Abstract
Purpose of Study
Multiple measurements have been described for the assessment of developmental dysplasia of the hip (DDH). In particular, the centre edge angle (CEA) has been described by Wiberg to assess the position of the femoral head in relation to the acetabular edge in patients over the age of five years. The purpose of this study is twofold. Firstly to assess the reliability of all measurements available in the literature and secondly to evaluate whether or not the CEA can be reliably measured below five years of age.
Methods
Eighty seven patients were included for assessment. Radiographs were measured within six months of spica cast/Batchelor cast removal, depending on whether closed or open reduction was performed. A web based computer programme was used to store the radiographs electronically and with the help of an electronic template the following measurements were recorded: CEA, AI, centre head distance discrepancy ratio (CHDDR), Smith's c/b and h/b ratios. Three readers recorded measurements at two intervals, to determine intra and inter reader reliability.
Results
The mean age at measurement was 2.26 years (Range 0.60–5.99). Regarding intra reader reliability, the AI and CEA were the most reliable measurements with a mean intraclass correlation coefficient (ICC) of 0.87 [CI 0.78–0.94] and 0.78 [CI 0.43–0.94] respectively. Regarding inter reader reliability, the CEA was the most reliable measurement with a mean ICC of 0.84 [CI 0.79–0.90].
Conclusion
This study confirms the reliability of the CEA, AI, CHDDR, Smith's c/b and h/b ratios in children with DDH. It also describes the reliable use of the CEA at a younger age in DDH than previously described which has prognostic implications.
NO DISCLOSURES
