Strangulated trapdoor type orbital blow-out fractures in children. Fracture pattern and clinical outcome

Abstract

We report four typical cases of a strangulated trapdoor type, blow-out fracture of the orbital floor in children under the age of 10 years. Diplopia and restricted eye movement were observed soon after the accident, and surgical interventions were performed approximately within 2 weeks from the impact in all four cases. Close intraoperative observations revealed all the fractures to be trapdoor-like, with the “hinge” located medially and the “door” bounded by a bony defect of a few millimetres wide along the infraorbital groove and two fracture lines in a coronal direction running from the groove, perpendicularly and medially. Furthermore, we found strangulation of soft tissue in the fracture line along the infraorbital groove. We believe that this type of fracture occurs due to the premature development of the orbit in children. All children were surgically treated with release of the trapped orbital tissue, but recovery of ocular movement required 2 to 3 months. Consensus has it that early operation is favourable for this type of fracture. However our cases show that favourable results can be attained by operation done even after 2 weeks. Understanding of the bony structure and the fracture pattern of the orbit in children will help in the accurate imaging diagnosis and selection of operative procedures.