In this issue of The Journal a Japanese group reports an overall diminished incidence of total knee arthroplasty (TKA) in a group of patients with longstanding rheumatoid arthritis (RA) receiving methotrexate (MTX) plus tumor necrosis factor (TNF) inhibitor, versus another group receiving TNF inhibitor but not MTX1.
If true, the findings are certainly of interest. Perhaps one of the first questions that might occur to a clinical rheumatologist is this: How many subjects may have had knee osteoarthritis (OA) leading to their surgical procedure and how many may have had knee disease secondary to RA, or some combination of both?
Patients were well matched for age and disease duration although fewer knee arthroplasties were performed in subjects receiving infliximab (IFX) versus those taking etanercept (ETN). Adalimumab was not included because it was apparently not prescribed in the Japanese population studied at the single center during the duration of the trial.
Because modifications of the Sharp scores typically used …
Address correspondence to Dr. J.M. Kremer; E-mail: jkremer{at}joint-docs.com