RESUMO
PURPOSE: The ability to monitor and study developmental dysplasia of the hip (DDH) requires validated radiographic outcome measures. The sourcil method of acetabular index measurement (AI-S) has not yet been shown to be a reliable measure of acetabular dysplasia in a DDH population, despite its widespread use. The aims of this study were to test the reliability of the AI-S method in a DDH population, and to compare the reliability of the AI-S method with that of the classic lateral edge method (AI-L). METHODS: From an institutional database, standardized anteroposterior hip radiographs were obtained from a cohort of 35 female patients (70 hips) at two and five years of age who had been treated nonoperatively for DDH. Three observers independently measured the acetabular index using the AI-L and AI-S methods on all 70 hips at two time points, four weeks apart. RESULTS: The inter-rater reliability intraclass correlation coefficient (ICC) for the AI-L and AI-S methods was between good and excellent at 0.94 (confidence interval (CI) 0.89 to 0.96) and 0.91 (CI 0.87 to 0.94), respectively. The ICCs for intra-rater reliability for the AI-L method were excellent at 0.93 (CI 0.90 to 0.95), 0.95 (CI 0.93 to 0.97) and 0.95 (CI 0.94 to 0.97) for raters 1, 2 and 3, respectively. The ICCs for intra-rater reliability for the AI-S method were between good and excellent at 0.91 (CI 0.87 to 0.93), 0.93 (CI 0.90 to 0.95) and 0.90 (CI 0.86 to 0.93) for raters 1, 2 and 3 respectively. CONCLUSION: Both AI-S and AI-L methods are equally reliable radiographic measures of DDH. LEVEL OF EVIDENCE: Level III (diagnostic).
RESUMO
Developmental dysplasia of the hip (DDH) is the most common orthopaedic disorder in newborns. While the Pavlik harness is one of the most frequently used treatments for DDH, there is immense variability in treatment parameters reported in the literature and in clinical practice, leading to difficulties in standardizing teaching and comparing outcomes. In the absence of definitive quantitative evidence for the optimal Pavlik harness management strategy for DDH, we addressed this problem by obtaining international expert-based consensus on the subject. METHODS: An initial list of items relevant to Pavlik harness treatment was derived by a review of the literature. Delphi methodology was used to guide serial rounds of surveying and obtaining feedback from content matter experts from the International Hip Dysplasia Institute (IHDI), which continued in the same manner until consensus based on standard statistical analysis was reached. This was followed by a corroboration of face validity to derive the final set of management principles. RESULTS: Four rounds of structured surveying were required to reach consensus. Following 2 rounds of peer review, and from an initial list of 66 items in 8 categories, we were able to derive 2 simplified, yet comprehensive, print-friendly tables consisting of 28 items in 8 categories to assist clinicians in managing DDH with a Pavlik harness. The tables contain principles of treatment initiation, application and follow-up of the harness, complications, weaning, and end-of-treatment decision-making as well as specific criteria based on the severity of the DDH. Furthermore, highly contentious items were identified as important areas of future study. CONCLUSIONS: We developed a comprehensive set of principles based on expert consensus to assist clinicians in the management of DDH using the Pavlik harness. This study also generated a list of the most controversial areas in the nonoperative management of DDH, which should be considered high priority for future study to further refine and optimize outcomes. LEVEL OF EVIDENCE: Therapeutic Level V. See Instructions for Authors for a complete description of levels of evidence.