Orbital fracture
Orbital fractures can be complex due to the variability of injuries and their proximity to the globe, brain and cranial nerves.
Fractures are usually defined in terms of their anatomical location:
- Fractures involving the orbital rim
- Isolated orbital rim fractures
- Contiguous with internal wall fracture
- Zygomatic-maxillary complex fracture
- Naso-ethmoidal fractures
- Other pan-facial fracture i.e. Le Fort
- Fractures limited to the internal orbital skeleton
- Blow-out fracture (floor and medial orbital walls most common)
- Trap door fracture
Epidemiology[edit | edit source]
Orbital trauma accounts for 8-25% of all facial fracture presentations
BAOMS National Facial Injury Survey this has increased by 35% over a 10yr period
5-19% of patients presenting to A&E with isolated head injury with also have concomitant orbital injury
Clinical Features[edit | edit source]
Presentation ranges depending on force of mechanism:
- Orbital ecchymosis/ swelling/ laceration
- Enophthalmos/ Hypoglobus
- Bony step
- Surgical emphysema
- Reduced sensation to maxillary branch of trigeminal nerve (V2)
Eye signs:
- Subconjunctival haemorrhage without posterior boarder
- Ophthalmoplegia resulting in diplopia: Monocular v Binocular
- Reduced visual acuity &/ or colour vision
- Globe injury: abrasion, hyphema, detachment, rupture etc
- Relative afferent pupillary defect
Note trap door fractures in the paediatric population can be subtle and the only sign maybe restricted upward gaze or signs of the oculocardiac reflex: recurrent nausea & vomiting and bradycardia on looking up
Differential Diagnosis[edit | edit source]
Following conditions should be considered when assessing orbital trauma:
- Orbital Compartment syndrome
- Superior orbital fissure syndrome (SOF) (<1% of trauma)
- Characterized by ophthalmoplegia, ptosis, proptosis of eye, dilation and fixation of the pupil, loss of corneal reflex and anaesthesia of the upper eyelid and forehead
- Optic nerve not affected
- Traumatic optic neuropathy
- Like SOFS with CNII involvement
- Due to compression/ laceration of CNII through direct trauma or coupe/ contrecoup injury intracranially
Aetiology and Pathogenesis[edit | edit source]
Aetiology[edit | edit source]
- Dependent on mechanism of injury
- Low velocity: floor and medial wall fractures
- High velocity: rim and lateral wall fractures
- Most common mechanisms:
- Assault 52%
- Falls 31%
- Sport injury 14%
- Road traffic accidents 3%
- Don't forget domestic abuse and NAI
Pathogenesis[edit | edit source]
Hydraulic theory: The globe itself is struck directly from an object and is thrust posteriorly, transiently raising the pressure within the orbit causing the floor to ‘blow out’ into the maxillary sinus at its greatest point of weakness, above the infraorbital neurovascular bundle.
Buckling theory: Blunt trauma to the face transmits a pressure wave along the bone of the orbit causing them to “buckle” and crack.
Note in trap door fracture, due to bony compressibility and elasticity the fractured bone recoils back into position entrapping orbital contents notably fat and the inferior rectus muscle.
Investigations[edit | edit source]
Initial Assessment[edit | edit source]
Assessment as per ATLS guidelines
- 4-8% may have associated c-spine injury with roof and lateral walls showing higher association
Rule out sight threatening injury Full eye assessment:
- Visual acuity
- Visual Fields
- Occular movement
- Pupillary reflexes
Imaging[edit | edit source]
Plain film radiographs CT Orbits
Other[edit | edit source]
Ocular pressure
Management[edit | edit source]
- Conservative
- Surgical: if functional or aesthetic concerns
Prognosis and Complications[edit | edit source]
General:
- Depends on fracture pattern and incision made
Trapdoor:
- Operative time within 24hrs carries highest success rates in terms of recovery time and diplopia
Blowout:
- Extent of defect and volume loss
- Intraoperative techniques used: 3D printed, intraoperative navigation
Follow up:
- Standard surgical follow up for OMFS
- Ophthalmology f/u in case of strabismus correction