JOINT REPLACEMENT IN THE OVERWEIGHT PATIENT. A LOGICAL APPROACH OR NEW FORM OF RATIONING?

Abstract

Introduction: Primary Care Trusts (PCT) in Suffolk have recently withdrawn funding for hip (THA) or knee replacement (TKA) surgery for obese patients (Body Mass Index (BMI) > 30). We have estimated the number of patients affected by this restriction by reviewing our joint replacement database and have sought evidence for this decision being evidenced based.

Materials and Methods: All patients undergoing joint replacement at our hospital have their BMI recorded prospectively. We have established the number of patients having hip or knee replacements with a BMI of greater than 30. A Medline literature search identified studies that examined the influence of BMI on outcome of joint replacement surgery

Results: 328 (24%) of 1366 people undergoing THA between 2000–2005, and 225 (38.5%) of 567 undergoing TKA between 2003–2005 had a BMI > 30. The difference between these groups is significant (p 0.001 CI 0.095 to 0.191.). There was no difference between the sexes in the hip group, but more women than men were obese in the knee group (p< .001 CI 0.096–0.25). We identified 19 studies that examined the impact of BMI on joint replacement surgery.

Discussion: Based on National joint register figures, a similar policy enacted in England and Wales would affect about 20,000 patients a year.

The literature produces some evidence of a higher early complication rate in obese patients undergoing THA, and operative time seems to be longer and blood loss greater than for matched controls. The only study looking at long-term outcome of THA showed no difference in hip survivorship at 10–18 years between obese and normal weight patients. We conclude that where THA is concerned, the PCT policy has no clinical or evidence based justification.