Orbital fractures and head injury 2

Question 1

What is a lateral wall fracture

Answer 1

A lateral wall fracture is
usually part of a complex fracture, associated with extensive facial injuries. It’s less common as the lateral
wall consists of more solid bone than other parts of the orbit

Question 2

What is a zygomatic fracture/ displacement

Answer 2

A fracture of the zygoma can occur, but more commonly it is displaced upwards or
downwards from its attachment, which is determined by the direction of the blow. It
may be associated with an orbital floor blow out fracture as well.

Question 3

What are the characteristics of zygomatic fracture/ displacement

Answer 3

 Oedema and haemorrhage
 Downward displacement can cause enophthalmos, pseudoptosis and a
flattened cheek bone
 Upward displacement can cause exophthalmos and an accentuated cheek
bone
 May also have damage to EOM or nerves causing diplopia
 May also have disturbed motility of lower jaw if affecting temporomandibular
joint

Question 4

What are nasa orbital fractures and cause

Answer 4

A fracture to the nasal bones may be isolated or associated with an orbital fracture.
Often caused by direct trauma to the mid third of the face.

Question 5

What are the characteristics of nasa orbital fractures

Answer 5

 Flattened nose
 Traumatic telecanthus (12-20%) ~ increased distance between medial canthi
 Oedema - swollen medial canthal area
 Epitaxis (nose bleed)
 Nasal obstruction
 Damage to lacrimal apparatus

 Emphysema
 Damage to inferior oblique origin (or other EOM or nerve)
 Lack of skeletal support on palpation of nose
 CSF leak – consider a fracture of the cribriform plate

Question 6

Orbital blow out fractures

Answer 6

A blow-out fracture is a fracture due to an increase in orbital pressure, which causes
the thinnest parts of the orbit to ‘blow out’. The weakest and thinnest part of the orbit
is the maxilla, causing a blow-out fracture of the orbital floor. The next weakest part
is the ethmoid, causing a blow-out fracture of the medial wall

Question 7

Commonness of blow out fracture

Answer 7

Although different
patterns of injury can exist in different ethnicities, orbital floor blow out fracture more
common in Caucasian and Asian individuals, whereas medial wall blow out fracture
more common in Afro-Caribbean individuals (De Silva & Rose, 2011).

Question 8

Types of blow out fracture

Answer 8

Pure blow out fracture
Impure blow out fracture

Question 9

Pure blow out fracture

Answer 9

a fracture of the internal orbital walls only, i.e. orbital floor

Question 10

Impure blow out fracture

Answer 10

a fracture of the internal orbital walls plus a fracture of the orbital rim

Question 11

Size of object causing blow out..

Answer 11

often determines the injury. An object
smaller than the diameter orbital rim i.e. golf ball, is likely to cause globe damage. An
object much larger than the diameter of the orbital rim i.e. dash board in RTA, is
likely to cause an impure blow-out fracture, An object the same size or slightly bigger
than the diameter of the orbital rim i.e. fist or tennis ball, is likely to cause a pure
blow-out fracture.

Question 12

2 mechanisms of injury causing blow out fractures

Answer 12

Hydraulic theory/ blow out
Bucking theory

Question 13

Hydraulic theory

Answer 13

the force of the object displaces the globe
backwards, increasing the intraorbital pressure with a resulting fracture in the area of least resistance i.e. posterior orbital floor (Smith and Regan, 1959).

Question 14

Bucking theory

Answer 14

the force of the blow is transmitted through the bone from the
orbital rim to the floor of the orbit.

Question 15

Bucking theory characteristics

Answer 15

Size of fracture- small
Medial wall- never
Herniation- never
Roof involved- no
Produced by- forced to orbital rim

Question 16

Hydraulic theory characteristics

Answer 16

Size of fracture- large
Medial wall- always
Herniation- common
Roof involved- no
Produced by- force to globe

Question 17

Typed of pure blow out fracture

Answer 17

Linear / trap door
Hanging top of hinged bony fragment
Depressed
Comminuted

Question 18

Types of pure blow out fractures

Answer 18

Linear or trap door: fracture is open and closed after injury with no loss of orbital
contents, yet there may be incarceration of soft tissue/muscle in trap door

Hanging drop of hinged bony fragment: herniation of orbital contents into fracture
Depressed: a piece of the fractured orbit is punched out

Comminuted: fracture of the orbit which shatters into several bony fragments. In an orbital floor blow out fracture of this type the bony fragments are displaced into the
maxillary antrum

Question 19

Characteristics of orbital blow out fractures

Answer 19

 Ecchymosis - ‘black eye’
 Subconjunctival haemorrhage
 Oedema – swelling
 Enophthalmos and pseudoptosis - due to increased orbital space
 Anaesthesia / hypoanaesthesia - ipsilateral cheek and upper lip and teeth in
an orbital floor blow-out fracture (if infraorbital nerve affected )
 Limitation of ocular movement and diplopia – this is a mechanical defect, so
the limitation will be in the position away from the defect
 Orbital floor blow-out fracture – limited elevation (?also depression)
 Medial wall blow-out fracture – limited ABDuction (?also ADDuction)
 Pain on attempted movement
 Globe retraction on attempted movement
 Increased IOP on attempted movement
 Orbital emphysema - warned not to blow nose

Question 20

Muscle/ soft tissue entrapment

Answer 20

An extraocular muscle and/or surrounding soft tissue may become trapped in an
orbital fracture site. A trap door orbital floor blow-out fracture is the most common
fracture for this to occur. The inferior rectus and/or surrounding soft tissue become
trapped – this causes restricted elevation and there may also be globe retraction on
attempted elevation.

