Purpose: The purpose of this study was to assess the risk of injury to the posterolateral structures of the knee when performing anterior cruciate ligament reconstruction from the anteromedial portal while fixing the graft with a femoral cross-pin system.
Methods: The anterior cruciate ligament was reconstructed arthroscopically with hamstring graft in 10 fresh cadaveric knees. Femoral fixation was performed with a cross-pin system. This was originally developed for a transtibial drilling technique. A femoral tunnel measuring 30 mm in length was drilled through the anteromedial portal in each knee. The knee flexion angle was set at 110 degrees . Lateral dissection was then performed to measure the distances from the cross-pin system to the lateral collateral ligament, the popliteus tendon, the lateral gastrocnemius tendon, and the peroneal nerve.
Results: The lateral collateral ligament was partially torn by the pin in 1 case. In 8 cases the distance to the lateral collateral ligament was shorter than 3 mm (range, 0 to 2.43 mm). In 7 specimens, the cross-pin system was within 4.5 mm of the popliteus tendon. The lateral gastrocnemius tendon was pierced by the cross-pin device in 2 cases. The minimal distance to the peroneal nerve was 23.89 mm.
Conclusions: Fixation of a hamstring graft with a cross-pin system initially developed for an upper femoral tunnel, following the aforementioned technique, presents the possibility of a high risk of injury to the lateral collateral ligament. The popliteus tendon and the lateral gastrocnemius tendon may also be injured.
Clinical relevance: The risk of injury to the lateral stabilizers of the knee suggests discarding the technique used in this study.