Repair of complex and avascular meniscal tears and meniscal transplantation.

A functional meniscus is critical to the long-term health of the knee joint. The repair of meniscal tears that extend into the central avascular region requires understanding the appropriate indications, contraindications, surgical techniques, and postoperative rehabilitation protocols. An inside-out repair technique using multiple vertical divergent sutures with an accessory posteromedial or posterolateral incision is recommended for optimal stability. In young, active patients, the risk of repair failure and the need for revision are outweighed by the benefit of meniscal preservation. Although many meniscal tears are repairable, not all are salvageable, especially if considerable tissue damage has occurred. The goals of transplantation of human menisci are to restore partial load-bearing meniscal function, decrease patient symptoms, and provide chondroprotective effects. Clinical studies have shown that meniscal transplantation decreases tibiofemoral joint pain in the short term. The procedure remains in an evolving state with an unpredictable long-term outcome; however, most meniscal transplants gradually deteriorate, tear, or shrink in size over time, thereby losing the ability to provide function. The current goal is to provide short-term benefits to the patient until a superior meniscal transplant is clinically available.