ORAL SURG zygomatic fractures Flashcards
what are the 2 categories of tx goals for zygomatic fractures?
- restore facial projection/ symmetry
- restore orbital volume/ globe position/ shape palpebral fissure
what factors affect treatment of zygomatic fractures?
- timing
- type
- mechanism
- presentation
what are the 3 categories of treatment timing for zygomatic fractures?
- immediate
- early
- delayed
when do you ideally want to treat a zygoma fracture?
early (few days-1 week) - this allows for reduction of swelling to understand anatomy better and surgical access
what are the 2 mechanisms (fracture types) of zygomatic fractures?
low energy - minimal/ no comminution
high energy - comminution at segment and fracture lines
what are the 3 overall zygomatic fracture types?
- non-displaced
- displaced, minimally comminuted
- complex and comminuted
- isolated zygomatic arch fractures
what landmark is the most reliable indicator of proper reduction and orientation of zygomatic fractures?
zygomaticosphenoidal suture
what type of treatment is usually given for zygomatic fractures?
open reduction and internal fixation (ORIF)
in treating zygomatic fractures, what is ORIF dependent on?
- degree of comminution
- stability of fracture
- presence of other features:
- orbital content/ volume derangement
- facial symmetry
- inf orb nerve issues
- functional issues
- associated fractures
what are the 4 poor outcomes of zygomatic fracture tx?
- inadequate tx
- inadequate exposure
- inadequate reduction
- failure to restore orbital volume
what tx is required for a displaced, minimally comminuted zygomatic fracture?
ORIF
how is a non-displaced ZMC confirmed?
CT scan
tx for non-displaced ZMC?
non-surgical mx
monitor for facial asymmetry and functional deficit
soft diet
tx required for displaced, minimally comminuted ZMC?
- reduction alone
- fixation (1point,2 point,3 point+orbital floor)
best managed with ORIF at 2/3 points
what is the risk of just reducing a ZMC fracture?
displacement
where is one-point fixation carried out?
zygomaticomaxillary buttress
where are the 3 points for reduction?
frontozygomatic suture
zygomaticomaxillary buttress
inferior orbital areas
what are the advantages of ORIF?
improved alignment
fixation of zygomaticomaxillary buttress provides vertical support
orbital rim exposure allows inspection of orbital floor
inspection of fractures sites prior to closure
when exploring the orbital floor, what do we look for?
defects larger than 5mm on CT scan
severe displacement
comminution
soft tissue entrapment with limited upwards gaze
orbital contents herniation into max sinus
when do you consider reconstruction of the orbital floor?
enophthalmos
larger defects (5-10mm)
defects posterior to the axis of the globe
when do you consider 2 point fixation of ZMC fractures?
- minimally displaced fractures
- zygomaticomaxillary complex fracture remains stable after initial reduction with no palpable step deformity in infraorbital rim
- minimal changes on orbital vol and globe displacement is not evident on CT scan
when do you consider 3 point fixation of ZMC fracture?
instability
exploration of orbital floor required
list the fixation methods?
titanium plates and screws
resorbable plates and screws
what are the 4 sites of fixation?
- frontozygomatic
- infraorbital margin
- zygomaticomaxillary buttress
- zygomatic arch
what is the aim of reduction?
to provide force in the direction opposite to that which caused the fracture and to re-approximate the bone to the original position
what are the reduction options?
- stab incision and intro of an instrument
- intra-oral approach - vestibular incision
- screw insertion
- carroll-girard T-bar screw
what does stab incision and instrument reduction involve?
introduction of an instrument (percutaneous bone hook) to hook under the bone to provide traction
what does the intra-oral reduction approach involve?
vestibular incision and introduction of bone hook to hook under bone and provide traction
what does screw reduction involve?
insert screw percutaneously and wire threaded through to manipulate
for isolated arch fractures, where can you approach from?
oral or temporal
describe gillies temporal reduction?
incision in hair line - superior and anteriorly to the helix of the ear (avoid the superficial temporal artery)
dissect temporalis fascia
incise temporalis fascia
introduce instrument and navigate beneath zygomatic arch
introduce elevator to reduce
no requirement for fixation
what are the 2 gillies temporal instruments and what do they do?
bristow - lifts laterally and superiorly
rowe - provides traction through additional handle
explain fixation of the frontozygomatic suture?
surgical exposure of suture
apply mini plates and screws
explain fixation of the zygomaticomaxillary buttress?
intraoral vestibular approach
plates along fracture line and screws in place
what does 3 point fixation include?
frontozygomatic suture
zygomaticomaxillary buttress
infra orbital margin
where does 2 point fixation include?
frontozygomatic and zygomaticomaxillary butress regions
describe orbital floor repair/ grafting?
Molded orbital floor plate - orbital contents are lifted and plate placed underneath to replace unstable fractures, supporting contents of the orbit
what does 4 point fixation include?
reconstruction of the zygomatic arch through a bicoronal flap
list the complications to ZMC surgery?
pain
facial asymmetry
scarring
bleeding
hardware failure
infraorbital nerve paraesthesia
temperature sensitivity
facial paresis or paralysis
poor cosmetic result
trisimus
what does an eye exam include?
visual activity
visual fields
extraocular movements
what are the complications of orbital reconstruction?
decreased visual activity
ectropion/ entropion/ lip malposition
corneal exposure/ abrasion
ptosis
epiphora
diplopia
blindness
SOFS
RBH+OCS
