Systems and instrumentalities for use in removal of tibial prostheses of total ankle replacements

A system comprising instrumentalities and methods for removing intramedullary stem component pieces of a tibial implant from a distal tibia.

FIELD OF THE INVENTION

This invention relates generally to systems and instrumentalities for use in removal of tibial prostheses of total ankle replacements, and, in particular, to systems and instrumentalities for removing a tibial prosthesis having an intramedullary stem.

BACKGROUND OF THE INVENTION

Generally, there are several designs of total ankle replacement prostheses. One type of total ankle replacement prostheses comprises a tibial implant with an elongated intramedullary stem. This type of prosthesis is exemplified by a total ankle replacement prostheses sold by Wright Medical Technology, Inc. (5677 Airline Road, Arlington, Tenn. 38002, USA) under the trademark INBONE Total Ankle System. In this system, the total ankle replacement prostheses is comprised of a tibial implant having an elongated intramedullary stem formed by a plurality of modular stem component pieces, a talar implant, and a polyethylene spacer.

Generally, this system has five sizes of implant sets that are employed as a function of the size of the ankle bones of a particular patient. Additionally, the tibial implant is constructed from different stem component pieces. The inferior part is a tibial tray. This has a set size and morphology specified by the size of the implant set chosen. Superior to this is a base, which also has a set size and morphology specified by the size of the implant set chosen. Superior to this are a variable number and size of stem component pieces that are chosen by the surgeon during the procedure to give the best fit in the tibial intramedullary canal. Furthermore, the talar implant has a set size and morphology specified by the size of the implant set chosen. There is a stem that fits into the inferior portion of the talar implant and extends inferiorly either 10 mm or 14 mm at a defined angle. The choice of which stem length to use is made by the surgeon during the procedure. Moreover, each implant set has a defined number of polyethylene spacers of varying height that fit into the tibial tray on the tibial implant. The height of the spacer to be used is chosen by the surgeon during the procedure, after the tibial and talar implant have been fit into the bones.

During the surgical procedure, the elongated intramedullary stem is constructed by coupling together the plurality of modular stem component pieces through an anterior ankle opening in a space formed between the lower end of the tibia and the upper end of the talus. This construction is performed after bone cuts have been made in those two bones, and the cut sections of bone have been removed to form the space. A second opening in the skin is made on the bottom of the heel, and a channel is drilled up through this skin incision, and then further up through the calcaneus and talus bones. That channel allows passage of instruments that aid in coupling the modular stem component pieces together to form the elongated intramedullary stem of the tibial prosthesis at a desired location in the tibia. The combination of these modular component pieces to form the tibial implant requires an intramedullary approach to the distal tibia.

There is a need to overcome the significant shortcomings in the removal of total ankle replacement prostheses such as the total ankle replacement prostheses delineated above during revision surgical procedures. In particular, there is a need to overcome the significant shortcomings in the removal of the elongated intramedullary stem of the tibial implant from the distal tibia during revision surgical procedures.

Of particular concern in the existing techniques for the removal of the tibial implant is the requirement for large bone windows to be cut into the lower end of the tibia to remove the elongated intramedullary stem component pieces of the tibial implant that have become fixed into the bone during the initial surgical procedures. The result of this bone destruction yields a tibia that makes further reconstructive procedures particularly problematic.

Accordingly, there is a particular need to overcome the significant shortcomings in the removal of the elongated intramedullary stem component pieces of the tibial implant from the distal tibia during revision surgical procedures.

BRIEF SUMMARY OF THE INVENTION

Accordingly, and in one aspect, an embodiment of the invention ameliorates or overcomes one or more of the significant shortcomings of the known prior art by providing a system: instruments and methods for removing intramedullary stem component pieces of a tibial implant from a distal tibia without the requirement for large bone windows to be cut into the lower end of the tibia to remove the intramedullary stem component pieces of the tibial implant for conserving the bone of the distal tibia.

In one aspect, an embodiment of the invention provides a tibial prosthesis removal system: instruments and methods for removing intramedullary stem component pieces of a tibial implant from a distal tibia by forming a channel or passageway through a calcaneus and talus that is aligned with the longitudinal axis of the modular tibial stem component implant even if the modular tibial stem component implant has shifted into a slight angulation off the alignment of the original insertion axis; stabilizing the ankle, foot, and leg of the patient with the modular tibial stem component implant; circumferentially cutting tibia bone circumscribing an inferior most stem component piece of the modular tibial stem component implant by utilizing the aligned channel; unscrewing the inferior most stem piece by utilizing the aligned channel; grasping and removing the unscrewed inferior most stem piece by utilizing the aligned channel, determining if further stem component pieces remain implanted; and repeating the circumferentially cutting, unscrewing, and grasping and removing steps until all implanted stem component pieces have been removed.

Accordingly, it should be apparent that numerous modifications and adaptations may be resorted to without departing from the scope and fair meaning of the claims as set forth herein below following the detailed description of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Introduction

Considering the drawings, wherein like reference numerals denote like parts throughout the various drawing figures, reference numeral3010is directed to a system for use in removal of a tibial stem of total ankle prosthesis such as, but not limited to, total ankle prosthesis370.

The total ankle prosthesis370is sold by Wright Medical Technology, Inc. (5677 Airline Road, Arlington, Tenn. 38002, USA) under the trademark INBONE Total Ankle System and is presently available in five sizes (number 2, 3, 4, 5, or 6), left and right.

A system for use in the total ankle replacement with the total ankle prosthesis370is described in detail in U.S. Patent Application Publication No.: 2010/0262150 and U.S. Patent Application Publication No.: US 2011/0218542, which are both incorporated herein by reference in their entireties as though fully set forth herein and wherein each has the same inventor as the inventor of system3010.

Total Ankle Prosthesis370

In one embodiment, and referring toFIGS. 1 and 2, prosthesis370is comprised of a modular tibial stem component372, a tibial tray component382, a polyethylene or poly insert component384, a talar dome component388, and a talar stem component390.

As illustrated inFIGS. 2 and 3, the talar stem component390is connected to an inferior side of the talar dome component388and extends at a precise angle inferiorly away from the talar dome component388and has, in one embodiment, a 10 mm diameter and is available in 10 and 14 mm lengths.

The talar dome component388includes an upper convex surface that mates with a lower concave surface of the poly insert component384that is carried by the tibial tray component382to form a complementary ball-and-socket type structure.

As illustrated inFIG. 4, the tibial tray component382also comprises oppositely spaced, inwardly tapered side rails440. The side rails440extend in an anterior to posterior direction along the underside442of the tibial tray component382. The tapered side rails440form a channel444between them. The underside442of the tibial tray component382includes a shaped depression or notch446near its anterior edge wherein the shaped depression or notch446is in open communication with the channel444.

