Risk factors for late deep infection after total hip arthroplasty in patients with rheumatoid arthritis

Postoperative infections, a serious complication of orthopedic surgery, occur 2-4 times more frequently in patients with rheumatoid arthritis (RA) without adjustment for medication. Some studies have demonstrated a similar risk of postoperative infection following orthopedic surgery regardless of whether patients underwent tumor necrosis factor-α (TNF-α) inhibitor therapy; however, other studies have reported a higher risk with TNF-α inhibitor use. However, few reports have focused on the correlation between TNF-α inhibitor use and postoperative late infection. Therefore, we investigated the correlation between TNF-α inhibitor therapy and serious postoperative late infection in patients with RA who underwent total hip arthroplasty (THA).

Ninety-nine patients with RA who were enrolled in our institution's and Konan Kakogawa Hospital's THA registry between January 2003 and December 2012 were eligible to participate. Data collected included clinical parameters and medications, including biological drugs, disease-modifying antirheumatic drugs, and glucocorticoids. Logistic regression analysis was performed to examine the association between clinical parameters, medications, and the development of postoperative late infection.

One risk factor was identified in the multivariate analysis. TNF inhibitor therapy was found to be significantly associated with the development of late infection after THA (biological drugs: OR: 9.5, 95% CI: 1.0-88.8; TNF inhibitor: OR: 11.7, 95% CI: 1.2-109.7).

Biological drug therapy, especially TNF inhibitors, may be associated with an increased rate of late deep infection after THA. When the use of TNF-α inhibitor therapy is considered, rheumatologists must be attentive to patients after THA.