Biomechanics and healing response of the meniscus

The menisci are important in many aspects of knee function, including load bearing, shock absorption, joint stabilization, joint lubrication, and proprioception. Total and partial meniscectomy significantly increase the load per unit area in the tibiofemoral joint and result in early osteoarthritis. Meniscus repair has generally been limited to the peripheral vascular area of the meniscus, but efforts have been made to promote the healing of tears in the avascular inner area. Recent studies have demonstrated the potential for cytokines to increase extracellular matrix synthesis by meniscal cells, suggesting the ability to improve meniscus healing. Meniscus allograft transplantation represents one of the few available treatment options after total meniscectomy. Novel strategies for meniscal repair using gene therapy techniques and engineered tissue are exciting options for the future. This review will discuss these basic aspects of the meniscus, focusing on meniscus biomechanics, the healing response of meniscal cells after injury and allograft transplantation, and future directions for meniscal repair and regeneration.