ObjectiveTo investigate the effectiveness of a modified surgical treatment of old Monteggia fracture. MethodsBetween March 2006 and December 2013, 40 cases of old Monteggia fracture were treated with modified operation. Modified operation procedure included expanding excision of pedicled forearm fascia flap for reconstruction of the annular ligament and repair of elbow radial lateral collateral ligament complex and extending osteotomy of the ulna, callus replantation, and internal fixation with steel plate. There were 26 boys and 14 girls, aged 2-10 years with an average age of 4 years. Injury was caused by falling in 24 cases, by traffic accident in 8 cases, and by falling from height in 8 cases. The disease duration was 2-11 months (mean, 4 months). Four patients had combined radial nerve palsy. ResultsIncision healed by first intention after operation, without early complication of radial nerve palsy, fascial compartment syndrome, or decreased hand extensor muscle strength. All the children were followed up 1-5 years (mean, 2.5 years). X-ray films showed fracture healing, and the healing time was 10-20 weeks (mean, 15 weeks). During follow-up, 3 cases had re-dislocation. Neither hand dysfunction caused by hand muscle adhesion nor radial head bottleneck shape change was found. On the basis of the functional evaluation criteria by Mackay, the results were excellent in 32 cases, good in 5 cases, and poor in 3 cases; the excellent and good rate was 92.5% at last follow-up. ConclusionThe modified surgical treatment of old Monteggia fracture is an effective method, with good matching of humeroradial joint and without internal fixation of the humeroradial joint.