股四头肌力线异常与原生膝复发性髌股关节不稳密切相关
简介
本研究回顾性分析20例复发性髌股不稳患者与20例内侧间室骨关节炎对照组的CT影像，测量股四头肌腱轴向角（QTAx）及相关解剖参数。关键发现：不稳组QTAx平均外旋24.8°±12.0°，显著大于对照组的2.5°±9.4°（p<0.001）；股四头肌力线异常与复发性髌股不稳强相关（AUC=0.94），其预测价值高于滑车发育不良（AUC=0.75）和髌骨高位（A…
英文摘要
PURPOSE: Patellofemoral instability (PFI) has been associated with multiple anatomical risk factors. The recent development of accurate quadriceps muscle measurements using three-dimensional imaging techniques have demonstrated that quadriceps alignment is highly variable and frequently leads to a lateralised force vector on the patella. This study aimed to determine the association between quadriceps malalignment and recurrent patella instability in native knees. METHODS: This is a preliminary retrospective comparative cohort study where computed tomography (CT) scans of patients presenting with recurrent PFI relative to a control group of patients with medial compartment osteoarthritis were retrospectively analysed. Twenty patients were identified in each group. The quadriceps alignment was measured using the quadriceps tendon axial angle (QTAx) in both cohorts. Other commonly used anatomical measurements including the tibial tuberosity to trochlear groove distance (TT-TG), Dejour classifications, sulcus angle, trochlear groove shape and patella height were also measured and compared between groups using one-way ANOVA and Student t-tests for parametric variables and χ2 test for nonparametric variables. RESULTS: The quadriceps tendon axial angle in the patella instability group averaged 24.8° ± 12.0° external rotation, compared to 2.5° ± 9.4° external rotation (p < 0.001). 65% of the patients in the PFI group had trochlear dysplasia (Dejour 3.0 classification 1 to 3) compared to 10% in the control group (p < 0.001). Quadriceps malalignment was strongly associated with PFI as determined by area under the curve (AUC) analysis of 0.94. PFI was also associated with trochlear dysplasia (AUC = 0.75) and patella alta (AUC = 0.78). CONCLUSIONS: Externally rotated quadriceps alignment was found to be strongly associated with the development of recurrent patellofemoral instability in native knees. This is likely due to the increased lateral force vector on the patella caused by external rotation of the quadriceps muscle around the femoral shaft. Assessment of quadriceps malalignment in patients with PFI has the potential to influence surgical decisions and determine prognosis in patients treated both surgically and non-operatively. LEVEL OF EVIDENCE: Level III.