As illustrated in5, the modular tibial stem component372comprises a superior stem component piece or segment374, a first medial stem component piece or segment376, a second medial stem component piece or segment378, and an inferior stem component piece or segment380. The stem component pieces or segments range from 14-18 mm in diameter with a typical 4-piece construct measuring 50 mm in length. This is completely customizable per individual patient need. This segmented design allows for a less invasive approach in prosthetic placement, and more robust anchoring; however, the robust anchoring of the stem pieces or segments into the bone of a distal tibia304makes removal of the modular tibial stem component372problematic.

Each of the modular stem component pieces or segments374,376,378, and380includes a respective external circumferential groove375,377,379, and381which may be faceted and which runs along the entire inferior exterior edge of the side of each of the modular stem component pieces or segments374,376,378, and380.

The modular stem component pieces or segments374,376,378, and380each have a specific height and diameter, and different sizes can be combined together to construct the final tibial stem component or tibial prosthetic stem372.

FIG. 6exemplifies a blind bore450that is disposed through an inferior surface452of each tibial stem component piece or segment374,376,378, and380. Each blind bore450includes internal threads454. Each blind bore450has an internal diameter that is configured and sized to receive the outer diameter of a superior threaded protuberance456that extends out of a superior surface458of each stem component piece and includes external threads460that are complemental to the internal threads454in the bore450of each stem component piece or segment374,376,378, and380. This allows the modular stem component pieces or segments374,376,378, and380to be screwed together to form the final tibial stem component or tibial prosthetic stem372.

FIG. 7exemplifies a recessed pattern470disposed in the superior surface or closed end of the blind bore454. In one embodiment, the recessed pattern470has a female cruciate slot pattern or shape.

Referring again toFIG. 1, an embodiment of the tibial prosthesis removal system3010is comprised of a double fork cage260, a tibial tray alignment insert3020, a tuning forked shaped adaptor630, a C-shaped outrigger alignment guide600, a drill bit guide234, a drill bit418, a drill420, a skeleton cage240, a bone cutting means3060, a long handle instrument3190, a long handle insert3230, and a central grasping device3250.

Now referring toFIG. 8, an embodiment of the tibial prosthesis removal system3010is further comprised of a tibial prosthesis removal process3310for removing the in situ tibial or intramedullary stem component372of the total ankle prosthesis370.

Referring toFIGS. 8 and 9, and back toFIG. 1, an embodiment of the tibial prosthesis removal method3310comprises a step3312of utilizing the double fork cage260, the tibial tray insert3020, the tuning forked shaped adaptor630, the C-shaped outrigger alignment guide600, the drill bit guide234, the drill bit418, and the drill420for making a channel3012in the calcaneus360and talus330of a patient that has the in situ tibial or intramedullary stem component372that is to be removed.

Double Fork Cage260

FIG. 10illustrates one embodiment of the double fork cage or first internal frame260of the tibial prosthesis removal system3010. In this embodiment, the double fork cage260is comprised of an anterior frame262having three members outlining three sides of a trapezoid. Specifically, the anterior frame262is comprised of a superior base member264rigidly connected between superior ends of two spaced apart, non-parallel frame members266,268. The anterior frame262is substantially the size of a tibial-talar space342as illustrated inFIG. 11.

Additionally, the double fork frame260is comprised of four spaced apart, generally parallel tines270,272,274, and276that are operatively coupled to and extend posteriorly off the anterior frame262into the superior medial, the superior lateral, the inferior medial, and the inferior lateral edges of the tibial-talar space342. Anterior frame262is comprised of an external handle278that extends off an anterior face of one of three members264,266, or268to aid in manipulating the double fork frame260into and out of position.FIG. 10illustrates the operative connection of the external handle278to the frame member266. The double fork frame260is further comprised of two perforated tabs280,282that can be used to connect the frame260to the tibia300via wires or screws284as illustrated inFIG. 11.

In one embodiment, double fork frame260is made out of, but not limited to, a metal material or polyethylene.

FIG. 12illustrates one embodiment of the tibial tray alignment insert3020of the tibial prosthesis removal system3010. In this embodiment, the alignment insert3020comprises a generally pyramidal frustum shaped or trapezoidally shaped alignment insert body3022that is designed to fit into the tibial-talar space342(FIG. 14) defined as the space between the tibia300and the talus330after the talar dome component388and the talar stem component390have been removed, and the polyethylene or poly insert component384has been removed from the tibial tray component382of the in situ tibial prosthesis396. The tibial tray alignment insert3020corresponds to the size of the chosen prosthesis370to be removed, so if there are five different prosthesis sizes to choose from then there are five different tibial tray alignment insert sizes for providing a one to one correspondence between the two.

Referring toFIGS. 12 and 13, the alignment insert body3022is comprised of six faces: a superior face3024, an inferior face3026, an inner face3028, an outer face3030, a posterior face3032, and an anterior face3034. The superior face3024and the inferior face3026have a generally square or rectangular shape while the inner face3028, outer face3030, posterior face3032, and anterior face3034have a generally trapezoidal shape.

Additionally, and referring toFIG. 12, the alignment insert body3022is comprised a pair of generally parallel and spaced apart notched and recessed patterns forming a pair of generally parallel and spaced apart superior grooves3036and3038. Superior groove3036is defined as the first superior groove3036that extends along the superior longitudinal edge of inner face3028and superior groove3038is defined as the second superior groove3038that extends along the superior longitudinal edge of outer face3030. This groove pattern corresponds to the pair of the spaced apart trackways or inwardly tapered side rails440disposed on the underside or inferior surface442of the tibial tray382of the in situ tibial prosthesis396such that the first and second superior grooves3036,3038are able to respectively slide on the spaced apart trackways or side rails440of the tibial tray382after the poly insert component384has been removed.

Furthermore, and referring toFIG. 12, an embodiment of the alignment insert body3022is further comprised of an upwardly projecting protrusion or detent3040near a superior edge of the anterior face3034.

Referring now toFIGS. 12 and 14, the protrusion or detent3040is sized and configured to rest within the notch446disposed in the underside442of the tibial tray component382.

In one embodiment, the upwardly projecting protrusion or detent3040(FIG. 12) briefly rides against the underside442of the tibial tray component382and then fits into the notch446thereof when the first and second superior grooves3036,3038are respectively slid onto the spaced apart trackways or inwardly tapered side rails440of the tibial tray component382while the stop flange448along the posterior edge of the tibial tray component382precludes over-travel of the tibial tray alignment insert3020in a posterior direction by engaging with the posterior face3032of the alignment insert body3022in an abutting relation.

The abutment of the posterior face3032and the stop flange448is sized and configured to occur in concert with the snap-fit engagement of the protrusion or detent3040within the notch446disposed in the underside442of the tibial tray component382for positioning the tibial tray alignment insert3020into the tibial-talar space342as illustrated inFIG. 15.

Referring now toFIG. 16and in one embodiment of use and operation, the double fork cage260is placed in the tibial-talar space342(FIG. 14).

Then, the tibial tray alignment insert3020is passed through a central anterior open portion286(FIG. 10) of the double fork cage260and coupled to the inferior tibial tray component382as described herein.

The double fork cage260and the tibial tray alignment insert3020remain therein until the channel3012is formed as delineated hereinbelow.

