The purpose of this study was to evaluate clinical and radiological results in patients operated for recurrent patellar instability with a surgical approach consisting of Insall proximal realignment with/without tibial tubercle osteotomy (TTO). Patients that underwent surgery for recurrent patellar instability at one centre with a uniform technique between 2004 and 2020 were included. Eligible patients were assessed by clinical examination and the disease-specific Banff Patellofemoral Instability Instrument 2.0 (BPII 2.0). Pre- and postoperative radiographs were analysed for patellofemoral osteoarthritis (OA) according to Iwano. Preoperative Magnetic Resonance Imaging (MRI) and radiographs were analysed for anatomical risk factors for patellar instability. Student t-test, chi-square test and ANOVA-analyses were used to investigate whether anatomical risk factors and/or patient characteristics could predict an inferior outcome. Forty-six patients (47 knees) were included at a mean follow-up time of 6.6 years (SD 4.6; range 1–17). Mean BPII 2.0 score was 60.4 (SD 18.4; range 26–98), and 10.6% (n = 5) had suffered a postoperative redislocation. Progression to evident patellofemoral OA was seen in 15% of the patients (p < 0.05). The presence of pathoanatomic risk factors did not correlate with recurrent postoperative instability or inferior BPII 2.0 score at the final evaluation. Patients treated with the current approach reported acceptable medium- to long-term results, but the risk of patellofemoral OA progression is significant. These findings add to the knowledge of expected outcomes after procedures involving Insall proximal realignment, and can guide clinical decision making for surgeons using similar methods. Level IV, case series.

中文翻译：

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Insall 近端重新排列联合/不联合胫骨结节截骨术治疗复发性髌骨不稳定产生可接受的中长期结果，但骨关节炎进展的风险相当大

本研究的目的是评估因复发性髌骨不稳而手术的患者的临床和影像学结果，该手术方法包括 Insall 近端重新排列加/不加胫骨结节截骨术 (TTO)。纳入 2004 年至 2020 年间在一个中心采用统一技术接受复发性髌骨不稳手术的患者。符合条件的患者通过临床检查和疾病特异性 Banff 髌股关节不稳仪器 2.0 (BPII 2.0) 进行评估。根据 Iwano 的说法，分析了髌股骨关节炎 (OA) 的术前和术后 X 光片。分析了术前磁共振成像 (MRI) 和 X 光片的髌骨不稳的解剖危险因素。学生 t 检验，卡方检验和 ANOVA 分析用于调查解剖危险因素和/或患者特征是否可以预测较差的结果。包括 46 名患者（47 膝），平均随访时间为 6.6 年（标准差 4.6；范围 1-17）。平均 BPII 2.0 评分为 60.4（SD 18.4；范围 26-98），10.6%（n = 5）发生术后再脱位。15% 的患者进展为明显的髌股骨 OA（p < 0.05）。在最终评估中，病理解剖学危险因素的存在与复发性术后不稳定或较差的 BPII 2.0 评分无关。接受当前方法治疗的患者报告了可接受的中长期结果，但髌股骨 OA 进展的风险显着。这些发现增加了对 Insall 近端重新排列手术后预期结果的了解，并可以指导使用类似方法的外科医生的临床决策。第四级，案例系列。