FEMORAL COMPONENT ROTATIONAL ALIGNMENT USING THE EXTRAMEDULLARY TIBIAL SHAFT AXIS - A TECHNICAL NOTE

The transepicdndylar axis has been shown to have a constant relationsh ip to the knee flexion axis, the mechanical axis of the lower extremit y, and the limb axis of the lower leg in both extension and flexion. U sing this constant relationship, we have developed a technique which u ses a long rod centring on the extramedullary tibial shaft axis to det ermine the exact position of the posterior condylar resection to creat e the flexion gap in total knee arthroplasty (TKA). This technique has been used in over 100 cases and two cases of bilateral TKA underwent computed tomographs to evaluate the accuracy of the technique. Compare d with the contralateral knee which had a resection parallel to the po sterior condyles, using the extramedullary alignment allowed the poste rior condyle resection to parallel the transepicondylar axis.