Oblique in situ screw fixation of stable slipped capital femoral epiphysis.

BACKGROUND: Percutaneous in situ single screw fixation is the preferred treatment for stable slipped capital femoral epiphysis. The recommended screw placement is in the center of the epiphysis and perpendicular to the physis. We reviewed the results of in situ fixation with the screw placed oblique to the physis.

METHODS: Thirty-six stable slips were treated with a modified technique. The screw was started as close to the mid lateral cortex of the proximal femur as possible while maintaining the screw anterior to the posterior cortex of the femoral neck and ending at the apex of the epiphysis ignoring the resultant angle to the physis. Thirty-five of these hips were followed till physeal closure.

RESULTS: Thirty-five of the 36 hips showed physeal closure at an average of 5 months. There were no screw-related complications or symptoms. The oblique screw path allowed for an extra screw thread to be placed in the epiphysis and also allowed adequate femoral neck osteoplasty.

CONCLUSIONS: Oblique placement of the screw for in situ fixation in stable slipped capital femoral epiphysis did not cause any deleterious effects and offered several potential advantages.

LEVEL OF EVIDENCE: IV - Case series.