Pin removal after in-situ pinning for slipped capital femoral epiphysis.

We retrospectively reviewed 28 pin-removal procedures in 20 patients with slipped capital femoral epiphysis, who were all treated by in-situ pinning with Kowles pins. Failure to extract the pins occurred in 8 cases (28.6%), and in another 8 cases (28.68%), pin retrieval was only possible after major excavation of the lateral femoral cortex. In view of these data we do not recommend routine removal of Knowles pins used for in-situ pinning of slipped capital femoral epiphysis.