Although the overall rate of orthopedic surgery for patients with rheumatoid arthritis did not change between 1999 and 2015 in Spain, there was a decrease in the rate of arthrodesis for all ages, total hip arthroplasty in patients under the age of 80, and upper limb arthroplasty and total knee arthroplasty for patients under the age of 60, according to a study published in The Journal of Rheumatology.
This retrospective observational study was designed to analyze the trend of orthopedic surgery rates in patients with rheumatoid arthritis based on data from the Spanish National System of Hospital Data Surveillance. All hospitalizations for orthopedic surgery among patients with rheumatoid arthritis over the age of 20 (total hip arthroplasty, upper limb arthroplasty, total knee arthroplasty, and arthrodesis) between 1999 and 2015 (N=21,088, 77.9% women) were analyzed. Age-adjusted rates were calculated and trend analysis was performed using generalized linear models.
The age-adjusted orthopedic surgery rate was 754.63/100,000 patient years (women 707.4; men 861.1). Neither an increasing nor a decreasing trend was observed for global orthopedic surgery; however, trend and age did interact. In the age ranges of patients of 20 and 40 years and 40 and 60 years, an annual decrease was noted of 2.69% (incidence rate ratio [IRR], 0.973; 95% CI, 0.99-1.017) and 2.97% (IRR, 0.973; 95% CI, 0.962-0.979), respectively. In the age ranges of over 80 years and 60 to 80 years, an annual increase was noted of 5.40% (IRR, 1.054; 95% CI, 1.04-1.068) and 1.1% (IRR, 1.011; 95% CI, 1.003-1.019), respectively.
During the time period analyzed, the average age at time of surgery increased by 5.5 years (P <.05). Surgery-specific, age-adjusted analyses found that overall rates for arthrodesis dropped by 2.89% (IRR, 0.971; 95% CI, 0.944-0.999) in men and 3.04% (IRR, 0.97; 95% CI, 0.957-0.983) in women, annual total hip arthroplasty rates in patients over 80 increased by 4.64% (IRR, 1.046; 95% CI, 1.031-1.062), and total knee arthroplasty rates reduced by 3.79% (IRR, 0.962; 95% CI, 0.946-0.979) in patients 20 to 40 years of age and by 2.86% (IRR, 0.971; 95% CI, 0.961-0.982) in patients aged 40 to 60. Upper limb arthroplasty rates decreased as well, but reductions were non-significant.
Study limitations included being unable to establish causal relationships in a retrospective observational study, the fact that the data encompassed 99% and not 100% of the Spanish population, the possibility of coding disparities or problems that could cause issues such as rates of patients with rheumatoid arthritis being underestimated, and that the Spanish National Hospital (CMBD) discharge database did not include information related to exact treatment regimens.
However, the study researchers did find “a global reduction trend for arthrodesis in [total hip arthroplasty] in subjects under 80, and in [total knee arthroplasty] and [upper limb arthroplasty] in subjects under 60 among [rheumatoid arthritis] patients in Spain. Likewise, we noted an increase in the average age at [orthopedic surgery] of 5.5 years during the period studied.”
Peña M, Quirós-Donate J, Fernández EP, et al. Orthopaedic surgery trend in rheumatoid arthritis – results of the National Registry of Hospitalised Patients (CMBD) over a 17 year period (1999-2015). TREND-AR Study [published online June 15, 2019]. J Rheumatol. doi: 10.3899/jrheum.190182