Course-based intra-articular injection of medical chitosan mitigates excessive deposition of triacylglycerides in the synovial tissue of the knee osteoarthritis

Background: This study aimed to investigate the clinical efficacy of intra-articular injections of medical chitosan for treating knee osteoarthritis (KOA) and measure the lipid metabolism profiles of the synovial tissue. Methods: 60 patients with KOA undergoing conservative treatment were recruited and randomized into two groups: one without pharmacological intervention (OA group) and the other receiving course-based intra-articular medical chitosan injections (CSI group). Quantitative lipidomic profile of synovial tissue was analyzed. Functional scores, including Kellgren-Lawrence rating (K-L), VAS, WOMAC scoring, and AKS scoring were conducted. Results: Survival from the initial conservative treatment to final knee arthroplasty was significantly longer in the CSI group compared to the OA group. Except for the pre-surgery VAS score, no statistically significant differences were observed in the other scores, including K-L, initial VAS, WOMAC, and AKS. However, the CSI group experienced a slightly more pronounced decline in AKS-Knee subscores compared to the OA group. Compared to the CSI group, the OA group exhibited a significant upregulation in most differential lipids, particularly triacylglycerides (TAGs, 77%). The OA group had notably higher levels of long-chain unsaturated fatty acids. Conclusion: Intra-articular injection of medical chitosan significantly prolongs the survival period before knee arthroplasty and reduces the deposition of TAGs metabolites.