[Southwick osteotomy in stable slipped capital femoral epiphysis: a long-term outcome study].

Objectives: Moderate to severe chronic stable slipped capital femoral epiphysis (SCFE) produce permanent irregularities in the femoral head and acetabulum. We report a single centre long-term outcome study of Southwick's procedure for the management of moderate or severe stable chronic SCFE with irregularity of the femoral head.

Methods: In the period from January 1978 to January 1990, 20 patients (16 girls, 4 boys; mean age 13 years; range 11 to 15 years) underwent 22 Southwick osteotomies for chronic stable SCFE with closure or partial closure of the growth plate and a slip between 30 degrees and 70 degrees . All osteotomies were performed by the same surgeon. Patients were followed-up for an average of 22 years (range 16 to 28 years).

Results: External rotation deformity was corrected, and the Trendelenburg sign was hardly observable in any of the patients from six months of surgery. Radiographically, all patients showed full consolidation of the osteotomy within two months of surgery. There was no further epiphyseal slipping. We did not encounter any infection or avascular necrosis. Only one patient developed chondrolysis, which resolved fully in eight months. At the latest follow-up, no limb length discrepancy was seen in 18 patients, while two patients had a mean of 0.8 cm shortening. Eight patients (36.4%) showed radiographic evidence for degenerative joint disease, but none were symptomatic.

Conclusion: The management of chronic stable (moderate to severe) SCFE by Southwick's osteotomy is safe, but technically demanding. It affords good predictable outcome with a low complication rate.