Sanders Thomas L, Pareek Ayoosh, Johnson Nicholas R, Stuart Michael J, Dahm Diane L, Krych Aaron J
Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota, USA.
Am J Sports Med. 2017 Apr;45(5):1012-1017. doi: 10.1177/0363546516680604. Epub 2016 Dec 22.
The rate of patellofemoral arthritis after lateral patellar dislocation is unknown. Purpose/Hypothesis: The purpose of this study was to compare the risk of patellofemoral arthritis and knee arthroplasty between patients who experienced a lateral patellar dislocation and matched individuals without a patellar dislocation. Additionally, factors predictive of arthritis after patellar dislocation were examined. The hypothesis was that the rate of arthritis is likely higher among patients who experience a patellar dislocation compared with those who do not.
Cohort study; Level of evidence, 3.
In this study, 609 patients who had a first-time lateral patellar dislocation between 1990 and 2010 were compared with an age- and sex-matched cohort of patients who did not have a patellar dislocation. Medical records were reviewed to collect information related to the initial injury, recurrent dislocation, treatment, and progression to clinically significant patellofemoral arthritis (defined as symptoms with degenerative changes on patellar sunrise radiographs). Factors associated with arthritis (age, sex, recurrence, osteochondral injury, trochlear dysplasia) were examined.
At a mean follow-up of 12.3 ± 6.5 years from initial dislocation, 58 patients (9.5%) in the dislocation cohort were diagnosed with patellofemoral arthritis, corresponding to a cumulative incidence of arthritis of 1.2% at 5 years, 2.7% at 10 years, 8.1% at 15 years, 14.8% at 20 years, and 48.9% at 25 years. In the control cohort, 8 patients (1.3%) were diagnosed with arthritis, corresponding to a cumulative incidence of arthritis of 0% at 5 years, 0% at 10 years, 1.3% at 15 years, 2.9% at 20 years, and 8.3% at 25 years. Therefore, patients who experienced a lateral patellar dislocation had a significantly higher risk of developing arthritis (hazard ratio [HR], 7.8; 95% CI, 3.9-17.6; P < .001) than individuals without a patellar dislocation. However, the risk of knee arthroplasty was similar between groups (HR, 2.8; 95% CI, 0.6-19.7; P = .2). Recurrent patellar dislocations (HR, 4.5; 95% CI, 1.6-12.6), osteochondral injury (HR, 11.3; 95% CI, 5.0-26.6), and trochlear dysplasia (HR, 3.6; 95% CI, 1.3-10.0) were associated with arthritis after patellar dislocation.
Patellar dislocation is a significant risk factor for patellofemoral arthritis, as nearly half of patients have symptoms and radiographic changes consistent with arthritis at 25 years after lateral patellar dislocation. Osteochondral injury, recurrent patellar instability, and trochlear dysplasia are associated with the development of arthritis.
髌骨外侧脱位后髌股关节炎的发生率尚不清楚。目的/假设：本研究的目的是比较经历过髌骨外侧脱位的患者与未发生髌骨脱位的匹配个体之间髌股关节炎和膝关节置换术的风险。此外，还研究了髌骨脱位后关节炎的预测因素。假设是，与未发生髌骨脱位的患者相比，发生髌骨脱位的患者患关节炎的几率可能更高。
队列研究；证据等级，3级。
在本研究中，将1990年至2010年间首次发生髌骨外侧脱位的609例患者与年龄和性别匹配的未发生髌骨脱位的患者队列进行比较。查阅医疗记录以收集与初始损伤、复发性脱位、治疗以及进展为具有临床意义的髌股关节炎（定义为髌骨日出位X线片上有退变改变的症状）相关的信息。研究了与关节炎相关的因素（年龄、性别、复发、骨软骨损伤、滑车发育不良）。
自初次脱位起平均随访12.3±6.5年，脱位队列中有58例患者（9.5%）被诊断为髌股关节炎，5年时关节炎的累积发病率为1.2%，10年时为2.7%，15年时为8.1%，20年时为14.8%，25年时为48.9%。在对照组中，有8例患者（1.3%）被诊断为关节炎，5年时关节炎的累积发病率为0%，10年时为0%，15年时为1.3%，20年时为2.9%，25年时为8.3%。因此，经历过髌骨外侧脱位的患者患关节炎的风险显著高于未发生髌骨脱位的个体（风险比[HR]，7.8；95%置信区间[CI]，3.9-17.6；P<.001）。然而，两组之间膝关节置换术的风险相似（HR，2.8；95%CI，0.6-19.7；P = 0.2）。复发性髌骨脱位（HR，4.5；95%CI，1.6-12.6）、骨软骨损伤（HR，11.3；95%CI，5.0-26.6）和滑车发育不良（HR，3.6；95%CI，1.3-10.0）与髌骨脱位后的关节炎有关。
髌骨脱位是髌股关节炎的一个重要危险因素，因为在髌骨外侧脱位25年后，近一半的患者出现与关节炎一致的症状和影像学改变。骨软骨损伤、复发性髌骨不稳定和滑车发育不良与关节炎的发生有关。
