Risk of fracture in Ankylosing spondylitis patient on TNF inhibitor

According to data published in Arthritis Care & Research, the introduction of tumor necrosis factor inhibitors (TNFi) in 2003 was not successful in preventing fracture rates in individuals with ankylosing spondylitis from more than doubling from 2000 to 2020. 

Dr. Sali Merjanah and his team evaluated the trends in fracture risk among individuals with ankylosing spondylitis (AS). Additionally, they investigated whether the introduction of TNFi has changed the fracture rates among AS veterans and non-AS comparators. A total of 3,794 patients with AS and 1,152,805 control subjects were analyzed. According to the study, the number of fractures per 1,000 patient-years among AS patients increased from 7.9 in 2000 to 21.6 in 2020. The ratio comparing individuals with and without AS remained steady, while the rate rose among the comparator population as well. 

A 2021 multidatabase cohort analysis covering the period from 2008 to 2019 demonstrated no differences in the risk of nonvertebral osteoporotic fractures (NVFs) across various biologic and targeted synthetic disease-modifying antirheumatic drugs (b/tsDMARDs) for rheumatoid arthritis (RA). This finding offers reassurance to doctors who prescribe b/tsDMARDs, particularly for patients at a high risk of developing NVFs. The analysis identified a total of 134,693 b/tsDMARD initiators from three databases. When comparing all b/tsDMARD exposures to adalimumab, the adjusted hazard ratios (HRs) for the following drugs indicated a similar risk of composite NVFs: abatacept, HR 1.03 (95% CI 0.82-1.30); certolizumab, HR 1.08 (95% CI 0.79-1.49); etanercept, HR 1.12 (95% CI 0.89-1.40); golimumab, HR 0.91 (95% CI 0.59-1.00). Secondary analyses produced comparable findings. 

For both ankylosing spondylitis (AS) and non-AS comparators, the rates of fracture have increased over time. Despite the introduction of tumor necrosis factor (TNF) inhibitors in 2003, the fracture rate in individuals with AS did not decrease. The multidatabase cohort analysis revealed that starting or switching to abatacept, certolizumab, etanercept, golimumab, infliximab, rituximab, tocilizumab, and tofacitinib resulted in a comparable NVF risk when compared to those on adalimumab. 

In conclusion, the 2021 multi-database cohort analysis spanning the years 2008 to 2019 highlights the ongoing challenge of managing fracture risk within these populations, despite the introduction of tumor necrosis factor (TNF) inhibitors. The study adds to the existing literature evidence and assists clinicians in making informed decisions when tailoring treatment plans to individual patient needs. 


  1. Merjanah S, Liew JW, Bihn J, Fillmore NR, Brophy MT, Do NV, et al. Trends in fracture rates over two decades among veterans with ankylosing spondylitis. Arthritis Care & Research. 2023 Jun 12. 
  2. Pawar A, Desai RJ, He M, Bessette L, Kim SC. Comparative Risk of Nonvertebral Fractures Among Patients With Rheumatoid Arthritis Treated With Biologic or Targeted Synthetic Disease‐Modifying Antirheumatic Drugs. ACR open rheumatology. 2021 Aug;3(8):531-9.