The Kind of Arthritis Matters in Surgery

Rheumatoid arthritis total hip replacement patients have worse outcomes than osteoarthritis patients

(RxWiki News) Arthritis is painful, no matter the cause. If hip surgery is needed, though, patients with one kind of arthritis could benefit longer down the line compared to patients with the other kind of arthritis.

A study showed that patients with rheumatoid arthritis had more pain and did not function as well two years after hip replacement surgery compared to patients with osteoarthritis who underwent the same procedure.

Though the findings have not yet been peer-reviewed, they are important to pass on to patients with rheumatoid arthritis so they know what to expect, according to the study authors.

"Ask your surgeon what to expect after hip replacement surgery."

Researchers led by Susan Goodman, MD, from the Department of Medicine at the Hospital for Special Surgery in New York, looked at the differences between osteoarthritis patients who had a total hip replacement compared to rheumatoid arthritis patients.

In osteoarthritis, the cartilage between bones wears away, causing the bones to hit each other directly.

With rheumatoid arthritis, inflammation in the membrane surrounding the cartilage between bones can cause bone loss.

Though the findings have not yet been peer-reviewed, this study involved 6,012 total hip replacements performed on arthritis patients and 503 revised total hip replacement procedures listed in a single institution joint replacement registry between May 2007 and July 2010.

Among the regular total hip replacements, 202 involved patients with rheumatoid arthritis. And among the revised procedures, 58 involved rheumatoid arthritis patients.

Total hip replacements and revised total hip replacement procedures were both included in the study. The researchers verified whether patients had rheumatoid arthritis either based on patients' self-reports or through their medical records.

The researchers surveyed patients on their level of pain and ability to function at the start of the study and two years after having the procedure.

For the patients who had two eligible procedures, the researchers only included data from the second procedure. Patients who had any other systemic rheumatic disease or fractures were excluded.

The researchers noted patients' age, gender and body mass index, a measure of height and weight.

A greater number of rheumatoid arthritis patients were women. Rheumatoid arthritis patients who underwent a single total hip replacement did not differ in average age or BMI compared to osteoarthritis patients undergoing the same procedure.

At the same time, rheumatoid arthritis patients who had a total hip replacement revision (surgery to fix original joint replacement) tended to be younger with a lower BMI.

Patients with rheumatoid arthritis who had a hip replacement procedure were four times more likely to have increased pain and worse functioning two years after surgery than osteoarthritis patients, the researchers found.

Rheumatoid arthritis patients who had a revised procedure were twice as likely to have significantly more pain and worse functioning two years after their procedure compared to osteoarthritis patients.

Also, compared with osteoarthritis patients, rheumatoid arthritis patients were as satisfied with their pain relief, but were less likely to be satisfied overall.

Osteoarthritis and rheumatoid arthritis patients who had a revised hip replacement showed no difference in their level of satisfaction compared to one another.

"Contemporary rheumatoid arthritis total hip replacement patients have similar absolute improvements in pain and function compared with osteoarthritis but significantly worse 2-year pain and function," the researchers wrote in their report. "This is important information to convey to rheumatoid arthritis patients to ensure appropriate expectations."

The study was presented June 14 at the Annual Congress of the European League Against Rheumatism in Madrid, Spain. No conflicts of interest were declared.

Review Date: 
June 17, 2013