Comparable outcomes for knee replacements in obese

New findings suggest there is no justification for denying obese patients total knee arthroplasty (TKA) for osteoarthritis of the knee. According to the online first report long-term outcomes are nearly as good as their normal-weight peers. The English investigators comment that whilst about 55,000 knee replacements are performed every year in England, in some parts of the country the surgery is offered only to patients who are not clinically obese (body mass index (BMI) below 30 kg/m2), on the grounds that obesity is itself a risk factor for knee osteoarthritis. To investigate further the authors followed 325 patients from for approximately six years after TKA, along with 363 controls selected from the general population. At baseline, physical function was markedly worse in the obese patient group than in the controls (p<0.001). However, at follow-up, physical function scores had improved for the patient group, while that of controls had worsened (p<0.001). In the subgroup of subjects with baseline BMI > 30, median physical function score increased by 3 points among the 108 patients, while deteriorating by 36 points among the 36 controls. And among those over the age of 75 who had not had the surgery, mobility score fell 40 points. "The long term improvement in physical function that we observed in patients who have undergone TKA [knee replacement surgery] is striking when set against the decline that occurred in [the comparison group]," say the authors. "These benefits extend to patients [who are obese] and, provided appropriate selection criteria are applied with regard to fitness for surgery, there seems no justification for withholding [knee replacement surgery] from patients who are obese," they conclude. Reference Cushnaghan, J. Bennett, J. Reading, I. et al. 2008, ‘Long-term outcome following total knee arthroplasty: a controlled longitudinal study’ Annals of the Rheumatic Diseases, Online First. Volume and Edition to be announced....