Background:It remains unclear which subset of patients with recurrent patellofemoral instability would benefit from a concomitant bony realignment procedure in addition to a medial patellofemoral ligament (MPFL) reconstruction.Purpose:To provide midterm results for patients who underwent an isolated MPFL reconstruction as part of an ongoing prospective trial.Study Design:Case series; Level of evidence, 4.Methods:Patients with recurrent patellar instability were prospectively enrolled in an institutional registry beginning in March 2014. Exclusion criteria included history of a previous surgery for patellar instability, an off-loadable (inferior/lateral) chondral defect, anterior knee pain ≥50% of their chief complaint, and a “jumping J” sign. All patients underwent primary, unilateral, isolated MPFL reconstruction regardless of their bony anatomic characteristics. Patient-reported outcome measures (PROMs), episodes of recurrent instability, and ability to return to sport were obtained annually. Radiographic measurements of baseline radiographs and MRI were obtained at baseline.Results:A total of 138 patients underwent isolated MPFL reconstruction between March 2014 and December 2019. The mean radiographic measurements were tibial tubercle–trochlear groove, 15.1 ± 4.9 mm; Caton-Deschamps index, 1.14 ± 0.16; patellar trochlear index, 46.9% ± 15.1%; trochlear depth index, 2.5 ± 1.2 mm; tibial tubercle to lateral trochlear ridge, −8.4 ± 5.7 mm; and patellar tendon to lateral trochlear ridge, 5.7 ± 6.2 mm. Trochlear dysplasia, defined as a trochlear depth index <3 mm, was present in 79/125 (63%) patients. A total of 50 patients reached ≥5 years, of whom 40 (80%) completed follow-up PROMs. A total of 119 patients reached ≥2 years, of whom 89 (75%) completed follow-up PROMs. Six patients (5%) reported recurrent instability with a mean time of 2.97 years after surgery. All PROMs improved over time except for the Pediatric Functional Activity Brief Scale (Pedi-FABS), which had no change. At 2 years, the mean changes from baseline for Knee injury and Osteoarthritis Outcome Score (KOOS) Quality of Life subscale (QOL), Pedi-FABS, International Knee Documentation Committee (IKDC) score, KOOS Physical Function Short Form (PS), and Kujala score were 42.1, 0.6, 35.1, –23.5, and 32.3, respectively. All changes had P values <.001 except for Pedi-FABS, which showed no change and had P > .999. At 5 years, the mean changes from baseline for KOOS-QOL, Pedi-FABS, IKDC, KOOS-PS, and Kujala score were 42.6, –2.8, 32.6, –21.5, and 31.6, respectively. All changes had P values <.001 except for Pedi-FABS, which showed no change and had P > .453. In total, 89% of patients returned to sport with a mean of 9.1 months.Conclusion:Midterm outcomes for patients who underwent isolated MPFL reconstruction were favorable and were maintained at 5 years. Outcomes for the expanded cohort of patients with a minimum 2-year follow-up support previously published results.

中文翻译：

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孤立内侧髌股韧带重建治疗复发性髌骨不稳定，无论胫骨结节 - 滑车沟距离和髌骨高度如何：至少 5 年结果


背景：目前尚不清楚，除了内侧髌股韧带 (MPFL) 重建之外，哪些复发性髌股不稳患者会受益于伴随的骨重新排列手术。目的：为接受孤立性 MPFL 重建作为治疗的一部分的患者提供中期结果。研究设计：案例系列；正在进行的前瞻性试验。证据级别，4。方法：从 2014 年 3 月开始，前瞻性地将复发性髌骨不稳的患者纳入机构登记处。排除标准包括既往髌骨不稳手术史、可卸载（下/外侧）软骨缺损、前部软骨缺损。膝关节疼痛占主诉的 50% 以上，且出现“跳跃 J”征。所有患者均接受了初次、单侧、孤立性 MPFL 重建，无论其骨解剖特征如何。每年都会获得患者报告的结果指标（PROM）、反复不稳定的发作以及重返运动的能力。在基线时获得基线X光片和MRI的放射学测量结果：2014年3月至2019年12月期间，共有138名患者接受了孤立性MPFL重建。平均放射学测量结果为胫骨结节-滑车沟，15.1±4.9mm；卡顿-德尚指数，1.14±0.16；髌骨滑车指数，46.9%±15.1%；滑车深度指数，2.5±1.2毫米；胫骨结节至滑车外侧嵴，-8.4 ± 5.7 mm；髌腱至滑车外侧嵴，5.7 ± 6.2 毫米。滑车发育不良，定义为滑车深度指数 <3 id=0> .999。 5 年时，KOOS-QOL、Pedi-FABS、IKDC、KOOS-PS 和 Kujala 评分相对于基线的平均变化分别为 42.6、–2.8、32.6、–21.5 和 31.6。所有变化的 P 值均<。001，但 Pedi-FABS 除外，Pedi-FABS 没有变化且 P > .453。总共有 89% 的患者恢复运动，平均时间为 9.1 个月。结论：接受孤立性 MPFL 重建的患者的中期结果良好，并维持在 5 年。扩大的患者队列的结果具有至少 2 年的随访支持之前发布的结果。