title: Femoral Neck Anteversion and Lesser Trochanteric Retroversion in Patients With Ischiofemoral Impingement: A Case-Control Magnetic Resonance Imaging Study.
abstract: OBJECTIVE
  To assess the relationship between the femoral neck version (FNV) and lesser trochanteric version (LTV) in symptomatic patients with ischiofemoral impingement (IFI) as compared with asymptomatic hips.
  
  
  METHODS
  The FNV and LTV of patients with symptomatic IFI who underwent magnetic resonance imaging assessment including a standardized femoral version study protocol were compared with those of patients with asymptomatic hips in this retrospective, observational study. Patients with isolated intra-articular pathology, prior hip fracture, and lesser trochanter deformity were excluded. The FNV, LTV, ischiofemoral space, and quadratus femoris space were evaluated on axial magnetic resonance imaging, as well as the angle between the LTV and the FNV. Independent t-tests were used to determine differences between groups.
  
  
  RESULTS
  Data from 11 out 15 symptomatic patients and 250 out of 320 asymptomatic patients were analyzed. The mean ischiofemoral space (11.9 v 22.9 mm; P < .001; 95% confidence interval [CI], 6.9 to 15.2) and mean quadratus femoris space (7.2 mm v 14.9 mm; P < .001; 95% CI, 5.4 to 8.6) were significantly smaller in symptomatic patients versus asymptomatic patients. There was no difference in mean LTV between groups (-23.6° v -24.2°; P = .8; 95% CI, -7.5 to 6.4), however, the mean FNV (21.7° v 14.1°; P = .02; 95% CI, -14.2 to -1.1) and the angle between the FNV and LTV on average (45.4° v 38.3°; P = .01; 95% CI, -12.9 to -1.3) were higher in symptomatic than in asymptomatic patients, with statistical significance.
  
  
  CONCLUSIONS
  The femoral mean neck anteversion and the mean angle between the FNV and LTV are significantly higher in patients with symptomatic IFI. The mean LTV is not increased in patients with symptomatic ischiofemoral impingement as compared with those patients with asymptomatic hips.
  
  
  METHODS
  Level III, diagnostic study.
authors.affiliation: Hip Preservation Center, Baylor University Medical Center Dallas, Texas, U.S.A.. Electronic address: juangomezhoyos@gmail.com.
authors.forename: Juan
authors.initials: J
authors.lastname: Gómez-Hoyos
authors.affiliation: Hip Preservation Center, Baylor University Medical Center Dallas, Texas, U.S.A.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Schröder
authors.affiliation: Hip Preservation Center, Baylor University Medical Center Dallas, Texas, U.S.A.
authors.forename: Manoj
authors.initials: M
authors.lastname: Reddy
authors.affiliation: Hip Preservation Center, Baylor University Medical Center Dallas, Texas, U.S.A.
authors.forename: Ian James
authors.initials: IJ
authors.lastname: Palmer
authors.affiliation: Hip Preservation Center, Baylor University Medical Center Dallas, Texas, U.S.A.
authors.forename: Hal David
authors.initials: HD
authors.lastname: Martin
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D005260:Female; D005272:Femur Neck / Q000473:pathology*; D006621:Hip Joint / Q000473:pathology*; D006801:Humans; D007592:Joint Diseases / Q000473:pathology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D055815:Young Adult