title: Distribution of bone density and cortical thickness in the proximal femur and their association with hip fracture in postmenopausal women: a quantitative computed tomography study.
abstract: The quantitative computed tomography (QCT) scans in an individually matched case-control study of women with hip fracture were analysed. There were widespread deficits in the femoral volumetric bone mineral density (vBMD) and cortical thickness of cases, and cortical vBMD and thickness discriminated hip fracture independently of BMD by dual-energy X-ray absorptiometry (DXA).
  
  
  BACKGROUND
  Acknowledging the limitations of QCT associated with partial volume effects, we used QCT in an individually matched case-control study of women with hip fracture to better understand its structural basis.
  
  
  METHODS
  Fifty postmenopausal women (55-89 years) who had sustained hip fractures due to low-energy trauma underwent QCT scans of the contralateral hip within 3 months of the fracture. For each case, postmenopausal women, matched by age (±5 years), weight (±5 kg) and height (±5 cm), were recruited as controls. We quantified cortical, trabecular and integral vBMD and apparent cortical thickness (AppCtTh) in four quadrants of cross-sections along the length of the femoral head (FH), femoral neck (FN), intertrochanter and trochanter and examined their association with hip fracture.
  
  
  RESULTS
  Women with hip or intracapsular (IC) fracture had significantly (p < 0.05) lower vBMD and AppCtTh than the controls in the majority of cross-sections and quadrants of the proximal femur, and both cortical and trabecular compartments are involved. Cortical vBMD and AppCtTh in the FH and FN were associated with hip and IC fractures independent of hip areal BMD (aBMD). The combination of AppCtTh and trabecular or integral vBMD discriminated hip fracture, whereas the combination of FH and FN AppCtTh discriminated IC fracture significantly (p < 0.05) better than the hip aBMD.
  
  
  CONCLUSIONS
  Deficits in vBMD and AppCtTh in cases were widespread in the proximal femur, and cortical vBMD and AppCtTh discriminated hip fracture independently of aBMD by DXA.
authors.affiliation: Academic Unit of Bone Metabolism, Mellanby Centre for Bone Research, School of Medicine, University of Sheffield, Beech Hill Road, Sheffield, S10 2RX, UK, l.yang@sheffield.ac.uk.
authors.forename: L
authors.initials: L
authors.lastname: Yang
authors.forename: W J M
authors.initials: WJ
authors.lastname: Udall
authors.forename: E V
authors.initials: EV
authors.lastname: McCloskey
authors.forename: R
authors.initials: R
authors.lastname: Eastell
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods; D000368:Aged; D000369:Aged, 80 and over; D015519:Bone Density / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D005270:Femur Head / Q000000981:diagnostic imaging / Q000503:physiopathology; D006620:Hip Fractures / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D008875:Middle Aged; D015663:Osteoporosis, Postmenopausal / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D058866:Osteoporotic Fractures / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods