The treatment of slipped capital femoral epiphysis (SCFE) has been well described by many authors. However, few studies report the results of treatment at very long term. The purpose of this study is to observe late results and to distinguish which factors can influence the development of osteoarthrosis.
Twenty-six patients (30 hips) with SCFE treated between 1945 and 1980 were reviewed with a minimal follow-up of 10 years. The measure of the displacement was done in 3 groups: slipping inferior to 30 degrees, slipping between 30 degrees and 60 degrees and slipping superior to 60 degrees. There were 14 cases in group 1, 12 in group 2 and 4 in group 3. Four cases had bilateral involvement. 24 hips underwent surgical treatment: 10 in situ fixation, 10 orthopedic reduction and screw fixation, 2 cervical osteotomies and 1 Dunn's operation. 5 cases had no treatment or simple traction in bed and 2 cases had reduction and spica cast.
Clinical evaluation was done with the Merle d'Aubigné hip score and the radiographical revision on anteroposterior and Lauenstein projections. Osteoarthrosis was assessed according to the narrowing of articular space and the flattening of the head.
Early complications: 4 cases of chondrolysis appeared 3 times after orthopedic reduction and fixation. Two material effractions and one hyperreduction of the displacement were observed. Radiographic degradation was constant. 2 cases of segmental collapse were also seen, once associated with hyperreduction and once with material fixation. Revision: the average follow-up was 19 years (11 to 46 years). 20 hips (66 per cent) had very good functional results. 18 hips (60 per cent) had radiographic arthrosis. No statistic tests were done because of the small number of cases. However 9 out of 10 in situ fixation and 6 out of 10 reduction and fixation had very good results. When the residual slip was less than 40 degrees (12 cases), osteoarthrosis was never seen. 40 degrees represented the limit between arthrosic and non arthrosic evolution. The mean time of development of arthrosis was 25 years.
The worst results appeared to happen after reduction and spica cast, cervical osteotomy and traction in bed. Best results after in situ fixation, Dunn's operation and no treatment. Reduction and fixation gave divided results. The osteoarthrosis increased with time. The limit of 40 degrees as factor leading to osteoarthrosis was found to be nearly similar to that of others authors. Discrepancy was superior to 1 cm in 84 per cent of cases, but most of the time neglected or unknown by patients.
In our series, osteoarthrosic hips are seen in 60 per cent cases. Radiographic degradation was constant after 25 evolution years. The hips with less than 40 degrees slipping after treatment have the best results and no arthrosis. Thus, in situ fixation is recommended for slipping inferior to 40 degrees. If displacement is greater than 40 degrees, Dunn's operation or trial orthopedic reduction to obtain a reduction of slipping is preferred, according to the character (chronic or acute) of the slip.