Location and classification of popliteus tendon's origin: cadaveric study.

BACKGROUND: In posterolateral insufficiency, many investigators have proposed a lateral tunnel for PT reconstruction. Although they were usually located at the anterior and proximal to the lateral femoral epicondyle, there are still controversies regarding the exact location of PT tunnel. The aim of the present study was to describe our novel findings of femoral attachment of popliteus tendon (PT) and lateral collateral ligament (LCL) and to present an adequate femoral tunnel site, based on the cadaver dissection.
METHODS: Nine embalmed cadavers (18 knees), which were fully extended, were dissected to determine a precise anatomic description of the PT attachment compared to the femoral epicondyle and the LCL. The anatomic variations and attachment of the LCL and PT around the epicondyle were described.
RESULTS: The LCL (mean length: 53 mm, mean width 9 mm) was attached uniformly at the lateral epicondyle of the femur, which was slightly inferior and posterior to the top of the lateral epicondyle, but the PT (mean length: 36 mm, mean width: 8 mm) had the multiform attachments around the epicondyle and our dissection identified three different locations of the PT's attachment; postero-inferior attachment (13 knees), just inferior attachment (2 knees), and double attachment by bifurcate bundles (3 knees). These results demonstrate that the attachment for the PT is mostly located at the postero-inferior site of the epicondyle in the fully extended position and can be seen only when the knee is fully extended because the attachment of the PT shifts anteriorly with regard to the LCL in higher flexion angles.
CONCLUSION: If the original site of the PT's attachment cannot be seen, the recommendation of the femoral tunnel for the PT reconstruction should be located at the postero-inferior site as compared with the LCL attachment in the fully extended position.