Mitchell First Metatarsal Neck Displacement Osteotomy

Mitchell's first humeral neck displacement osteotomy for the treatment of toe valgus. The valgus deformity is more common in women. The main clinical features are excessive lateral deviation in the plane of the metatarsophalangeal joint (outer angle >15°), and the first metatarsal varus (the angle between the first and second metatarsal >10°) ), the first metatarsal bone forms osteophytes and bursitis. In severe cases, the second toe is sometimes squeezed to the dorsal side of the toe to form a hammer toe, and the dorsal joint of the interphalangeal joint forms a hernia. If the symptoms are severe, you can wear shoes and walk because of the pain. The cause of the valgus deformity is related to many factors, which are closely related to the wearing of narrow pointed shoes and high heels. For those with mild symptoms, you can change the habit of wearing shoes, do not wear narrow pointed shoes and high heels, so that the toe and the first metatarsal head can be prevented from being squeezed and rubbed, and the symptoms can be alleviated. If the deformity and pain are heavier, surgery can be performed. There are many surgical methods, including soft tissue surgery, bone surgery and soft tissue combined with bone surgery. The appropriate surgical method can be selected according to the situation. Treatment of diseases: congenital toe valgus Indication Mitchell's first humeral neck displacement osteotomy is suitable for young toe valgus deformities with young toe valgus deformities, with the first and second metatarsal angles reaching or exceeding 10°. Contraindications The metatarsophalangeal joint has obvious degenerative changes or toe stiffness. Preoperative preparation These include skin preparation, osteotome, pneumatic bone saws and orthopedic instruments such as bone drills or hand drills. Surgical procedure 1. Make an arcuate incision on the dorsal aspect of the first metatarsophalangeal joint, starting from the middle of the proximal phalanx and extending proximally to the middle of the first metatarsal. The flap is freed and retracted to the temporal side, and the medial joint capsule is in a Y-shaped incision. The U-shaped joint capsule is turned to the distal side, and the base of the joint capsule is at the base of the proximal phalanx. 2. The periosteum of the joint capsule and the neck of the tibia was dissected to the dorsal and temporal sides, and the bone of the medial epiphysis of the humeral head and the neck of the humerus was exposed. A sharp bone knife was used to make a score on the proximal side of the epiphysis of the humeral head. The protruding callus is then removed from the distal side to the proximal side, and the rough surface of the bone is smoothed with the callus. 3. The tibial neck osteotomy and the humeral head externally moved about 1.3 cm proximal to the humeral head joint surface near the inside of the humeral neck, and the first bone hole was drilled from the dorsal side to the iliac crest. A second bone hole was drilled near the outside of the humerus neck about 1.3 cm proximal to the first bone hole. Perform two transverse osteotomy in the middle of the two bone holes, the first time to completely cut the humerus in the proximal side, and the second time to make a partial osteotomy 2 to 4 mm from the far side of the first osteotomy surface, the outer part of the humerus remains. The bone is not cut off, the severe deformity retains about 1/3 of the width of the backbone, and the moderate deformity retains about 1/6. The bone piece between the two osteotomy surfaces is removed, and the spurs on the outer side of the proximal end of the humeral head are retained. The humeral head is pushed to the outside and rotated slightly to the temporal side to completely correct the toe valgus deformity. The humeral head and the humerus are fixed together by a thick wire or a chrome gut through the two bone holes. 4. Hold the toe in the correct position and push the medial joint capsule proximally to make an overlapping suture. 5. Suture the incision in layers. complication The main complication of Mitchell's first humeral neck displacement osteotomy is uncorrected or recurrent deformity, or non-union at the osteotomy, which should be prevented during and after surgery.