Risks associated with obesity

Obesity is a condition that increases the risk of complications during and after total joint replacement surgery. Statistics show that a morbidly obese patient is six times more likely to develop a medical and/or surgical site complication than a patient with a healthy weight. Persons with a Body Mass Index (BMI) greater than 39 are considered morbidly obese.

Morbid obesity results in increased medical care costs and a less satisfying quality of life. There is a greater chance of loosening or failure of the prosthesis, requiring the patient to return to the operating room for revision surgery. Obese patients could experience difficulty breathing deeply enough, especially while sleeping because lung volume is decreased. The airway in the upper throat may be partially obstructed, limiting air intake. The resulting decrease in oxygen makes it more difficult for the patient to heal and to regain energy. The hearts of obese people may contain fatty tissue that decreases the heart muscle’s resilience, which leads to irregular rhythms, particularly dangerously slow heart rates.

Some overweight people may be malnourished because of unhealthy food choices. If dietary protein is low, the ability to heal is lessened and drainage from the incision may be increased, thus increasing the chance of infection. The thicker the fat layer just under the skin, the more difficult it is to keep the wound held together. This is because adipose tissue (fat) is less dense with less blood supply and can separate more easily. That, in turn, creates small pockets of bodily fluid that could potentially allow an environment for bacteria to collect and multiply, causing infection throughout the new joint.

Therefore, you are encouraged to lose as much weight as is safe and possible before surgery to maximize your surgical outcomes.

If weight loss does not occur and you wish to proceed with surgery, your pre-operative medical clearance will include screening for the following conditions:

  • Sleep apnea (not getting enough oxygen while you sleep at night due to snoring, partial obstruction of the airway or irregular breaths)
  • Malnutrition (low protein intake)
  • Antibiotic-resistant bacteria residing in your body that can cause infection in the surgery site.

If the screening tests show that you have any of these conditions, you will undergo treatment prior to surgery to correct them. Once corrected, you may then proceed with surgery. Additional steps taken during and after surgery will include sterile techniques, antibiotic cement to hold your prosthesis in place, and antiseptic surgical site cleansing.