title: Femoroacetabular impingement after slipped upper femoral epiphysis: the radiological diagnosis and clinical outcome at long-term follow-up.
abstract: Deformity after slipped upper femoral epiphysis   (SUFE) can cause cam-type femoroacetabular impingement (FAI) and   subsequent osteoarthritis (OA). However, there is little information   regarding the radiological assessment and clinical consequences   at long-term follow-up. We reviewed 36 patients (43 hips) previously   treated by in situ fixation for SUFE with a mean   follow-up of 37 years (21 to 50). Three observers measured the femoral   head ratio (FHR), lateral femoral head ratio (LFHR), α-angle on   anteroposterior (AP) and frog-leg lateral views, and anterior femoral   head-neck offset ratio (OSR). A Harris hip score < 85 and/or   radiologically diagnosed osteoarthritis (OA) was classified as a   poor outcome. Patients with SUFE had significantly higher FHR, LFHR   and α-angles and lower OSR than a control group of 22 subjects (35   hips) with radiologically normal hips. The interobserver agreement   was less, with wider limits of agreement (LOA), in hips with previous   SUFE than the control group. At long-term follow-up abnormal α-angles   correlated with poor outcome, whereas FHR, LFHR and OSR did not. We conclude that persistent deformity with radiological cam FAI   after SUFE is associated with poorer clinical and radiological long-term   outcome. Although the radiological measurements had quite wide limits   of agreement, they are useful for the diagnosis of post-slip deformities   in clinical practice.
authors.affiliation: Oslo University Hospital, Department of Orthopaedic Surgery, Postbox 4950, Nydalen 0424 Oslo, Norway. e-wensaa@online.no
authors.forename: A
authors.initials: A
authors.lastname: Wensaas
authors.forename: R B
authors.initials: RB
authors.lastname: Gunderson
authors.forename: S
authors.initials: S
authors.lastname: Svenningsen
authors.forename: T
authors.initials: T
authors.lastname: Terjesen
mesh_terms: D000328:Adult; D005260:Female; D057925:Femoracetabular Impingement / Q000175:diagnosis* / Q000000981:diagnostic imaging; D005500:Follow-Up Studies; D006621:Hip Joint / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D015207:Osteoarthritis, Hip / Q000000981:diagnostic imaging / Q000209:etiology*; D011379:Prognosis; D011859:Radiography; D060048:Slipped Capital Femoral Epiphyses / Q000150:complications* / Q000000981:diagnostic imaging