Evaluation and compensation of lower limb length discrepancy after surgical treatment of developmental hip dysplasia

The aim of this study was to find a solution for lower limb length discrepancy following surgical treatment of developmental hip dysplasia (DDH) in neglected cases. For this purpose, radiographic examination of 49 hips of 33 children with DDH was made. They were surgically treated by one-stage combined procedure that consisted of open reduction, modified innominate osteotomy and proximal femoral osteotomy. Mean age was 3.5 years and mean follow-up was 34.3 months. In bilateral cases this procedure did not cause notable lower limb length discrepancy. In unilateral cases, it was seen that limb length could be balanced by performing a modified innominate osteotomy producing transiliac lengthening in children older than 4 years. In children younger than 4 years there was no need to perform an acetabuloplasty producing transiliac lengthening because extensive femoral shortening was not needed and femoral overgrowth was sufficient to balance the length of lower limbs. Also avascular necrosis of the femoral head was observed as one of the important factors producing limb length discrepancy in variable degrees.