Modular talar fixation method and system

Abstract

A talar implant system comprises a body. The body includes a bone contact surface and an articulation surface located opposite the bone contact surface. The body defines at least one angled fastener hole extending therethrough from the articulation surface to the bone contact surface along a longitudinal axis. The articulation surface is configured to mimic articulation of the talar dome. A fastener is sized and configured to be received within the at least one fastener hole at a first angle with respect to the longitudinal axis of the fastener hole. A fastener cap is sized and configured to be received within a proximal end of the at least one fastener hole. The fastener cap couples the body to the fastener.

What is claimed is: 
     
         1 . A talar implant system comprising:
 an implant having a bone contact surface arranged in spaced relation to an articulation surface, the implant defining an opened ended, threaded fastener hole communicating between the articulation surface and the bone contact surface;   a fastener sized and configured to be partially received within a distal end of the threaded fastener hole, the fastener having a head; and   a fastener cap configured to threadingly engage a proximal end of the fastener hole, the fastner cap defining external threads configured to engage the threads of the fastener hole and a distal cavity sized and configured to couple to the head of the fastener after the head is partially received within the distal end of the fastener hole.   
     
     
         2 . The talar implant system of  claim 1 , wherein the distal cavity defines internal threads and the head of the fastener includes external threads configured to engage the internal threads of the cavity. 
     
     
         3 . The talar implant system of  claim 1 , wherein the head of the fastener is rounded. 
     
     
         4 . The talar implant system of  claim 1 , wherein the fastener comprises at least one of a bone screw and a peg. 
     
     
         5 . The talar implant system of  claim 1 , wherein the fastener cap includes a transverse wall at the a proximal end of the distal cavity. 
     
     
         6 . The talar implant system of  claim 1 , wherein a maximum diameter of the fastener is less than a diameter of the internal threads of the fastener hole. 
     
     
         7 . A talar implant system comprising:
 an implant having a bone contact surface spaced-away from an articulation surface, the implant defining an opened ended, threaded fastener hole communicating between the articulation surface and the bone contact surface;   a fastener arranged so as to be partially received within a distal end of the fastener hole, the fastener having a head; and   a fastener cap configured to be couplingly received in the fastener hole of the implant, the fastener cap defining a distal cavity sized to receive the head of the fastener so as to provide for coupling of the implant to the fastener, with a transverse wall located at a proximal end of the distal cavity, wherein the fastener cap is configured to be threadingly coupled to a proximal end of the fastener hole after the head of the fastener is partially received within the distal end of the fastener hole.   
     
     
         8 . The talar implant system of  claim 7 , wherein the head of the fastener comprises a ball. 
     
     
         9 . The talar implant system of  claim 7 , wherein the fastener comprises a bone screw. 
     
     
         10 . The talar implant system of  claim 7 , wherein the distal cavity of the fastener cap includes internal threads and the head of the fastener includes external threads configured to engage the internal threads of the cavity. 
     
     
         11 . The talar implant system of  claim 10 , wherein the fastener hole defines internal threads and the fastener cap defines external threads sized and arranged so as to engage the internal threads of the fastener hole. 
     
     
         12 . The talar implant system of  claim 11 , wherein a maximum diameter of the fastener is less than a diameter of the internal threads of the fastener hole. 
     
     
         13 . A talar implant system comprising:
 an implant body including spaced-apart bone contact and articulation surfaces, the implant body defining at least one opened ended fastener hole communicating between the articulation surface and the bone contact surface, the implant body defining at least one threaded fastener hole communicating between the articulation surface to the bone contact surface;   a fastener having a head, and being sized to be partially received within a distal end of the at least one threaded fastener hole at a first angle with respect to the threaded fastener hole, the fastener; and   a fastener cap including a distal cavity arranged to interface with the head of the fastener, the fastener further being sized and configured so as to be threadingly received within a proximal end of the at least one threaded fastener hole, wherein the fastener cap couples the body to the fastener.   
     
     
         14 . The system of  claim 13 , wherein the fastener has a diameter less than a diameter of the internal threads of the fastener hole. 
     
     
         15 . The system of  claim 14 , wherein the fastener cap includes a plurality of external threads sized and configured to couple to the internal threads of the at least one fastener hole. 
     
     
         16 . The system of  claim 15 , wherein the distal cavity comprises a socket and the head of the fastener comprises a ball. 
     
     
         17 . The system of  claim 16 , wherein the distal cavity defines a plurality of internal threads and wherein the head of the fastener defines a plurality of external threads sized and configured to interface with the plurality of internal threads of the distal cavity. 
     
     
         18 . The system of  claim 13 , wherein the fastener comprises a bone screw.