Joint Replacement Complications More Frequent in RA Than OA

Janis C. Kelly

December 04, 2012

Patients with rheumatoid arthritis (RA) have more complications after total joint arthroplasty (TJA) than patients with osteoarthritis (OA) and are at notably higher risk for dislocation of replaced hip joints, according to data from a systematic review and meta-analysis published online November 28 and in the December issue of Arthritis & Rheumatism.

Lead author Bheeshma Ravi, MD, from Women's College Hospital, the University of Toronto, Ontario, Canada, told Medscape Medical News that the researchers' key findings were that compared with patients with OA, patients with RA had increased risk for dislocation after total hip replacement and increased risk for infection after total knee replacement, but did not have higher revision rates, 90-day mortality rates, or venous thromboembolic events following either joint replacement procedure.

Dr. Ravi said, "It is particularly interesting that we saw no difference in the revision rates for hip or knee joints. This runs contrary to the prevailing perception amongst clinicians that rheumatoid arthritis patients are more likely to experience these complications."

The analysis included 40 reports published between 1990 and 2011 that describe primary TJA of the hip or knee in patients with RA (n = 2842) or OA (n = 61,861). Outcomes included revision, hip dislocation, infection, 90-day mortality, and venous thromboembolic events.

Hip Dislocation Risk a Surprise

The researchers found that patients with RA had double the risk for hip dislocation after total hip arthroplasty compared with patients with OA (adjusted odds ratio, 2.16; 95% confidence interval, 1.52 - 3.07). Adjustments were made for age, sex, surgical approach, and surgeon's volume.

Dr. Ravi said that the increased risk for dislocation after total hip arthroplasty in patients with RA was a surprise and might be in part a result of greater soft tissue damage or poorer hip abductor strength in patients with RA vs patients with OA.

Infection risk was up to a 10-fold higher in patient with RA after total knee arthroplasty, particularly in patients with prior infection in the replaced joint, prior infection in any joint, or longer duration of operating. There was no association between infection risk and perioperative systemic corticosteroid use or withdrawal of biologic treatment before surgery. However, the authors write, "[m]eta-analysis was not possible due to variable definitions of infection and preoperative antibiotic protocols."

Johannes Cornelis Schrama, MD, lead author on a review of risk for revision in primary total hip and knee arthroplasty from the Norwegian Arthroplasty Register, reviewed the article for Medscape Medical News. Dr. Schrama said that that the researchers do not appear to have overlooked any major factors in their analysis, but he was cautious about possible clinical application. "It is difficult to define clinical implications other than possible preventive measures [against infection] in patients undergoing [total knee arthroplasty]," said Dr. Schrama, who was not involved in the study and is from the Department of Orthopaedic Surgery at Haukeland University Hospital in Bergen, Norway.

Dr. Ravi has disclosed no relevant financial relationships. Coauthors have received consulting fees, speaking fees, honoraria, and/or research grants from Eli Lilly, Procter & Gamble, Merck Frosst Canada, Merck Sharp & Dohme, Novartis Canada, the Alliance for Better Bone Health, Amgen Canada, and Warner Chilcott. Dr. Schrama has disclosed no relevant financial relationships.

Arthritis Rheum. 2012;64:3839-3849. Abstract