THE EFFECTS OF OBESITY ON SYMPTOMS, FUNCTION AND PSYCHOLOGICAL DISTRESS IN PATIENTS UNDERGOING KNEE ARTHROPLASTY

Abstract

The study aims to determine the effects of obesity on the patients’ symptoms and their knee function before knee arthroplasty, as well as their states of anxiety and depression.

Ethical approval was obtained before the start of the study. Weights and heights of all patients were measured and BMI calculated on admission. Anxiety and depression states were recorded using the Hospital Anxiety and Depression Scale (HADS). The severity of pain and loss of function of the knees undergoing arthroplasty was measured using the Oxford Knee Score and the American Knee Society Score. All scores were measured per-op and again at 6 weeks post-op.

To date, 28 patients were included. The mean body mass index was 28.9. Only six patients had a BMI of < 25. Patients with normal BMI (< 25) had mean anxiety and depression scores of 6.8 and 5.67 respectively. Overweight patients (BMI > 25) had scores of 5.59 and 4.9 respectively. Patients with BMI > 30 had scores of 6.71 (p= 0.22) and 7.0 (p= 0.04) respectively.

Patients with BMI > 30 had an improvement in anxiety scores of 1.33 points compared with 0.55 for patients with BMI < 30 (p= 0.3). Depression scores improved by 4 points in the BMI > 30 group compared with 0.67 in the BMI < 30 group (p= 0.03).

Improvements in the knee scores were comparable in both groups.

Obese patients with BMI of > 30 have higher rates of anxiety and depression pre-operatively. At 6 weeks follow up, there is an improvement in both measures of psychological distress but this is more pronounced for depressive symptoms.