Ankle prosthesis and methods of using the same

Abstract

The present disclosure pertains to ankle prostheses. In an example embodiment, the ankle prosthesis comprises an adjustable and replaceable intermediate implant that is disposed between a tibial implant and a talar implant. The intermediate implant is adjustable relative to the tibial implant and can be interlocked therewith once adjusted. Methods of using, fitting, and adjusting the device are also described. Still other embodiments are described.

1 - 48 . (canceled) 
     
     
         49 . A method of adjustably implanting an intermediate implant of an ankle prosthesis comprising a tibial implant and a talar implant, the method comprising:
 implanting an intermediate implant between the tibial implant and the talar implant, the intermediate implant comprising a projecting member defining an axis of rotation;   rotating the intermediate implant about the axis of rotation of the projecting member and relative to the tibial implant while the tibial implant, the talar implant, and the intermediate implant are implanted in the ankle; and   fixing the position of the intermediate implant relative to the tibial implant by inserting an implant lock between the tibial implant and the talar implant, the implant lock applying a force that is substantially perpendicular to the axis of rotation of the projecting member.   
     
     
         50 . The method of  claim 49 , the fixing step comprising the implant lock traversing linearly in a direction substantially perpendicular to the axis of rotation to engage the projecting member thereby resisting the rotation of the projecting member 
     
     
         51 . The method of  claim 49 , the fixing step comprising the implant lock moving in the anterior-posterior direction relative to the projection member, thereby resisting the rotation of the projecting member 
     
     
         52 . The method of  claim 49 , wherein the intermediate implant further comprises a first surface and a second, curved surface opposite the first surface, the projecting member extending outwardly from the first surface,
 wherein the tibial implant further comprises a recess, and   the implanting step comprises inserting the projecting member into the recess of the tibial implant.   
     
     
         53 . The method of  claim 52 , wherein during the rotating step, the projecting member can rotate at least one of 70 degrees, at least 180 degrees, or 360 degrees relative to the tibial implant when disposed in the recess. 
     
     
         54 . The method of  claim 49 , where the projecting member comprises a substantially circular transverse cross-section and a cross section of the projecting member perpendicular to the transverse cross-section is a quadrilateral. 
     
     
         55 . The method of  claim 49 , wherein the projecting member comprises a lateral surface that is substantially parallel to the axis of rotation of the projecting member and comprises one or more interlocking surface features, and
 the fixing step further comprising engaging the implant lock with the one or more interlocking surface features.   
     
     
         56 . The method of  claim 49 , wherein the projecting member comprises a lateral surface comprising one or more interlocking surface features,
 wherein the implant lock comprises a first end and a second end opposite the first end, the first end comprising one or more interlocking surface features, and   the fixing step further comprising engaging the interlocking surface features of the implant lock with the one or more interlocking surface features of the lateral surface of the projecting member to resist rotation of the projecting member relative to the tibial implant.   
     
     
         57 . The method of  claim 52 , wherein the tibial implant comprises a slot that is in communication with the recess, and
 during the fixing step, the inserting of the implant lock comprises inserting the implant lock into the slot along a direction that is within 10° of an axis perpendicular to the axis of rotation.   
     
     
         58 . The method of  claim 57 , the fixing step further comprising releasably interlocking the implant lock with a portion of the tibial implant. 
     
     
         59 . The method of  claim 58 , wherein the implant lock comprises a protrusion and the slot further comprises a sidewall and a notch in the sidewall, and
 the fixing step further comprises engaging the protrusion with the notch of the slot such that the implant lock is releasably interlocked with the slot.   
     
     
         60 . The method of  claim 59 , wherein the slot comprises a width and the implant lock comprises a width that is less than the width of the slot. 
     
     
         61 . The method of  claim 49 , wherein the implant lock comprises an insert, the insert comprising a first portion and a second portion, and
 the fixing step further comprising moving the first portion relative to the second portion.   
     
     
         62 . The method of  claim 61 , wherein the first portion of the implant lock comprises a screw, and wherein the insert comprises a bore,
 the fixing step further comprising tightening the screw in the bore.   
     
     
         63 . The method of  claim 62 , wherein the first portion and the second portion of the insert of the implant lock are configured to move away from each other as the screw is rotated in a first direction and toward each other as the screw is rotated in a second direction. 
     
     
         64 . A method of trialing an intermediate implant of an ankle prosthesis comprising a tibial implant and a talar implant, the method comprising:
 inserting a first intermediate implant into the ankle prosthesis, the first intermediate comprising a projecting member;   determining, using a measurement tool, an optimal anteroposterior position of the projecting member for alignment with the talar implant;   removing the first intermediate implant from the ankle prosthesis;   selecting a second intermediate implant comprising a projecting member defining an axis of rotation, the second intermediate implant comprising a configuration of the projecting member that corresponds to the determined optimal anteroposterior position;   inserting the second intermediate implant into the ankle prosthesis such that the second intermediate implant can rotate relative to the tibial implant about the axis of rotation; and   fixing the position of the second intermediate implant relative to the tibial implant by engaging the implant lock with the tibial implant, the implant lock applying a force that is substantially perpendicular to the axis of rotation.   
     
     
         65 . The method of  claim 64 , further comprising:
 before inserting the first intermediate implant, coupling the measurement tool with the projecting member of the first intermediate implant.   
     
     
         66 . The method of  claim 64 , wherein the tibial implant comprises a recess and the measurement tool comprises a bar,
 the step of using the measurement tool comprises inserting the bar of the measurement tool into the recess of the tibial implant, and   the implanting of the second intermediate implant step comprises inserting the projecting member of the second intermediate implant into the recess.   
     
     
         67 . The method of  claim 64 , wherein the optimal anteroposterior location of the projecting member is selected from a group comprising: posterior, neutral, or anterior. 
     
     
         68 . A method of implanting an ankle prosthesis or a portion thereof from a prosthesis kit, the method comprising:
 providing a prosthesis kit comprising a talar implant, a first tibial implant, a second tibial implant, a first intermediate implant configured to be coupled in fixed relation to the first tibial implant, and a second intermediate implant configured to slide or rotate relative to the second tibial implant;   implanting the talar implant into a patient;   selecting either a fixed bearing configuration or a mobile bearing configuration;   if the fixed bearing configuration is selected:
 implanting the first tibial implant and the first intermediate implant, and 
 fixing the position of the first intermediate implant relative to the first tibial implant by inserting a first implant lock between the tibial implant and the talar implant, the first implant lock applying a force that is substantially perpendicular to the axis of rotation of the projecting member; 
   if the mobile bearing configuration is selected:
 implanting, the second tibial implant and the second intermediate implant, and 
 constraining the position of the second intermediate implant relative to the second tibial implant, wherein the second intermediate implant is configured to rotate relative to the second tibial implant when constrained, 
   wherein both the first and second intermediate implants comprise a lower bearing surface that is shaped to correspond to an upper bearing surface of the talar implant.