Orthopedic Surgery in Rheumatoid Arthritis: Results from the Spanish National Registry of Hospitalized Patients over 17 Years.

Objective: To analyze the trend of orthopedic surgery (OS) rates on patients with rheumatoid arthritis (RA).

Methods: Retrospective observational study based on information provided by the Spanish National System of Hospital Data Surveillance. All hospitalizations of patients with RA for orthopedic surgery [total hip arthroplasty (THA), total knee arthroplasty (TKA), arthrodesis, and upper limb arthroplasty (ULA)] during 1999-2015 were analyzed. The age-adjusted rate was calculated. Generalized linear models were used for trend analysis.

Results: There were 21,088 OS in patients over 20 years of age (77.9% women). OS rate adjusted by age was 754.63/100,000 RA patients/year (women 707.4, men 861.1). Neither an increasing nor a decreasing trend was noted for the total OS. However, trend and age interacted, so in the age ranges 20-40 years and 40-60 years, an annual reduction of 2.69% and 2.97%, respectively, was noted. In the age ranges over 80 years and 60-80 years, we noted an annual increase of 5.40% and 1.09%, respectively. The average age at time of OS increased 5.5 years during the period analyzed. For specific surgeries, a global annual reduction was noted in rates for arthrodesis. In THA, there was an annual reduction in patients under 80 years. In TKA and ULA, there was an annual reduction in patients under 60 years.

Conclusion: Although the overall OS rate has not changed, there is a decrease in the rate of arthrodesis at all ages, THA in patients under 80 years of age, as well as TKA and ULA in patients under 60 years of age.