Abstract
BACKGROUND: The formation of a stable fibrin clot plays an important role in early tissue repair. Tranexamic acid (TXA), a potent fibrinolysis inhibitor, prevents fibrin clot dissolution. PURPOSE: We sought to test the effect of intra-articular TXA administration on meniscus healing and articular cartilage status in a rabbit model. METHODS: Thirty-two rabbits underwent bilateral knee surgery with creation of a 1.5-mm circular defect in the anterior horn of the lateral meniscus and a 3-mm longitudinal tear with repair in the anterior horn of the medial meniscus. Twelve rabbits were used for an initial TXA dose determination study. Twenty rabbits were then injected with 50 mg/mL of TXA in the left knee while the right knee served as a control. Animals were sacrificed at 2-, 4-, and 8-week timepoints. Eight rabbits underwent biomechanical analysis. Semiquantitative histological analysis compared meniscal healing and articular cartilage between TXA-treated and control knees. RESULTS: Both circular defects of the lateral meniscus and longitudinal tear injuries of the medial meniscus showed no difference in healing across all timepoints. At 2 weeks post-surgery, TXA-treated knees exhibited reduced tibial articular cartilage structure compared to controls. By week 8, control knees had higher proteoglycan content in all femoral articular cartilage zones compared to TXA-treated knees. Biomechanical analysis was inconclusive. CONCLUSION: This rabbit study found that TXA administration did not enhance healing following meniscus repair. Moreover, intra-articular TXA appeared to have exerted an adverse effect on articular cartilage, possibly due to the detrimental effects of persistent blood in a joint. Further studies will be critically important to determine the effect of TXA administration at various time points after surgical repair.