Treatment is more complicated when there is a fracture of both the ulnar radius forming an osteonecrosis, especially when there is a significant bone defect or infection. I would like to contribute my experience in the treatment of infected radial and ulnar osteonecrosis to the interested party. In this case, the ulnar nonunion has already failed twice with internal fixation of the plate, with “honeycomb” nail holes in the broken end, with residual broken nails and sclerosis, and further plate fixation is wrong and will further disrupt the blood flow and make the fixation unsound. The more reasonable surgical method is to use locking intramedullary nail with bone graft for ulnar osteoconnections. The initial surgery was performed with internal fixation of the plate, and later recurrent drug-resistant Staphylococcus aureus infection occurred. We removed the plate and filled the fracture end with bone cement containing gentamicin and vancomycin, which quickly cured the infection. The post-operative X-rays are shown in the figure below. The treatment of several cases: 1. Both ulnar and radial bones are defective: the sclerotic bone can be removed, allowing the fracture end to be removed up to 4 cm, so that the two bones are of the same length, plate fixation + bone graft or ulnar intramedullary nail and radial plate fixation . The upper extremity allows a greater margin for length loss, so more sclerotic bone can be removed appropriately to facilitate healing, and the patient needs to be explained clearly and signed in advance. Avoid misunderstanding and doctor-patient disputes. 2, the above method will make too much forearm shortening, ulnar radius should be treated separately: small defects do not do too much shortening, large defects implant bone bridging. If the defect of ulnar radius is large, both need to be bridged. The best material for bridging is autogenous fibula, I have emphasized the advantages of autogenous fibula many times, and it also needs to be explained clearly in advance. The next best material is iliac bone with three sides of cortical bone. 3, a bone had an infection, first do non-infected bone, a few weeks between the other bone alone radial or ulnar bone discontinuity 4, a bone defect and the other bone is normal, the bone defect will be difficult to heal – bridging bone defect than shortening the normal bone is better.