Continued Growth of the Femoral Neck Leads to Improved Remodeling After In Situ Fixation of Slipped Capital Femoral Epiphysis

BACKGROUND:Globally, the most common method for in situ fixation of slipped capital femoral epiphysis (SCFE) is a threaded screw, which causes physeal arrest. The standard treatment in Sweden is unthreaded fixation using the Hansson hook-pin, which leads to continued growth of the femoral neck. Our purpose was to study remodeling during the remaining growth after fixation with the Hansson hook-pin. METHODS:We performed a retrospective study of 54 patients with SCFE who were treated with the Hansson hook-pin between 2001 and 2009. The immediate postoperative radiograph and the radiograph taken after physeal closure (mean interval, 34 mo) were analyzed. Three radiographic assessments were usedthe head-shaft angle (HSA), the alpha angle (Nötzli), and the displacement from Klein’s line. RESULTS:Significant remodeling was detected in all measured parameters. The mean postoperative HSA decreased by 9.0 degrees (P