Long-term results after two-stage operative treatment of late developmental displacement of the hip.

The purpose of this study was to evaluate the long-term results of 43 patients who underwent two-stage operative treatment of late developmental displacement of the hip (LDH). The average age at the time of open reduction was 20.7 months. An intertrochanteric osteotomy was performed after an average of 6.7 weeks. The mean clinical and radiological follow-up was 32.75 years. Degenerative changes were documented according to Kellgren. For assessment of outcome we used Severin's classification and score according to Merle d'Aubigné. One patient required a total hip replacement. Complications included one superficial infection and three recurrent dislocations. One patient developed coxa magna and two additional avascular necrosis of the hip. The score according to Merle d'Aubigné was 16.1. At the latest follow-up 35 hips had degenerative changes grade 0 or 1 and 7 grade 2. Using the Severin classification 13 hips had a satisfactory result (class I), 14 were rated as class II, 7 as class III, 5 as class IV and 2 as class V. The two-stage procedure seems to be a successful principle in the operative treatment of LDH.