Orbital fractures Flashcards
7 bones surrounding orbit
Frontal bone
Sphenoid bone
Ethmoid bone
Lacrimal bone
Palatine bone
Zygomatic bone
Maxillary bone
Others:
Optic foramen
Inferior orbital fissure
Superior orbital fissure
Wall thickness
• Medial to the infraorbital foramen (0.5mm)
• Lamina papyrecea is 0.2 to 0.4mm
• Lesser wing of the sphenoid bone 3 mm
Eye muscles
- Superior oblique
- Inferior oblique
- Superior rectus
- Lateral rectus
- Inferior rectus
- Levator palpebrae Superioris
Structures passing through superior orbital fissures
LOAN FIST
- Lateral part
- Superior ophthalmic vein
- Lacrimal nerve
- Frontal nerve
- Trochlear nerve - Middle part
- Upper and lower division of oculomotor
- Nasociliary nerve
- Abducent nerve - Medial part
- Inferior ophthalmic vein
Structures passing through inferior orbital fissures
Emissary veins
Infraorbital nerve
Maxillary nerve
Zygomatic nerve
Infraorbital vessels
Classification of orbital fractures
- Pure/Isolated
- Impure/complex
Impure/Complex fractures
- Orbital rim fractures
• Simple orbital rim fractures(misnomer)
• Tripod (ZMC) or Tetrapod
• Lefort II
• Lefort III
• NOE complex
Pure/ Isolated fractures
- Blow out fractures
• Medial wall
• Floor: trap door, tear drop
• Lateral wall
• Roof
• Any combination(s) of medial, lateral, floor, roof - Blow-in fractures
Related impure Fractures
- Dento-alveolar trauma
- Lower face
• Mandibular fractures
• Condylar fractures - Midface
• Orbital fractures
• NOE fractures
• Lefort fractures
• Palatal fractures
• ZMC fractures
• Zygomatic arch fractures
• Nasal bone fractures - Upper face
• Frontal sinus
Naso-Orbital-Ethmoidal fractures (NOE)
- Incomplete type I fracture
- Complete unilateral and bilateral type II fractures
- Type III comminuted fracture involving attachment of the canthal tendon
3 mechanisms of blow out injuries
3 accepted mechanisms of blow-out have so far been described
- Hydraulic or “retropulsion” theory (Smith & Regan)
Pressure is distributed to the walls and the weakest bone breaks - Buckling or “bone conduction” theory
Force to the orbital rim is distributed through bone to the back - Globe to wall theory
Pressure to the globe spreads to the rest of the bones
In essence the maxillary sinus and ethmoid sinus serves as air bags or shock absorbers to protect direct injury to the eyeball and orbital contents i.e. globe rapture is relatively uncommon in orbit fracture
Increasing force to the eyeball leads to medial wall fractures.
Timing of presentation
• The mean delay: 15.5 days (STD +/- 38.8 days).
• Range: hours to 2 years.
Clinical features of orbital fractures
Peri-orbital oedema
Subconjuctival haemorrhage
Step deformity on the rim
Peri-orbital ecchymosis
Trismus
Eyelid laceration and avulsion
Paresthesia
1. Infra-orbital
2. Supra-orbital/trochlear
Malar collapse
Telecanthus
Vision
1. Blindness
2. Partial loss
3. Not assessable
(pain, oedema, comatose)
Diplopia /entrapment
Enophthalmos
Vertical dystopia
Exophthalmos
Ptosis
CSF leak
Nasal telescoping
Management of orbital fractures
Management objectives
• Form
• Function
Techniques
1. Conservative treatment
2. ORIF
Conservative Treatment of orbital fractures
60% managed conservatively :
TTI, antibiotics, soft diet, wound care, cold compression, corticosteroid therapy and in some cases MMF.
