[Indication for and results of intertrochanteric osteotomy in slipped capital femoral epiphysis].

The progression of degenerative changes of the hip after slipped capital femoral epiphysis (SCFE) largely correlates with the patient's age at the time the deformity occurs and with the degree of the epiphyseal gliding. From the pathogenetic point of view, the altered biomechanical conditions of the hip joint with deformation of the proximal femur may result in an impingement of the femoral neck metaphysis against the anterior acetabular rim. Observations of the "natural course" or after "in situ fixation" of the epiphysis show the development of secondary hip arthritis at an average of 20 years after SCFE, specifically in slips with more than 30 degrees of epiphyseal gliding. The intertrochanteric osteotomy as introduced by G. Imhäuser aims at restoring joint congruity to reduce the prearthrotic deformity and thus to decrease the incidence of later hip arthritis. The reorientation of the predominantly posteriorly slipped femoral epiphysis is achieved by an intertrochanteric flexion osteotomy, which reduces the potential for femoroacetabular impingement. On the basis of a long-term evaluation, the indication for and results of an intertrochanteric osteotomy for chronic unilateral SCFE were presented. Of the 51 patients operated on between 1962 and 1972 and examined clinically and radiographically at an average follow-up time of 24 years (20-29 years) after osteotomy, 55% showed a hip free of degenerative changes, 28% had developed moderate degenerative changes, and 17% had advanced arthritis. Aside from a few technical errors, the correction at the intertrochanteric level for moderate slips proved to be a safe procedure regarding risk for femoral head necrosis. The long-term development after SCFE is most important for patients with SCFE. More than half of the patients have hip joints free of degenerative changes more than 20 years after intertrochanteric osteotomy according to G. Imhäuser, which compares favorably to the "natural course" or to "in situ fixation" and which supports the indication for this corrective procedure in SCFE.