Meniscal injury is the most common lesion for arthroscopic knee surgery. The medial meniscus is more likely to be injured because the medial meniscus is closely attached to the joint capsule, while the lateral meniscus has a free zone. Meniscal injuries are rare in children and can be seen in adolescents, with a peak incidence in the thirties and forties. After the age of fifty, meniscal injuries are more often due to osteoarthritic factors. Meniscal injuries are characterized by pain in the joint space, snagging sensation, popping and interlocking. The types of meniscal injuries include incomplete tears, barrel stem tears, flap tears, radial tears, and compound tears. Stable meniscal injuries that are asymptomatic may be treated conservatively. Meniscal injuries that cause persistent symptoms require arthroscopic surgical treatment. Currently, meniscus is treated by excision of the tear site or meniscal suturing whenever possible. The inner 2/3 of the meniscus has no blood flow and usually needs to be removed at the time of injury. In adults, there is blood flow in the outer 1/3 of the meniscus and tears in this area often heal spontaneously if they are less than 15 mm. Larger tears require suturing. Meniscal suturing techniques include inside-out suturing outside-in suturing total intra-articular suturing or incisional suturing. In recent years, the use of absorbable staples in meniscal repair has led to the widespread adoption of the total intra-articular suture technique. Unfortunately, however, there have been reports of detachment of the absorbable nail, and biomechanical studies have shown that the fixation strength of this method is inferior to that of suture fixation. Incisional sutures are frequently employed for tears in the marginal region of the meniscus. Sutureable meniscal injuries often coexist with ACL injuries, and reconstruction of the ACL to restore joint stability can protect the sutured meniscus, which has a much higher success rate than an unstable joint. In patients with meniscectomy and some early osteoarthritis, meniscal transplantation may be used. Short-term follow-up results show satisfaction in 2/3 of patients. In the future, bioprosthesis technology will make regeneration after meniscectomy possible.