Rationing joint replacements

Editor—The decision of the East Suffolk primary care trusts not to fund joint replacements for patients unless the patient has a body mass index (BMI) below 30 and conservative means have failed to alleviate the pain and disability breaches basic principles of health care that do not seek to judge patients for their illness.¹ The decision confuses three separate questions: does obesity cause osteoarthritis, does weight loss improve it, and is surgery more dangerous or less successful in obese patients?

Obesity and risk for osteoarthritis of the knee (especially bilateral) are associated, as is a response of symptoms to weight loss²; the links with hip osteoarthritis are less clear. Weight loss is a logical initial management for painful knee osteoarthritis but does not obviate the potential benefit of surgery for symptomatic patients, whether they have lost weight or have been able to reduce their BMI below 30.

No evidence supports withholding joint replacement from obese people, even on utilitarian grounds. For knee replacement, there is “no evidence that age, gender, or obesity is a strong predictor of functional outcomes.”³ A UK health technology assessment of hip replacement concluded that obese patients (with a BMI > 30) could benefit from total primary hip arthroplasties without cement and that obesity did not noticeably increase the operative risk.⁴ Chan et al found no significant difference in the improvement in scores (of quality of life) between the non-obese and obese groups, concluding that relative body weight alone does not influence the benefit derived from primary total hip arthroplasty.⁵

Since obesity does not increase the risks or diminish the benefits of joint replacement, the trust's decision to deny such treatment seems to be based on prejudice or attribution of fault, or both. Logically extended, such a policy would deny treatment to, among others, smokers, most patients with HIV infection, and those who sustain sports injury.