In situ screw fixation of slipped capital femoral epiphysis with a novel approach: a double-cohort controlled study

Purpose In situ fixation for mild to moderate slipped capital femoral epiphysis (SCFE) remains an acceptable treatment methodology in most centers. Satisfactory fixation results have been reported with the procedure using either the fracture table or radiolucent table, both of which allow the hip to be imaged during the procedure. The position of the pin within the center of the femoral head is important to secure adequate fixation of the capital femoral epiphysis and prevent further slippage with minimal risk for articular penetration and avascular necrosis (AVN) or chondrolysis. Methods We describe a pre-operative planning technique to determine the pin-entry point for percutaneous pinning of SCFE on a radiolucent operating table. A retrospective review of patients who underwent in situ screw fixation with the usage of a cannulated screw on a radiolucent table or fracture table over a 6-year period was conducted. Results The pin-entry point with this technique was reliable in 92% of procedures and comparable in both accuracy and complications to in situ screw fixation on a fracture table. In situ screw fixation on a regular radiolucent table was straightforward and required significantly less surgical time than on the fracture table (P = 0.01). It was also more efficient during a bilateral procedure, as it required only a single preparation and draping of the patient. Conclusion This pre-operative planning technique for deciding the starting point on the proximal femur is helpful in executing an accurate in situ screw fixation of hips with SCFE.