Influence of body mass index in revision total knee arthroplasty

OBJECTIVE : To evaluate the influence of the body mass index (BMI) on the functional assessment of patients who underwent revision total knee arthroplasty (RTKA). METHODS : Thirty patients who un-derwent RTKA between January 2008 and January 2012 were retrospectively assessed using the WOMAC questionnaire. The patients were divided into three groups according to the BMI ca-tegories defined by the World Health Organization (WHO): Group I with normal BMI (18-24.9 Kg/m(2)), with eight patients; Group II, overweight (BMI 25-29.9 Kg/m(2)), with 15 patients, and Group III obesity with BMI ≥ 30 Kg/m(2), with seven patients. The post-ope-rative function scores obtained through the WOMAC questionnaire were compared with the BMI of each group. The statistical analysis between BMI and WOMAC scores was performed with the Spe-arman correlation test. RESULTS : The average functional WOMAC score for individuals in Group I was 16.7; in Group II it was 47.7; and in Group III it was 69.9, with a statistically significant differen-ce between groups I, II and III (p< 0.0001). CONCLUSION : Patients with BMI > 25 Kg/m(2) had a worse functional evaluation through WOMAC scores when compared to patients with normal BMI after RTKA. Level of Evidence III, Tranversal Retrospective Study.