title: Is hip dysplasia a common deformity in skeletally mature patients with hereditary multiple exostoses?
abstract: BACKGROUND
  Various deformities appear in hereditary multiple exostoses (HMEs). Deformities around the knee or ankle joints are easy to detect in this disease because such deformities are visible in appearance. However, deformities in the hip joints of skeletally mature patients are not well understood because their tumors are invisible.
  
  
  METHODS
  To understand deformities around the hip joint in HMEs, we investigated 36 hip joints in 19 skeletally mature patients (12 males, 7 females). The mean age at last X-ray imaging investigation was 29.2 years (14.5-66.5 years). We evaluated the lesions of exostoses around the acetabulum and proximal femur, Wiberg's center-edge angle (CEA), neck-shaft angle (NSA), acetabular depth-width ratio (ADR), and Sharp's acetabular angle.
  
  
  RESULTS
  No exostoses were present in four hips of three cases. Thirty-one hip joints had exostoses on the medial side of the femoral neck. Exostoses existed on the lateral side of the femoral neck in 16 hips. None of the patients had acetabuluar tumors. One patient experienced pain because of impingement between the acetabular rim and medial tumors of the femoral neck. The increase in NSA, which is an index of proximal femoral deformity, was common with a mean NSA of 147.3 °. Two indices of acetabular deformity, Sharp's angle and ADR, were within normal limits with a mean Sharp's angle of 41.3 ° and mean ADR of 269. The average CEA was 29.9 °.
  
  
  CONCLUSIONS
  Hip dysplasia is not necessarily common in skeletally mature patients with HMEs. To determine the possibility of hip dysplasia in skeletally immature patients with HMEs, ADR may be a useful reference index.
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Japan. Electronic address: c-higuchi@umin.ac.jp.
authors.forename: Chikahisa
authors.initials: C
authors.lastname: Higuchi
authors.affiliation: Department of Orthopaedic Medical Engineering, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita City, Osaka 565-0871, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Sugano
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Department of Orthopaedic Surgery, Osaka University Graduate School of Medicine, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Yoshikawa
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D015331:Cohort Studies; D015897:Comorbidity; D060906:Coxa Valga / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D005097:Exostoses, Multiple Hereditary / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D005260:Female; D006617:Hip Dislocation / Q000000981:diagnostic imaging* / Q000453:epidemiology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D011859:Radiography / Q000379:methods; D012720:Severity of Illness Index; D017678:Sex Distribution; D014057:Tomography, X-Ray Computed / Q000379:methods; D055815:Young Adult