A blow-in fracture is an inwardly displaced fracture of the orbital rim or wall resulting in decreased orbital volume. The purpose of this study is to classify orbital blow-in fractures, describe the distinguishing clinical and radiologic features, and review the result of treatment.
The series consists of 41 patients with blow-in fractures (34 males and 7 females). The mean age of the patients was 36 years. All were treated between 1979 and December of 1986 at Sunnybrook Medical Centre in Toronto.
Clinical features of blow-in fractures were primarily related to the decrease in volume of the orbital cavity. Proptosis was a consistent finding, and in 27 percent of patients, the globe was further displaced in a coronal plane. Restricted ocular motility and diplopia were documented in 24 and 32 percent of patients, respectively. Fracture fragments displaced into the orbit resulted in globe rupture in 12 percent of patients, superior orbital fissure syndrome in 10 percent, and optic nerve injury in 1 patient.
Blow-in orbital injuries were classified as pure fractures, consisting of an isolated blow-in of a segment of the roof, floor, or walls, or impure fractures, where the orbital rim itself was disrupted. In all cases, early decompression of the orbit and open reduction of fractures was necessary.
Late sequelae of blow-in fractures were primarily related to injuries of intraorbital contents. Twelve percent of patients underwent enucleation and 8 percent reported persistent diplopia. Despite the presence of superiororbital fissure syndrome and complete ophthalmoplegia in 10 percent of patients, early orbital decompression resulted in resolution of nerve palsies in all but one patient.