Question 21

Medial rectus and trap door

Answer 21

A medial rectus may become trapped in a medial wall fracture has also been reported (Thering & Bogart, 1979).

Question 22

Findings in trap door fracture

Answer 22

A trap door fracture is more common in children. In a study of 24 children with orbital fractures, 11 were found to have trap door fractures.
Early surgery is important

Question 23

Symptoms of entrapment

Answer 23

nausea, vomiting, pain on eye movement and oculo-cardiac reflex
(bradycardia, heart block, nausea, vomiting or syncope). Some patients can achieve complete resolution of their symptoms post-operatively (Egbert et al, 2000). Early
diagnosis is important and early surgery is necessary to prevent EOM damage and
improve prognosis (Foulds et al, 2013).

Question 24

Investigating suspected orbital fracture

Answer 24

Ophthalmic Investigation
 Visual acuity
 Slit lamp examination (anterior segment & posterior segment)
 Measurement of exophthalmos / enophthalmos using a Hertle
exophthalmometer or can use CT scans (Sung et al, 2013; Shah et al, 2013)
 Measurement IOP (intraocular pressure)
 FDT (Forced Duction Test)
 Electromyography/saccadic velocities
Radiological Investigations
 X-rays - readily available, but small fractures are difficult to detect and may be
missed
 CT scans – more readily available than they used to be. Coronal sections are
taken to determine the extent of the fracture and determine the nature of the
antral soft tissue densities. CT scanning therefore allows visualisation of the
EOM and soft tissues, but the CT evidence of a fracture may be minimal, they
need to be carefully evaluated (Criden & Ellis, 2007)
 MRI scans – take longer and may be less readily available. Particularly useful
to see herniation and entrapment more clearly
Heran F et al. (2012) A wander through the land of the orbit. Diagnostic and
Interventional Imaging. 93: 962-974. A nice paper about orbital imaging & talks
through cases of orbital trauma (as well as other clinical findings).
Orthoptic investigation: Observation. Description. Documentation.

Question 25

Further investigating orbital fracture

Answer 25

Case History
 Crucial – may be a recent history of trauma, but may be late presenting,
consider events may be unwitnessed. Consider whether a head injury has
also occurred.
Symptoms
 Diplopia – note type and any changes or reversal in different gaze position
Shah et al (2013) found that herniation of soft tissue into orbital floor fracture site (in
small & medium fractures only) were associated with a high risk of diplopia.
 Pain, especially on attempted eye movement
 Anaesthesia or hypoanaesthesia
 Orbital emphysema (air trapped in the orbit) – indicates a fracture of ethmoid
sinuses. Patients are advised not to blow their nose post orbital fracture.
 Epistaxis (nose bleed) – advised not to blow the nose after a suspected orbital
fracture.
Signs
 Ecchymosis and oedema – lids may be closed. May need to hold lids open to
test VA and examine the eye.
 Enophthalmos / exophthalmos
 Facial asymmetry – esp. in impure blow out with displacement of orbital rim
 Subconjunctival haemorrhage
 Hyphaema etc – damage to globe
 Unequal pupil sizes - sphincter muscle of iris may be damaged
 AHP as appropriate for deviation
VA may need patient to open their eye / lift swollen lid to test VA
Cover Test: with and without AHP

Question 26

OMs in orbital fracture

Answer 26

 Looking particularly for restrictions, but may also see under and
overactions
 Typically, mechanical (revise mechanical OM defects)
 Restriction of elevation - orbital floor fracture
 Restriction of ABDuction - medial wall fracture
 Reversal of diplopia – from upgaze to downgaze
 Retraction of the globe
 Superior oblique defects may indicate trochlear damage
 ? tissue entrapment (see ‘trap door’ or ‘white eyed blow out’ fracture)
 ? an associated nerve palsy (see Scolozzi et al, 2022)
 ? an associated head injury as well
 General limitations of gaze are indicative of retrobulbar haemorrhage –
important to consider ON function (VA, CV, CS, VEP)
 Pupil function
OM, measurements of deviation (1, 2 and 3 positions of gaze), Hess Chart, Field of
BSV, Field of uniocular fixation, investigation of BSV, Measurement of
accommodation.
Hess – see Hess Area Ratio % (Wood and Adeoye, 2021; Osaki et al, 2022)

Question 27

Do you suspect there is entrapment of muscle or soft tissue in a fracture?

