髌股关节紊乱行关节镜手术治疗对髌股关节生物力学改变的三维有限元分析

目的采用三维有限元方法分析关节镜下行外侧髌骨支持带松解、内侧髌骨支持带紧缩手术前后髌股关节应力分布的改变情况。方法建立髌股关节紊乱患者关节镜手术前后髌股关节三维模型,并计算分析在加载200 N载荷下模型在不同屈膝角度(30°、60°、90°、120°)时的髌股关节最大应力和应力分布。结果关节镜术后模型不同屈膝角度的髌股关节最大应力较术前明显减小;术前髌股关节应力集中在髌股外侧关节面,而术后髌股关节应力得到重新分配。结论关节镜下外侧髌骨支持带松解、内侧髌骨支持带紧缩手术后,髌股关节不同屈膝角度的应力得到改善,为关节镜手术方法可以有效恢复髌股关节内外侧关节面压力平衡提供客观理论依据。对于临床上存在力线异常的早期髌股关节紊乱患者,建议应尽早手术干预。

Three-dimensional finite element analysis on biomechanical changes after arthroscopic surgery for patients with patellofemoral joint disorders

Objective To analyze stress distribution changes in patellofemoral joints before and after arthroscopic surgery by lateral retinacular release and medial retinaculum placation using three-dimensional (3D) finite element method. Methods The 3D finite element model of pre-and post-operative patellofemoral joints for patients with patellofemoral joint disorders were constructed, and the maximum stress and stress distributions on patellofemoral joints at different flexion angles (30°,60°,90°,120°) under the load of 120 N were calculated and analyzed. Results The maximum stress of patellofemoral joints at different flexion angles after arthroscopic surgery significantly smaller than that before arthroscopic surgery. The stress concentrated on the lateral patellofemoral joints before the surgery, but was redistributed after the surgery. Conclusions The stress on patellofemoral joints at different flexion angles is reduced after arthroscopic surgery by lateral retinacular release and medial retinaculum placation, which provides an objective theoretic reference for arthroscopic surgery to effectively restore stress balance between lateral and medial patellofemoral joints. It is suggested that patients with early patellofemoral joint disorders and abnormal force line should be treated with surgery intervention as early as possible.