Chondroitin sulphate reduces both cartilage volume loss and bone marrow lesions in knee osteoarthritis patients starting as early as 6 months after initiation of therapy: a randomised, double-blind, placebo-controlled pilot study using MRI

Abstract

Objective: To determine the effect of chondroitin sulphate (CS) treatment on cartilage volume loss, subchondral bone marrow lesions (BML), synovitis and disease symptoms in patients with knee osteoarthritis (OA).

Methods: In this pilot multicentre, randomised, double-blind, controlled trial in primary knee OA, 69 patients with clinical signs of synovitis were randomised to receive CS 800 mg or placebo once daily for 6 months followed by an open-label phase of 6 months in which patients in both groups received CS 800 mg once daily. Cartilage volume and BML were assessed by MRI at baseline and at 6 and 12 months; synovial membrane thickness was assessed at baseline and at 6 months.

Results: The CS group showed significantly less cartilage volume loss than the placebo group as early as 6 months for the global knee (p=0.030), lateral compartment (p=0.015) and tibial plateaus (p=0.002), with significance persisting at 12 months. Significantly lower BML scores were found for the CS group at 12 months in the lateral compartment (p=0.035) and the lateral femoral condyle (p=0.044). Disease symptoms were similar between the two groups.

Conclusion: CS treatment significantly reduced the cartilage volume loss in knee OA starting at 6 months of treatment, and BML at 12 months. These findings suggest a joint structure protective effect of CS and provide new in vivo information on its mode of action in knee OA.

Figure 1

Patient disposition. CS, chondroitin sulphate; DB, double-blind; OL, open-label.

Figure 2

Cartilage volume loss in percentage and changes in bone marrow lesions (BML) score over time compared with baseline (0–6 months and 0–12 months). Solid line, chondroitin sulphate (CS) group; dotted line, placebo group. p Values of the corresponding subregions were assessed by analysis of covariance (ANCOVA) for the cartilage volume (where the dependent variable was the cartilage volume at 6 and 12 months and the independent variables were the cartilage volume at baseline and the treatment) and by the non-parametric Mann–Whitney U test for the BML scores. *p<0.05,**p<0.01. At 6 months n for cartilage: CS = 32, placebo = 28, for BML: CS = 32, placebo = 29. At 12 months n for cartilage: CS = 30, placebo = 22, for BML: CS = 30, placebo = 23. BL, baseline; m, months.