Comparative Analysis of the Radiology of Osteoporotic Vertebral Fractures in Women and Men: Cross-Sectional and Longitudinal Observations from the Canadian Multicentre Osteoporosis Study (CaMos)†

We compared two methods for osteoporotic vertebral fracture (VF) assessment on lateral spine radiographs, the Genant semi-quantitative (GSQ) technique and a modified algorithm-based qualitative (mABQ) approach. We evaluated 4465 women and 1771 men > 50 years old from the Canadian Multicentre Osteoporosis Study with available X-ray images at baseline. Observer agreement was lowest for grade 1 VFs determined by GSQ. Among physician readers, agreement was greater for VFs diagnosed by mABQ [ranging from 0.62 (95% confidence interval: 0.00; 1.00) to 0.88 (0.76; 1.00)] than by GSQ [ranging from 0.38 (0.17; 0.60) to 0.69 (0.54; 0.85)]. GSQ VF prevalence [16.4% (95% confidence interval: 15.4; 17.4)] and incidence [10.2/1000 person-years (9.2; 11.2)] were higher than with the mABQ method [prevalence: 6.7% (6.1; 7.4); and incidence: 6.3/1000p-y (5.5; 7.1)]. Women had more prevalent and incident VFs relative to men as defined by mABQ but not as defined by GSQ. Prevalent GSQ VFs were predominantly found in the mid-thoracic spine whereas prevalent mABQ and incident VFs by both methods co-localized to the junction of the thoracic and lumbar spine. Prevalent mABQ VFs, compared to GSQ VFs, were more highly associated with reduced adjusted L1-L4 bone mineral density (BMD) [-0.065g/cm2 (-0.087; -0.042)], femoral neck BMD [-0.051g/cm2 (-0.065; -0.036)] and total hip BMD [-0.059g/cm2 (-0.076; -0.041)]. Prevalent mABQ VFs, compared to prevalent GSQ, were also more highly associated with incident VF by GSQ [OR 3.3 (2.2; 5.0)], incident VF by mABQ [9.0 (5.3; 15.3)], and incident non-vertebral major osteoporotic fractures [1.9 (1.2; 3.0)]. Grade 1 mABQ VFs, but not grade 1 GSQ VFs, were associated with incident non-vertebral major osteoporotic fractures [OR 3.0 (1.4; 6.5)]. We conclude that defining VF by mABQ is preferred to the use of GSQ for clinical assessments. This article is protected by copyright. All rights reserved