The Influence of Obesity on Clinical Outcomes after Total Knee Arthroplasty -A Five-year Minimum Follow-up-

Purpose: To evaluate the effects of obesity on clinical outcomes following total knee arthroplasty in osteoarthritis patients. Materials and Methods: Between June 1999 and February 2002, 239 osteoarthritis patients underwent total knee arthroplasty, and 118 knees of 94 patients treated during this period were followed for a minimum of 5 years. Seventy knees belonged to 56 obese patients (body mass index, BMI≥25 kg/m2), while 48 knees belonged to 38 non-obese patients (BMI＜25 kg/m2). All patients were fitted with the same type of prosthesis by the same surgeon. The Knee Society objective and functional scores, range of motion, patellofemoral symptoms, complication rate, and revision rate were analyzed and compared between the two groups. Results: Analysis showed that the obese and non-obese groups were similar in terms of Knee Society scores, range of motion, patellofemoral symptoms, complication rate, and infection rate. Ninety percent of knees in the obese group and 92% of knees in the non-obese group had a successful outcome (i.e., Knee Society score ≥80 points at final follow-up) (p＞0.05). With regard to revision, 4 liner exchanges took place in the obese group due to liner dislodgement, and no liner exchanges took place in the non-obese group. However, there was no significant difference in the incidence of liner exchange between the two groups (p＞0.05). Conclusion: Obesity (BMI≥25 kg/m2) has no effect on total knee arthroplasty outcomes in osteoarthritis patients at 5 years follow-up.ope