title: Radiological findings that may indicate a prior silent slipped capital femoral epiphysis in a cohort of 2072 young adults.
abstract: The reported prevalence of an asymptomatic slip of the contralateral hip in patients operated on for unilateral slipped capital femoral epiphysis (SCFE) is as high as 40%. Based on a population-based cohort of 2072 healthy adolescents (58% women) we report on radiological and clinical findings suggestive of a possible previous SCFE. Common threshold values for Southwick's lateral head-shaft angle (≥ 13°) and Murray's tilt index (≥ 1.35) were used. New reference intervals for these measurements at skeletal maturity are also presented. At follow-up the mean age of the patients was 18.6 years (17.2 to 20.1). All answered two questionnaires, had a clinical examination and two hip radiographs. There was an association between a high head-shaft angle and clinical findings associated with SCFE, such as reduced internal rotation and increased external rotation. Also, 6.6% of the cohort had Southwick's lateral head-shaft angle ≥ 13°, suggestive of a possible slip. Murray's tilt index ≥ 1.35 was demonstrated in 13.1% of the cohort, predominantly in men, in whom this finding was associated with other radiological findings such as pistol-grip deformity or focal prominence of the femoral neck, but no clinical findings suggestive of SCFE. This study indicates that 6.6% of young adults have radiological findings consistent with a prior SCFE, which seems to be more common than previously reported.
authors.affiliation: University of Bergen, Department of Surgical Sciences, Haukeland University Hospital, Bergen, Norway. trude.gundersen.lehmann@helsebergen.no
authors.forename: T G
authors.initials: TG
authors.lastname: Lehmann
authors.forename: I Ø
authors.initials: IØ
authors.lastname: Engesæter
authors.forename: L B
authors.initials: LB
authors.lastname: Laborie
authors.forename: S A
authors.initials: SA
authors.lastname: Lie
authors.forename: K
authors.initials: K
authors.lastname: Rosendahl
authors.forename: L B
authors.initials: LB
authors.lastname: Engesæter
mesh_terms: D000293:Adolescent; D058070:Asymptomatic Diseases; D005260:Female; D006801:Humans; D008297:Male; D011859:Radiography; D060048:Slipped Capital Femoral Epiphyses / Q000000981:diagnostic imaging*; D055815:Young Adult