Patent ID: 7608112
Filing Date: 2009-10-27
Classification: A61F

Abstract:
1. Apparatus for interoperatively determining, during a trialing procedure conducted in connection with total hip arthroplasty at an implant site, a femoral head offset and neck length required in a femoral component to be engaged with an acetabular component in a prosthetic hip joint to be implanted at the implant site for establishing appropriate hip mechanics in the prosthetic hip joint, by determining a trial distance, along a predetermined direction, between a trial femoral head component and a trial femoral stem component of a femoral trial placed at the implant site with the trial femoral head component engaged with a trial acetabular component in a trial hip joint, the trial distance corresponding to the required femoral head offset and neck length in the prosthetic hip joint, the apparatus comprising: a connecting arrangement connecting the trial femoral head component with the trial femoral stem component for selective movement relative to one another through trial distances between the trial femoral head component and the trial femoral stem component, the connecting arrangement being dimensioned and configured for enabling the selective movement during the trialing procedure, along the predetermined direction, while the trial femoral head component and the trial femoral stem component remain connected to one another at the implant site for establishing a trial hip joint having a selected trial distance between the trial femoral head component and the trial femoral stem component while the trial femoral head component and the trial femoral stem component remain connected to one another at the implant site; and a spacer dimensioned and configured for interposition between the trial femoral head component and the trial femoral stem component while the trial femoral head component and the trial femoral stem component remain connected to one another at the implant site so as to enable the selected trial distance between the trial femoral head component and the trial femoral stem component to be maintained during subsequent interoperative trialing to evaluate hip mechanics in the trial hip joint, thereby determining interoperatively an appropriate trial distance, the appropriate trial distance corresponding to the femoral head offset and neck length required in the femoral component for establishing the appropriate hip mechanics in the prosthetic hip joint; and wherein the connecting arrangement includes: a trial femoral neck component for assembly with the trial femoral head component, the trial femoral neck component including a shaft; and a passage in the trial femoral stem component, the passage being dimensioned and configured for receiving the shaft for sliding motion enabling movement of the trial femoral head component and the trial femoral stem component relative to one another; and the spacer includes a sleeve having a prescribed longitudinal length, the sleeve being split along the length thereof to enable selective lateral placement of the sleeve over the shaft for spacing the trial femoral head component from the trial femoral stem component according to the prescribed length of the sleeve.