AIM:To analyze the treatment of orbital Trapdoor fracture in children and the application of absorbable plate in surgery, so as to accumulate experience for clinical diagnosis and treatment.

METHODS: Retrospective analysis of 55 cases(55 eyes)orbital Trapdoor fractures in children. The fracture site was simple orbital floor fracture. All patients were approached by palpebral conjunctiva of lower eyelid. During operations, the embedded extraocular muscles and orbital tissues were returned. A resorbable implant was implanted into the orbit after trimming to proper sizes and shaped according to the fracture defect range. The therapeutic effect was evaluated by preoperative and postoperative ocular examination and orbital CT scan. Repeated measure analysis of variance was used to compare the differences of postoperative outcome evaluation indexes among patients with different operation timing.

RESULTS: No serious complications happened during and after surgeries in all patients. The postoperative CT scan showed that the fractures had good anatomical restoration. After the operation, diplopia and limitation of extraocular muscle movement(EOM)recovered obviously. The earlier the operation performed after the injury, the better the postoperative recovery effect was. At the same time, the resorbable implant could repair orbital Trapdoor fracture in children well. It serves as a better material of orbital fracture repairment.

CONCLUSION: Operation is an effective method to treat orbital Trapdoor fracture in children, and should be performed as soon as possible after injury. The resorbable implant is a good orbital repair material.