Effect of chondroitin sulfate on cartilage volume loss and subchondral bone marrow lesions in osteoarthritis knee

Background Chondroitin sulfate (CS) is a major component of the extracellular matrix of many connective tissues, including cartilage, bone, skin, ligaments, and tendons. Objective The aim of this work was to study the effect of CS treatment for short time (6 months) clinically and using MRI on cartilage volume loss, subchondral bone marrow lesions (BMLs), and synovitis in patients with primary knee osteoarthritis (OA). Patients and methods A total of 50 patients with primary knee OA and clinical signs of synovitis were included in this study. They were divided into two treatment groups. Group 1 included 30 patients who received two capsules of CS (structum capsule 500 mg) once daily for 6 months. Group 2 included 20 patients who received placebo once daily for 6 months. Clinical, radiological, and laboratory assessments were performed for all patients. Cartilage volume loss, subchondral BMLs, and synovial membrane thickness were assessed with MRI at baseline and after 6 months for both groups. Results The CS group showed significantly less cartilage volume loss compared with the placebo group after 6 months for the global knee, lateral compartment and tibial plateaus. However, there were no significant differences in the medial compartment and trochlea between the two groups. Significantly lower BML scores were found for the CS group compared with the placebo group after 6 months, and there were no significant differences in synovial membrane thickness between the two groups. Disease symptoms were similar in both groups. Conclusion CS treatment significantly reduces the cartilage volume loss and subchondral BMLs in primary knee OA after 6 months of treatment. These findings suggested a joint structure-protective effect of CS