Talar dome with angled holes

Abstract

A talar implant includes a post projecting from a superior surface of the plate and includes at least one threaded hole. A talar dome having an inferior surface is configured to face the plate and an opening in the inferior surface is shaped to receive the post. The talar dome includes at least one through hole having a threaded surface and a groove. The groove has a larger outer diameter than the threaded surface. At least one fastener is configured to engage the threaded hole of the post and the threaded surface of the through hole. The at least one fastener has a groove that is aligned with the groove of the through hole when the fastener is inserted in the talar dome and the post. At least one clip is configured to engage the groove of the through hole of the talar dome and the groove of the fastener.

What is claimed is: 
     
         1 . A talar implant, comprising:
 a plate configured for attachment to a talus, the plate having a post projecting from a surface, the post having at least one threaded hole;   a talar dome having a surface configured to face the plate, and an opening in the surface shaped to receive the post, the talar dome defining at least one through hole by a threaded surface and a groove, the groove having a larger outer diameter than the threaded surface;   at least one fastener configured to engage the threads that define the at least one through hole of the post, the at least one fastener having a groove that is aligned with the when the fastener is inserted into the talar dome and the post; and   a clip configured to engage the groove of the through hole of the talar dome and the groove of the fastener.   
     
     
         2 . The talar implant of  claim 1 , wherein the at least one through hole has a longitudinal axis that is oriented at an oblique angle with respect to the surface configured to face the plate. 
     
     
         3 . The talar implant of  claim 2 , wherein the post has an axis, and the longitudinal axis of the at least one through hole does not extend through the post axis. 
     
     
         4 . The talar implant of  claim 1 , wherein the at least one fastener has a head, the head having a larger diameter than the threaded surface, and the groove of the fastener is located on a surface of the head. 
     
     
         5 . The talar implant of  claim 1 , wherein the clip is configured to prevent removal of the fastener from the talar dome while the clip engages the groove of the through hole and the groove of the fastener. 
     
     
         6 . A method of inserting a talar implant, comprising:
 attaching a plate to a talus so that the plate abuts the talus, the plate having a post projecting from a superior surface of the plate, the post having at least one threaded hole;   placing a talar dome over the plate, so that a surface of the talar dome abuts the plate, and an opening in the surface of the talar dome receives the post, the talar dome having at least one through hole, the through hole being defined by a threaded surface and a groove;   inserting at least one fastener through the threaded surface that defines the through hole to engage the threaded hole of the post, the fastener having a groove; and   inserting a clip into the through hole, so as to engage the groove of the through hole of the talar dome and the groove of the fastener.   
     
     
         7 . The method of  claim 6 , wherein the step of placing the talar dome is performed without applying an impact to the talar dome. 
     
     
         8 . The method implant of  claim 6 , wherein the step of inserting at least one fastener is performed so that a longitudinal axis of the fastener is oriented at an oblique angle with respect to the surface of the talar dome. 
     
     
         9 . The talar implant of  claim 8 , wherein the post has a central axis, and the step of inserting at least one fastener is performed so that the longitudinal axis of the at least one fastener does not extend through the central axis. 
     
     
         10 . The method of  claim 9 , further comprising inserting a second fastener through a threaded surface of a second through hole of the talar dome to engage a second threaded hole defined by the post, so that a longitudinal axis of the second fastener is oriented at an oblique angle with respect to the surface of the talar dome, and the longitudinal axis of the second fastener does not extend through the central axis. 
     
     
         11 . An ankle prosthesis comprising:
 a tibial component configured for attachment to a tibia of a person;   a plate configured for attachment to a talus of the person, the plate having a post projecting from a surface and defining first and second threaded holes;   a talar dome having an articulating surface configured to face the tibial component with a surface configured to face the plate, and an opening defined in the surface shaped to receive the post, the talar dome defining first and second through holes by respective first and second threaded surfaces each having a diameter and first and second grooves, respectively, the first and second grooves having an outer diameter larger than the diameter of the first and second threaded surfaces;   first and second fasteners configured to engage the first and second threaded holes, and the first and second threaded surfaces of the talar dome, respectively, the first and second fasteners each having a groove that is aligned with the first and second grooves of the talar dome, respectively, when the first and second fasteners are inserted in the talar dome and the post; and   first and second clips configured to engage the first and second grooves of the first and second through holes and the first and second grooves of the first and second fasteners, respectively.   
     
     
         12 . The ankle prosthesis of  claim 11 , wherein each of the first and second through holes has a respective longitudinal axis that is oriented at an oblique angle with respect to the surface of the talar dome. 
     
     
         13 . The ankle prosthesis of  claim 12 , wherein the post has a central axis, and the longitudinal axes of the first and second through holes do not extend through the central vertical axis. 
     
     
         14 . The ankle prosthesis of  claim 11 , wherein the first and second fasteners have first and second heads, respectively, the first and second heads having a larger diameter than the first and second threaded surfaces, and the first and second grooves of the first and second fasteners are located on respective circumferential surface of the first and second heads. 
     
     
         15 . The ankle prosthesis of  claim 11 , wherein each of the first and second clips is a C clip having top and bottom chamfers on top and bottom surfaces thereof.