Departments of Orthopedic Surgery (E.L.v.d.V., H.W., and R.J.B.S.), Radiology (E.J.B.), and Pediatrics (P.M.v.H.), University Medical Center Utrecht, Utrecht, the Netherlands.
Department of Biomechanical Engineering, Technical University Delft, Delft, the Netherlands.
J Bone Joint Surg Am. 2021 Mar 17;103(6):489-496. doi: 10.2106/JBJS.20.00515.
The introduction of stem cell transplantation has improved life expectancy and cognitive outcome in patients with mucopolysaccharidosis I, but this condition remains associated with substantial residual disease in several parts of the body. Many patients have hip dysplasia with progressive medial flattening of the femoral head. Quantitative evidence on the effect of surgery on remodeling to sphericity of flattened femoral heads is lacking. In the present study, we used statistical shape modeling to quantify the effect of hip surgery on the sphericity of the femoral head in patients with mucopolysaccharidosis I.
We performed a retrospective case control study involving a series of 23 patients with hip dysplasia due to mucopolysaccharidosis I. Surgery was not offered to the first 11 children (control group). Following a change in treatment protocol, the next 12 children underwent bilateral proximal femoral varus derotation osteotomy and Pemberton osteotomy for the treatment of acetabular dysplasia with progressive femoral head flattening (surgery group). The surgery and control groups were compared with a reference group of patients with normal hips. Statistical shape modeling was used to quantify the shape of the femoral head (i.e., flattening and/or roundness of the epiphysis).
The mean age at the time of stem cell transplantation in the surgery and control groups was comparable (1.2 years). The mean age at the time of surgical intervention was 5.5 years, and mean duration of postoperative follow-up was 3.3 years. Statistical shape modeling showed variations within the total group in terms of medial indentation, width, height, and sphericity of the femoral heads. In contrast to the progressive femoral head flattening in the control group, the surgery group showed improvement of the sphericity of the femoral head after surgery. The overall shape characteristics of the femoral head in the surgery group were similar to those of the reference group of patients with normal hips.
To our knowledge, this is the first study in patients with mucopolysaccharidosis I that has shown quantitative remodeling of the dysplastic, flattened femoral head to normal sphericity after increasing containment of the femoral head.
Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.
干细胞移植的引入提高了黏多糖贮积症 I 型患者的预期寿命和认知结果，但该疾病在身体的多个部位仍存在大量残留疾病。许多患者患有髋关节发育不良，伴有股骨头内侧逐渐变平。关于手术对扁平股骨头重塑为球形的效果的定量证据尚缺乏。本研究中，我们使用统计形状建模来定量评估黏多糖贮积症 I 型患者髋关节手术对股骨头球形度的影响。
我们进行了一项回顾性病例对照研究，纳入了 23 例因黏多糖贮积症 I 型导致髋关节发育不良的患者。前 11 例患儿未接受手术（对照组）。改变治疗方案后，接下来的 12 例患儿接受双侧股骨近端内旋截骨术和 Pemberton 截骨术治疗髋臼发育不良伴股骨头渐进性扁平（手术组）。手术组和对照组与髋关节正常的患者参考组进行比较。使用统计形状建模来定量评估股骨头的形状（即骨骺的扁平程度和/或圆度）。
手术组和对照组在干细胞移植时的平均年龄相当（1.2 岁）。手术干预的平均年龄为 5.5 岁，术后随访的平均时间为 3.3 年。统计形状建模显示，总组内存在股骨头内侧凹陷、宽度、高度和球形度的变化。与对照组中渐进性股骨头扁平相反，手术后手术组的股骨头球形度得到改善。手术组股骨头的整体形状特征与髋关节正常的患者参考组相似。
据我们所知，这是首例黏多糖贮积症 I 型患者的研究，该研究表明，通过增加股骨头的包容，可以使发育不良的扁平股骨头定量重塑为正常球形。
治疗性 III 级。欲了解完整的证据水平说明，请参见作者指南。
