Soft knees and shaky legs with weakness may be meniscus injury, osteoarthritis of the knee or synovitis, which need to be treated with medication or surgery according to the condition. 1. Meniscus injury: For meniscus injury caused by trauma, pain and dysfunction are the main causes in the acute stage, and symptoms such as limp legs, weakness or knee popping will appear in the later stage. In mild cases, oral non-steroidal anti-inflammatory drugs such as bisacodyl capsules and cartilage nutritive drugs such as glucosamine capsules are needed for treatment, while in severe cases, surgical treatment may be needed. 2. Knee osteoarthritis: knee osteoarthritis due to cartilage degeneration, resulting in cartilage wear and tear, peeling, in the knee joint activities will be stimulated by the activities of the degenerative cartilage damage to the area and lead to pain, the knee, the big soft leg, shivering, or weakness, etc., arthritis can be treated by taking oral celecoxib and strong bones and joints capsule, etc., and in the late stage, it is necessary to replace the joint treatment. 3. Knee synovitis: the acute stage not only leads to swelling and fluid accumulation in the knee joint, but also leads to weakness and tenderness in the knee when walking. In the early stage, oral non-steroidal anti-inflammatory drugs, such as bisacodyl, are needed to treat synovitis, and in severe cases, arthroscopic treatment of synovial hyperplasia is needed to alleviate the symptoms. In severe cases, arthroscopic treatment of synovial membrane is needed to alleviate the symptoms. Weakness of the knees and shaky legs need to be treated as soon as possible, with oral medication under the guidance of a doctor, and surgery if necessary.