Brenner Jason D, Henick Steven M, Mehraban Alvandi Leila, Gjonbalaj Edina, Lo Yungtai, Schulz Jacob, Fornari Eric D, Levy Benjamin J, Drummond Mauricio
Albert Einstein College of Medicine, New York, New York, USA.
Department of Orthopedic Surgery, Montefiore Einstein, New York, New York, USA.
Orthop J Sports Med. 2025 Jul 28;13(7):23259671251356632. doi: 10.1177/23259671251356632. eCollection 2025 Jul.
Identifying anatomic risk factors for recurrent patellar dislocations can help guide clinical decision making and counseling on operative management for patients at the time of the initial dislocation.
To determine if there are significant differences in anatomic factors between patients with a one-time patellar dislocation (OTPD) and those with multiple patellar dislocations (MPDs).
Case-control study; Level of evidence, 3.
Patients aged 9 to 21 years who had at least one patellar dislocation between 2012 and 2023 were retrospectively categorized into 1 of 2 groups (verified by telephone communication with at least 2 years' follow-up): MPDs (≥2 patellar dislocations) and OTPD. Patient characteristics and several magnetic resonance imaging measurements, including proximal tibial tubercle-trochlear groove (pTT-TG) distance, Caton-Deschamps index (CDI), relative tibial external rotation (rTER), and patellar tilt (PT), were collected. Trochlear dysplasia was also assessed using the 2-image lateral trochlear inclination (LTI), sulcus angle (SA), and trochlear depth (TD). Multiple logistic regression was used to determine the association of anatomic risk factors with the likelihood of experiencing MPDs.
In total, 177 knees (104 female, 73 male) were included in analyses: 108 had MPDs, and 69 had an OTPD. Patients with MPDs had a significantly less TD ( < .001), greater SA ( < .001), greater CDI ( = .03), and greater PT ( = .001). LTI ( = .65), rTER ( = .72), and pTT-TG distance ( = .12) were not strongly associated with having MPDs. A multiple logistic regression model of SA and CDI found an area under the curve of 0.72 for having MPDs; a patient with an SA of 170° and a CDI of 1.5 had a .78 probability of experiencing MPDs.
Measures of trochlear dysplasia (SA and TD), patella alta (CDI), and PT may be useful to distinguish between patients with MPDs and those with an OTPD. pTT-TG distance, LTI, and rTER were not found to have statistically significant differences between the groups. The combination of SA and CDI distinguished between the groups with reasonable accuracy (area under the curve = 0.72). Applying this model, a patient with an SA of 170° and a CDI of 1.5 would have a .78 probability of experiencing MPDs. This may be helpful in counseling patients after an initial dislocation event on the likelihood of experiencing MPDs.
识别复发性髌骨脱位的解剖学风险因素有助于指导临床决策，并为初次脱位患者的手术治疗提供咨询。
确定一次性髌骨脱位（OTPD）患者和多次髌骨脱位（MPD）患者在解剖学因素上是否存在显著差异。
病例对照研究；证据等级，3级。
回顾性分析2012年至2023年间至少有一次髌骨脱位的9至21岁患者，将其分为2组中的1组（通过至少2年随访的电话沟通进行核实）：MPD组（≥2次髌骨脱位）和OTPD组。收集患者特征以及多项磁共振成像测量数据，包括胫骨近端结节 - 滑车沟（pTT - TG）距离、卡顿 - 德尚指数（CDI）、相对胫骨外旋（rTER）和髌骨倾斜度（PT）。还使用双图像外侧滑车倾斜度（LTI）、沟角（SA）和滑车深度（TD）评估滑车发育不良情况。采用多因素逻辑回归分析确定解剖学风险因素与发生MPD可能性之间的关联。
总共177个膝关节（104例女性，73例男性）纳入分析：108个为MPD组，69个为OTPD组。MPD组患者的TD显著更小（<0.001），SA更大（<0.001），CDI更大（=0.03），PT更大（=0.001）。LTI（=0.65）、rTER（=0.72）和pTT - TG距离（=0.12）与发生MPD的相关性不强。SA和CDI的多因素逻辑回归模型显示，发生MPD的曲线下面积为0.72；SA为170°且CDI为1.5的患者发生MPD的概率为0.78。
滑车发育不良（SA和TD）、高位髌骨（CDI）和PT的测量指标可能有助于区分MPD患者和OTPD患者。pTT - TG距离、LTI和rTER在两组之间未发现有统计学显著差异。SA和CDI的组合能以合理的准确性区分两组（曲线下面积 = 0.72）。应用该模型，SA为170°且CDI为1.5的患者发生MPD的概率为0.78。这可能有助于在初次脱位事件后为患者提供关于发生MPD可能性的咨询。
