Rheumatoid Arthritis Study: Hip, Knee Replacement

http://www.emaxhealth.com/11306/caution-advised-rheumatoid-arthritis-patients-considering-hip-or-knee-replacement

Caution advised for rheumatoid arthritispatients considering hip or knee replacement

By Robin Wulffson Md on November 30, 2012 - 5:26pm  for eMaxHealth

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Victims of rheumatoid arthritis can develop problems with their joints throughout the body, including the knee and hip. These joints can be replaced with an artificial one with a procedure known as arthroplasty. Researchers affiliated with the University of Toronto (Toronto, Ontario, Canada) conducted a study to evaluate the complication rate of a total hip or knee arthroplasty among patients with rheumatoid arthritis, compared to patients with osteoarthritis. They published their findings online on November 28 in the journal Arthritis & Rheumatism.

The researchers noted that most of the evidence regarding complications following total hip arthroplasty and total knee arthroplasty is based on studies of patients with osteoarthritis; thus, little information regarding the outcomes in patients with rheumatoid arthritis has been published. Therefore, they conducted a study with the objective of reviewing the current evidence regarding rates of total hip and knee arthroplasty complications in rheumatoid arthritis patients compared to osteoarthritis patients.

The researchers reviewed data from Medline, EMBase, Cinahl, Web of Science, and reference lists of articles. They included reports published between 1990 and 2011 that described studies of primary total joint arthroplasty of the hip or knee and contained information on outcomes in 200 or more rheumatoid arthritis and osteoarthritis joints. Outcomes of interest included revision, hip dislocation, infection, 90-day mortality, and venous thromboembolic (blood clot) events. Two reviewers independently evaluated each study for quality and extracted data. Where appropriate, meta-analysis was performed; if this was not possible, the level of evidence was assessed qualitatively.

The review comprised 40 studies. The investigators found that patients with rheumatoid arthritis are at increased risk of dislocation following a total hip arthroplasty (2.16 times greater risk). In addition, the found fair evidence to support the concept that risk of infection and risk of early revision following total knee arthroplasty are increased in rheumatoid arthritis, compared to osteoarthritis. There was no evidence of any differences in rates of revision at later time points, 90-day mortality, or rates of venous thromboembolic events following total hip replacement or total knee replacement in patients with rheumatoid arthritis versus osteoarthritis. Rheumatoid arthritis was explicitly defined in only three studies (7.5%), and only 11 studies (27.5%) included adjustment for covariates (i.e., age, sex, and comorbidity

The researchers concluded that the findings of their literature review and meta-analysis indicate that, compared to patients with osteoarthritis, patients with rheumatoid arthritis are at higher risk of dislocation following total hip arthroplasty and higher risk of infection following total knee arthroplasty.

Arthritis is inflammation of one or more joints, which results in pain, swelling, stiffness, and limited movement. There are over 100 different types of arthritis. Rheumatoid arthritis is considered an autoimmune disease. The body's immune system normally fights off foreign substances, such as viruses. But in an autoimmune disease, the immune system confuses healthy tissue for foreign substances. As a result, the body attacks itself. Osteoarthritis is related to aging. In osteoarthritis, the cushioning (cartilage) between the bones wears away in the joints. As osteoarthritis gets worse, the cartilage disappears and bone rubs on bone. Bony spurs or growths usually form around the joint. The ligaments and muscles around the joint loosen and become weaker.

Reference: Arthritis & Rheumatism