Knee sprain three months is not good, need to see a doctor as soon as possible to review, if the muscle and ligament sprain, can be through the magnetic heat therapy and other physical methods to promote recovery; if there is a meniscus, ligament tear and other serious injuries, conservative treatment is difficult to recover, the need for surgical treatment. Three months after the knee sprain is still not well, it is recommended to go to the orthopedic clinic in time to clarify the specific situation of the sprain. If it is determined to be muscle and ligament sprain, pay attention to strengthen rest. Magnetic heat therapy with intermediate frequency electrical stimulation can help relax the surrounding muscles and promote blood circulation, thus promoting recovery and relieving symptoms. If the knee sprain is serious, with meniscus damage or tendon tear, etc., it is difficult to recover from conservative treatment, and needs to be treated by surgery, such as knee arthroscopy repair. And can take with the compound chondroitin sulfate and other nutritional joint cartilage drugs. After the knee sprain should be timely medical intervention, not delay, in order to prevent the impact of the recovery effect, daily attention to strengthen the nutrition, avoid exertion, do not blindly use drugs.