The role of trabecular bone score, inaddition to FRAX, for the measurementof fracture risk in patients withdegenerative lumbar spine stenosis

Objectives: To investigate the relevance of Concomitant Trabecular Bone Score (TBS) and Areal Bone Mineral Density (aBMD) assessments to estimate fracture risk in patients with Degenerative Lumbar Spine Stenosis (DLSS). Methods: A cross-sectional prospective study was performed. Dual energy X-ray absorptiometry scans of the lumbar spine and hip were acquired in 50 patients with DLSS. TBS and aBMD were calculated from the anteroposterior views of L1-L4 vertebrae. The World Health Organisation Fracture Risk Assessment Tool (FRAX) was utilised to estimate hip or Major Osteoporotic Fracture (MOF) risk. Results: L1-L4 TBS scores revealed degraded microarchitecture, (TBS ≤ 1.20), partially degraded microarchitecture (TBS >1.20 and <1.35) or normal appearances (TBS ≥ 1.35) in 9 (18%), 14 (28%) and 27 (54%) patients, respectively. L1-L4 aBMD assessment demonstrated osteoporosis (T-score ≤- 2.5), osteopenia (T-score between -1.1 and -2.4) or normal bone density in 15 (30%), 11 (22%) and 24 (48%) patients, respectively. There was no relationship seen between L1-L4 aBMD and TBS measurements (r = 0.046; p = 0.75). A negative relationship was observed between TBS and body mass index (r = -0.438; p = 0.001) andbetween L1-L4 aBMD and FRAX (r = -0.617; p < 0.001); the latter included MOF and risk of hip fracture (r = -0.497; p < 0.001).No relationship was observed between TBS and FRAX included MOF and risk of hip fracture (r = -0.118; p = 0.416 and r = -0.014; p = 0.926, respectively) Conclusion: In patients with DLSS, TBS is a reliable, strong and standalone indicator of fracture risk