Resident Manual of Trauma to the Face, Head and Neck

drainage system will produce epiphora, which requires further evalua- tion with lacrimal probing at the time of the surgical repair. C. Classification of Medial Canthal Tendon Injuries Medial canthal tendon injuries are classified according to three types: y y Type I: Single-fragment bone segment with intact canthal tendon insertions (Figure 3.19). y y Type II: Comminuted central bone segment with fractures remaining external to the medial canthal tendon insertion (Figure 3.20). y y Type III: Comminuted single fragment with fractures extending into bone bearing the canthal insertion.

Figure 3.19 Type I medial canthal region fracture, unilateral.

Figure 3.20 Type II medial canthal region comminuted fracture, right medial orbit.

The injury type can be identified on imaging studies and confirmed at surgical exploration and repair. Though uncommon, blunt trauma can also result in a rupture of the anterior and/or posterior insertions of the canthal slips near their insertion on the lacrimal fossa. It would be seen in the lax eyelid, without evidence of distracted lacrimal fossa fractures. D. Lacrimal System Injuries Laceration of the medial eyelids with discontinuity of the lacrimal canaliculi will be seen in vertical lacerations medial to the puncta. Deep

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