We stumbled upon three recent studies of knee osteoarthritis (OA) that shed interesting new light on a condition that all orthopaedists deal with.
–A “network” meta-analysis in the Annals of Internal Medicine looked at 137 randomized trials of OA treatments comprising more than 33,000 participants. Treatments analyzed included acetaminophen, diclofenac, ibuprofen, naproxen, celecoxib, intra-articular (IA) steroids, IA hyaluronic acid, oral placebo, and IA placebo. For pain, all active treatments except acetaminophen yielded clinically significant improvement. IA hyaluronic acid came out on top for pain relief, although the authors postulated that an “integrated” placebo effect may explain that finding.
–A cost-modeling study in Arthritis Care & Research, co-authored by JBJS Deputy Editors for Methodology and Biostatistics Jeffrey Katz, MD and Elena Losina, PhD, revealed that the per-patient cost attributable to symptomatic knee OA over 28 years is $12,400. Any expanded indications for total knee arthroplasty (TKA) and a trend toward increased willingness among patients to undergo knee surgery will increase that cost. The researchers found that patients tried nonsurgical regimens for a mean of 13.3 years before opting for TKA, and they stress the need for more effective nonoperative therapies for knee OA.
–Wine drinkers, rejoice! A retrospective case-control study in Arthritis Research & Therapy found that people who drank four to six glasses of wine per week were less likely to develop knee OA than nondrinkers. Meanwhile, beer drinkers may want to switch to wine. The same study found that people who drank 8 to 19 half-pints of suds per week had an increased risk of developing knee OA. Researchers found no link between total alcohol consumption and risk of knee OA. The authors postulate that the resveratrol found in wine may be chondroprotective, and that the linkage between beer and increased blood levels of uric acid may explain the opposite finding. It’s wise to remember that studies investigating one or two dietary items can be less-than-definitive because they are usually retrospective, subject to recall bias, and do not account for complex interactions among many nutrients.
According to a recent study in the Annals of the Rheumatic Diseases, women who take hormone replacement therapy (HRT) for at least 6 months after a total hip or knee replacement may cut the risk of revision surgery by almost 40%. This potential reduction in revision rate becomes even more impressive when one considers estimates that put the number of knee replacements in the US at close to 3.5 million annually by the year 2030.
The study, which compared joint-replacement outcomes in 2,700 female HRT users with outcomes in 8,100 matched nonusers, found no difference in revision rates relative to HRT use before surgery.
Elena Losina, PhD., JBJS deputy editor for methodology and biostatistics, called this study “well designed and executed” in an article in Arthritis Today. But she was quick to add that “to consider these results more definitively in clinical practice, they need to be confirmed and reproduced in a multicenter randomized controlled trial.”