Kitoh Hiroshi, Kawasumi Motoaki, Ishiguro Naoki
Department of Orthopaedic Surgery, Nagoya University School of Medicine, Nagoya, Aichi, Japan.
J Pediatr Orthop. 2009 Sep;29(6):552-7. doi: 10.1097/BPO.0b013e3181b2f200.
The Pavlik harness is a widely used and effective means of initial treatment of developmental dysplasia of the hip (DDH), but some hips fail to stabilize with the use of harness and avascular necrosis (AVN) of the femoral head can occur. Predictive factors for unsuccessful Pavlik harness treatment should be determined for appropriate indication of the treatment and prevention of AVN.
The outcome of Pavlik harness treatment for DDH was retrospectively examined in 221 hips of 210 patients who were treated initially at our institution and followed up for at least 1 year after the application of the harness. Univariate analysis was performed to determine predictors for failure of reduction and for the incidence of AVN by using the Mann-Whitney U test for continuous variables and the Fisher exact test or the Pearson test for categorical variables. Next, independent multivariate predictors for the failure of reduction and the incidence of AVN were identified using logistic regression analysis.
One hundred and eighty-one hips were reduced and the overall rate of reduction was 81.9%. AVN that was diagnosed according to the criteria of Salter et al was identified in 16 of the 181 reduced hips and the rate of incidence of AVN was 8.8%. Bilaterality and decreased distance "a," as defined by Yamamuro and Chene, were statistically significant univariate and multivariate risk factors for the failure of reduction. Between them, distance a was the most powerful predictor. Adduction contracture of the hip (abduction with the hips flexed to 90 degrees <60 degrees) was the only significant univariate and multivariate predictor for the incidence of AVN.
Distance a and adduction contracture of the hip were important predictors for the outcome of Pavlik harness treatment. We concluded that the Pavlik harness is a very safe and effective means of DDH treatment for the hips with abduction > or = 60 degrees and distance a > or = 6 mm.
Therapeutic studies, level III (retrospective study).
Pavlik吊带是治疗发育性髋关节发育不良（DDH）的一种广泛应用且有效的初始治疗方法，但有些髋关节在使用吊带治疗时未能实现稳定，并且可能会发生股骨头缺血性坏死（AVN）。应确定Pavlik吊带治疗失败的预测因素，以便合理选择治疗方法并预防AVN。
回顾性分析了210例患者的221个髋关节，这些患者最初在我院接受Pavlik吊带治疗，并在使用吊带后至少随访1年。采用Mann-Whitney U检验分析连续变量，采用Fisher精确检验或Pearson检验分析分类变量，进行单因素分析以确定复位失败和AVN发生率的预测因素。接下来，使用逻辑回归分析确定复位失败和AVN发生率的独立多因素预测因素。
181个髋关节实现了复位，总体复位率为81.9%。根据Salter等人的标准，在181个复位的髋关节中有16个被诊断为AVN，AVN发生率为8.8%。双侧受累以及Yamamuro和Chene定义的“a”距离减小，是复位失败的单因素和多因素统计学显著危险因素。其中，a距离是最有力的预测因素。髋关节内收挛缩（髋关节屈曲90度时外展<60度）是AVN发生率的唯一单因素和多因素显著预测因素。
a距离和髋关节内收挛缩是Pavlik吊带治疗效果的重要预测因素。我们得出结论，对于外展>或=60度且a距离>或=6mm的髋关节，Pavlik吊带是一种非常安全有效的DDH治疗方法。
治疗性研究，III级（回顾性研究）。
