If the meniscus is left untreated for a long time after the injury, firstly, it may be because the injury is mild at the beginning, but if it is left untreated for a long time, the small fissure will become a large fissure due to long-term friction without protection, and it will turn from mild to severe. The second, the meniscus because the blood supply is not very good, so no injury after long-term untreated, the injury site may become scarred. This will reduce the elasticity and reduce the mobility, which is still relatively mild. Finally, if the meniscus is left untreated for a long time and the damage is not too light, it has tears and crushing, and it is still not treated, it will easily become crushed and aggravated, resulting in the loss of cartilage, and at the same time there is fluid pain and activity flexibility is obviously limited, it will also cause muscle atrophy, affecting the ability to move and exercise, especially when going up and down the stairs in semi-flexion, the damage to the meniscus of the knee is greater, and if there is damage, then it is easy to aggravate the extrusion causing Pain.