Outcomes Following Joint Replacement in RA

March 5, 2018

Researchers identify risk factors for revision surgery, prosthetic joint infection, and death after hip or knee replacement.

Key points
• After hip or knee replacement, patients with rheumatoid arthritis (RA) had lower rates of joint revision surgery than patients with osteoarthritis.

• However, patients with RA had higher rates of death and prosthetic joint infections following hip or knee replacement compared with patients with osteoarthritis.

• Taking biologic disease modifying anti-rheumatic drugs (DMARDs) did not increase the risk of prosthetic joint infection or death in patients with RA after joint replacement.

• Both glucocorticoid exposure and increased disease activity were associated with increased mortality in patients with RA following joint replacement.

Background
Immunosuppressive drugs used to treat RA have been linked to increases in various infections. The introduction of a foreign object, such as a prosthetic knee or hip joint, can also supply a focus for troublesome infections.

Lindholm Cordtz and fellow researchers in Denmark state, "PJI is a serious complication associated with inferior outcomes in terms of pain, morbidity and mortality; and it constitutes an economic burden in healthcare budgets with longer duration of hospital stays, extensive antibiotic treatment and prolonged recovery."1

The researchers sought to estimate the risk of revision due to non-infectious causes as well as prosthetic joint infections. They also hoped to define the mortality risk for patients with RA following hip or knee replacement. They recently presented their findings in Annals of the Rheumatic Diseases.

The study
The researchers conducted a register-based cohort study, which ultimately included 3913 patients with RA who had primary total hip or knee replacements. These patients were compared with 120,499 patients with osteoarthritis.

The results
• 2% of patients with RA and 2.5% of patients with osteoarthritis underwent surgical revision of a primary hip or knee replacement for reasons other than infection.

• 1.6% of patients with RA had a prosthetic joint infection, compared with 1% of patients with osteoarthritis.

• 2.2% of patients with RA died within 1 year following joint replacement, compared with 1.7% of patients with osteoarthritis.

• Taking a biologic DMARD was not associated with any of the outcome measures.

• Glucocorticoid use and high disease activity scores were more strongly associated with prosthetic joint infection than the use of DMARDs.

Implications for clinicians
• Be vigilant in monitoring patients with RA after joint replacement because they are at higher risk than those with osteoarthritis for death and prosthetic joint infection.

• Patients with RA can be reassured, however, that they are not at higher risk for requiring a joint revision following primary knee or hip replacement.

• DMARDs are safe to use in patients undergoing joint replacement.

• Corticosteroids should be used with caution, however, in patients undergoing joint replacement because of the increased risk of death.

References:

1. Lindholm Cordtz R, Zobbe K, Hojgaard P, et al. Predictors of revision, prosthetic joint infection and mortality following total hip or total knee arthroplasty in patients with rheumatoid arthritis: a nationwide cohort study using Danish healthcare registers. Ann Rheum Dis. 2018;77:281-288.