of the elongate guide 144.

[0173] As Figure 31 and 32 shown, the clamping tool 150 is used with the jaws 152, 154, which can be supported respectively against the first and second support members 128, 130, respectively, to pull the support members 128, 130 towards each other, as shown by the arrow 156. This is permitted by the elongate configuration of the openings 32c, 32c'. When this occurs, the carpal member fixed to the cup-shaped wall 36 is pulled towards the radius 64 along the line of the double-headed arrow 158 into the desired relationship, with at least one of the engaged carpals being pressed against the distal end of the radius 64. Although a scissor-type clamping tool 150 is depicted, any type of device or devices can be used to effect this compression movement at the fusion site.

[0174] As Figure 33 and 34 shown, once the desired relationship is established between the carpal bones and the radius 64, the drill 159 can be placed through the drill sleeve 160 and used to form openings 162a, 162b, 162d through the radius 64 that are aligned with the openings 32a, 32b, 32d in the rod 18, and thus the rod 18 can be fixed relative to the radius 64 using the fasteners 20.

[0175] In Figure 35 and 36 the user's wrist region is shown with all of the fasteners 20 secured and the outer frame guide assembly 126 removed.

[0176] In Figure 37 and 38 additional details of the relationship of the outer frame guide assembly 126 to the implant 10 are more clearly shown.

[0177] In Figure 37 , the first support member 128 (which is an integral part of the outer frame guiding assembly 126) is shown as being releasably fixed in place on the implant by the anchor 134 and without the elongate guide 144 thereon.

[0178] As Figure 38 shown, the elongate guide 144 has a guide channel 164 that is aligned to form an opening in the radius 64 to receive the fastener 20 that is guided through the opening 166 in the region near the connection of the stem 18 and the cup wall 36.

[0179] Figure 38 Depth guides 168, 170 are also shown to facilitate controlled drilling of the bone to receive the fastener 20.

[0180] As described above, the body 12 can include a body portion 28 that can be suitably fixed to one or more metacarpals. The body portion 28 can cover and / or be inserted into one or more of the metacarpals.

[0181] As described above, the inventive implant is not limited to use with wrist fusion applications. The same concept can be used to achieve fusion at other anatomical locations. By way of example only, as Figure 39 shown, the implant 10 can be used to achieve fusion between the tibia 172 and the tarsus 174.

[0182] Alternatively, as Figure 40 shown, the implant 10 can be used to achieve fusion between the metatarsal 176 and the tarsus 178.

[0183] In these particular applications, the stem 18 can be inserted into the tibia or metatarsal while the cup wall 36 is fixed to the tarsus.

[0184] As Figure 4 , 7 and 9 shown, the flat surface 50 on the bottom wall portion 48 is angled in two dimensions relative to a reference plane P that approximates the flat profile of the stem 18 extending through the central longitudinal axis 180 of the stem 18. In other words, the cup wall 36 is angled dorsally relative to the plane of the patient's forearm and is angled rotationally in a supinated position.

[0185] As visible in Figure 4 , 7 and 9, the plane P is angled by an angle α relative to a reference plane P1 that includes the bottom wall surface 50, which in turn is generally parallel to a reference plane P2 that spans the edge 46 of the side. In a preferred form, the angle α is on the order of at least 10°.

[0186] Using fasteners that secure the implant 10 to multiple bone components on the opposite side of the fusion site, the implant 10 can resist forces with a large moment arm across the joint. At the same time, in a wrist application, the presence of the rod 18 within the radial canal eliminates the need to secure plates that require complexly curved implants, mill channels for the plates, and use bulky surface plates. Since the carpal bones are centered above the articular surface of the distal radius, the rod 18 aligns directly with the cup wall 36.

[0187] As shown in the exemplary Figure 36 the second anchoring portion 16 is effectively recessed over its entire footprint so as not to add protrusions that may cause discomfort (such as from soft tissue irritation) and / or potential harm to the patient (such as tendon rupture or surface deformity).

[0188] The ability to direct the fasteners through the cup wall 36 at different angles strengthens the connection between the multiple bone components.

[0189] Due to the complementary tapered cups on the cup wall 36 and the cavity 106, when the cup wall 36 is guided into the cavity 106, the convex surface 44 and the surface defining the cavity 106 mate to consistently guide the cup wall 36 into the cavity 106 where the second anchoring portion 16 assumes its operative position.

[0190] Since an implant is provided that is centered near the neutral axis of the exemplary radius, the bending loads on the implant can be reduced compared to other conventional implants.

[0191] Due to the use of an intramedullary configuration and recessing the second anchoring portion 16 at least to some extent, this inventive implant may reduce: implant protrusion; surface deformity; soft tissue irritation; and tendon problems.

