Last week, one of my patients presented with a BMI of 49 and two canes. Knee x-ray shows marked medial compartment narrowing bilaterally. We will inject her knees with steroids, but this will be temporary.
As the obesity epidemic continues to rage, native joints are rapidly being replaced with metal ones. Our pitiful homegrown joints were not designed to carry all this human weight. Joint forces in the hip and knee have been estimated to be 3 times body weight when walking on level ground and 6-10 times body weight when stooping or bending. Combine this with all the ‘screen time’ (average 8 hours a day for U.S. adults) and all the trips to the bathroom from the poorly controlled diabetes, and we are set up for needing a lot more orthopedic surgeons.
Dr. Jon O. Ebbert
So should we push for surgery?
I am reluctant to immediately and eagerly pursue surgery based upon data from Ward et al. elucidating the increased risk for complications after joint surgery among patients with a BMI > 40 (J.Arthroplasty. 2015 Jun 3. pii: S0883-5403(15)00474-X. doi: 10.1016/j.arth.2015.03.045. [Epub ahead of print]). Data from the bariatric literature suggest that the risk of complications following joint replacement is lower if bariatric surgery is performed first. Weight loss as we look toward joint replacement is a good idea for both our orthopedic colleagues and our patients.
So we will work on weight loss first
In patients with osteoarthritis, a moderate amount of weight loss can significantly improve knee function. The short term efficacy of weight loss is comparable to joint replacement. But clinicians need to be wary of the “pain-exercise block”: patients telling us they cannot lose weight because the pain prevents them from exercising. I tell my patients that weight loss and weight maintenance can be managed effectively through dietary modification and that they do not have to run a marathon, they just need to walk if they can. But patients do not always want to hear this. Caloric restriction is psychologically painful for many. I remind them that 30 minutes of exercise can be undone in 30 seconds with a bar of chocolate, so we need to skip the chocolate bar if we do light exercise or forgo exercise altogether. Exercise is important for a million other reasons, but many of our patients can’t engage, especially when presenting with gait assist devices.
My patient and I started the discussion of bariatric surgery. In the meantime, we are going to try a trial of lorcaserin and hope the knees hold out. We are likely going to need more steroids.
Dr. Ebbert is professor of medicine, a general internist at the Mayo Clinic in Rochester, Minn., and a diplomate of the American Board of Addiction Medicine. The opinions expressed are those of the author and do not necessarily represent the views and opinions of the Mayo Clinic. The opinions expressed in this article should not be used to diagnose or treat any medical condition nor should they be used as a substitute for medical advice from a qualified, board-certified practicing clinician. Dr. Ebbert has no relevant financial disclosures about this article. Follow him on Twitter: @jonebbert.