Background: The presence of femoroacetabular impingement (FAI) after a slipped capital femoral epiphysis is thought to predispose the subsequent development of osteoarthritis (OA); however, there is a lack of evidence to support this hypothesis.
Methods: One hundred twenty-one patients with stable slipped capital femoral epiphysis treated with in situ fixation were reviewed at a minimum of 20-year follow-up; the presence of a pistol grip deformity and FAI was determined. The Harris Hip Score (HHS) was used to measure clinical outcome, and the Tönnis grade for qualifying the presence of OA was determined.