<aside>
A medial orbital wall fracture involves the lamina papyracea of the ethmoid bone, which forms the medial wall of the orbit. Due to its thinness, it is prone to fracture in orbital trauma, often accompanying other orbital or facial fractures.
</aside>
Anatomy involved:
| Structure | Description |
|---|---|
| Medial orbital wall | Composed mainly of lamina papyracea (ethmoid bone), also includes lacrimal bone and lesser sphenoid contributions |
| Adjacent structures | Ethmoid air cells, medial rectus muscle, lacrimal sac, anterior/posterior ethmoidal arteries, optic nerve (posteromedial orbit) |
| Function | Protects the globe and separates orbit from ethmoid sinus |
| Feature | Explanation |
|---|---|
| Medial orbital pain or pressure | Fracture through lamina papyracea |
| Diplopia | Entrapment of medial rectus or orbital fat herniation |
| Enophthalmos | Medial orbital volume increase |
| Epistaxis or nasal fullness | Air tracking into ethmoid sinuses |
| Orbital emphysema | Communication with ethmoid sinuses, worsened by nose blowing |
| Telecanthus | If fracture extends into NOE complex (medial canthal ligament disrupted) |
| Complication | Cause |
|---|---|
| Enophthalmos | Orbital content herniation, uncorrected volume loss |
| Persistent diplopia | Muscle fibrosis or unrelieved entrapment |
| Orbital cellulitis | From ethmoid sinus contamination |
| Vision loss | Rare; from optic nerve stretch or compression |
| Telecanthus | If medial canthal tendon is disrupted (NOE involvement) |
Key CT findings:
| Feature | Significance |
|---|---|
| Fracture of lamina papyracea | Medial orbital wall defect; may be subtle |
| Orbital emphysema | Air in orbit from ethmoid sinus breach |
| Herniation of orbital fat or medial rectus muscle | Entrapment; risk of restricted eye movement |
| Disruption of medial canthus anatomy | Consider NOE involvement |
| Ethmoid sinus fluid level or opacification | Associated sinus hemorrhage/infection |
| Condition | Distinguishing Features |
|---|---|
| Isolated orbital floor fracture | Located inferiorly, not medial |
| NOE fracture | More complex; involves nasal bones, ethmoid, and medial canthal ligament |
| Orbital cellulitis | Post-infectious; may mimic fracture on imaging but with systemic signs |
| Orbital hematoma | No bony fracture; shows soft tissue density without defect |
Non-surgical indications: