Joints are generally composed of bones, cartilage, ligaments, periarticular muscles, tendons and other tissues. Patients with different joint diseases require different tests. The common joint surgical diseases are as follows: 1, meniscal injury, meniscus is a fibrous cartilage tissue, ordinary X-rays and CT can not be visualized, MRI (magnetic resonance imaging) is preferred. 2, anterior and posterior cruciate ligament, medial and lateral collateral ligament injury, because it is a soft tissue structure, ordinary X-ray and CT can not be visualized, the first choice of MR (magnetic resonance) examination. 3, osteoarthritis, the disease is caused by the wear and tear of joint cartilage, degeneration, the first choice of ordinary X-ray examination, observation of the general morphology of the joint, the presence of bone superfluous formation, the presence of joint space narrowing, inversion deformity, the presence of free body formation, etc.. For further examination, MR (magnetic resonance imaging) can be chosen. MR can clearly show the specific degree of wear and tear of articular cartilage. 4. For femoral head necrosis, general X-ray examination is preferred, which can basically clarify the diagnosis. For early patients with high suspicion of femoral head necrosis, MR (magnetic resonance) examination can be further performed if ordinary X cannot make a clear diagnosis, because MR (magnetic resonance) can detect the early changes of femoral head necrosis. 5. For patients with chronic pain in the shoulder joint, general X-ray examination should be performed first to exclude bone tumor, acromion impingement, osteoarthritis, calcific tendonitis and other diseases. If rotator cuff injury is suspected, MRI (magnetic resonance imaging) should be performed. In short, different diseases require different examinations, and generally follow the principle of simple first and then complex, general examination first and then special examination.