The scope of foot and ankle arthroscopy is not only for the ankle joint, but also for the subtalar joint, talocrural joint, heel dice joint, metatarsophalangeal joint and interphalangeal joint disorders. Foot and ankle arthroscopy can provide a more accurate assessment of the integrity of the articular cartilage, ligament pattern and tension, and synovial structures within the joint than previous incisional procedures. The spectrum of diseases treated by foot and ankle arthroscopy: cartilage or osteochondral injury, osteoarthritis, intra-articular free bodies, transarticular surface fractures, synovitis, bony impingement and soft tissue impingement syndrome of the ankle, early to mid-stage talar osteonecrosis, medial and lateral collateral ligament injury or joint instability of the ankle, joint infection, arthroscopically assisted joint fusion, intra-articular tumors, unexplained swelling and pain, interlocking, etc., can be solution. Advantages of foot and ankle arthroscopy: minimally invasive, less traumatic, smaller wounds, aesthetic skin appearance, less tissue trauma than previous open surgery, quicker postoperative recovery, and ability to move early. Anesthesia and surgical approach of ankle arthroscopy Generally, intra-vertebral anesthesia (lumbar beat anesthesia) is used, supine position, tourniquet on the thigh, inflation, one incision on the medial and one on the lateral side of the anterior ankle joint, first injecting saline into the joint with a syringe until the joint is filled, and then extending the arthroscope and instruments through the two incisions respectively for operation. Sometimes the procedure requires additional incisions, such as an anterior internal incision underneath and an anterior external incision underneath, while the posterior joint cavity is handled in a prone position with posterior internal and posterior external incisions. The procedure begins with an exploration of the joint cavity to make an overall determination and identify the lesion, followed by therapeutic manipulation with instruments. Soft tissue disease can be removed using a planer. Minor cartilage injuries can be repaired until the surface is flush and the edges are smooth. Heavy cartilage injuries (cartilage exfoliation and exposure of the subchondral bone surface) require repair, and sometimes incision is required during the repair procedure. In osteoarthritis, the degenerated cartilage is repaired arthroscopically, some of the inflamed synovial membrane is removed, the joint cavity is fully flushed, and the free body, if present, is removed. In soft tissue impingement syndrome of the ankle, the impinging soft tissue, osteochondral or paraphyseal bone is excised or removed arthroscopically with a planer or clamp. For early or mid-stage talar osteonecrosis, arthroscopic drilling to reach the lesion can be used with some effectiveness. In the treatment of transarticular surface fracture, arthroscopy is mainly used to monitor the neatness of the joint surface after repositioning, and internal fixation can be done after the fracture joint disappears and the joint surface is flat, which can reduce the occurrence of arthritis. Joint infection can be treated by arthroscopic cleaning and irrigation. Some benign intra-articular tumors can be removed by arthroscopy and tumor tissue can be taken for pathological examination. Arthroscopy is mainly used to observe the morphology and tension of the ligaments and to treat combined intra-articular injuries in ligament rupture and late post-rupture joint instability. In advanced joint destruction requiring arthrofusion, arthroscopy is used to remove cartilage and to trim the bone surface. Complications of foot and ankle arthroscopy, such as neurovascular injury, infection, and joint adhesions, are relatively rare and, when they do occur, usually do not have serious consequences. Therefore, foot and ankle arthroscopy is relatively safe and effective. After arthroscopic surgery, recovery is faster than incisional surgery. On the second day after routine arthroscopic exploration and cleaning, the patient can walk with partial weight-bearing on the ground with the help of crutches. 3 days after the dressing change, the cotton splint for fixation is replaced with an elastic bandage and the foot and ankle flexion and extension exercises are started. One to two weeks after surgery, the patient could resume normal weight-bearing walking, continue flexion and extension exercises, and start muscle strength training. One to one and a half months after surgery, the mobility of the ankle will be normalized and the movement will be resumed. If microfracture surgery, ligament reconstruction, joint fusion, total synovectomy, etc. are performed, the rehabilitation time should be extended.