Oral Virtual Presentation (Virtual only) ESA-SRB-ANZBMS 2021

Trabecular bone score is associated with prospective fracture and refracture risk in Australian adults (#17)

Kara B Anderson 1 , Pamela G Rufus-Membere 1 , Natalie K Hyde 1 , Didier Hans 2 , Julie A Pasco 1 3 4 5 , Mark A Kotowicz 1 3 5 , Kara L Holloway-Kew 1
  1. Deakin University, Geelong, VIC, Australia
  2. Bone & Joint Department, Centre of Bone Diseases, Lausanne University, Lausanne, Switzerland
  3. Barwon Health, Geelong, Victoria, Australia
  4. Department of Epidemiology and Preventative Medicine, Monash University, Melbourne, Victoria, Australia
  5. Department of Medicine-Western Health, Melbourne Medical School, The University of Melbourne, Melbourne, VIC, Australia

Background

Trabecular bone score (TBS) applies an algorithm to lumbar spine (LS) dual x-ray absorptiometry (DXA) scans to assess trabecular microarchitecture. TBS may improve the assessment of fracture risk, complementary to bone mineral density (BMD), and may be useful for identifying those likely to refracture. This study aimed to investigate associations between TBS and incident fracture, including after a prior fracture.

Methods

Men (n=894) and women (n=681) aged 24-98yr from the Geelong Osteoporosis Study were included. LSBMD L2-L4 (Lunar Prodigy) and TBS L1-L4 (TBS iNsight V2.2) were calculated and incident fractures identified radiologically (any low trauma fracture; major osteoporotic fracture [MOF; hip, spine, proximal humerus, wrist]). Cox-proportional hazards modelling (from date of DXA scan to first fracture, death, or 31/12/2016) were used to explore associations between lower TBS and fracture in the whole cohort and in a subset of participants with prior fracture (<10yr before TBS measurement), adjusting for age, height, weight, smoking, mobility, alcohol consumption, falls and medication use.

Results

Fifty-five participants reported an incident fracture (17 clinical spine, 4 wrist, 9 hip, 2 proximal humerus, 7 distal tibia/fibula, 6 tarsals/metatarsals, 6 rib, 3 metacarpal, 2 pelvis and femur, 1 each proximal tibia/fibula, elbow, carpal, scapula, patella), at a rate of 5.8/1000 person-years (95%CI:4.4-7.5). Of 151 participants with a prior fracture, 13 reported an incident fracture (9 MOFs), incidence 16.4/1000 person-years (95%CI:9.5-28.2).

Lower TBS was associated with increased risk of fracture (unadjusted HR=1.30, 95%CI:1.09-1.56) and MOF (HR=1.56, 95%CI:1.24-1.97); adjustment for confounders and LSBMD attenuated results (HR=1.04, 95%CI:0.86-1.27 and HR=1.21, 95%CI:0.93-1.57 respectively). Among participants with prior fracture, results for refracture (HR=1.59, 95%CI:1.11-2.27) were attenuated with adjustment (HR=1.39, 95%CI:0.91-2.12); results for MOFs were sustained (unadjusted HR=1.73, 95%CI:1.15-2.59, adjusted HR=2.42, 95%CI:1.09-5.36).

Conclusion

Lower TBS was associated with incident fracture and refracture. The relationship between TBS and MOF refractures was independent of LSBMD.