SAN DIEGO – but the rate of small-joint procedures is declining for both sexes. However, no differences in rates of large-joint procedures between sexes were observed during the same time period.
Those are key findings from a retrospective study which set out to determine if there are sex differences in the incidence and trends of large- versus small-joint surgery rates in rheumatoid arthritis over time. “Why is orthopedic surgery important to rheumatology? The main reason is because it’s a surrogate for failed medical management,” lead study author Michael D. Richter, MD, said at the annual meeting of the American College of Rheumatology.
Dr. Michael D. Richter
Dr. Richter, an internal medicine resident at Mayo Clinic, Rochester, Minn., said that women with RA generally present with more severe symptoms and higher rates of disability, while men have a better treatment response and a higher remission rate. For example, results from the multinational Quantitative Standard Monitoring of Patients with RA study found that remission rates were around 30% in men and 17% in women (Arthritis Res Ther. 2009;11[1]:R7). “However, a lot of these studies are criticized because it’s thought that gender can play a role in the disease measures,” he said. “By looking at joint surgery we have an objective outcome, and we can look at differences in treatment efficacy.”
Dr. Richter and his associates drew from the Rochester Epidemiology Project to identify 1,077 patients from Olmstead County, Minn., who fulfilled ACR criteria for RA between 1980 and 2013, and who were followed up until death, migration, or July 1, 2016. They classified surgeries as small joint (wrist, hand, or foot) or large joint (shoulder, elbow, hip, knee, or ankle). A majority of the patients (70%) were women. Compared with women, men were slightly older at diagnosis (a mean of 58 years vs. 55 years, respectively), were more likely to have a history of smoking (67% vs. 46%), and were more likely to have large-joint swelling upon initial presentation (49% vs. 42%). The mean follow-up was 12 years. No differences between men and women were noted in obesity, inflammatory biomarkers, or seropositivity.
During the study period, 112 patients underwent at least one small-joint surgery, 90 of whom were women (80%). The cumulative incidence of small-joint surgery at 15 years was nearly double that of men: 14.4% vs. 7.6%, respectively (P = .008). “Prior to the year 2000 there were no significant trends in the rate of small-joint surgery but it was more common in women,” he said. “After 2000 there was a significant decline for men and women (P = .002), but no significant difference between sexes.”
At the same time, 204 patients underwent at least one large-joint surgery during the time period, 141 of whom were women (69%). The cumulative incidence of large-joint surgery at 15 years was 20.2% for women and 18.8% for men, which was statistically similar (P = .55). “We saw no significant change over time in the rate of large-joint surgery from 1980 to 2016,” Dr. Richter said. “This is in contrast to what we see in the general population, where orthopedic procedures for osteoarthritis are more common.”
He acknowledged certain limitations of the study, including its retrospective design and the fact that the researchers were unable to include specific surgical indications in the analysis. “This becomes particularly important for the large-joint procedures,” he said. “We don’t know if osteoarthritis or chronic inflammatory arthritis is leading to the large-joint procedure.”
The National Institute of Arthritis and Musculoskeletal and Skin Diseases and the National Institute on Aging funded the study. Dr. Richter reported having no financial disclosures.