title: Association of 3D Geometric Measures Derived From Quantitative Computed Tomography With Hip Fracture Risk in Older Men.
abstract: We investigated the associations of 3D geometric measures and volumetric bone mineral density (vBMD) of the proximal femur assessed by quantitative computed tomography (QCT) with hip fracture risk among elderly men. This study was a prospective case-cohort design nested within the Osteoporotic Fractures in Men Study (MrOS) cohort. QCT scans of 230 men (65 with confirmed hip fractures) were evaluated with Mindways' QCTPRO-BIT software. Measures that are indicative of bone strength for the femoral neck (FN) and for the trochanteric region (TR) were defined. Bending strength measures were estimated by minimum section modulus, buckling strength by buckling ratio, and a local thinning index (LTI). Integral and trabecular vBMD measures were also derived. Areal BMD (aBMD) of the total proximal femur from dual-energy X-ray absorptiometry (DXA) is presented for comparison. Associations of skeletal measures with incident hip fracture were estimated with hazard ratios (HR) per standard deviation and their 95% confidence intervals (CI) from Cox proportional hazard regression models with adjustment for age, body mass index (BMI), site, and aBMD. Men with hip fractures were older than men without fracture (77.1 ± 6.0 years versus 73.3 ± 5.7 years, p < 0.01). Age, BMI, and site-adjusted HRs were significant for all measures except TR_LTI. Total femural BMD by DXA (HR = 4.9, 95% CI 2.5-9.9) and QCT (HR = 5.5, 95% CI 2.5-11.7) showed the strongest association followed by QCT FN integral vBMD (HR = 3.6, 95% CI 1.8-6.9). In models that additionally included aBMD, FN buckling ratio (HR = 1.9, 95% CI 1.1-3.2) and trabecular vBMD of the TR (HR = 2.0, 95% CI 1.2-3.4) remained associated with hip fracture risk, independent of aBMD. QCT-derived 3D geometric indices of instability of the proximal femur were significantly associated with incident hip fractures, independent of DXA aBMD. Buckling of the FN is a relevant failure mode not entirely captured by DXA. Further research to study these relationships in women is warranted. © 2016 American Society for Bone and Mineral Research.
authors.affiliation: Sektion Biomedizinische Bildgebung, Klinik für Radiologie und Neuroradiologie, Universitätsklinikum Schleswig-Holstein, Kiel, Germany.|Institut und Poliklinik für Diagnostische Radiologie, Uniklinik Köln, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Borggrefe
authors.affiliation: Sektion Biomedizinische Bildgebung, Klinik für Radiologie und Neuroradiologie, Universitätsklinikum Schleswig-Holstein, Kiel, Germany.
authors.forename: Timm
authors.initials: T
authors.lastname: de Buhr
authors.affiliation: Bone and Mineral Unit, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Smriti
authors.initials: S
authors.lastname: Shrestha
authors.affiliation: Bone and Mineral Unit, Oregon Health & Science University, Portland, OR, USA.|Department of Orthopaedics and Rehabilitation, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Lynn M
authors.initials: LM
authors.lastname: Marshall
authors.affiliation: Bone and Mineral Unit, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Orwoll
authors.affiliation: California Pacific Medical Center Research Institute, San Francisco, CA, USA.
authors.forename: Kathy
authors.initials: K
authors.lastname: Peters
authors.affiliation: Department of Epidemiology and Biostatistics, University of California, San Francisco, CA, USA.
authors.forename: Dennis M
authors.initials: DM
authors.lastname: Black
authors.affiliation: Sektion Biomedizinische Bildgebung, Klinik für Radiologie und Neuroradiologie, Universitätsklinikum Schleswig-Holstein, Kiel, Germany.
authors.forename: Claus C
authors.initials: CC
authors.lastname: Glüer
mesh_terms: D000368:Aged; D015992:Body Mass Index; D016001:Confidence Intervals; D000071538:Cortical Bone / Q000000981:diagnostic imaging / Q000473:pathology; D005269:Femur / Q000000981:diagnostic imaging / Q000473:pathology; D005272:Femur Neck / Q000000981:diagnostic imaging / Q000473:pathology; D005500:Follow-Up Studies; D006620:Hip Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000473:pathology*; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D012307:Risk Factors; D018709:Statistics, Nonparametric; D014057:Tomography, X-Ray Computed / Q000379:methods*
keywords: FRACTURE RISK; HIP FRACTURE; MEN; OSTEOPOROSIS; QCT; VOLUMETRIC BONE FRAGILITY ANALYSIS