BACKGROUND Anterior distal femoral hemiepiphysiodesis (ADFH) is a surgical treatment choice to correct flexed knee gait and fixed knee flexion deformities in children with cerebral palsy who are skeletally immature. Increased anterior pelvic tilt has been reported after surgeries that correct knee flexion deformities, including hamstring lengthening (HSL) and distal femoral extension osteotomies, but anterior pelvic tilt has not been studied after ADFH. We hypothesized that anterior pelvic tilt would increase after ADFH, especially when combined with HSL, and it would correlate with the change in minimum knee flexion in stance and dynamic hamstring lengths. METHODS Thirty-four eligible participants (age: 13.0, SD: 2.0) were included. Change in mean pelvic tilt across the gait cycle was compared as a function of clinical and gait parameters using linear mixed models. The relationship of change in pelvic tilt to change in other variables was examined using Pearson correlation. RESULTS Overall, anterior pelvic tilt increased significantly after ADFH by 4.4 degrees (P = 0.02). Further, the analysis revealed anterior pelvic tilt only increased significantly in the group that had concurrent HSL (11.1 degrees, P < 0.001). Overall, minimum knee flexion significantly decreased (increase in knee extension) in stance (-19.1 degrees, P < 0.001) and there was an increase in maximum normalized dynamic hamstring lengths (0.03, P < 0.001). The anterior pelvic tilt increased significantly in Gross Motor Function Classification System levels III to IV (5.9 degrees, P = 0.02) but did not change significantly in Gross Motor Function Classification System I to II (2.5 degrees, P = 0.37). Change in pelvic tilt was correlated with change in maximum dynamic hamstring lengths (r = 0.87, P < 0.0001) and change in minimum knee flexion in stance (r = -0.71, P < 0.0001). CONCLUSIONS Anterior distal hemiepiphysiodesis without concurrent HSL for flexion knee deformities does not result in increased anterior pelvic tilt. Surgeons should consider anterior distal hemiepiphysiodesis in patients with cerebral palsy and flexed knee gait, who preoperatively have long dynamically modeled hamstrings, are skeletally immature, and when maintenance of pelvic tilt is desired. LEVEL OF EVIDENCE Level III-retrospective comparative study.

中文翻译：

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股骨远端前侧半骨骺固定术不会改变脑瘫儿童的骨盆倾斜度。

背景股骨远端前侧半骨骺固定术（ADFH）是一种手术治疗选择，用于纠正骨骼未成熟的脑瘫儿童的膝关节屈曲步态和固定膝关节屈曲畸形。据报道，矫正膝关节屈曲畸形的手术（包括腘绳肌延长术 (HSL) 和股骨远端延长截骨术）后骨盆前倾增加，但 ADFH 后骨盆前倾尚未进行研究。我们假设 ADFH 后骨盆前倾会增加，尤其是与 HSL 结合时，并且它与站立时最小膝关节屈曲和动态腘绳肌长度的变化相关。方法 纳入 34 名符合条件的参与者（年龄：13.0，SD：2.0）。使用线性混合模型将步态周期中平均骨盆倾斜度的变化作为临床和步态参数的函数进行比较。使用皮尔逊相关性检查骨盆倾斜度变化与其他变量变化的关系。结果 总体而言，ADFH 后骨盆前倾显着增加 4.4 度（P = 0.02）。此外，分析显示，骨盆前倾仅在患有 HSL 的组中显着增加（11.1 度，P < 0.001）。总体而言，站立时最小膝关节屈曲显着下降（膝关节伸展增加）（-19.1 度，P < 0.001），最大标准化动态腘绳肌长度增加（0.03，P < 0.001）。粗大运动功能分类系统III至IV级中骨盆前倾显着增加（5.9度，P = 0.02），但粗大运动功能分类系统I至II级中骨盆前倾没有显着变化（2.5度，P = 0.37）。骨盆倾斜的变化与最大动态腘绳肌长度的变化（r = 0.87，P < 0.0001）和站立时最小膝关节弯曲的变化（r = -0.71，P < 0.0001）相关。结论 对于膝关节屈曲畸形，前远端半骨骺固定术不同时进行 HSL 不会导致骨盆前倾增加。对于脑瘫和屈膝步态的患者，外科医生应考虑前远端半骨骺固定术，这些患者术前具有较长的动态模型腿筋，骨骼不成熟，并且需要维持骨盆倾斜。证据级别 III 级——回顾性比较研究。