Hallux valgus (exostosis). Hallux valgus is a foot deformity in which the toes are deflected outward beyond the normal physiologic angle and is one of the most common foot diseases. It is generally considered to be diagnosed as a bunion when the hallux valgus angle is greater than 200. The onset of bunion is related to a variety of factors: ①Shoe wearing: shoe wearing is not the only cause of bunion, but wearing narrow, high-heeled shoes is considered to be one of the important external causes of bunion. (ii) Genetic factors: Many patients with valgus have a family history of the disease and develop valgus deformity at a young age. (③) Structural abnormalities of the foot: certain structural abnormalities of the foot, such as flatfoot syndrome, excessive length of the second metatarsal, excessive length of the proximal phalanx of the first phalanx, and inversion of the first metatarsal, can cause ectropion. ④Other causes: improper treatment after trauma, second toe defect, deformed healing of metatarsal fracture, imbalance of foot muscle strength, rheumatoid arthritis, etc. can also occur ectropion deformity. Ectropion manifestation: the first metatarsal head medial bone superfluous formation, friction with the shoe surface to form bursitis, also into bursitis, with the aggravation of the disease later often appear droopy toe, 2 toe riding across, small toe bursitis, plantar callus formation and other symptoms. Pathological changes: inversion, rotation forward and elevation of the first metatarsal head; formation of bursitis complicating the formation of the medial bursa of the first metatarsal head; valgus and rotation forward of the first toe; outward displacement of the seed bone; relaxation of the medial joint capsule of the metatarsal toe, contracture of the lateral joint capsule, contracture of the medial retractor tendon and the lateral head of the [long flexor tendon; weakening or disappearance of the transverse arch of the forefoot, widening of the forefoot, etc. Although there are two different treatment methods for valgus, surgical and non-surgical, the correction of deformity is still based on surgical treatment. Surgical treatment is an effective way to correct deformity, relieve pain and restore foot function. The choice of ectropion surgery: so far, no single method can treat all [ectropion. There are more than a hundred surgical methods for the treatment of [exostosis at home and abroad, each with its own advantages. The surgical method needs to be selected according to the degree of deformity, physical condition, whether there is osteoarthritis, whether the 2 toes are deformed, whether the forefoot is collapsed, and the mental state of the patient. Now we introduce several surgical methods commonly used at home and abroad: 1. Soft tissue surgery: mainly consists of 3 parts: ① excision of the medial bone superfluity of the first metatarsal head; ② release of the lateral soft tissue of the first metatarsophalangeal joint, including [medial retractor tendon cutting and lateral joint capsule incision; ③ strengthening of the medial soft tissue of the first metatarsophalangeal joint and joint capsule tightening and suturing. The main methods are the Silver and McBride procedures, some of which require simultaneous wedge osteotomy of the proximal phalanges of the toes (Akin procedure). These surgeries are mostly suitable for patients with mild bunion deformity, mainly manifesting as capsulitis symptoms. 2. Bone surgery: Bone surgery is generally more thorough, with good results in correcting deformities and a low recurrence rate after surgery. The most commonly used distal metatarsal osteotomy at home and abroad is the Chevron osteotomy, in which the distal metatarsal head is pushed outward after herringbone osteotomy and fixed with a single Clinique pin or dowel pin. It is suitable for patients with mild to moderate enlargement of the intermetatarsal angle. ②Metatarsal stem osteotomy: Scarf and Ludloff osteotomies are commonly used at home and abroad for patients with moderate to severe enlargement of the intermetatarsal angle, with the advantage of complete correction and the disadvantage that the time to go down is later than that of distal osteotomies, and higher surgical skills are required. (3) Basal osteotomy and fusion of the first metatarsal cuneiform joint: Basal osteotomy is suitable for patients with severe intermetatarsal angle enlargement, because it has the disadvantage of postoperative elevation of the metatarsal head, so it is only used in some special cases. The fusion of the metatarsocuneiform joint is commonly used in patients with instability of the first metatarsocuneiform joint or [ectropion with osteoarthritis of the first metatarsocuneiform joint, and the commonly used procedure is: Lapidus surgery. ④There are three options for patients with arthritis in the first metatarsophalangeal joint ①Keler surgery: for patients who are too old and frail to tolerate prolonged surgery or who require only local pain resolution. ②Arthrofusion: for those who are physically active or prefer sports. ③Artificial metatarsophalangeal joint replacement: for patients who require better post-operative joint movement, easy work and good economic conditions. 3.Minimally invasive surgery with small incisions: It is a kind of bony surgery, in which three 0.5cm incisions are made in the distal metatarsal bone to remove the hyperplasia, lateral joint capsule incision, distal metatarsal osteotomy, and after osteotomy, the metatarsal head is pushed outward, and instead of fixing it with kerf pins or dowel pins, it is tied with gauze bandage, which can often achieve satisfactory results clinically. In Europe, the United States and large general hospitals in China, in order to avoid intraoperative blind incision damage to nerves, blood vessels, tendons, and postoperative displacement of the metatarsal bone, they often prefer to fix the metatarsal bone with a Kirschner pin or screw after surgical osteotomy under direct vision.