Three-dimensional finite element analysis of the influence of different surgical methods on the stress of meniscus and patellofemoral joint in the treatment of episodic patellar dislocation

Abstract

Abstract BACKGROUND: At present, there are many surgical methods for the treatment of episodic patellar dislocation, and it is still unclear which surgical method can provide appropriate meniscus and patellofemoral joint stress. OBJECTIVE: To explore the influence of different surgical methods simulating episodic patellar dislocation in three-dimensional finite element software on the stress of knee meniscus and patellofemoral joint surface under different flexion conditions. METHODS: Acquire the knee joint CT and MRI of patients with episodic patellar dislocation and import them into Mimics and Geomagic to extract the model, then use Soildworks to complete the 0 °, 30 °, 60 °, 90 ° and 120 °buckling construction of the model, for each model, medial patellofemoral ligament reconstruction, medial retinaculum plication, lateral retinaculum release, medial patellofemoral ligament combined with medial patellotibial ligament reconstruction, medial patellofemoral ligament reconstruction combined with lateral retinaculum release be operation respectively.Finally, the model is imported into the mechanical software Ansys for biomechanical analysis, and the stress results of knee meniscus and patellofemoral joint surface are output. RESULTS : The medial patellofemoral ligament combined with medial patellotibial ligament reconstruction has the smallest meniscus stress compared with other methods. The medial patellofemoral ligament combined with medial patellotibial ligament reconstruction and the medial patellofemoral ligament reconstruction combined with the lateral retinaculum release have smaller stress on the patellofemoral joint surface compared with the other three methods. CONCLUSION :The medial patellofemoral ligament combined with medial patellotibial ligament reconstruction can provide well patellofemoral contact stress and meniscus stress, effectively restore the stability of the knee joint, and delay the purpose of joint and cartilage degeneration.Medial patellofemoral ligament reconstruction combined with lateral retinaculum release can also provide better patellofemoral joint stress, but the meniscus stress is slightly higher, so we should be alert to the complications related to the meniscus after surgery.Due to the high stress between patellofemoral joints and meniscus, the medial patellofemoral ligament reconstruction should prevent the risk of redislocation and the high incidence of patellofemoral osteoarthritis.