Zoe B. Cheung, MD, MS

The medial meniscus root attachment plays an integral role in resisting hoop stresses across the tibiofemoral joint, and disruption of the posterior root has been shown to be biomechanically equivalent to a complete meniscectomy. Disruption of the medial meniscus root results in meniscal extrusion, which can alter knee kinematics and lead to progressive, rapid articular cartilage degeneration. Tears of the posterior medial root attachment are typically either traumatic or degenerative. Traumatic tears frequently occur in young patients with concomitant knee ligamentous injuries and are more frequently true avulsions of the root attachment. This is contrasted with degenerative tears that occur during low-energy injuries and are more often full-thickness radial tears located within 1 cm of the root attachment.