Background: Prior to 1993, slipped capital femoral epiphysis (S.C.F.E.) was generally classified by the severity of the slip and (or) by the duration of symptoms prior to treatment. Recently, two classifications emphasizing epiphyseal stability have been published. In these classifications, epiphyseal stability is determined by the patients ability to walk1 or by a sonographic exam of the hip.2
Methods: Since 1980, the Senior Author has routinely performed fluoroscopic evaluations under general anesthesia of most patients with S.C.F.E., prior to treatment with internal fixation. This study is a retrospective review of 49 patients with 66 hips with S.C.F.E. who underwent fluoroscopic evaluation prior to treatment. We classified each affected hip on the basis of epiphyseal stability. If gentle flexion and rotation of the leg revealed that the femoral head and neck moved together, the hip was classified as being stable. If the femoral head and neck moved independently, the hip was classified as being unstable.
Results: We found 14 unstable and 52 stable slips. We correlated our results with other classifications based on duration of symptoms or epiphyseal stability determined by ability to walk. Six patients with unstable slips by fluoroscopy were able to walk and two patients with stable slips by fluoroscopy, were unable to walk.
Our unstable slips were treated in most cases by a partial reduction and in some cases by a gentle full reduction of the fluoroscopically unstable portion of the slip only. Radiographs of the unstable slips were reviewed at a minimum follow-up of one year after surgery, to determine the incidence of avascular necrosis (AVN).