Functional and radiologic results of posteromedial limited surgery in developmental dysplasia of the hip

Abstract

PURPOSE OF THE STUDY In treatment algorithm of developmental dysplasia of the hip, posteromedial limited surgery is placed between closed reduction and medial open articular reduction. The aim of the present study was to assess the functional and radiologic results of this method. MATERIAL AND METHODS This retrospective study was performed in 37 Tönnis grade II and III dysplastic hips of 30 patients. The mean age of the patients at operation was 12.4 months. The mean follow-up time was 24.5 months. Posteromedial limited surgery was applied when sufficient stable concentric reduction was not achieved by closed technique. No pre-operative traction was applied. Postoperatively, human position hip spica cast was applied for 3 months. Outcomes were evaluated regarding modified McKay functional results, acetabular index and presences of residual acetabular dysplasia or avascular necrosis. RESULTS Thirty-six hips had satisfactory and one hip had poor functional result. The mean pre-operative acetabular index was 34.5 degrees. It improved to 27.7 and 23.1 degrees at the postoperative 6th month and the last control X-Rays. The change in acetabular index was statistically significant (p<0.05). At the last control, 3 hips had findings of residual acetabular dysplasia and 2 hips had avascular necrosis. CONCLUSIONS Posteromedial limited surgery for developmental dysplasia of the hip is indicated when closed reduction remains insufficient and medial open articular reduction remains unnecessarily invasive. This study, in line with the literature, provides evidences that this method might decrease the incidences of residual acetabular dysplasia and avascular necrosis of the femoral head.