OBJECTIVE The Pavlik harness (PH) has been widely used as the standard treatment for infants with developmental dysplasia of the hip (DDH). When the initial application of the PH fails, alternative treatments, such as closed reduction, open reduction, and reapplication of the PH will be considered. Compared with other treatments, reapplication of the PH offers certain advantages, including simplicity and reduced physical, and psychological stress, on both infants and caregivers. This study aims to investigate the effectiveness of reapplying the PH in patients with DDH. METHODS This study included patients with DDH (complete dislocation) who were treated by reapplication of PH between 1988 and 2012. Patients who were able to follow-up for more than 5 years were included. We examined the reduction rate and several factors to identify indicators associated with successful reduction during reapplication, including age, sex, side of hip dislocation, and the presence of the Ortolani sign. At the final follow-up, hip development was assessed using the Severin classification, whereas avascular necrosis (AVN) was evaluated using the Kalamchi classification and the Salter criteria. RESULTS A total of 56 patients (48 females and 8 males) and 57 hips were included in this study. The mean age at first and second application of PH was 4.2 months old (range: 0.12 to 6.4), and 5.8 months old (3.0 to 11.4), respectively. The reduction rate was 49% (28 out of 57 hips). Among the successfully reduced hips, the AVN rate was 3.6% (1 out of 28 hips). The Severin classification revealed 27 hips in class I and 1 hip in class III. Statistical analysis indicated a significantly higher proportion of left hip involvement in the reduction group (85% vs 41%, χ2 test, P < 0.001). Although not statistically significant, the rate of positive Ortolani sign tended to be higher in the reduction group (61% vs 38%, χ2 test, P = 0.06). CONCLUSION The reapplication method demonstrated a 49% reduction rate and a low AVN rate of 3.6% in our study. It is worth considering for patients who fail the initial PH treatment, particularly in cases of left-side dislocation and a positive Ortolani sign during the initial application.

中文翻译：

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最初 Pavlik 安全带失效后重新应用 Pavlik 安全带治疗髋关节发育不良。

目的 Pavlik 安全带 (PH) 已广泛用作婴儿发育性髋关节发育不良 (DDH) 的标准治疗方法。当初次应用 PH 失败时，将考虑替代治疗，如闭合复位、切开复位、重新应用 PH。与其他治疗相比，重新应用 PH 具有一定的优势，包括简单并减少婴儿和护理人员的身体和心理压力。本研究旨在探讨 DDH 患者重新应用 PH 的有效性。方法 本研究纳入了 1988 年至 2012 年间通过重新应用 PH 治疗的 DDH（完全脱位）患者。能够随访 5 年以上的患者也纳入其中。我们检查了复位率和几个因素，以确定在重新应用期间与成功复位相关的指标，包括年龄、性别、髋关节脱位一侧以及 Ortolani 征的存在。在最后一次随访中，使用 Severin 分类评估髋关节发育，使用 Kalamchi 分类和 Salter 标准评估股骨头缺血性坏死 (AVN)。结果 本研究共纳入 56 名患者（48 名女性和 8 名男性）和 57 个髋关节。第一次和第二次应用 PH 的平均年龄分别为 4.2 个月（范围：0.12 至 6.4）和 5.8 个月（3.0 至 11.4）。缩小率为 49%（57 个臀部中的 28 个）。在成功缩小髋关节的患者中，AVN 率为 3.6%（28 个髋关节中有 1 个）。Severin 分类显示 27 个髋关节属于 I 级，1 个髋关节属于 III 级。统计分析表明复位组左髋关节受累比例显着较高（85% vs 41%，χ2 检验，P < 0.001）。尽管没有统计学意义，但复位组 Ortolani 征阳性率较高（61% vs 38%，χ2 检验，P = 0.06）。结论 在我们的研究中，重新应用方法显示出 49% 的减少率和 3.6% 的低 AVN 率。对于初次 PH 治疗失败的患者，尤其是在初次治疗期间出现左侧脱位且 Ortolani 征阳性的患者，值得考虑。