I was going to have a spinal fusion but the surgeon placed me in the morbidly obese category with too many risks for surgery. I’d like to know two things: where is the cut off in terms of weight between obese and morbid obesity? (I had never heard that term). And am I being discriminated against because of my size?

eing overweight is a definite risk factor for back pain associated with spinal degeneration. Surgery in the form of spinal fusion may benefit obese patients but is also linked with higher complication rates, especially for those who are in the category of morbid obesity.

Obesity is defined by a body mass index (BMI) of 30 or greater. Morbid obesity is determined by a BMI of 40 or more. The BMI is a measure of body fat based on height. It isn’t the only way to identify obesity but it is a quick and easy method to get a general idea of relative sizes.

You can go to the U.S. Department of Health & Human Services website and easily calculate your own BMI (http://www.nhlbisupport.com/bmi/).

In a recent study from California, researchers looked at the effect of morbid obesity on complications and complication rates. California has a database with information on every patient who goes into the hospital anywhere in the state. Information is collected on a broad range of patient demographics such as age, gender, race, insurance coverage, and procedure performed. Patient body weight is another variable entered into the database. Using this database, the researchers were able to find 1,455 morbidly obese patients who had spinal fusion surgery.

The type of surgery was divided into four groups: cervical and lumbar fusions and anterior or posterior approach for those two locations. Total time in the hospital, total costs, and all complications were also recorded and available for comparison among the four groups. They found that morbid obesity was, in fact, the single most significant predictor of postoperative complications.

The rate of complications among the morbidly obese was 97 per cent higher than among patients of normal weight. That high rate was consistent for all types of postoperative problems (e.g., heart attacks, blood clots, pneumonia, infections). Fortunately, the death rate was not higher in those who were morbidly obese. Overall costs were increased by 28 per cent. Older age combined with morbid obesity resulted in even higher complication rates.

The authors of the California study were not suggesting that morbidly obese individuals should not have spinal fusion. On the contrary, they pointed out that individuals who are morbidly obese seem to benefit from spinal fusion as much as adults who are not obese. The main idea from these findings is the need to reduce patient risks when pre-operative weight loss is not an option.