Correlation between Body Mass Index (BMI), Visual Analogue Scale (VAS) score and knee osteoarthritis grading

Introduction: Osteoarthritis (OA) causes pain and disability in patients such that it interferes with daily activities. Pain becomes the main major symptom in joints that suffer from OA. Because of its chronic progressive nature, OA has a great socio-economic impact in developed and developing countries. This study aims to examine the correlation between Body Mass Index (BMI),the degree of pain based on Visual Analogue Scale (VAS) score, and knee osteoarthritis grading viewed from Kellgren–Lawrence criteria in patients with osteoarthritis of the knee joint.
Methods: This research was an analytic study using a cross-sectional method. BMI was obtained by measuring the height and weight of the patients; the degree of pain was obtained through interviews using VAS score, and knee osteoarthritis grading was measured by Kellgren–Lawrence criteria from a conventional anteroposterior projection of knee X-ray.
Results: Of the 60 samples of patients with knee OA, most of the samples are female (70% or 42 people) and the rest are male (30% or 18 people). No knee OA was found in patients with BMI below normal, three patients with normal BMI, and 57 patients (95%) with BMI above normal. Knee OA grading based on Kellgren–Lawrence criteria indicates that the most frequent grade is 3 (36.7% or 22 people), followed by Grade 2 (30% or 18 people). The highest degree of pain is severe VAS (56.7% or 34 people), followed by moderate VAS (38.3% or 23 people). The most frequent therapy given is surgery (53.3% or 32 people). The result of ANOVA correlation test indicates a significant correlation between BMI and knee osteoarthritis grading, with p = 0.039 (p < 0.05), in which the higher the BMI value, the more severe the knee OA grading. The pain scale assessed by VAS score is strongly correlated with knee OA grading suffered, with p < 0.001, in which the more severe the knee osteoarthritis grading, the higher the pain scale (VAS). Conclusion: The higher the BMI value, the heavier the grading of OA of the knee. As well, the heavier the grading of OA of the knee, the higher the pain scale (VAS).