| 摘要 |
A stem extension for surgical implants such as tibial or femoral knee implants. The stem extension is interposed between the stem and its load bearing component (i.e., tibial tray or condylar component) and angularly orients the attached stem relative to the load bearing component to facilitate positioning of the stem in the bone canal and alignment of the load bearing component with the mechanical axis of the leg. The extension includes a female taper that engages the load bearing component. The extension also includes a male taper having a longitudinal axis oriented at an angle relative to the longitudinal axis of the female taper. Engagement of the male taper with the stem thereby orients the stem at an angle relative to the longitudinal axis of the load bearing component. Because the bone canal into which the stem is inserted is oftentimes angled relative to the mechanical axis of the leg, such orientation of the stem adjusts for the contour and/or angulation of the canal and facilitates positioning of the stem in the canal in a manner that promotes the desired alignment between the load bearing component and the mechanical axis of the leg, thereby allowing the implant to more closely replicate the geometry of the knee and leg. In addition to being oriented angularly, the female and male taper of the extension may also be offset parallel to facilitate insertion of the stem into canals that are not only angled relative to, but also offset from, the mechanical axis of the leg.
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