The Influence of Obesity on Pain and Function in Knee Osteoarthritis: Comparison of Body Mass Index With Seven Knee Function Scales and Two Pain Scales

Obesity is a health problem that is rapidly increasing both in local societies and internationally. It is well known that obesity has a risk relationship with many different diseases. The scale for obesity is Body Mass Index (BMI), which has been widely accepted worldwide for many years. The relationship between BMI and disease is a frequently studied topic. This study aimed to evaluate and measure knee function and pain in patients with knee osteoarthritis. A total of 100 patients in radiologically advanced stage (Kellgren/Lawrence grade 3-4) who were scheduled for knee arthroplasty were administered seven knee osteoarthritis scales (Timed up and Go (TUG), American Knee Society Score (AKSS), the Lequesne Knee Index, Knee injury and Outcome Subtotal Pain Score (KOOS-PS), Western Ontario and McMaster Universities Index (WOMAC), Oxford Knee Score, and International Knee Documentation Committee (IKDC)), and two pain scales, the McGill Pain Questionnaire and a visual analog pain scale (VAS), which were completed simultaneously on the same form. Data that did not show a normal distribution were analyzed with Spearman and Kendall correlation tests. The mean age of the 100 consecutive patients, 92% of whom were female, was 65.2 years (48-81 years). There was a strong correlation between BMI and all functional knee scales, but no significant association was found between pain scales and BMI. In our hypothesis, we expected that all functional and pain scales would moderately or strongly correlate with BMI. However, while a strong correlation with the functional pain scales is an expected result, the expected strong positive correlation between pain scales and BMI was not found in the study.