Prevalence of obesity among patients admitted for elective orthopaedic surgery.

The aim of this work was to test the hypothesis that obesity is more common among patients requiring elective orthopaedic surgery than in the general population. A cross-sectional survey was carried out on 2673 consecutive patients admitted from the waiting list for four common types of operation: removal of lumbar intevertebral disc herniation, total hip replacement, elective knee arthroscopy or total knee replacement. Patients with primarily inflammatory joint disease were excluded. The immediate preoperative relative body weight, calculated as body mass index (BMI), of the patients was compared with data available on a general population sample of 44,034 people. Obesity was defined as BMI greater than the BMI + one standard deviation of the corresponding age and sex category of the general population. By these criteria, 256 patients (27%) with lumbar intervertebral disc herniation, 192 (24%) with total hip replacement, 135 (22%) with knee arthroscopy and 80 (27%) with knee replacement were obese, whereas the proportion in the general population was 16%. A major difference with the general population emerged in young patients of both sexes operated on for lumbar disc herniation and in women admitted for knee arthroscopy. The mean BMI of men aged 20 to 49 years subjected to knee arthroscopy did not differ from the general population. It was concluded that overweight people seem to be strongly over-represented among the patients requiring common orthopaedic surgical procedures.