Epiphyseal growth after pinning of slipped capital femoral epiphysis.

Seventy-seven hips in 61 patients (mean age, 13 years) with slipped capital femoral epiphysis treated with in situ pinning were retrospectively evaluated to determine the frequency and magnitude of epiphyseal growth after pinning. Threaded Steinmann pins, Knowles pins, and cannulated screws were used. Evidence of the epiphysis "growing off" the pins was seen in 29 and 18% of the hips treated with Steinmann and Knowles pins, respectively. No hips with cannulated screws continued to grow after surgery. The use of one cannulated screw in the treatment of mild and moderate slipped capital femoral epiphysis is recommended.