Differences in the Risk of Orthopedic Surgery for Patients With RA, Psoriatic Arthritis

While recent changes in medical treatment have reduced the risk of orthopedic surgery in patients with rheumatoid arthritis (RA), the same cannot be said about patients with psoriatic arthritis (PsA), according to a new study.

Researchers in Norway compared a historic cohort of 1010 patients with RA who were diagnosed between 1972 and 2009 with a cohort of 590 patients with PsA who were diagnosed between 1954 and 2011. They compared medical treatment received and the frequency of orthopedic surgery for patients with RA and PsA, as well as trends over time.

In previous research, the authors found that 31% of patients with RA and 20% of patients with PsA needed surgery, but that the risk of surgery declined over time for patients with RA. Over time, there has been an increased use of biologic and synthetic disease-modifying antirheumatic drugs (DMARDs) for both RA and PsA, although the impact has been larger in RA.

“Orthopaedic surgery is an important outcome measure in inflammatory rheumatic joint disease, and gives an objective measure of inflammation not sufficiently handled by medical treatment,” the authors explained.

Use of synthetic and biologic DMARDs and the occurrence of orthopedic surgery among the 2 groups were compared, and the researchers found that patients with PsA received less treatment than patients with RA.

While a higher percentage of patients with RA underwent surgery for the overall study period, the risk of surgery decreased. There was a significant difference between the patients with RA and PsA if they were diagnosed before 1986 or between 1986 and 1998, but the difference had disappeared for patients diagnosed in 1999 or later.

The authors did note that treatment for PsA seemed to be more aggressive in the later years of the study. More patients with RA had biologic drugs prescribed when they were diagnosed between 1986 and 1998, but there was no difference between the groups for patients diagnosed in 1999 or later.

Patients with PsA had an overall lower risk of surgery during the time studied with a less severe prognosis, and lower disease activity as measured by erythrocyte sedimentation rate. The research also showed that patients with PsA had a higher mean body mass index compared with the patients with RA, which may contribute to the risk of large joint prosthesis surgery, the authors noted.

Reference

Nystad TW, Fenstad AM, Fevang BT. Major differences in medical and surgical treatment of psoriatic arthritis and rheumatoid arthritis: a comparison of two historic cohorts. Scand J Rheumatol. 2020;49(4):267-270. doi:10.1080/03009742.2020.1739327