Ten-year vertebral fracture outcomes and bone mineral density trajectories in patients with systemic rheumatic diseases versus osteoarthritis: a retrospective cohort study

Objective: To compare 10-year bone mineral density (BMD) changes and vertebral fracture (VFx) progression among patients with osteoarthritis (OA), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE) and to evaluate the role of vertebral fracture assessment (VFA) using lateral spine radiographs in conjunction with dual-energy X-ray absorptiometry (DXA). Methods:We retrospectively analyzed data of 94 patients (OA, n=33; RA, n=24; SLE, n=37) from a single tertiary center who underwent DXA and VFA over 10 years.VFx were defined as grade ≥2 by Genant's semi-quantitative method.Factors associated with incident VFx were evaluated using age-adjusted Firth's penalized logistic regression.Results: At baseline, the systemic rheumatic disease (SRD; RA and SLE) group had significantly lower total hip BMD (p<0.001) and higher osteoporosis prevalence (18.0% vs. 0%, p=0.007) than the OA group.Severe osteoporosis (T-score <-3.0) was exclusive to the SRD group (13.1% vs. 0%; p=0.047).The 10-year incidence of new VFx was similar between the two groups (31.1% vs. 24.2%,p=0.640).A marked decline in the T-score (ΔT≥1.0)was an independent predictor of new VFx (adjusted odds ratio 3.81, 95% confidence interval 1.40~10.38).Conclusion: Despite lower BMD and greater osteoporosis burden in patients with SRD, the 10-year VFx incidence was similar to that of patients with OA.A marked T-score decline was a crucial predictor of new fractures and VFA plays a complementary role in screening high-risk patients not captured by BMD alone.An integrated approach for long-term follow-up should consider absolute BMD values and rates of bone loss with VFA.