Referring now toFIG. 17, the alignment insert body3022of the tibial tray alignment insert3020is further comprised of two attachment channels3042,3044for respectively receiving a pair of spaced apart furcations or tines638,640of a forked end portion636of a tuning forked shaped adapter630. The two attachment channels3042,3044pass from the anterior surface3034of the alignment insert body3022and may pass through the entire body3022or partially therethrough to a depth that accommodates, but that is limited to, the full length of the tines638,640of the tuning forked shaped adapter630.

Additionally, a width of separation between the channels3042,3044corresponds to the width of separation between the tines638,640on the corresponding tuning fork adapter630as illustrated inFIG. 17.

In one embodiment, the tibial tray alignment insert3020is made out of, but not limited to, a metal material or polyethylene, and is constructed as, but not limited to, an integrally formed one piece insert.

Tuning Fork Shaped Adaptor630

Referring now toFIGS. 17 through 19, and more particularly, the tuning forked shaped adapter630is comprised of a body632having a friction fitting end portion634sized and shaped to be received and frictionally fit within a blind bore614of a friction fitting end610of the C-shaped outrigger alignment guide600as further delineated below.

Additionally, the body632of the tuning forked shaped adapter630includes an opposing forked end portion636comprised of the spaced apart furcations or tines638,640having a specific length for attaching or coupling to the alignment insert body3022of the tibial tray alignment insert3020as delineated above.

The tuning fork shaped adapter630further comprises a stop portion642disposed at a distal end of the friction fitting end portion634of adaptor630for abutting against a front face of a circumscribing wall612of the friction fitting end610of the C-shaped outrigger alignment guide600for precisely locating the tuning fork shaped adapter630onto the C-shaped outrigger alignment guide600as further delineated below.

In one embodiment, a specifically sized tuning fork shaped adapter630can be provided for each different size of each tibial tray alignment insert3020for each different size of chosen prosthesis370. Accordingly, a specific size of the tuning fork shaped adapter630can be provided for each specific size of the tibial tray alignment insert3020such that for each matching set a width between the tines on the adaptor matches a width between corresponding channels of the tibial tray alignment insert. The length of the tines can also be specific to each matching set.

Additionally, and in one embodiment, each tuning fork shaped adapter is made out of, but not limited to, a metal material or polyethylene, and is constructed as, but not limited to, an integrally formed one piece adapter.

Referring toFIG. 19, the C-shaped outrigger alignment guide600is comprised of an arcuate or generally C-shaped body602comprised of a medial section604transitioning at one end to a superior section606and at the other end to an inferior section616.

The superior section606generally perpendicularly extends away from the medial section604in substantially the same plane as the medial section604, and then arches or bends out of the plane of the medial section604and transitions to the superior end or head608supporting a friction fitting610. In one embodiment, the friction fitting610circumferentially steps down from and is integrally formed with the superior end608. The friction fitting end610is comprised of the posteriorly extending wall612circumscribing an interior surface defining the blind bore614. As noted above, the blind bore614is sized to receive and frictionally fit with the complementally shaped end634(FIG. 18) of the tuning forked shaped adaptor630which, in turn, is received by the tibial tray alignment insert3020as delineated above for aligning the C-shaped outrigger alignment guide600in a stable position relative to a central long axis398(FIG. 11) of the in situ tibial prosthesis396and, in particular, the in situ tibial or intramedullary stem component372that is to be removed as will be further delineated below.

The inferior section616generally perpendicularly extends away from the medial section604in substantially the same plane as the medial section604, and then arches or bends out of the plane of the medial section604and transitions to an inferior end618supporting an inferior cylindrically shaped inferior sleeve attachment or distal sleeve620having an open ended cylindrically shaped bore622axially extending therethrough and having a central axis624.

The distal sleeve620is integrally formed with and extends from both sides of the inferior end618, and is spaced from and generally parallel with the medial section604.

The open ended cylindrically shaped bore622of the distal sleeve620is sized to closely receive the inner drill and driver bit guide234having open ended cylindrically shaped interior bore236extending therethrough (FIG. 21). The open ended cylindrically shaped interior bore236of the drill and driver bit guide234is sized to closely receive and pass the drill bit418therethrough.

In an alternative embodiment, the open ended cylindrically shaped bore622of the distal sleeve620is sized to closely receive and pass the drill bit418therethrough without utilizing the drill and driver bit guide234.

In one embodiment, the C-shaped outrigger alignment guide600is made out of, but not limited to, a metal or polyethylene material and is constructed as, but not limited to, an integrally formed one piece guide.

Additionally, and in one embodiment, the drill bit418and guide234are made out of, but not limited to a metal or polyethylene material.

Furthermore, and in another embodiment, the tuning-fork adaptor630and the C-shaped outrigger alignment guide600may be integrally formed together as one piece instrument.

Moreover, and in a further embodiment, the tuning-fork adaptor630, the C-shaped outrigger alignment guide600, and the tibial tray alignment insert3020may be integrally formed together as one piece instrument.

Referring toFIG. 20, and in one embodiment, the central long axis398of the in situ tibial or intramedullary stem component372of the total ankle prosthesis370will align or be coincident with the axis624of the distal sleeve620of the C-shaped outrigger alignment guide600when the posterior face3032of the tibial tray alignment insert3020abuts against the stop flange448of the in situ tibial tray component382, the tines638,640of the tuning fork shaped adapter630are fitted into the respective channels3042,3044disposed in the tibial tray alignment insert3020(FIG. 17) until the anterior surface3034of the tibial tray alignment insert3020is completely seated against the body632(FIG. 18) of the tuning fork shaped adapter630, and the friction fitting634of the tuning fork shaped adapter630is engaged with the friction fitting end610(FIG. 19) of the C-shaped outrigger alignment guide600until the stop portion642of adaptor630abuts against front face of circumscribing wall612of the friction fitting end610of the C-shaped outrigger alignment guide600thereby making the axis624of the distal sleeve620of the C-shaped outrigger alignment guide600coextensive with the central long axis398of the in situ tibial or intramedullary stem component372as illustrated inFIG. 20.

Referring toFIG. 21, and as discussed above, the open ended cylindrically shaped bore622of the distal sleeve620is sized to closely receive the inner sleeve drill and driver bit guide234having open ended cylindrically shaped interior bore236extending therethrough. The open ended cylindrically shaped interior bore236of the drill and driver bit guide234is sized to closely receive and pass a drill bit418therethrough.

In an alternative embodiment, the inner sleeve drill and driver bit guide234is eliminated and the open ended cylindrically shaped bore622of the distal sleeve620is sized to closely receive and pass the drill bit418therethrough.

In one embodiment, the drill bit has a diameter of at least six millimeters (6 mm).

As illustrated inFIGS. 20 and 21, the central axis624of the inferior sleeve attachment or drill guide620is aligned with the central long axis398of the in situ tibial stem component372. With this alignment, an incision is formed on the bottom of the heel at a location on the heel that is axially aligned with the central axis624of the inferior sleeve attachment620of the C-shaped outrigger alignment guide600.

