Fusion surgery is a disfiguring surgery that has the advantage of increasing joint stability and relieving symptoms of localized pain in the joint, but its disadvantage is that the joint cannot be moved after the surgery and mobility of the joint will be lost. Fusion surgeries include lumbar fusion, ankle fusion, and knee fusion. The benefits of lumbar fusion for patients with lumbar disc herniation are that the surgery increases spinal stability and can relieve symptoms such as low back pain caused by the condition. The disadvantage is that the surgically fused lumbar segment loses mobility of the lumbar joints and the patient cannot perform movements such as bending. Patients with rheumatoid arthritis or tuberculous arthritis of the ankle or knee joints can undergo ankle fusion or knee fusion. The advantage of the surgery is that it can relieve localized pain and terminate the disease, but the disadvantage is that the ankle and knee joints lose their mobility after the surgery, and the patient is unable to squat or bend the knee. If fusion surgery is required, please follow the doctor’s instructions for treatment.