The effects of bariatric surgery weight loss on knee pain in patients with osteoarthritis of the knee

Abstract

Studies have shown that osteoarthritis (OA) is highly associated with obesity, and individuals clinically defined as obese (BMI > 30.0 kg/m(2)) are four times more likely to have knee OA over the general population. The purpose of this research was to examine if isolated weight loss improved knee symptoms in patients with osteoarthritis. Adult patients (n = 24; age 18-70; BMI > 35 kg/m(2)) with clinical and radiographic evidence of knee OA participated in a one-year trial in which WOMAC and KOOS surveys were administered at a presurgery baseline and six and twelve months postsurgery. Statistical analysis was performed using Student's t and Wilcoxon Signed Rank tests. Weight loss six and twelve months following bariatric surgery was statistically significant (P < 0.05) compared to presurgery measurements. All variables from both KOOS and WOMAC assessments were significantly improved (P < 0.05) when compared to baseline. Isolated weight loss occurring via bariatric surgery resulted in statistically significant improvement in patient's knee arthritis symptoms at both six and twelve months. Further research will need to be done to determine if symptom relief continues over time, and if the benefits are also applicable to individuals with symptomatic knee arthritis that are overweight but not obese.

Figure 1

Comparison of body weight from baseline (presurgery) to 12 month postsurgery follow-up appointment. Standard error bars are present. The (∗) indicates significant weight loss at 6 months and 12 months when compared to baseline. n = 24.

Figure 2

Comparison of Body Mass Index (BMI) from baseline (pre-surgery) to 12 month postsurgery follow-up appointment. Standard error bars are present. The (∗) indicates significant weight loss at 6 months and 12 months when compared to baseline. n = 24.

Figure 3

WOMAC pain, stiffness, and physical function comparisons from baseline (pre-surgery) to 12 month follow-up. The bars are standard error. The (∗) indicates significant differences (P < 0.05) when compared to baseline. n = 24.

Figure 4

Comparison between KOOS scores reported at baseline and then 6- and 12-month postsurgery. Bars are standard error. The (∗) indicates significance (P < 0.05). n = 24. QOL = quality of life.