Then, the drill guide234is placed in the inferior sleeve attachment620and the drill bit418having, in one embodiment, at least a 6 mm diameter is driven by drill420up through the calcaneus360and talus330bones as illustrated inFIG. 22, forming or creating the channel3012through bones360,330that comprises a channel axis3014that is substantially coincident or coextensive with the central long axis398of the in situ tibial stem component372as illustrated inFIG. 23.

After the channel2012is formed, the drill bit418is removed from the channel2012.

Next, the drill guide234is removed from the inferior sleeve attachment620of C-shaped outrigger alignment guide600.

This is followed by the sequential removal of the C-shaped outrigger alignment guide600, the tuning fork shaped adapter630, and the tibial tray alignment insert3020.

Then, the inferior tibial tray component382is decoupled from the inferior stem piece380of the chosen prosthesis370and removed.

After the inferior tibial tray component382removed, the double fork cage or first internal frame260is then removed as described below.

Ankle Stabilization

Referring again to the flowchart ofFIG. 8, and with channel3012formed, an embodiment of the tibial prosthesis removal process3310comprises a step3314of utilizing the skeleton cage240for stabilizing at least the ankle of the patient having the in situ tibial or intramedullary stem component372that is to be removed.

The skeleton cage240is configured to fit snugly in the space between the tibia300and talus330defined as the tibial-talar space342.

With the inferior tibial tray component382removed, the double fork cage or first internal frame260can be removed and replaced with the skeleton cage240.

Referring now toFIGS. 24 and 25, and as noted above, an embodiment of the tibial prosthesis removal system3010is comprised of the skeleton cage240which replaces the double fork cage260. The skeleton cage240is comprised of a posterior transverse member242rigidly connected between two superior portions of two spaced apart, rectangularly shaped, and inwardly slanting frames244,246for providing the skeleton cage240with an external shape that is generally congruent with the generally pyramidal frustum shape of the tibial tray alignment insert3020so as to fit snugly in the space between the tibia300and talus330defined as the tibial-talar space342as illustrated inFIG. 25.

In one embodiment, the skeleton cage240has an external handle248operatively connected to and extending from an anterior edge of at least one of frame members244,246to aid in manipulating the skeleton cage240into and out of the tibial-talar space342.FIGS. 24 and 25illustrate the operative coupling of the external handle248to the outer frame member244.

Additionally, the skeleton cage240is comprised of two perforated tabs252,254that can be used to connect the skeleton cage240to the tibia via wires or screws256as illustrated inFIG. 25.

In one embodiment, each skeleton cage is made out of, but not limited to, a metal material or polyethylene.

Circumferentially Cutting Tibia Circumscribing Inferior Most Stem Piece

Referring again toFIG. 8, and with channel3012formed and the ankle is stabilized with the skeleton cage240, an embodiment of the tibial prosthesis removal process3310comprises a step3316of circumferentially cutting the tibia bone circumscribing an inferior most stem piece of the in situ tibial or intramedullary stem component372for forming a circumscribing tibia bone cut around the inferior most stem piece.

Referring now toFIG. 26, an embodiment of the bone cutting means3060is in the form of, but not limited to, an offset chisel device3070having a central longitudinal axis3072. The offset chisel device3070is comprised of an elongated shaft3074and a chisel head portion3082. The elongated shaft3074is sized and configured to pass through the channel3012formed in the calcaneus360and talus330and up through the tibial-talar space342. In one embodiment, the elongated shaft3074is cylindrically shaped with a diameter that slideably fits within channel3012. Additionally, the elongated shaft3074comprises a threaded proximal end3076that is sized to pass through channel3012and an opposing distal end3078that, in one embodiment, terminates to a handle3080for grasping.

FIG. 27illustrates the chisel head portion3082of the offset chisel device3070. The chisel head portion3082is comprised of a hollow annular base3084having a central threaded interior surface3086defining a central opening for the threaded proximal end3076of the elongated shaft3074to pass into and threadedly couple therewith such that the central longitudinal axis of the shaft is coincident with a central longitudinal axis of the hollow annular base3084. Offset from the opening of the hollow annular base3084is a chisel3088. The chisel3088includes an offset portion3090upwardly and outwardly diverging from the exterior surface of the hollow annular base3084and a cutting portion or blade3092upwardly transitioning away from the offset portion3090in a direction that is parallel with the central longitudinal axis3072of the offset chisel device3070or, in other words, the central longitudinal axis of the hollow annular base3084and elongated shaft3074. The cutting portion or blade3092of the chisel3088is formed with at least a superior sharp edge3094and has a radius of curvature3096that matches the radius of curvature of the most inferior tibial stem piece as illustrated inFIG. 28.

As also illustrated inFIG. 29, the offset portion3090is such that the central longitudinal axis3072of the offset chisel device3070and the central long axis398of the in situ tibial or intramedullary stem component372are coextensive or coincident with one another. In this configuration, the chisel3088should then just pass beyond the vertical surface of the most inferior tibial stem piece and be configured to have a length that just passes beyond the vertical surface of the body of the most inferior tibial stem piece. Accordingly, the offset chisel device3070that is used at any given time is sized in accordance with the size of the most inferior tibial stem piece that is currently being removed.

The offset chisel device3070is designed to be assembled by passing the elongated shaft3074through the channel3012and then have the chisel head portion3082placed into the tibial-talar space342from the anterior incision and central anterior open portion250(FIG. 24) of the skeleton cage or frame240. The threaded proximal end3076of the elongated shaft3074then engages the central threaded interior surface3086of the hollow annular base3084of the chisel head portion3082. The offset chisel device3070is then reciprocated to free any bone around the sides of the inferior most stem piece of the in situ tibial or intramedullary stem component372that is to be removed. Preferably, the height of the cutting portion or blade3092is approximately the height of the inferior most stem piece of the in situ tibial or intramedullary stem component372. It cannot be substantially larger, because it must be small enough to fit into the tibial-talar space342.

In one embodiment, each offset chisel device is made out of, but not limited to, a metal material.

Referring now toFIG. 30, and in another embodiment, the bone cutting means3060is in the form of, but not limited to, a cylindrical saw device3100having a central longitudinal axis3102. The cylindrical saw device3100is comprised a cylindrical saw head3114detachably coupled to a cylindrical saw driver3104.

The cylindrical saw driver3104is comprised of an elongated shaft3106sized and configured to pass through the channel3012formed in the calcaneus360and talus330and up through the tibial-talar space342.

In one embodiment, the elongated shaft3106is cylindrically shaped with a diameter that slideably fits within channel3012.

Additionally, the elongated shaft3106comprises a threaded proximal end3108that is sized to pass through channel3012and an opposing distal end3110that, in one embodiment, terminates to a handle3112for grasping and rotating the cylindrical saw device3100.

In one embodiment, the cylindrical saw driver3104is made out of, but not limited to, a metal material.

