The decision to operate after an ACL tear depends on your requirements for knee function, the accompanying injury, your age, and the degree of degeneration in the knee. Non-surgical treatment may be an option in the following cases 1. If you rarely exercise, travel, and have a low level of daily activity. Or you are over 50 years old and do not do much activity. 2.If you love sports or work with a high load on the knee joint, but you are able to give up sports, change sports or transfer to another job, etc. 3, If you have no other concomitant injuries such as meniscus other than ACL. 4.The ACL reconstruction is not recommended for the middle-aged and elderly population where the knee joint is already severely worn.