ObjectiveTo investigate the technique and clinical results of curved osteotomy under the metatarsal head's cartilage for improving reconstructed metacarpophalangeal joint function of fingers with second toe transplantation. MethodsThere were total 21 cases with 21 digits. During second toe transplantation with the metatarsophalangeal joint, the bottom of the second metatarsal head was incised. Then a curved osteotomy were carried out on about 5.0 mm under the metatarsal head's cartilage until the passive range of motion could be 90°.Longitudinal or cross-Kirschner wires were used to fix the joint.Finally,the conventional methods were used to reconstruct the blood supply, movement and nerves. ResultsAll 21 digits of the 21 cases survived uneventfully.The follow-up time was ranged from 6 to 24 months.Their average passive range of motion of the reconstructed metacarpophalangeal joint was 75°,ranging from 65° to 85°.The average active range of motion was 65°, ranging from 45° to 80°. Postoperative X-ray revealed fracture healed well without joint degeneration. ConclusionCurved osteotomy under the metatarsal head's cartilage is an effective way to improve active and passive activities function of the reconstructed metacarpophalangeal joint with second toe transplantation.