As noted above, and referring toFIG. 31, the cylindrical saw device3100is further comprised of the cylindrical saw head3114. The cylindrical saw head3114comprises an inferior circular base3116having an outer circumscribing periphery3117transitioning into a cylindrically shaped side wall3118arising from the inferior circular base3116forming a shell of a cylinder and defining an internal cylindrically shaped cavity3120. The cylindrically shaped side wall3118terminates to superior circular cutting edge or cutting rim3122.

There are different sizes of the cylindrical saw head3114corresponding to the different sizes of the modular stem component pieces or segments374,376,378, and380of modular tibial stem component372. The chosen saw diameter and depth should allow the most inferior tibial stem component piece that is being removed to fit within the cavity3120of the cylindrical saw head3114. Thus, for each modular stem component piece or segment, the internal diameter of the cylindrical saw head3114or the diameter of cavity3120, should be just greater than the diameter of the most inferior tibial stem component piece being removed, and the internal depth of the cylindrical saw head3114or cavity3120minus the height of an interior portion of an interior protruding member3124should be just greater than the height of the most inferior tibial stem component piece being removed.

Preferably, the cylindrical saw had3114has a very thin cylindrically shaped side wall for ensuring that the kerf of the circumscribing bone cut from the sides of the most inferior tibial stem component is minimal during removal of the most inferior tibial stem component piece or segment.

Still referring toFIG. 31, the cylindrical saw head3114further comprises the hollow cylindrically shaped protruding member3124extending superiorly and inferiorly from the surfaces of the circular base3116. The protruding member3124comprises a circular opening3126extending therethrough and defined by a central threaded interior surface3128having threads complemental to the threaded proximal end3108of the cylindrical saw driver3104for threadedly coupling thereto.

In one embodiment, the cylindrical saw head3114is made out of, but not limited to, a metal material.

Referring now toFIGS. 30 through 32, the cylindrical saw device3100is designed to be assembled by passing the elongated shaft3106of the cylindrical saw driver3104through the channel3012and into the tibial-talar space342(FIG. 25) and then have the cylindrical saw head3114placed into this space from the anterior incision and central anterior open portion250(FIG. 24) of the skeleton cage or frame240. The threaded proximal end3108of the elongated shaft3106then engages the central threaded interior surface3128of the protruding member3124of the cylindrical saw head3114. The cylindrical saw device3100is put into place over the most inferior tibial stem component piece or segment being removed and rotated for cutting a circumscribing cut around and adjacent to the exterior circumscribing side surface of the most inferior tibial stem component piece or segment of the in situ tibial or intramedullary stem component372that is to be removed.

In another embodiment, the cylindrical saw driver3104is devoid of the handle3112adjacent distal end3110such that the distal end3110can be operatively coupled to and driven by drill420(FIG. 21) for rotating cylindrical saw head3114for cutting a circumscribing cut around and adjacent to the exterior circumscribing side surface of the most inferior tibial stem component piece or segment of the in situ tibial or intramedullary stem component372that is to be removed.

Cylindrical Saw and Threaded Centering Device3130

Referring now toFIG. 33, and in another embodiment, the bone cutting means3060is in the form of, but not limited to, a cylindrical saw and threaded centering device3130having a central longitudinal axis3132. The cylindrical saw and threaded centering device3130is comprised of a cylindrical saw head3134, a cylindrical saw driver3154, and a centering device3170.

The cylindrical saw head3134comprises an inferior circular base3136having an outer circumscribing periphery transitioning into a cylindrically shaped side wall3138arising from the inferior circular base3136forming a shell of the cylindrical saw head3134and defining an internal cylindrically shaped cavity or socket3140. The cylindrically shaped side wall3138terminates to a superior circular cutting edge or cutting rim3142.

The cylindrical saw head3134further comprises a hollow cylindrically shaped interior protruding member3144extending superiorly from the inferior circular base3136and an exterior protruding member3146extending inferiorly from the inferior circular base3136and axially aligned with the interior protruding member3144. The exterior protruding member3146having a centrally located and axially elongated slot3148disposed therein.

Additionally, the axially aligned interior and exterior protruding members3144and3146, and the inferior circular base3136, comprise a central circular opening or bore3150extending therethrough. The central circular opening or bore3150is parallel to the cylindrically shaped side wall3138and perpendicular to the inferior circular base3136.

Furthermore, the central axis of the central circular opening3150is axially aligned or coincident with the central longitudinal axis3132of the cylindrical saw and threaded centering device3130.

Analogous to the cylindrical saw head3114, the cylindrical saw head3134is provided in different sizes corresponding to the different sizes of the modular stem component pieces or segments374,376,378, and380of modular tibial stem component372.

The chosen saw diameter and depth should allow the most inferior tibial stem component piece that is being removed to fit within the cavity or socket3140of the cylindrical saw head3134.

Thus, for each modular stem component piece or segment, the internal diameter of the cylindrical saw head3134or the diameter of cavity3140, should be just greater than the diameter of the most inferior tibial stem component piece being removed, and the internal depth of the cylindrical saw head3114or cavity3140minus the height of the interior protruding member3144should be just greater than the height of the most inferior tibial stem component piece being removed.

Furthermore, the cylindrical saw head3134has a very thin cylindrically shaped side wall for ensuring that the kerf of the circumscribing bone cut from the sides of the most inferior tibial stem component is minimal during removal of the most inferior tibial stem component piece or segment.

In one embodiment, the cylindrical saw head3134is made out of, but not limited to, a metal material.

Still referring toFIG. 33, and as noted above, the cylindrical saw and threaded centering device3130is further comprised of the cylindrical saw driver3154. The cylindrical saw driver3154is comprised of a cylindrically shaped elongated shaft3156sized and configured to pass through the channel3012formed in the calcaneus360and talus330and up through the tibial-talar space342. In one embodiment, the elongated shaft3156is cylindrically shaped with a diameter that slideably fits within channel3012. Additionally, the elongated shaft3156comprises a proximal end3158that transitions into a tab or key head3160. Opposing the proximal end3158is a distal end3162of the elongated shaft3156. The elongated shaft3156is hollow with a bore3164extending therethrough. The bore3164has a diameter substantially equal to the diameter of the circular opening3150of the cylindrical saw head3134and has a longitudinal axis that is centrally located along the central long axis of the elongated shaft3156.

As illustrated inFIG. 33, the central axis of the elongated shaft3156and thus, the hollow bore3164, is axially aligned or coincident with the central longitudinal axis3132of the cylindrical saw and threaded centering device3130.

In one embodiment, the distal end3162of the elongated shaft3156is operatively coupled to and driven by drill420for rotating the cylindrical saw head3134while the threaded centering device3170remains stationary.

In one embodiment, the cylindrical saw driver3154is made out of, but not limited to, a metal material.

Still referring toFIG. 33, and as noted above, the cylindrical saw and threaded centering device3130is further comprised of the threaded centering device3170. The threaded centering device3170comprises an elongated pin shaft3172having a diameter that is just less than both the diameter of the central circular opening3150of the cylindrical saw head3134and the diameter of the central bore3164of the cylindrical saw driver3154for being closely received therein as further delineated below. The elongated pin shaft3172of the threaded centering device3170includes a lower or distal end3174and an opposing upper or proximal end3176.

