Obesity often increases complication rates. In three separate studies, Michael Mont, M.D. and colleagues studied how obesity, morbid obesity and super obesity influence total knee arthroplasty (TKA) outcomes.

In the first study, Kimona Issa, M.D. Mont and colleagues found that obese patients had excellent clinical outcomes at early to midterm follow-up of primary TKA. However, obese patients had significantly higher complication rates and significantly lower mean postoperative UCLA activity scores. Length of hospital stay was similar in both groups.

A literature review by Mont, mark J. McElroy, M.D., and colleagues on TKA outcomes in normal-weight, obese and morbidly obese patients showed that at a mean 5-year follow-up, morbidly obese patients had significantly lower implant survivorship rates compared with obese and non-obese patients. Morbidly obese patients had lower postoperative mean Knee Society objective and function scores than nonobese patients. The complication rate was 9% for nonobese patients, 15% for obese and 22% for morbidly obese patients.

Finally, a comparison of survivorship and complication rates for super-obese patients (minimum BMI of 50 kg/m2) who had undergone primary TKA and nonobese patients yielded no differences in aseptic implant survivorship (94% vs. 98%).

Furthermore, Mont, Qais Naziri, M.D., and colleagues found that super obese patients had significantly higher rates of medical and surgical complications (14% vs. 5%). Patients in the super obese group had lower Knee Society functional scores and smaller gains in fixation arc range of motion.

How will the increasing number of obese patients affect the future of healthcare?

While currently living in an era of unprecedented rates of obesity, now considered to be a worldwide epidemic, the mean body mass index (BMI) of the population has increased globally since 1980, with adults in the United States demonstrating an overall prevalence of 68% for being overweight and 33.8% for being obese.

Obesity is well-associated with an increased incidence of major diseases such as diabetes, cardiovascular disease, asthma and most cancers– problems that will only get worse as more of the population becomes overweight.

Three factors are thought to be responsible for increasing burden of treating obesity; increase in the number of people that are obese, the increasing cost of treatments specific to obesity-related illnesses and the demographic shift in the population with a trend for older individuals to be obese.” Kenneth E. Thorp, PhD, of Emory University wrote in Health Affairs.

To put the scope of the problem in perspective, it is estimated that by 2018, the direct costs of obesity at a national level is proposed to be $ 1,425 per person, increasing from $ 361 today, according to Thorp.

OrthopaedicsToday