[0192] Using this inventive construction, a relatively short surgical incision can be provided to maintain the blood supply to the bone.

[0193] As described above, this inventive implant can be made without complex shapes to accommodate a wide range of applications without the need for extensive bone carpentry or implant bending to avoid implant protrusion at the surgical site. At the same time, the implant can be made with a significant vertical thickness to provide bending strength and stiffness while avoiding soft tissue protrusion.

[0194] Using this inventive construction, reliable fixation can be provided that does not necessarily require extending the fixation and complication risks to unrelated areas, such as across the carpometacarpal joint and the need to place screws into the metacarpals.

[0195] In addition, the specific designs described herein (which are exemplary in nature) provide a wide enough variety of fastener openings and variable fastener angular placement ranges into small bones that may be part of a fusion mass (such as into carpal bones).

[0196] Strategic use and placement of the fasteners can also allow for their removal without substantial bone disruption.

[0197] The foregoing disclosure of specific embodiments is intended to illustrate the broad concepts encompassed by the present invention.

Claims

1. An implant for fusing at least two bone components, the implant comprising: a body including a first anchoring portion and a second anchoring portion, the first anchoring portion including a stem configured to be guided into a first bone component when the first anchoring portion is in an operative position, the first anchoring portion configured to cooperate with at least a first fastener that can be used to fix the stem relative to the first bone component when the first anchoring portion is in its operative position, the second anchoring portion configured to be fixed to at least a second bone component, the second anchoring portion configured such that when in the operative position, at least a portion of the second anchoring portion is located within a cavity created in the at least second bone, the second anchoring portion further configured to cooperate with at least a second fastener that can be used to fix a portion of the second anchoring portion relative to the second bone component, thereby holding the second anchoring portion in its operative position, wherein at least a portion of the second anchoring portion has a cup-shaped wall having a cup-shaped concave surface and an opposing cup-shaped convex surface, the opposing cup-shaped convex surface being guided into a cavity in the at least second bone component so as to be juxtaposed with at least a portion of a surface on the at least second bone component defining the cavity; and wherein the second anchoring portion includes an opening passing through the cup-shaped wall and defined to receive the second fastener, the second fastener being guided through the cup-shaped concave surface and the opposing cup-shaped convex surface of the cup-shaped wall.

2. The implant for fusing at least two bone components according to claim 1, wherein, The stem has an opening therein to cooperate with the first fastener that can be used to fix the stem relative to the first bone component and thereby hold the first anchoring portion in its operative position.

3. The implant for fusing at least two bone components according to claim 2, the implant further combined with a first fastener configured to extend into the first bone component and the stem opening to fix the stem relative to the first bone component.

4. The implant for fusing at least two bone components according to claim 1, wherein, The second anchoring portion has an opening therein through which the second fastener can extend to be guided into the second bone component, thereby fixing a portion of the second anchoring portion relative to the second bone component.

5. The implant for fusing at least two bone components according to claim 4, the implant further combined with a second fastener configured to extend through the opening in the second anchoring portion and into the second bone component to fix a portion of the second anchoring portion relative to the second bone component.

6. The implant for fusing at least two bone components according to claim 1, wherein, The body includes a single rigid piece defining the first anchoring portion and the second anchoring portion.

7. The implant for fusing at least two bone components according to claim 1, wherein, The body has an elongated shape having a length and a width between a first end and a second end, wherein the stem extends to the first end of the body and the second anchoring portion is at the second end of the body.

8. The implant for fusing at least two bone components according to claim 1, wherein, In the case where the second anchoring portion is in its operative position, at least a portion of the surface of the second anchoring portion extending into the cavity has a convex shape.

9. The implant for fusing at least two bone components according to claim 1, wherein, The second anchoring portion has a cup-shaped surface.

10. The implant for fusing at least two bone components according to claim 9, wherein, The cup-shaped surface has a central axis, the body includes an elongated portion defining the stem, the elongated portion extending away from a portion of the second anchoring portion and having a longitudinal centerline, and the longitudinal centerline is offset from the central axis.

11. The implant for fusing at least two bone components according to claim 9, wherein, The cup-shaped surface extends to an edge, and discrete incisions extend through the edge.

12. The implant for fusing at least two bone components according to claim 1, wherein, The cup-shaped wall has a central axis and a convex outer surface that defines a surface on the second anchoring portion that extends into the cavity, and the convex outer surface is symmetric about the central axis and tapers axially.

13. The implant for fusing at least two bone components according to claim 12, wherein, The cup-shaped wall has a plurality of openings through which fasteners can be directed at different angles.

14. The implant for fusing at least two bone components according to claim 12, wherein, The cup-shaped wall has discrete receptacles therein for a quantity of bone graft material.

15. The implant for fusing at least two bone components according to claim 14, wherein, The cup-shaped wall has at least one flat portion, and the discrete receptacles are formed in the flat wall portion.

