| Objective: This study aimed to investigate the effects of anterior cruciate ligament reconstruction(ACLR)on the biomechanics of patellofemoral joints(PFJs).Methods: A three-dimensional finite element model of the knee joint was established.The diameter of anterior cruciate ligament(ACL)was set to 8 mm.The tibial attachment was centered at the anatomical footprint(AF).The femoral attachment was on the AF and eight positions centered at the AF.The Lachman test was simulated to measure the PFJ pressure and the Von Mises stress on patella and femur.Results: The PFJ pressure and the Von Mises stress on patella and femur changed with femoral-end positions of the ACL graft.The ACL graft positioning at the superior and posterior superior AF resulted in minimal PFJ stress and Von Mises stress on femur and patella with 90° knee flexion.However,the ACL graft positioning at the anterior inferior AF produced the maximal PFJ stress and the maximal Von Mises stress on patella.The positioning at the anterior AF produced the maximum Von Mises stress on femur.Conclusions: During single-bundle ACLR,the positioning of the femoral tunnel had a direct impact on the PFJ stress and the Von Mises stress on patella and femur,which was probably the primary cause of patellofemoral crepitus and patella pain after ACLR.The ACL graft positioning at the posterior superior AF with 90° knee flexion exerted the minimal PFJ stress and the least Von Mises stress on patella and femur,matching the biomechanical environment of the PFJ. |
