The rate of decline of joint space width in patients with osteoarthritis of the knee: a systematic review and meta-analysis of randomized placebo-controlled trials of chondroitin sulfate

Background: Chondroitin sulfate has been shown to relieve pain and improve functional limitation in patients with osteoarthritis (OA) of the knee in numerous clinical trials and meta-analyses. Its role as a potential structure-modifying drug for knee OA, however, remains controversial. Objective: To perform a meta-analysis of randomized double-blind placebo-controlled clinical trials to assess the efficacy of chondroitin sulfate as a structure-modifying drug for knee OA. Research design and methods: A Medline search was conducted from 1996 through 2007 and five articles that reported results from three trials were identified; one additional trial was identified through review of presentations at annual rheumatology meetings. There was no evidence of heterogeneity across the trials and results were pooled using a fixed effects meta-analysis. Results: Pooled results demonstrated a small significant effect of chondroitin sulfate on the reduction in rate of decline in minimum joint space width of 0.07 mm/year (95% CI 0.03, 0.10) that corresponded to an effect size of 0.26 (95% CI 0.14, 0.38) (p < 0.0001). This result was robust in sensitivity analyses. Limitations: The individual studies included in the meta-analysis varied in the number of patients enrolled and the techniques used to acquire knee radiographs and to measure joint space width. Conclusion: These results demonstrate that chondroitin sulfate is effective for reducing the rate of decline in minimum joint space width in patients with OA of the knee. Chondroitin sulfate may have a role as a structuremodifying