Fractures of the nasolacrimal fossa and canal: a CT study of appearance, associated injuries, and significance in 25 patients.

The bony nasolacrimal fossa and canal, which protect the more distal excretory portion of the lacrimal apparatus, the nasolacrimal sac and duct, are contained within the medial portion of the orbit and lateral aspect of the nose, sites that are commonly injured in facial trauma. The CT scans of 25 patients who sustained fractures of the nasolacrimal fossa and/or canal as a result of motor vehicle accidents were reviewed to determine the appearance of the fractures and to determine types of facial fractures also present. The patients' clinical records were reviewed to determine the frequency of associated complications. Thirty-six fractures of the nasolacrimal fossa and canal were found in the 25 patients. In 20 patients these were associated with complex fractures of the midportion of the face; the other five patients had simple unilateral facial fractures. Three kinds of nasolacrimal fractures were identified: avulsion of the fossa, comminution of the fossa or canal, and linear fractures of the canal. Of the 19 fractures involving the nasolacrimal fossa, 15 consisted of an avulsed fragment of bone containing the nasolacrimal sac and four had comminution of the nasolacrimal fossa. The majority of the fractures of the nasolacrimal canal (15 patients) were comminuted. Our results show that nasolacrimal fractures occur in association with simple unilateral facial fractures and with more complex fractures of the midface and that the fractures follow certain patterns. Complications related to injury to the nasolacrimal sac and duct were documented in five patients. Although this number is significant, it is fewer than we expected, considering the severity of the injuries.