[Isolated blow out fracture of the medial wall of the orbit with medial rectus entrapment. Apropos of 3 cases]. / Fracture isolée de la paroi interne de l'orbite par "blow out" avec incarcération du muscle droit interne. A propos de trois cas.

We report three cases of isolated medial orbital wall blow out fracture with medial rectus entrapment. Few cases have been reported in the literature, predominantly in black people as in this paper. Predominance of this rare fracture in black population could be explained by an anatomic hypothesis based on racial origin. The diagnosis is often suggested by the medial rectus entrapment. Depending on the position of the incarceration in front of or behind the equator of the eyeball, the eye presents pseudo-Duane syndrome or exotropia with decreased adduction. The diagnosis is established by orbital computed tomography visualizing the lamina papyracea of the ethmoid bone fracture and the medial rectus incarceration. This exceptional fracture must be detected to avoid complications: enophthalmos and motility disturbances.