Abrasive forces are the main cause of meniscus tears, most of which are difficult to heal on their own, a few mild cases recover on their own, but most still require surgery.
Most of the lateral meniscus tears are caused by internal or external rotation when the knee is in semi-flexion. The force generated by gravity’s excessive compression and knee rotation is too much for the meniscus to withstand and results in a tear. The injury results in blood accumulation, swelling, inability to straighten the knee, and knee popping.
The lateral meniscus has only a small blood supply and is still mostly nourished by the synovial fluid in the knee joint, so it is difficult to heal on its own and surgery is often required. The torn meniscus can be sutured, repaired or partially removed; if the meniscus is so badly broken that it is difficult to be partially repaired, it should be completely removed and artificial meniscus replacement should be performed.
Meniscal tears are difficult to heal on their own, and long term untreated or incorrect treatment may lead to symptoms such as necrosis of the knee, which should not be left untreated to avoid surgery.