In one embodiment, the length of the elongated pin shaft3172is such that it is just greater than the distance between the inferior or lowermost surface of the exterior protruding member3146and the superior or uppermost surface of the cutting edge or cutting rim3142of the cylindrical saw head3134.

The threaded centering device3170is further comprised of a threaded head3178centered and mounted on the upper or proximal end3176of the elongated pin shaft3172. The threaded head3178includes an inferior surface having a patterned recess or notch3180disposed therein. In one embodiment, the patterned recess3180is in the form of a female cruciate slot pattern or configuration.

In one embodiment, the threaded centering device3170is made out of, but not limited to, a metal material or polyethylene.

Long Handle Instrument3190

Referring now toFIG. 34, and as noted above, the tibial prosthesis removal system3010is further comprised of the long handle instrument3190. The long handle instrument3190is comprised of a cylindrically shaped elongated shaft3192sized and configured to pass through the channel3012formed in the calcaneus360and talus320and up through the tibial-talar space342.

Additionally, the elongated shaft3192comprises a proximal end3194that transitions into a male patterned blade or head3196that is complemental to patterned recess3180. In one embodiment, the male patterned blade3196is in the form of a male cruciate pattern or configuration complemental to the female cruciate slot pattern or configuration of one embodiment of the patterned recess3180for receipt thereby. Opposing the proximal end3194is a distal end3198of the elongated shaft3192. The distal end3198transitions into a handle3200of the elongated shaft3192.

Furthermore, the elongated shaft3192is hollow with a bore3202extending therethrough along a central long axis3204of the elongated shaft3192. The bore3202has a diameter just greater than the diameter of the elongated pin shaft3172of the threaded centering device3170such that the elongated pin shaft3172can be received therein as illustrated inFIG. 35.

More specifically, and referring toFIGS. 35 and 36, the long handle instrument3190is configured to pass through the channel, receive the elongated pin shaft3172into its bore3202, and engage with the threaded centering device3170by way of an abutment between the male patterned blade3196of the long handle instrument3190and the patterned recess3180of the threaded centering device3170. After the abutment is made, the long handle instrument3190is rotated clockwise to screw the threaded centering device3170into the inferior threaded bore of the most inferiorly located tibial stem component piece and then, the long handle instrument3190is disengaged from the threaded centering device3170as illustrated inFIG. 36.

Referring toFIGS. 33 and 37, the cylindrical saw and threaded centering device3130is designed to be assembled by passing the elongated shaft3156of the cylindrical saw driver3154through the channel3012and into the tibial-talar space342and then tilting and placing the cylindrical saw head3134into this space from the anterior incision and central anterior open portion250of the skeleton cage or frame240. With the cylindrical saw head3134tilted, the elongated pin shaft3172is passed into the cavity3140of the cylindrical saw head3134. Then, cylindrical saw head3134is up righted and the elongated pin shaft3172is aligned with and passed through the circular opening3150. Next, the key head3160of the elongated shaft3156is mated with slot3148of the cylindrical saw head3134with the elongated pin shaft3172being received within the hollow bore3164of the elongated shaft3156of the cylinder saw driver3154operatively coupled to drill420to be driven thereby.

As illustrated inFIG. 38, the cylindrical saw head3134is put into place over the most inferior tibial stem component piece or segment being removed and rotated by drill420for cutting a circumscribing cut around and adjacent to the exterior circumscribing side surface of the most inferior tibial stem component piece or segment of the in situ tibial or intramedullary stem component372that is to be removed.

With the circumscribing cut accomplished and the cylindrical saw driver3154and cylindrical saw head3134removed, the cylindrically shaped elongated shaft3192of the long handle instrument3190is again passed up through the channel3012to remove the threaded centering device3170in a manner opposite to its insertion as described above and illustrated inFIGS. 39 and 40.

In one embodiment, the long handle instrument3190is made out of, but not limited to, a metal material.

Cylindrical Saw and Patterned Centering Device3210

Referring now toFIGS. 41 and 42, and in another embodiment, the bone cutting means3060is in the form of, but not limited to, a cylindrical saw and patterned centering device3210having a central longitudinal axis3212. The cylindrical saw and threaded centering device3210is comprised of a cylindrical saw head3214, a cylindrical saw driver taking the form of the long handle instrument3190, a long handle insert3230, and a patterned head centering device3240.

Referring toFIG. 41, the cylindrical saw head3214comprises an inferior circular base3216having an outer circumscribing periphery transitioning into a cylindrically shaped side wall3218arising from the inferior circular base3216forming a shell of the cylindrical saw head3214and defining an internal cylindrically shaped cavity or socket3220. The cylindrically shaped side wall3218terminates to a superior circular cutting edge or cutting rim3222.

The cylindrical saw head3214further comprises a hollow cylindrically shaped protruding member3224extending superiorly and inferiorly from the inferior circular base3216. The protruding member3224includes an inferior surface having a patterned recess or notch3226disposed therein. In one embodiment, the patterned recess3226is in the form of a female cruciate slot pattern or configuration.

Additionally, the protruding member3224and the inferior circular base3216comprise a central circular opening or bore3228extending therethrough. The central circular opening or bore3228is parallel to the cylindrically shaped side wall3218and perpendicular to the inferior circular base3216. Furthermore, the central axis of the central circular opening3228is axially aligned or coincident with the central longitudinal axis3212of the cylindrical saw and patterned centering device3210.

Analogous to the cylindrical saw heads3114and3134, the cylindrical saw head3214is provided in different sizes corresponding to the different sizes of the modular stem component pieces or segments374,376,378, and380of modular tibial stem component372.

The chosen saw diameter and depth should allow the most inferior tibial stem component piece that is being removed to fit within the cavity or socket3220of the cylindrical saw head3214as delineated with respect to cylindrical saw heads3114and3134.

Furthermore, the cylindrical saw head3214has a very thin cylindrically shaped side wall for ensuring that the kerf of the circumscribing bone cut from the sides of the most inferior tibial stem component is minimal during removal of the most inferior tibial stem component piece or segment.

In one embodiment, the cylindrical saw head3214is made out of, but not limited to, a metal material.

Referring toFIGS. 34 and 41, and as noted above, the cylindrical saw and patterned centering device3210is further comprised of a cylindrical saw driver which takes the form of the long handle instrument3190which has been described in detail hereinabove and which is illustrated inFIG. 34.

Long Handle Insert3230

Referring toFIG. 41, and as noted above, the cylindrical saw and patterned centering device3210is further comprised of the long handle insert3230. In one embodiment, the long handle insert3230is comprised of a pin like cylindrical shaft3232sized with a diameter that can be received through the inferior opening of the central bore3202of the long handle instrument3190and with a length that just exceeds the length of the long handle instrument3190so that insert3230can pass through the superior opening of the central bore3202of the long handle instrument3190. The cylindrical shaft3232includes a superior end3234and an opposing inferior end3236that transitions into a knob3238centered on the shaft3232and that allows the long handle insert to be grasped by fingers.

