title: Does native combined anteversion influence pain onset in patients with dysplastic hips?
abstract: BACKGROUND
  Combined anteversion is the sum of femoral and acetabular anteversion and represents their morphological relationship in the axial plane. Few studies have investigated the native combined anteversion in patients with symptomatic dysplastic hips.
  
  
  OBJECTIVE
  We hypothesized the following: (1) dysplastic hips have two distinct populations, which differ from each other and from normal hips in their combined anteversion; and (2) these populations differ clinically in terms of correlation between age of onset of symptoms and amount of anteversion.
  
  
  METHODS
  We measured radiographic parameters by CT of 100 dysplastic hips in 76 patients who were symptomatic enough to undergo periacetabular osteotomy and of 50 normal hips in 44 patients who had CT scans as part of preparation for computer-navigated TKAs; these patients had no visible hip arthritis or dysplasia and no hip symptoms. Dysplastic hips were divided into the anteversion (83 hips) and retroversion groups (17 hips) based on acetabular version. Age at pain onset was determined from their medical charts.
  
  
  RESULTS
  Combined anteversion in the anteversion group was greater than that in the retroversion and control groups: 47° ± 12°, 30° ± 16°, and 36° ± 9°, respectively. In the anteversion group, combined anteversion (r = -0.49; 95% confidence interval [CI], -0.66 to -0.27; p < 0.001) and femoral anteversion (r = -0.41; 95% CI, -0.60 to -0.19; p < 0.001) were associated with an earlier age at pain onset; however, no such relationships were observed in the retroversion group. After controlling for relevant potential confounding variables, we found that combined anteversion (hazard ratio [HR], 1.04; 95% CI, 1.01-1.07; p = 0.006) and Sharp angle (HR, 1.10; 95% CI, 1.02-1.17; p = 0.008) were associated with an earlier age of pain onset in the anteversion group.
  
  
  CONCLUSIONS
  These results suggest that not only lateral coverage of the femoral head, but also axial joint morphology is important for the development of pain in the anteversion group. Optimal combined anteversion should be considered during periacetabular osteotomy.
  
  
  METHODS
  Level IV, prognostic study.
authors.affiliation: Department of Orthopaedic Surgery, Graduate school of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Kohno
authors.affiliation: Department of Orthopaedic Surgery, Graduate school of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. yasunaka@ortho.med.kyushu-u.ac.jp.
authors.forename: Yasuharu
authors.initials: Y
authors.lastname: Nakashima
authors.affiliation: Department of Orthopaedic Surgery, Graduate school of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Mio
authors.initials: M
authors.lastname: Akiyama
authors.affiliation: Department of Orthopaedic Surgery, Graduate school of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Masanori
authors.initials: M
authors.lastname: Fujii
authors.affiliation: Department of Orthopaedic Surgery, Graduate school of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan.
authors.forename: Yukihide
authors.initials: Y
authors.lastname: Iwamoto
mesh_terms: D000077:Acetabulum / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D018771:Arthralgia / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology / Q000601:surgery; D001696:Biomechanical Phenomena; D005260:Female; D005269:Femur / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D006618:Hip Dislocation, Congenital / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D006621:Hip Joint / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D010027:Osteotomy; D010147:Pain Measurement; D011237:Predictive Value of Tests; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012307:Risk Factors; D014057:Tomography, X-Ray Computed; D055815:Young Adult