16. The implant for fusing at least two bone components according to claim 1, wherein, The body is made of polyetheretherketone.

17. The implant for fusing at least two bone components according to claim 1, wherein, The body is made of a metallic material or a non-metallic material that is not a PEEK material.

18. The implant for fusing at least two bone components according to claim 1, wherein, The body has an elongated shape having a length and a width between a first end and a second end, wherein at least a portion of the second anchoring portion is cup-shaped, the stem extends away from the cup-shaped portion of the second anchoring portion to the first end of the body, and another portion of the body extends away from the cup-shaped portion of the second anchoring portion at a location spaced from the location where the stem extends away from the cup-shaped portion of the second anchoring portion.

19. The implant for fusing at least two bone components according to claim 18, wherein, The other portion of the body extends away from the cup-shaped portion of the second anchoring portion in a direction away from the first end of the body.

20. The implant for fusing at least two bone components according to claim 1, wherein, The stem has an elongated shape having a central axis and a generally flat profile approximated by a reference plane containing the central axis, the second anchoring portion has a cup-shaped wall, a flat surface of the cup-shaped wall abuts the second bone member when the second anchoring portion is in its operative position, and the flat surface of the cup-shaped wall is angled relative to the reference plane in two dimensions.

21. The implant for fusing at least two bone components according to claim 1, wherein, At least a portion of the second anchoring portion has a cup-shaped surface with an axis, and the cup-shaped surface has an arcuate shape that extends at least partially around the axis.

22. The implant for fusing at least two bone components according to claim 1, wherein, The second anchoring portion includes a cup-shaped wall having a bottom wall portion, a first connector is provided at the bottom wall portion, and the implant is further combined with a first support member having a second connector, the first connector and the second connector being configured to be engageable to releasably hold the first support member in an operative position on the implant.

23. The implant for fusing at least two bone components according to claim 22, wherein, The cup-shaped wall has an axis, and the first support member is elongated and has a length such that when the first support member is in its operative position, the length of the first support member is aligned with the axis of the cup-shaped wall.

24. The implant for fusing at least two bone members according to claim 1, the implant being combined with a cutting tool that will be operated to produce a predetermined cavity shape in at least a second bone member, wherein when the second anchoring portion is in its operative position, at least a portion of the surface of the second anchoring portion that extends into the cavity is juxtaposed with at least a portion of the surface of the at least second bone member that defines the cavity.

25. The implant for fusing at least two bone components according to claim 24, wherein, The cutting tool includes a reamer having a shaft that is rotated to cause a cutting surface on the reamer to produce a predetermined cavity shape in the at least second bone member.

26. The implant for fusing at least two bone components according to claim 24, wherein, The predetermined cavity shape is cup-shaped.

27. The implant for fusing at least two bone components according to claim 1, wherein, The rod has a plurality of openings therein, each opening of the rod being adapted to cooperate with a fastener that can be used to secure the rod relative to the first bone member, and the implant is further combined with an outer frame guiding assembly that is releasably attached to the implant and has guiding openings to facilitate the controlled formation of a plurality of openings in the first bone member, each opening of the first bone member being capable of being aligned with one of the openings in the rod.

28. The implant for fusing at least two bone components according to claim 27, wherein, One of the openings in the rod is elongate.

29. The implant for fusing at least two bone components according to claim 28, further combined with a first support member, wherein, The outer frame guiding assembly is configured to facilitate the formation of a first opening among the plurality of openings in the first bone member such that the first support member can be guided into the first opening and into one of the elongate rod openings at one end thereof to allow the implant to move relative to the first support member and thereby reside at the opposite end of the one elongate rod opening.

30. The implant for fusing at least two bone components according to claim 1, wherein, The rod has a plurality of openings therein, each opening of the rod being adapted to cooperate with a fastener that can be used to secure the rod relative to the first bone member, and one of the openings in the rod is elongate.

31. The implant for fusing at least two bone components according to claim 24, wherein, The rod has a plurality of openings therein, each opening of the rod being adapted to cooperate with a fastener that can be used to secure the rod relative to the first bone member, and the implant is further combined with an outer frame guiding assembly that is releasably attached to the implant and has guiding openings to facilitate the controlled formation of a plurality of openings in the first bone member, each opening of the first bone member being capable of being aligned with one of the openings in the rod.

32. The implant for fusing at least two bone members according to claim 22, further combined with a second support member that is configured to be connected to the first bone member.

33. The implant for fusing at least two bone components according to claim 32, wherein, The rod has an elongate opening therein through which the second support member can extend.

34. The implant for fusing at least two bone members according to claim 33, further combined with a tool for engaging the first support member and the second support member and pushing the first support member and the second support member toward each other.

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