2024, Vol. 28 ›› Issue (24): 3796-3800

Three-dimensional finite element analysis of medial patellofemoral ligament reconstruction with transosseous and wire anchor fixation

Zhao Gai1, 2, Liu Lingjun2, Yin Hao2, Ning Rende2, Xu Bin1   

Abstract: BACKGROUND: Reconstruction of the medial patellofemoral ligament is the primary and basic treatment for patellofemoral dislocation. Generally, autologous or allogeneic tendons are used to fix the patellofemoral podogram area and the femoral insertion, respectively. There are various fixation methods. Patellar lateral insertion fixation methods are relatively diverse, mainly traditional transosseous fixation and recent anchoring methods, including single tunnel, double-tunnel transosseous fixation, and two-wire anchor fixation. However, which fixation method is more effective in reducing patellofemoral joint stress and is more biomechanical has not been determined.
OBJECTIVE: To observe the mechanical effects of patellofemoral joint and medial patellofemoral ligament reconstruction with transosseous and wire anchor fixation.
METHODS: A three-dimensional finite element model of the knee joint was constructed. The medial patellofemoral ligament was reconstructed by a single tunnel through the bony canal or two wire anchors at the medial edge of the patella. The femoral side was fixed by extrusion nails to the medial epicondyle of the femur and the midpoint of the adductor tubercle. We observed the effects of the two fixation methods on patellofemoral joint and medial patellofemoral ligament loading during knee flexion at 0°, 30°, 60°, 90°, and 120°.
RESULTS AND CONCLUSION: (1) The stress on the patellofemoral joint was large when the knee was at flexion of 0-60°, peaked at 30°, and gradually decreased at 90° and 120°. The two fixation methods had little difference in the stress on the patellofemoral joint. (2) The stress on the medial patellofemoral ligament peaked at 30° and decreased significantly at 60°, and the load on the medial patellofemoral ligament was significantly greater at all angles with anchor fixation than with bony canal fixation. (3) The results showed that there was no significant difference in patellofemoral joint loading between the two fixation methods, but the stress on the medial patellofemoral ligament in anchoring was significantly greater than that in transosseous fixation.

Key words: patellofemoral dislocation, medial patellofemoral ligament, three-dimensional reconstruction, stress, finite element analysis