In one embodiment the long handle insert3230is made out of, but not limited to, a metal material.

Referring toFIG. 41, and as noted above, the cylindrical saw and patterned centering device3210is further comprised of the patterned head centering device3240.

The patterned head centering device3240comprises an elongated pin shaft3242having a diameter that is just less than both the diameter of the central circular opening3228of the cylindrical saw head3214and the diameter of the central bore3202of the long handle instrument3190for being closely received therein. In one embodiment, the length of the elongated pin shaft3242is such that it is just greater than the cylindrical saw head3214.

The patterned head centering device3240is further comprised of a patterned head3248centered and mounted on the upper or proximal end3246of the elongated pin shaft3242. In one embodiment, the patterned head3248is in the form of a male cruciate slot pattern or configuration complementally shaped to be received by the recessed pattern462of the inferior most tibial stem component piece or segment of the in situ tibial or intramedullary stem component372that is to be removed.

Referring toFIG. 42, the use of the cylindrical saw and patterned centering device3210generally follows that of the cylindrical saw and threaded centering device3130. Specifically, the cylindrical saw and patterned centering device3210is designed to be assembled by passing the elongated shaft3192of the long handle instrument3190through the channel3012and into the tibial-talar space342and then tilting and placing the cylindrical saw head3214into this space from the anterior incision and central anterior open portion250of the skeleton cage or frame240. With the cylindrical saw head3214tilted, the elongated pin shaft3242is passed into the central circular opening3228of the cylindrical saw head3214. Then, cylindrical saw head3214is up righted and the elongated pin shaft3242is aligned with and passed through the circular opening3228. Next, the male patterned blade3196of the long handle instrument3190is mated with the patterned recess3226of the cylindrical saw head3214while the elongated pin shaft3242is received within the hollow bore3202of the elongated shaft3192of the long handle instrument3190via a superior opening of the hollow bore3202. Then, the superior end3234is received within the hollow bore3202of the elongated shaft3192of the long handle instrument3190via an inferior opening of the hollow bore3202and is pushed superiorly until abutting against the elongated pin shaft3242of the patterned head centering device3240. In this configuration, and with the knob3238of the long handle insert3230pressed up against the handle3200of the long handle instrument3190, the handle3200is utilized to place the cylindrical saw head3214in place over the most inferior tibial stem component piece or segment being removed and is rotated by for cutting a circumscribing cut around and adjacent to the exterior circumscribing side surface of the most inferior tibial stem component piece or segment of the in situ tibial or intramedullary stem component372that is to be removed.

Unscrewing Inferior Most Tibial Stem Component Piece

Referring again toFIG. 8, and with the circumscribing cut accomplished and the embodiment of the bone cutting means3060removed, an embodiment of the tibial prosthesis removal process3310comprises a step3318of unscrewing the most inferior tibial stem component piece or segment of the in situ tibial or intramedullary stem component372utilizing the aligned channel3012.

Referring toFIGS. 43 and 44, and in one embodiment, the cylindrically shaped elongated shaft3192of the long handle instrument3190is again passed up through the aligned channel3012to unscrew the most inferior tibial stem component piece or segment of the in situ tibial or intramedullary stem component372as illustrated.

Grasping and Removing Inferior Most Tibial Stem Component Piece

Referring again toFIG. 8, and with the most inferior tibial stem component piece or segment of the in situ tibial or intramedullary stem component372unscrewed, an embodiment of the tibial prosthesis removal process3310comprises a step3318of grasping and removing the unscrewed inferior most tibial stem component piece or segment of the in situ tibial or intramedullary stem component372by utilizing the aligned channel3012.

Referring toFIGS. 45 through 50, and as noted above, the tibial prosthesis removal system3010is comprised of a grasping means in the form of the central grasping device3250which is utilized as necessary to grasp, remove, and perhaps further unscrew the unscrewed inferior most tibial stem component piece or segment of the in situ tibial or intramedullary stem component372by utilizing the aligned channel3012.

Referring toFIG. 45, the central grasping device3250is comprised of an elongated chamber member3252having a longitudinal axis, an open distal end, and an open proximal end which transitions into a support handle3254terminating in an inferior finger loop3256. Additionally, the central grasping device3250comprises a pivot handle3258having a superior end3260pivotally coupled to the support handle3254via handle pivot pin3262at a location proximate the open proximal end of the elongated chamber member3252. Furthermore, the pivot handle3258comprises an inferior finger loop3264. Moreover, the central grasping device3250comprises an actuator3266slideably disposed within the elongated chamber member3252. Actuator3266includes a proximal end3268connected to the superior end3260of the pivot handle3258and a distal end3270having a groove3272disposed therein.

Referring toFIG. 46, the central grasping device3250further comprises two tines3274,3276that are mirror images of each other. On a distal end of each of the two tines3274,3276are respective outwardly facing grooves or threads3278,3280that preferably correspond to the internal threads454of the bore450of each of the modular stem component pieces or segments374,376,378, and380. Adjacent a medial portion of each of the two tines3274,3276is an elongated hole3282passing through the two tines3274,3276with a fixed pin3284closely fitted therein so that the two tines3274,3276can pivot thereabout. Adjacent a proximal portion of tine3274is an elongated hole3288passing through the tine3274with a fixed pin3292closely fitted therein to provide a slidable coupling between the actuator3266and the tine3274at a location within the groove3272of the actuator3266. Adjacent a proximal portion of tine3276is an elongated hole3286passing through the tine3276with a fixed pin3290closely fitted therein to provide a slidable coupling between the actuator3266and the tine3276at a location within the groove3272of the actuator3266.

Accordingly, when the pivot handle3258is in an unactuated state or position as illustrated inFIGS. 45, 46, and 49the two tines3274,3276are brought together as illustrated inFIG. 46. When the two tines3274,3276are brought together, the distance between the outer surfaces of the threads must be less than the internal diameter of the bore in the most inferior tibial stem piece as illustrated inFIG. 49.

Conversely, when the pivot handle3258is squeezed toward the support handle3254, the actuator3266slides forward within the elongated chamber member3252and the two tines3274,3276slideably coupled thereto are separated as illustrated inFIGS. 47, 48, and 50with the outwardly facing grooves or threads3278,3280radially outwardly separating from one another and with the proximate ends thereof being allowed to separate apart because of the groove3272of the actuator3266. Thus, as the handles3254,3258are squeezed together, the actuator3266gets pushed distally thereby spreading the two tines3274,3276apart and as the handles3254,3258are pulled apart, the actuator3266pulled back causing the two tines3274,3276to come together.

In one embodiment, the central grasping device3250is formed from, but not limited to, a metal material. Additionally, an embodiment of the elongated chamber member3252has an outer diameter that is less than six millimeters.

