Knee
Rising rates of obesity around the world has produced a variety of health care consequences, including exponentially increasing demand for total knee arthroplasty arising from the associated osteoarthritis.1-3 While this should keep our profession busy for years to come, it does pose considerable challenges around timely access to quality care due the finite size of health care resources.
Should obesity be a contra-indication to elective TKA? Does it have a negative impact on the outcome of TKA? A review of the literature will produce conflicting findings about its effect on complications, functional improvement, satisfaction, and implant longevity. Given the elective nature of TKA surgery, I find it difficult to refuse surgery to a well informed patient who makes the rational decision to accept the risks in return for a high probability of functional improvement and relief of pain. NICE appears to concur with this assessment, indicating that obesity should not be a barrier to referral.4
When I explain to my patients the relationship between obesity and development of osteoarthritis, the common refrain I hear is “if you replace my knee, I will be able to exercise and lose the extra weight”. Unfortunately, this rarely seems to occur.5 Perhaps our obese patients’ overall health and mobility might be better served by initially undertaking bariatric surgery – a procedure well documented to reduce weight and associated health problems.6 What remains unclear, however, is how much improvement in mobility is possible, and whether or not TKA can be delayed or prevented altogether. Further investigation into the inflammatory changes associated with obesity, and its role in the development of osteoarthritis is also warranted.1
The growing challenge of obesity and its related health effects will place a large strain on shrinking health care budgets. Is it time to pick up the scalpel or jump on the bicycle?
Dr Eric R Bohm BEng MD MSc FRCSC, Associate Professor, University of Manitoba, Concordia Joint Replacement Group, Winnipeg, Manitoba, Canada
References
1. Sowers MR, Karvonen-Gutierrez CA. The evolving role of obesity in knee osteoarthritis. Curr Opin Rheumatol 2010;22:533-7.
2. Bourne R, Mukhi S, Zhu N, Keresteci M, Marin M. Role of obesity on the risk for total hip or knee arthroplasty. Clin Orthop Relat Res 2007;465:185-8.
3. Kurtz S, Ong K, Lau E, Mowat F, Halpern M. Projections of primary and revision hip and knee arthroplasty in the United States from 2005 to 2030. J Bone Joint Surg [Am] 2007;89-A:780-5.
4. The National Collaborating Centre for Chronic Conditions. Osteoarthritis National clinical guideline for care and management in adults, 2008.
5. Zeni JA, Jr., Snyder-Mackler L. Most patients gain weight in the 2 years after total knee arthroplasty: comparison to a healthy control group. Osteoarthritis Cartilage 2010;18(4):510-4.
6. Buchwald H. Bariatric surgery for morbid obesity: health implications for patients, health professionals, and third-party payers. J Am Coll Surg 2005;200(4):593-604.
