Investigation of the Effects of Intra-articular Tranexamic Acid on Intact Cartilage Tissue and Cartilage Formation in Osteochondral Defects of the Rabbit Knee: An Experimental Study.

Background In this study, the effects of tranexamic acid (TXA) and saline on intact cartilage and the recovery of experimental osteochondral lesions following microfracture in a rabbit model were compared. Methods Twenty adult rabbits were divided into four groups (1A, 1B, 2A, and 2B) based on with or without TXA use and microfracture. In addition, these groups were categorized into two different subgroups based on the use of TXA in Groups 1 and 2 (Groups A and B). Full-thickness cartilage defects were created on the weight-bearing surface of the medial femoral condyles unilaterally in Group 2 for the effect of TXA or saline on healthy cartilage tissue while a repetitive injection was applied in Group 1 for the effect of TXA or saline on intact cartilage. A single dose of 10 mg/kg TXA was injected into the knee joints of Group A and 10 mg/kg 0.9% saline solution injected in Group B for three consecutive days. All animals were sacrificed for the extraction of the medial condyles for histologic evaluation eight weeks after surgery. The International Cartilage Repair Society (ICRS) II scoring system was used for histologic evaluation. Results No complications or adverse effects related to surgery were observed in all rabbits. All ICRS II parameters were similar in the TXA and saline solution groups in the intact cartilage group except for chondrocyte clustering, formation of a tidemark, subchondral bone abnormalities, and mid/deep zone assessment. Moreover, these parameters were higher in the saline solution group in the cartilage group, but no significant difference was observed in the TXA group in the intact cartilage group. All ICRS II parameters were higher in the saline solution group than in the TXA group in the microfracture group, but no significant difference was observed in the TXA group in the microfracture group except for inflammation, which was similar in the TXA and saline solution groups in the microfracture group. Conclusion We found that intra-articular TXA administration did not have a negative impact on healthy cartilage tissue and cartilage transformation and proliferation as compared to the saline infusion.