Kefala Vasiliki, Ali Azhar A, Hamilton Landon D, Mannen Erin M, Shelburne Kevin B
Department of Mechanical and Materials Engineering, University of Denver, Denver, CO, United States.
Stryker Orthopedics, Kalamazoo, MI, United States.
Front Bioeng Biotechnol. 2022 Apr 14;10:820196. doi: 10.3389/fbioe.2022.820196. eCollection 2022.
Quantification of natural knee kinematics is essential for the assessment of joint function in the diagnosis of pathologies. Combined measurements of tibiofemoral and patellofemoral joint kinematics are necessary because knee pathologies, such as progression of osteoarthritis and patellar instability, are a frequent concern in both articulations. Combined measurement of tibiofemoral and patellofemoral kinematics also enables calculation of important quantities, specifically patellar tendon angle, which partly determines the loading vector at the tibiofemoral joint and patellar tendon moment arm. The goals of this research were to measure the differences in tibiofemoral and patellofemoral kinematics, patellar tendon angle (PTA), and patellar tendon moment arm (PTMA) that occur during non-weight-bearing and weight-bearing activities in older adults.
High-speed stereo radiography was used to measure the kinematics of the tibiofemoral and patellofemoral joints in subjects as they performed seated, non-weight-bearing knee extension and two weight-bearing activities: lunge and chair rise. PTA and PTMA were extracted from the subject's patellofemoral and tibiofemoral kinematics. Kinematics and the root mean square difference (RMSD) between non-weight-bearing and weight-bearing activities were compared across subjects and activities.
Internal rotation increased with weight-bearing (mean RMSD from knee extension was 4.2 ± 2.4° for lunge and 3.6 ± 1.8° for chair rise), and anterior translation was also greater (mean RMSD from knee extension was 2.2 ± 1.2 mm for lunge and 2.3 ± 1.4 mm for chair rise). Patellar tilt and medial-lateral translation changed from non-weight-bearing to weight-bearing. Changes of the patellar tendon from non-weight-bearing to weight-bearing were significant only for PTMA.
While weight-bearing elicited changes in knee kinematics, in most degrees of freedoms, these differences were exceeded by intersubject differences. These results provide comparative kinematics for the evaluation of knee pathology and treatment in older adults.
量化自然膝关节运动学对于评估关节功能在疾病诊断中至关重要。由于膝关节疾病，如骨关节炎进展和髌骨不稳定，在两个关节中都是常见问题，因此有必要联合测量胫股关节和髌股关节的运动学。联合测量胫股关节和髌股关节的运动学还能够计算重要参数，特别是髌腱角，它部分决定了胫股关节处的载荷矢量和髌腱力臂。本研究的目的是测量老年人在非负重和负重活动期间胫股关节和髌股关节运动学、髌腱角（PTA）和髌腱力臂（PTMA）的差异。
采用高速立体放射摄影术测量受试者在进行坐位非负重膝关节伸展以及两项负重活动（弓步和从椅子上起身）时胫股关节和髌股关节的运动学。从受试者的髌股关节和胫股关节运动学中提取PTA和PTMA。比较不同受试者和活动中，非负重和负重活动之间的运动学及均方根差（RMSD）。
负重时内旋增加（弓步相对于膝关节伸展的平均RMSD为4.2±2.4°，从椅子上起身相对于膝关节伸展的平均RMSD为3.6±1.8°），并且向前平移也更大（弓步相对于膝关节伸展的平均RMSD为2.2±1.2毫米，从椅子上起身相对于膝关节伸展 的平均RMSD为2.3±１.4毫米）。髌骨倾斜和内外侧平移从非负重变为负重。髌腱从非负重到负重的变化仅在PTMA方面具有显著性。
虽然负重引起了膝关节运动学的变化，但在大多数自由度上，这些差异被个体间差异所超过。这些结果为评估老年人膝关节疾病和治疗提供了比较运动学数据。
