Surgical Technique: In-Situ Pinning of Unstable Slipped Capital Femoral Epiphysis

Abstract

An unstable slipped capital femoral epiphysis (SCFE) is one typically associated with prodromal hip pain and/or limp for days or weeks followed an acute event resulting in the patient’s inability to bear weight. The patient will present with severe fracture-like pain. An AP pelvic radiograph is the only radiograph needed to diagnose an unstable SCFE, but a lateral radiograph of the contralateral hip is mandatory to screen for a contralateral SCFE if not obvious on the AP radiograph. Unstable SCFE has been associated with a high rate of avascular necrosis (AVN) and slip progression with in situ pinning of the epiphysis. Biomechanical data from animal models suggests that double-screw fixation is superior to single-screw fixation, but the mechanical superiority must be weighed against the potential complications of a second screw. The author’s preferred technique is to accept the reduction obtained from positioning the patient on the operative table, perform double-screw fixation of the femoral epiphysis with 6.5 mm fully threaded cannulated screws, and decompress the hip capsule. Clinical data suggests that this technique offers superior results (lower rate of AVN and chondrolysis) compared to previous studies.