Referring toFIG. 49, the elongated chamber member3252is passed through the aligned channel3012with the tines3274,3276together. Still together, the tines3274,3276are located within the threaded blind bore450of the most inferior tibial stem component piece or segment of the in situ tibial or intramedullary stem component372. Next, and as illustrated inFIG. 50, the handles3254,3258are squeezed together thereby spreading the outwardly facing grooves or threads3278,3280of the two tines3274,3276into engagement with the threads454of the threaded blind bore450of the most inferior tibial stem component piece or segment of the in situ tibial or intramedullary stem component372. With the handles3254,3258squeezed together and the outwardly facing grooves or threads3278,3280of the two tines3274,3276engaged with the threads454of the threaded blind bore450, the most inferior tibial stem component piece or segment of the in situ tibial or intramedullary stem component372is grasped and can be further unscrewed if necessary and pulled down into the tibial-talar space342for removal.

Removing Remaining Tibial Stem Component Pieces or Segments

Referring again toFIG. 8, the tibial prosthesis removal process3310comprises a step3322of deciding if further tibial stem component pieces or segments remain implanted. If further tibial stem component pieces or segments do not remain implanted, then the process3310ends at step3324. If further tibial stem component pieces or segments do remain implanted, then the process3310loops back to step3316and repeats steps3316,3318, and3320until all of the tibial stem component pieces or segments have been removed.

In Use and Operation

In use and operation, and referring to the drawings, an embodiment of the tibial prosthesis removal system3010is illustrated for removing an embodiment of a tibial prosthesis having an intramedullary stem372comprised of a plurality of modular tibial stem component pieces disposed in a tibial blind bore328. Following an anterior ankle skin incision, the polyethylene insert component384, the talar dome component388, and the talar stem component390are removed from the in situ total ankle prosthesis370while the modular tibial stem component372comprised of a plurality of stem component pieces and the tibial tray component382remain in situ as illustrated inFIG. 14.

With these components removed, a method of use and operation of the system3010for removing the modular tibial stem component372comprises a step of forming a channel3012through the talus330and the calcaneus360that is substantially axially aligned with the longitudinal axis398of the in situ tibial stem component372even if the modular tibial stem component372has shifted into a slight angulation off the alignment of the original insertion axis for allowing a series of instruments, as will be delineated herein, to pass through the channel3012to aid in removing the plurality of stem pieces of the modular tibial stem component372. In one embodiment, the channel is substantially about 6 mm in diameter to allow for passage of the series of instruments.

More particularly, and in one embodiment, the channel forming step comprises placing the double fork frame260in the tibial-talar space342for holding the bones apart and allowing access to the tibial tray component382.

Then, the channel forming step comprises locating the tibial tray alignment insert3020into the tibial tray component382by sliding the grooves3036,3038of the tibial tray alignment insert3020onto the pair of the spaced apart trackways440of the tibial tray382such that the grooves slide on the trackways while the upwardly projecting detent member3040slides in the channel in an anterior to posterior direction until the detent member3040encounters the notch446and snap-fits thereto while the stop flange448along the posterior edge of the tibial tray382precludes over-travel in a posterior direction by engaging with the posterior face3032of the tibial tray alignment insert3020in an abutting relation. The engagement of the stop flange448and posterior face3032is sized and configured to occur in concert with the snap-fit engagement of the detent member3040within the notch446.

Then, the channel forming step comprises coupling the tuning fork shaped adaptor630to the C-shaped outrigger alignment guide600and fitting or coupling the C-shaped outrigger alignment guide600to the tibial tray alignment insert3020through the tuning fork shaped adaptor630wherein this coupling aligns the central axis624of the inferior sleeve attachment or drill guide620with the longitudinal axis398of the in situ tibial stem372.

Then, the channel forming step comprises making an incision on the bottom of the heel at a location on the heel that is axially aligned with the inferior sleeve attachment620of the C-shaped outrigger alignment guide600.

Next, the channel forming step comprises placing the drill guide234in the inferior sleeve attachment620and utilizing a drill bit418having, in one embodiment, at least a 6 mm diameter for drilling up through the calcaneus360and talus330bones, forming or creating the channel3012through these bones360,330that comprises a channel axis3014that is substantially centered along the longitudinal axis398of the modular tibial stem component372.

With the channel3012formed, and in one embodiment, the next step of the method of use and operation of the system3010comprises removing the drill bit418from the drill guide234and then removing the drill guide234, the C-shaped outrigger alignment guide600, and the tibial tray alignment insert3020together or separately.

The next step of the method of use and operation of the system3010comprises removing the tibial tray component382from the inferior stem piece380of the modular tibial stem component372.

Then, placing the skeleton cage240into the tibial-talar space342for holding the bones apart for allowing access to the most inferior tibial stem piece.

In one embodiment, the next step of the method of use and operation of the system3010comprises utilizing the bone cutting means3060as delineated hereinabove for cutting the tibial bone attached to the walls of the most inferior tibial stem piece until the bone has been cut completely away from the most inferior tibial stem piece circumferentially. The next step of the method of use and operation of the system3010comprises the removal of the bone cutting means3060.

Then, passing the long handle instrument3190back up through the channel3012and into the intramedullary passageway and rotating the long handle instrument3190as necessary for abuttingly and complementally engaging the patterned blade mounted on the superior end of the long handle insert with the patterned notch on the blind bore end of the most inferior tibial stem piece380,378,376, or374. Next, rotating the long handle instrument3190for unscrewing the most inferior tibial stem piece from the remaining stem piece above it. Then, removing the long handle instrument3190from the intramedullary passageway and channel3012and the most inferior tibial stem piece from the tibial-talar space342. If the stem piece remains in the intramedullary passageway, the next step is comprised of passing the central grasping device upward through the channel in the calcaneus and talus and into the intramedullary passageway for grasping the most the most inferior tibial stem piece as illustrated inFIGS. 49 and 50and positioning the most inferior tibial stem piece into the tibial-talar space342for removal through the anterior skin incision.

In an alternative use, the central grasping device may be employed to grasp the most inferior tibial stem piece that has not been unscrewed and pulling the central grasping device for locating the unscrewed inferior tibial stem piece in the tibial-talar space342, disengaging the central grasping device from the unscrewed most inferior tibial stem piece, unscrewing the most inferior tibial stem piece, and removing the unscrewed inferior tibial stem piece from the tibial-talar space342through the anterior skin incision.

In another alternative use, the central grasping device engages most inferior tibial stem piece before it is unscrewed or after it has been partially unscrewed from the remaining tibial stem372, and the central grasping device is rotated to unscrew the most inferior tibial stem piece from the remaining tibial stem372.

The next tibial stem piece in the tibial stem372then becomes the most inferior tibial stem piece. It is then treated with the method as above and this method is repeated until all of the tibial stem pieces have been removed.

The above delineation of the system3010and its method3310, and its use and operation, demonstrates the industrial applicability of this invention.

Moreover, it should be apparent that numerous modifications and adaptations may be resorted to without departing from the scope and fair meaning of the instant invention as set forth hereinabove and as described herein below by the claims.