Tischer Thomas, Geier Andreas, Lutter Christoph, Enz Andreas, Bader Rainer, Kebbach Maeruan
Department of Orthopaedics, Rostock University Medical Center, Rostock, Germany.
J Orthop Res. 2023 Apr;41(4):793-802. doi: 10.1002/jor.25425. Epub 2022 Aug 27.
The role of patella height is discussed controversially in total knee arthroplasty (TKA). Therefore, this computational study aims to systematically analyze the biomechanical effect of different patella heights on patellofemoral (PF) forces and kinematics after cruciate-retaining (CR) TKA. We implemented a CR bicondylar TKA with a dome patellar button in a validated dynamic musculoskeletal multibody model of a male human knee joint. Retropatellar dynamics (contact force [N], shear force [N], patellar shift [mm], tilt [°], and rotation [°]) were evaluated during dual-limb squat motion (flexion from 0° to 90°) with simulated active muscle forces and the effects of different patella heights (Blackburne-Peel [BP] ratio of 0.39, 0.49, 0.65, 0.85, 1.01, and 1.1 were systematically examined). As active knee flexion increased, PF contact force also increased. Patella alta (BP = 1.1) resulted in higher PF contact forces compared to normal patella height (BP = 0.65) by up to 16%. Contrarily, patella baja was associated with decreased PF forces by 7%. Compared to patella baja (BP = 0.39), patella alta (BP = 1.1) considerably increased the contact force by up to 25%. Different patellar heights mainly affected PF shear forces during early knee flexion. Concerning PF kinematics, patella alta (BP = 1.1) yielded a greater lateral tilt of more than 4° and higher patellar rotation by up to 3° during deep knee flexion, compared to normal patella height (BP = 0.65). Our computational study indicates that patella alta is associated with the highest PF contact and shear force after the implantation of a CR bicondylar TKA. This should be considered in PF disorders following TKA.
在全膝关节置换术（TKA）中，髌骨高度的作用存在争议。因此，本计算研究旨在系统分析不同髌骨高度对保留交叉韧带（CR）的TKA术后髌股（PF）力和运动学的生物力学影响。我们在一个经过验证的男性膝关节动态肌肉骨骼多体模型中实施了带有穹顶髌骨按钮的CR双髁TKA。在双下肢深蹲运动（从0°屈曲至90°）过程中，利用模拟的主动肌力评估髌后动力学（接触力[N]、剪切力[N]、髌骨移位[mm]、倾斜[°]和旋转[°]），并系统研究不同髌骨高度（Blackburne-Peel[BP]比值为0.39、0.49、0.65、0.85、1.01和1.1）的影响。随着主动膝关节屈曲增加，PF接触力也增加。与正常髌骨高度（BP = 0.65）相比，高位髌骨（BP = 1.1）导致PF接触力最高增加16%。相反，低位髌骨与PF力降低7%相关。与低位髌骨（BP = 0.39）相比，高位髌骨（BP = 1.1）使接触力大幅增加高达25%。不同的髌骨高度主要影响膝关节早期屈曲时的PF剪切力。关于PF运动学，与正常髌骨高度（BP = 0.65）相比，高位髌骨（BP = 1.1）在膝关节深度屈曲时产生超过4°的更大外侧倾斜和高达3°的更高髌骨旋转。我们的计算研究表明，在植入CR双髁TKA后，高位髌骨与最高的PF接触力和剪切力相关。这在TKA后的PF疾病中应予以考虑。
