A new, objective radiographic classification system for the assessment of treatment results in developmental dysplasia of the hip

Abstract

The new, objective radiographic classification system for the assessment of treatment results in developmental dysplasia of the hip includes three quantitative parameters: centre–edge angle of Wiberg, acetabular angle of Sharp and the centre–trochanter distance. Each parameter is divided into three subgroups and assigned a point score (0, 1 and 2) according to their previously determined values. Besides this, three corrective items on the existence of middle/posterior acetabular deficiency, secondary operation and resubluxation/redislocation are added to the classification system and in the presence of any of these items, one point for each item is extracted from the total points. A total of five or six points represents a satisfactory outcome and less than five points, an unsatisfactory outcome. The new system was found to have adequate intraobserver and interobserver agreement levels. It was also observed that, the gold standard Severin system could lead the raters to obtain somewhat more optimistic results with respect to the new system before and after skeletal maturity. It was concluded that the present system could evaluate both the final radiographic status of the hip and the success or failure of the primary treatment and could be capable of leading orthopaedic surgeons to speak the same language while assessing radiographic results in developmental dysplasia of the hip.