Bone Abstracts

Background: Osteoarthritis (OA), the prevalent joint-affecting disease characterized by cartilage damage, is the leading cause of disability in adults and contributes to the excess of morbidity and healthcare costs. We performed the current trial to evaluate biomarkers, specifically adiponectin in serum and synovial fluid, associated with cartilage damage severity assessed by arthroscopy, in patients with symptomatic knee osteoarthritis.

Methods: The 40 subjects (mean age 51.8, 35% female, mean BMI 28.8) were divided into two groups according to arthroscopy assessed cartilage damage, using Outerbridge (OB) grading: Group 1 included 20 patients without cartilages surface defects (OB grade 0, I), Group 2 included 20 patients with cartilages surface defects (OB grade II, III). Metabolic parameters, insulin resistance markers and serum adiponectin levels were determined.

Results: Both groups were similar in terms of serum adiponectin levels (P=0.806). Synovial fluid adiponectin levels tended to be lower (not statistically significant) in subjects with cartilage damage (1718.6 vs. 2738.1). Knee Society Score was significantly lower in subjects with cartilage damage (113.0±24.9 vs. 142.7±25.1, P<0.001). In multiple linear regression analysis BMI was a significant independent determinant of cartilage damage in non-obese patients with knee osteoarthritis, such that each one-unit increase in BMI was associated with a 21.7% increase in risk of cartilage damage (OR1.217, 95% CI 0.998–1.483, P=0.05).

Conclusions: We did not find an association between serum adiponectin as well as adiponectin in synovial fluid, and arthroscopy assessed cartilage damage severity. BMI was a significant independent determinant of cartilage damage in non-obese patients with knee osteoarthritis.