Objective To investigate the application and effectiveness of metatarsal mortise and tenon shortening osteotomy in the treatment of macrodactyly in children. Methods The clinical data of 17 children with macrodactyly (18 feet and 27 toes) admitted between January 2018 and January 2020 were retrospectively analyzed. There were 12 males (12 feet and 18 toes) and 5 females (6 feet and 9 toes); the age ranged from 1 to 13 years, with a median age of 5 years. All children were treated with metatarsal mortise and tenon shortening osteotomy. Ten cases of single-segment metatarsals were shortened, 7 cases of 2-segment metatarsals, and 1 case of 3-segment metatarsals; involved 1 foot of single toe, 9 feet of 2 toes, 3 feet of 3 toes, 3 feet of 4 toes, and 2 feet of 5 toes. Five cases had lameness, and 1 case had limited walking with the big toes of both feet, and there was no obvious pain in all children. X-ray films showed that the involved phalanges were thickened and increased in 18 feet, and the deformity of the distal segment was heavier than that of the proximal segment in 13 feet, and the two were similar in 5 feet. The length of metatarsal shortening was 0.7-2.5 cm, with an average of 1.2 cm. The clinical healing of shortened metatarsal fractures in children was observed after operation, and the occurrence of related complications was recorded. ResultsAll 17 children were followed up 6-22 months, with an average of 14 months. All incisions healed by first intention. The osteotomy ends of 27 toes were clinically healed after operation, and the healing time was 4-8 weeks. No nonunion, fracture displacement, malunion, epiphyseal plate premature closure, and needle tract infection occurred. ConclusionMetatarsal mortise and tenon shortening osteotomy is a good osteotomy method. It can improve the stability of the osteotomy end and increase the contact surface of the osteotomy end, which is conducive to the healing of the osteotomy end and is suitable for the treatment of macrodactyly.