Can you be overweight and still get a knee replacement?
While some doctors do have weight cutoffs for performing replacement knee surgery, and extra pounds add to the risk of complications, doctors are increasingly performing knee replacements on patients with extra pounds.
The primary reason patients need knee replacement surgery is arthritic joint damage resulting in serious pain and mobility issues. As cartilage wears away during the natural aging process, sometimes made worse by sports injury or poor habits, patients can experience bone rubbing directly on bone. It is never a pleasant experience.
The conflicting issue in knee replacement among the overweight is that, on the one hand, patients who are obese, by virtue of putting excess pressure on their weight-bearing joints, are more likely to need joint placement. On the other hand, however, the surgery is riskier for the obese who are also less likely to experience improvement than their slender counterparts.
Nonetheless, there is an increasing demand for joint replacements among overweight patients, especially for total knee replacements. (For no discernible reason, the demand for total hip replacements is not nearly as great in this population.) Because research has shown that obese patients are at greater risk of complications than patients of normal weight, and because the risk increases with increased body mass index (BMI), heavier patients are typically advised to lose weight before undergoing knee replacement surgery.
While we would all like to believe that, even if patients are unable to lose weight prior to surgery, they will be able to lose weight after the procedure because the absence of pain will make them more willing and able to exercise, studies about this phenomenon are conflicting. Some studies show that patients’ weights after knee replacement remain constant; some studies show weight loss; some even demonstrate weight gain after the procedure.
What are the increased risks of knee replacement surgery on obese patients?
Because of a combination of improved techniques and the realization that the general population is getting heavier, some orthopedic surgeons are rising to the challenge of operating on the obese. Still, the risks of complications among those whose BMI is 40 to 50 may be daunting. These risks include:
- Increased rate of infections
- Problems with wound healing
- Complications resulting from conditions more frequently found among obese patients, such as hypertension, sleep apnea, and diabetes.
- Decreased durability of the prosthesis since it will be subjected to more wear and tear
In spite of all this, studies show that, while obese patients do not improve functionally as much as those of lower weight, the satisfaction rate among heavy patients is approximately the same as it is among thinner patients. Both groups report that, after knee replacement, they experience less pain, better ability to perform daily tasks, and an improved quality of life.
Whatever your weight, if you are considering knee replacement surgery, you should consult with a skilled and experienced orthopedic surgeon who can help you realistically consider your options.