Obesity has been more precisely defined bythe National Institutes of Health (the NIH) as a BMI (Body Mass Index) of 30 and above. (A BMIof 30 is about 30 pounds overweight.) The BMI, a key index for relating body weight to height,is a person's weight in kilograms (kg) divided by their height in meters (m)squared.

Example: someone who weighs 68 kgs and is 165cms tall has a BMI = 68/(1.65)2     =24.97

A recent study in Journal of arthroplastystudied complications in 7 groups of patients. Patients were separated into 7 groups based on BMI (18.5-24.9kg/m2, 25.0-29.9 kg/m2, 30.0-34.9 kg/m2,35.0-39.9 kg/m2, 40.0-44.9 kg/m2, 45.0-49.9 kg/m2,and >50.0 kg/m2). They analyzed data on five 30-day compositecomplication variables, including any complication, major complication, woundinfection, systemic infection, and cardiac (heart related) and/or pulmonary (lungsrelated) complication.

Their study suggestedthat there was a positive correlation between BMI and incidences of 30-daypostoperative complications in both knee and hip replacement surgery patients.The odds of complications increased dramatically once BMI reached 45.0 kg/m2.

So it makes sense tolose weight before one undergoes an elective surgery like a joint replacementsurgery. However, I do routinely come across patients who have delayed surgeryfor a long time, have remained almost bedridden or “home-ridden” who keep puttingon weight simply because of lack of activity.

I would like tostrongly suggest two points

1: Disabling knee orhip pain casing weight gain is a sure shot sign to get the surgery done early

2. It is difficult to loseweight once you are disabled since burning calories is almost impossible. Take helpof bariatric surgery in such a situation.