Slipped upper femoral epiphysis: internal fixation using single central pins.

Eighteen patients with slipped upper femoral epiphyses were treated by internal fixation using single pins in the centre of the femoral head. In 15 patients, prophylactic pinning of the unaffected side was performed; therefore, 33 hips were pinned. Results were encouraging in that no slip progressed following fixation, no pins broke, and no late reslips occurred. The optimum position for a pin is in the centre of the femoral head, with subsequent pins in suboptimal sites. The method of single pinning is simple and, theoretically, minimizes the risk of joint penetration.