Rail-Fixing Implant

In an implant device for insertion in a joint having confronting first and second bones, which includes the following:

• an implant body having a substrate-interfacing element and, on an opposite side of the body but not confronting said element, a working surface configured to face the second bone and to be disposed in a predetermined position relative to the first bone when implanted;
• and
• a transversely elongated stem on the body having leading and pursuing ends for implantation in an elongated, resected passage of the first bone when the elongated, resected passage of the first bone:
• projects in a direction transverse to an axis generally perpendicular to the confrontation of the first and second bones;
• has respective first and second ends, at least the first end being open;
• has two opposing lateral walls, at least one lateral wall of which with a surface facing the first end to provide a laterally disposed feature for providing stopping of a transversely elongated stem having leading and pursuing ends inserted therein, with the leading end thinner laterally than the pursuing end;
• and
• optionally, projects in an anterior to posterior direction;
• wherein:
• the stem is configured to complementarily fit the resected passage in the first bone, and includes two opposing side walls for respectively engaging the two lateral walls of the elongated, resected passage, with at least one side wall of the two opposing side walls that can engage the aforesaid at least one lateral wall of the elongated, resected passage of the first bone to provide for stopping of the stem therein and to maintain the working surface in a predetermined position when the stem is inserted into the elongated,
• resected passage of the first bone from the first end thereof and the working surface is positioned in the predetermined position;
• the leading and pursuing ends of the stem are each in a form of a wall that projects in its entirety substantially perpendicular from the substrate-engaging element;
• the leading end of the stem is thinner laterally than the pursuing end of the stem;
• the two opposing side walls of the stem angle laterally outwardly away from one another from a first location by the implant body to a second location spaced apart from the implant body so as to form a first tapered dovetail configuration;
• and
• the stem is configured to angle the two opposing side walls from the leading end to the pursuing end laterally outwardly away from one another at an angle about from 1 to 10 degrees—
• the improvement which comprises:
• in addition to the transversely elongated stem, which is designated a first transversely elongated stem, provision of a second transversely elongated stem, which is spaced apart from the first transversely elongated stem so as to form a transverse rail stem system including a plurality of separate transverse rails, wherein the second transverse stem has second transverse stem leading and pursuing ends for implantation in a second elongated, resected passage of the first bone when the second elongated, resected passage of the first bone:
• projects in a direction transverse to the axis generally perpendicular to the confrontation of the first and second bones;
• has respective third and fourth ends, at least the third end being open;
• has two opposing lateral walls;
• and
• optionally, projects in an anterior to posterior direction;
• wherein the second transverse stem is configured to complementarily fit the second elongated, resected passage in the first bone, and includes two opposing second transverse stem side walls for respectively engaging the two lateral walls of the second elongated, resected passage in the first bone for maintaining the working surface in the predetermined position when the second transverse stem is inserted into the second elongated, resected passage of the first bone from the third end and the working surface is positioned in the predetermined position;
• provided that the implant body is not one which is adapted for arthroplasty of opposing spinal vertebrae such that the implant device is not a spinal vertebral implant.

A combination comprising, in kit form:

• (A) a joint prosthesis apparatus for implant at a selected transverse location in an articulating, weight bearing joint space presenting male and female joint components, the joint components having a predetermined transverse width and being formed with respective through, elongated wedge shaped, dovetail, transverse resection channels located at selected positions in the respective joint components and being of a predetermined shape, having opposite dovetail sides converging linearly along their lengths at a selected angle with respect to one another in the transverse direction from respective wide channel openings formed to open to the respective one transverse side of the joint and narrower channel openings formed to open on the transverse side of the joint opposite the one transverse side, the joint prosthesis apparatus including:
• prosthesis devices to implant in the articulating joint space, each of these having a body with a substrate-interfacing element, with a first of the devices including a truncated concave sphere shaped socket and a second of the devices including a truncated convex sphere shaped ball element to be received complementarily in the socket, wherein the substrate-interfacing element in the first of these devices is opposite but not confronting the socket and the substrate-interfacing element in the second of these devices is opposite but not confronting the ball element;
• each of the prosthesis devices including a pair of axial stems, each stem configured with opposite dovetail shaped stem side walls diverging linearly away from one another at the selected angle in a transverse wedge shape with a narrow leading end and a wide trailing end and constructed to be received transversely from the respective wide channel openings to be nested in close fit relationship in the respective resection channel to wedge against the side walls of the resected channels located at the selected location such that a surgeon can extend a bone-resecting instrument fully through in the lateral direction across the joint components to form the resection channels with channel side walls angling toward one another at the selected angle to define the predetermined shape in the joint components;
• the devices selected and the stems introduced through the wide openings of the respective channels to be driven transversely into the channels from the wide channel openings to wedge the stems in close fit relationship in the respective channels at the selected location;
• and
• (B) at least one template tool to be disposed adjacent the joint components, wherein the at least one template tool includes a tool body in substantially thick disc form having a first surface, a second surface opposing but not confronting the first surface, and an outer wall boundary connecting the first and second surfaces, the tool body constructed with a pair of guide grooves diverging away from one another at the selected angles, each guide groove passing through the first surface and, at two locations, the outer wall boundary, and configured and oriented to receive the bone-resecting instrument to project therefrom to form transverse resection channels for at least one of the joint components for receipt of one of the prosthesis devices configured with the predetermined shape.