It’s 2012 and by now most, if not all, healthcare professionals are aware of the epidemic this country is currently battling: obesity. The statistics are staggering. According to the CDC, over one-third (35.7%) of our nation’s adults are obese and 34% are overweight.  No state has an obesity prevalence of less than 20%. In the year 2000, there were no states with an obesity prevalence greater than 25%. Currently, however, there are no states where the prevalence of obesity is less than 20%.¹ Most healthcare providers are aware of the associated health problems when it comes to obesity, but are they aware of the associated costs? It is well known that obesity is associated with conditions such as hypertension, type 2 diabetes, metabolic syndrome, hyperlipidemia, sleep apnea, certain types of cancer, and osteoarthritis. These associated comorbidities have a price: it has been estimated that the added health care cost for an obese person is approximately $1400 more per year than that for a person of normal weight.^1,2 Clearly, this epidemic is affecting almost everyone in healthcare, regardless of specialty or level of patient care. There are few providers in the United States who have not seen the effects. This series will summarize how obesity is changing medicine in multiple specialties, starting with orthopedics.

Orthopedists (as well as other musculoskeletal specialists such as physiatrists, sports medicine physicians, and rheumatologists) see patients with osteoarthritis (OA) on a daily basis. It is a common degenerative disease process that affects the synovial joints in the body. OA of the hip and knee is the leading cause of walking-related disability in the United States.³ Although orthopedic and musculoskeletal specialists are not the only providers who treat patients with osteoarthritis, they are commonly the ones who receive referrals for definitive treatment. This is not news. As it relates to our topic, however, it has recently been estimated that greater than 66% of Americans with arthritis are obese.² Additionally, obesity is the single most important modifiable risk factor for OA of the knee. Compared with persons of normal weight, obese and overweight persons have almost 3 times the risk of knee OA.⁴ Obese patients who suffer from OA should be educated on healthy weight loss, as published results support this as effective treatment. For example, in the Framingham study, weight loss in women with a BMI>25 was associated with a significant decrease in risk for developing symptomatic OA.⁵ Biomechanically speaking, for every one pound of weight loss, the force through the knee with each step is decreased four-fold.⁶ The need for weight loss in this patient population is clear.

As the rate of obesity is increasing, so is the number of Americans receiving joint arthroplasties. In 2009, 905,000 knee and hip replacements were performed at a cost of $42.3 billion.⁷ Unfortunately, arthroplasty may not be a simple answer. It has been suggested that obesity is a risk factor for more pain and slower recovery after hip and knee arthroplasty.⁸ Obese patients also have decreased post-operative range of motion and higher incidence of requiring manipulation under anesthesia (to correct range of motion limitations) after knee replacement surgery compared with patients of normal weight.⁹ Additionally for obese patients, surgery is technically more challenging and carries more risk of complications.¹⁰ Operating room time and total cost of total knee arthroplasties in obese patients have also shown to be higher.^11,12 For these reasons, many surgeons are deferring replacement surgeries until patients can shed some of the weight.

Conservative measures should be utilized if an attempt at postponing arthroplasty is desired. Any or all of the following options should be considered to assist the patient: referral to a nutritionist for weight loss assistance, pain management with medications such as NSAIDs, and physical therapy for quadriceps strengthening and gait evaluation. Intra-articular injections should also be considered, if not already utilized. The patient must be encouraged to stay active, despite the limitations of pain, as inactivity and avoidance secondary to pain can lead to worsening of gait abnormalities, obesity, and weakness.¹³ Patient education in regards to surgical risks and conservative management is critical. The importance of weight loss in this patient population cannot be emphasized enough.

REFERENCES

1. Centers for Disease Control and Prevention. Adult Obesity Facts. http://www.cdc.gov/obesity/data/adult.html Updated April 27,2012. Accessed June 24, 2012.
2. Chaykin D. The Weight of the Nation. Home Box Office website. http://theweightofthenation.hbo.com/films/ 2012. Accessed July 3, 2012.
3. Felson DT, Lawrence RC, Dieppe PA, et al. Osteoarthritis: new insights. Part I: the disease and its risk factors. Ann Intern Med 2000;133:635-646.
4. Blagojevic M, Jinks C, Jeffrey A, Jordan KP. Risk factors for onset of osteoarthritis of the knee in older adults: A systematic review and meta-analysis. Osteoarthritis Cartilage 2010; 18:24-33.
5. Felson DT, Zhang Y, Anthony JM, Naimark A, Anderson, JJ. Weight loss reduces the risk for symptomatic knee osteoarthritis in women: the Framingham Study. Ann Intern Med 1992;116:535-539.
6. Messier, S. P.; Gutekunst, D. J.; Davis, C.; and DeVita, P. Weight loss reduces knee-joint loads in overweight and obese older adults with knee osteoarthritis. Arthritis Rheum 2005; 52(7): 2026-32.
7. Murphy L and Helmick CG. The impact of osteoarthritis in the United States: a population-health perspective. Am J Nurs 2012;112:S113-119.
8. Jones CA, Cox V Jhangri GS, Suarez-Almazor ME. Delineating the impact of obesity and its relationship on recovery after total joint arthroplasties. Osteoarthritis Cartilage 2012:20(6):511-518.
9. Gadinsky NE, Ehrhardt JK, Urband C, Westrich GH. Effect of body mass index on range of motion and manipulation after total knee arthroplasty. J Arthroplasty 2011;26(8):1194-1197.
10. Sridhar MS, Jarrett CD, Xerogeanes JW, Labib SA. Obesity and symptomatic osteoarthritis of the knee. JBJS 2012; 94(4):433-40.
11. Gadinsky NE, Manuel JB, Lyman S, Westrich GH. Increased operating room time in patients with obesity during primary total knee arthroplasty: conflicts for scheduling. J Arthroplasty 2012;27(6):1171-6.
12. Dowsey MM, Liew D, Choong PF. Economic burden of obesity in primary total knee arthroplasty. Arthritis Care Res 2011;63(10):1375-81
13. Nebel MB, Sims EL, Keefe FJ, et al. The relationship of self-reported pain and functional impairment to gait mechanics in overweight and obese persons with knee osteoarthritis. Arch Phys Med Rehabil 2009;90:1874-1879.