Long-term follow-up of open reduction surgery for developmental dislocation of the hip.

BACKGROUND: We posed 2 questions: what is the long-term result of open reduction surgery in developmental dysplasia of the hip, and is there an age at surgery above which the outcome was too poor to recommend the operation?

METHODS: Between 1955 and 1995, 148 patients with 179 dislocated hips had open reduction surgery for developmental dysplasia of the hip (141 anterior and 38 Ludloff medial approaches). We attempted to locate all 148 patients for the follow-up evaluation.

RESULTS: Fifty-three patients (36%) with 66 hips (37%) were located and participated in the study. These 66 hips represented 34% of the anterior open reductions and 47% of the Ludloff medial reductions. Twenty-two of the 66 hips had Severin IV or worse outcomes and included 7 with total hip arthroplasties and 2 with hip fusions. Age at surgery was significantly lower for Severin I, II, and III, compared with Severin IV and above (P=0.003, 0.001, 0.003) with outcomes deteriorating substantially after age 3. Approximately half of the hips required further surgery for dysplasia. All hips that sustained osseous necrosis had Severin IV or worse outcomes, and hips that redislocated and required revision surgery only achieved Severin I or II ratings 18% of the time. Nine "normal" hips became dysplastic and 3 had pelvic osteotomies as teenagers. Two other normal hips developed osseous necrosis during treatment of the contralateral hip.

CONCLUSIONS: Results deteriorate as the age at surgery increases. Osseous necrosis and redislocation predict a poor functional and radiographic result. The "normal" hip may develop insidious dysplasia and also may be injured during treatment of the involved hip. Above age 3, some patients may not have sufficient acetabular growth to remodel a surgically reduced hip.

LEVEL OF EVIDENCE: Level IV--case series.