Long-term result of combination of open reduction and femoral derotation varus osteotomy with shortening for developmental dislocation of the hip.

This study examined femoral derotation varus osteotomy with shortening performed on children with developmental dislocation of the hip. Each patient reached 14 years of age. Surgical outcomes were evaluated clinically and roentgenographically. We studied nine patients with 11 joints undergoing surgical repair. Age at the time of operation averaged 2 years and 1 month; the period of observation averaged 15 years and 7 months; and age at final investigation averaged 17 years and 8 months. Each patient underwent the study operation as an initial treatment. Salter pelvic osteotomy was reserved as a second treatment for those patients whose acetabular development proved inadequate during post-surgical observation. The evaluation method established by McKay was utilized to determine clinical results at the time of final investigation; 73% of the study group were established as having good results. Severin's evaluation method was used to assess roentgenographical results; 45% of the study group were determined to have good results. Kalamchi's evaluation method allowed six joints to be diagnosed with avascular necrosis of the femoral head; however, in all cases but one, necrosis had been present prior to surgery. Those six joints that did not have necrosis of the femoral head prior to surgery developed only one mild necrosis subsequent to surgery. Achieving a stable reduced position by femoral derotation varus osteotomy, as well as sufficient decompression of the femoral head by shortening osteotomy, are considered to have played very important roles in preventing the femoral head from developing necrosis.