title: Femoral neck shaft angle width is associated with hip-fracture risk in males but not independently of femoral neck bone density.
abstract: OBJECTIVE
  To investigate the specificity of the neck shaft angle (NSA) to predict hip fracture in males.
  
  
  METHODS
  We consecutively studied 228 males without fracture and 38 with hip fracture. A further 49 males with spine fracture were studied to evaluate the specificity of NSA for hip-fracture prediction. Femoral neck (FN) bone mineral density (FN-BMD), NSA, hip axis length and FN diameter (FND) were measured in each subject by dual X-ray absorptiometry. Between-mean differences in the studied variables were tested by the unpaired t-test. The ability of NSA to predict hip fracture was tested by logistic regression.
  
  
  RESULTS
  Compared with controls, FN-BMD (p < 0.01) was significantly lower in both groups of males with fractures, whereas FND (p < 0.01) and NSA (p = 0.05) were higher only in the hip-fracture group. A significant inverse correlation (p < 0.01) was found between NSA and FN-BMD. By age-, height- and weight-corrected logistic regression, none of the tested geometric parameters, separately considered from FN-BMD, entered the best model to predict spine fracture, whereas NSA (p < 0.03) predicted hip fracture together with age (p < 0.001). When forced into the regression, FN-BMD (p < 0.001) became the only fracture predictor to enter the best model to predict both fracture types.
  
  
  CONCLUSIONS
  NSA is associated with hip-fracture risk in males but is not independent of FN-BMD.
  
  
  CONCLUSIONS
  The lack of ability of NSA to predict hip fracture in males independent of FN-BMD should depend on its inverse correlation with FN-BMD by capturing, as the strongest fracture predictor, some of the effects of NSA on the hip fracture. Conversely, NSA in females does not correlate with FN-BMD but independently predicts hip fractures.
authors.affiliation: Struttura Semplice Dipartimentale di Medicina Generale, Istituto Ortopedico Rizzoli, Bologna, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Ripamonti
authors.forename: L
authors.initials: L
authors.lastname: Lisi
authors.forename: M
authors.initials: M
authors.lastname: Avella
mesh_terms: D015502:Absorptiometry, Photon; D000368:Aged; D015519:Bone Density / Q000502:physiology*; D005272:Femur Neck / Q000000981:diagnostic imaging* / Q000473:pathology; D006620:Hip Fractures / Q000000981:diagnostic imaging* / Q000473:pathology; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D016103:Spinal Fractures / Q000000981:diagnostic imaging