Total knee arthroplasty provides osteoarthritis patients with greater improvement in pain and health-related quality of life than it does for rheumatoid arthritis patients, possibly relating to the lower pain and younger age of RA patients at the time of surgery, according to a study based on patients’ responses to semiannual questionnaires.
The study included 834 patients diagnosed with RA and 315 patients diagnosed with osteoarthritis (OA), who had a primary total knee arthroplasty (TKA) between Jan. 1, 1999, and June 30, 2012. The patients were probed on their demographic characteristics, disease duration, mental health, functional status, health-related quality of life (HRQoL), pain, and usage of pain medication. All study participants participated in at least three consecutive sampling intervals: a 6-month preoperative period, a 6-month immediate postoperative period, and a subsequent 6-month “recovery” period. Of the patients who underwent a TKA, 144 (11%) did not complete all three sampling intervals.
At baseline, compared with OA patients, RA patients had significantly less severe scores for measures of pain, lesser usage of pain medications, and significantly more severe scores for measures of disease activity.
After recovering from a TKA, the RA and OA patients improved in almost all outcome measures of pain, function, and HRQoL. The surgery had a larger beneficial effect in OA patients than in RA patients for all measures of pain and HRQoL indices, except for the RA disease activity index (RADAI)/total joint count. In contrast to the OA patients, RA patients showed greater improvements in joint involvement.
For both groups, all outcome measures of pain and function worsened a year before TKA and improved immediately after the surgery; however, the improvement leveled off in the 6-12 months after the procedure.
“After adjusting for preoperative variables, post TKA, a diagnosis of RA (vs. OA) (P = .03), income (P < .01), and anxiety (P = .03) were most useful in predicting the reduction in [visual analog scale] pain scores,” noted Dr. Anand Dusad of the Veterans Affairs Nebraska–Western Iowa Health Care System, Omaha, and his colleagues.
“In summary, using a large cohort of arthritis patients, we have shown that TKA is performed in patients with severe disease and leads to marked improvements in pain function and HRQoL,” according to the researchers.
Read the full study published online July 20 in Arthritis & Rheumatology (doi:10.1002/art.39221).