The place of threaded pin fixation in the treatment of slipped upper femoral epiphysis.

Pin fixation in the treatment of slipped upper femoral epiphysis was evaluated in 60 patients admitted to the authors' hospital in Melbourne between 1970 and 1978. Forty-three cases were reviewed at an average of eight years following initial treatment. For chronic slips, in situ fixation with pins prevented further slip and promoted growth plate closure. The complication rate was low. Best results were achieved with two or three threaded pins placed into the posteroinferior segment of the femoral head to avoid avascular necrosis. Early upper femoral osteotomy was not required, as considerable bone remodeling occurred even after growth plate closure. In contrast, avascular necrosis was common following treatment of acute, severe slips, even with gentle internal rotation of the leg to reduce the acute component of the slip and pinning.