Retrospective follow-up of 51 patients with unilateral, moderate to severe slipped capital femoral epiphysis (indication: epiphyseal displacement angle of 30-60 degrees, average preoperative displacement angle 45 degrees) that was corrected surgically by Imhäuser intertrochanteric osteotomy and epiphyseal nailing. After an average observation time of 24 years (range: 20-29 years), 28 (55%) of the 51 hip joints were clinically asymptomatic and radiologically free of degenerative changes; moderate clinical and radiologic changes were recorded for 14 hip joints (28%), and advanced changes for nine (17%). Complications related to surgery were apparent in a total of six hip joints: in one case, the Steinmann nail broke after being damaged by the plate blade; in two cases, revision osteosynthesis of the intertrochanteric osteotomy was necessary due to incorrect implant positioning; partial femoral head necrosis developed in one hip joint; there were two cases of low-grade osteomyelitis that healed after implant removal.