Meniscal repair surgery usually takes 30-90 minutes, depending on the severity of the meniscus injury and the number of damaged areas. Second, if the meniscus injury is a large tear, involving the anterior and posterior meniscus horns, especially the posterior horn of the medial meniscus, it is often necessary for the assistant to externally rotate the knee joint, try to open the posterior gap of the medial meniscus, and expose the posterior horn of the meniscus.