Answer 27

Its a surgical emergency

Question 28

Do you suspect a head injury or neurogenic palsy?

Answer 28

There may be improvement in traumatic cranial nerve palsies as well, but the improvement is usually over a longer
period of time.

Question 29

What further investigations may aid diagnosis?

Answer 29

This may be ophthalmological,
radiological or surgical investigation.

Question 30

What short and long term management options are there?

Answer 30

Consider orthoptic
conservative options in short term, particularly during an observation period.

Question 31

Surgical management of orbital fractures aim

Answer 31

The aims of surgical intervention is to restore full orbital volume, restore globe
movement and restore cosmesis; whilst also minimising and preventing early and late sequelae and complications.
-Not all surgeons
will agree on whether surgery needed, type of surgery, surgical approach and the implant material to be used

Question 32

Timescale for surgical repair of an orbital fracture

Answer 32

Some cases are considered urgent. Often there is a slight delay where the patient
will be observed as the oedema and haemorrhages subside, during this time ocular
motility can be assessed and surgery may be planned more accurately. There is
however a risk that delaying surgery can cause a trapped muscle to become
fibrosed.
If a decision has been made to operate, the surgical approach must also be decided
and this depends on the location and extent of fracture (how much surgical exposure
is needed) and whether there is a clinical finding of muscle entrapment. Imaging
findings can also guide the decision, for example the amount of orbital prolapse
identified. Ultimately it may come down to the surgeon’s preference and technical
ability, for example some may prefer an endoscopy assisted approach (for example Polligkeit et al (2013) reported their experiences using an endoscope through roof of
mouth).

Question 33

Timescale for surgery opinions

Answer 33

Courtney et al (2000) surveyed all British maxillofacial surgeons
* >50% preferred to operate on orbital fractures 6-10 days post trauma
* 60% routinely sought ophthalmic opinion
* 88% preferred CT scan for imaging
* Subciliary and infraorbital approaches most common for surgical repair
* 66% preferred a silicone elastomer for reconstruction of the fracture
Dulley & Fells (1974) surgery within 14 days recommended for:
* Diplopia not resolving significantly in the early days after injury
* A fracture with large herniation of tissue into the antrum
* Incarceration of tissue in the fracture with resulting globe retraction, and
increased IOP on attempted up gaze
* Enophthalmos > 3mm

Question 34

Surgical incisions and approaches

Answer 34

• Subciliary or subciliary extended laterally (if need more lateral access to the
  orbital rim)
• Subtarsal
• Infra orbital (eyelid approach - incision made along the inferior orbital margin
  dissecting the orbicularis from the periosteum)
  Dr Gemma Arblaster – Year 2
  2023
• Caldwell-Luc approach (through the maxillary antrum, between the canine
  and second molar teeth)
• Transconjunctival approach (through the inferior fornix of the conjunctiva)
• Endonasal approach (through the nose)
• Endoscopic approaches may also be used as they are considered safe and
  effective (Cheung et al, 2013)

Question 35

Materials used for implants

Answer 35

Various biomaterials are available, including autogenous graft material (bone or cartilage), a variety of alloplastic graft materials (silicon, Teflon, rubber, methacrylate, supramid,
polyethylene and titanium (plate / mesh) and allogeneic graft materials (from a
genetically non-identical individual from the same species)

There is also no evidence so far of a long-
term benefit of one implant material type over another (Baek et al, 2014)

Question 36

Newer surgical intervention

Answer 36

With the advances in 3D modelling and 3D printing it is hoped that the planning of
surgery and the development or personalised orbital implants can improve surgical accuracy and outcomes (Cui et al, 2014). However, results using both surgical
techniques are thought to be comparable (Maher et al, 2022). Currently ‘bespoke’
orbital implants (or patient specific implants) are reserved for more complex fracture repairs. These are unlikely to be available as ‘standard clinical care’ in all centres you will visit.

Question 37

Complications from surgical intervention include:

Answer 37

Migration of the implant used in reconstruction - ‘extrusion’, which may occur later
Infection – consider the mechanism of injury, most surgeons routinely prescribe
antibiotics post-op (Courtney et al, 2000)
Ectropion - lower eyelid turns outwards
OM restriction and persistent diplopia
Lower eyelid oedema
Retrobulbar haematoma (rare) (Cheon et al, 201)

Question 38

Later surgical intervention is for

Answer 38

cases of significant enophthalmos
where it is persistent / progressive.

EOM surgery is undertaken later in cases of significant diplopia / motility problems,
often in depression & primary position, there may have also been a neurogenic palsy/ myogenic damage to IR. It needs to be considered if there was a previous fracture repair or not - diplopia post fracture repair may improve with time and some patients
may have residual diplopia relating to orbital implant / neurogenic / mechanical
defect (Loba et al, 2012). Imaging may again prove useful in these cases.