Blow out fractures

1. vidya

2. Definition
 Orbital floor fractures are common, and result from blunt orbital
trauma in which force is delivered to the thin bones of the orbital floor,
typically along the infraorbital canal.
 The risk of enophthalmos is greatest when both the floor and the
medial wall are fractured

3. Expanded orbit syndrome
 Multiple fractures in and around the orbit may lead roomy orbit with
extensive prolapse of orbital tissues.
 This expansion can be seen in orbital fracture along with mid facial
fracture as in tripod or Le Fort type III.
 Clinically patient has gross enophthalmos, inferior displacement of
globe (hypoglobus), deep superior sulcus, eyelid asymmetry and
diplopia.

4. pathophysiology
 Blow out fracture occurs when a blunt object greater in
diameter than the orbital rim such as fist, tennis or cricket
ball strikes the orbital cavity
 . The mechanisms proposed for blow out fracture are-
 Hydraulic theory
 Buckling theory

5. Hydraulic theory or Retropulsion theory or Direct injury theory:
Sudden compression and backward displacement of globe raises the
intra orbital pressure leading to fracture of orbital floor.
Buckling theory or transmission theory or Indirect injury theory:
External force to inferior orbital rim is transmitted along the orbital
walls causing a ripple effect leading to fracture at the weakest point in
the posterior medial region of the floor.

7. Types
 a) Pure blowout fracture: Fracture of the orbital floor with
intact orbital rim
 b) Impure blowout fracture: Associated fracture of the orbital
rim

8. Orbital blowout fracture in children
 The bones of a child’s orbit are more elastic than adults.
 Thus injury in children causes more anteroposterior buckling
creating a fracture with overlapping segments.
 This leads to ‘trapdoor-type’ fracture where prolapsed orbital tissue
gets caught in the fracture site leading to severe motility restriction
and diplopia in absence of marked congestion or ecchymosis.
 The condition is also called the ‘white-eyed’ blow-out fracture.

9.  Benign external periocular appearance with a remarkable paucity
of eyelid signs but with significant extraocular muscle restriction
(usually vertical) on examination ( WEBOF).
 Younger children often do not complain of binocular diplopia,
and may simply close one eye.
 severe oculocardiac reflex a vague history and may therefore be
misdiagnosed as having an intracranial injury (e.g., concussion).
 , CT may show a trapdoor fracture with rectus muscle
incarceration or a “missing” inferior rectus.
 The narrow configuration of the typical WEBOF is often missed
on CT imaging, particularly when fine cuts through the orbits are
not obtained. Careful examination of coronal views is critical in
such cases

10. Clinical features
 History.
 General condition of patient
 Other non ocular injury should be checked.
 Eyelid signs.
 Ecchymosis and edema of the eyelids may be present, but other
external
 signs of injury can be absent (white-eyed blowout).

11.  Periorbital haematoma: also proptosis of variable degree
seen initially due to orbital edema and haemorrhage
 Emphysema: Subcutaneous emphysema with crepitus seen
in fractures communicating with air filled sinuses.
 Paraesthesia over ipsilateral lower lid, cheek and upper lip
due to injury to infraorbital nerve.
 Diplopia: Due to restriction of ocular motility. With the
entrapment of inferior orbital tissue and inferior rectus
muscle, vertical diplopia is more prominent in upgaze.

12.  In patients with orbital floor fractures
 visual loss can result from globe trauma, injury to the
optic nerve, or increased orbital pressure causing a
compartment syndrome
 An orbital hemorrhage should be suspected if loss of
vision is associated with proptosis and increased lOP.
 Injuries to the globe and ocular adnexa may also be present.

13.  0.8–1 ml increase of bony orbital volume corresponds to
1 mm of enophthalmos on the Hertel exopthalmometer.
 Clinically significant enophthalmos (≥2 mm) occurs with
increase in the bony orbital volume of 1.5–2 ml.

14.  Enophthalmos: Caused by displacement of the
eye globe due to an enlargement of the bony orbit.
 Also displacement of orbital contents into maxillary sinus
and traction over globe caused by entrapped tissue leads to
posterior and inferior displacement of globe.
 Pseudoptosis occurs due to loss of support.

16. Evaluation
 visual acuity at presentation has medico-legal importance in
ocular trauma cases.
 If required eyelids can be gently separated to allow patient to read
the chart.
 Palpate orbital rim to look for deformity and crepitus
 Slit lamp evaluation of cornea and anterior segment should be
performed.
 RAPD points towards optic nerve injury.
 Fundus evaluation should be done to note for Berlin’s oedema

17.  Ocular motility
 Hertel exopthalmometer: To document enophthalmos.
 With passage of time and absorption of orbital fat over period can lead to
increase in enophthalmos.
 Force Duction Test (FDT): FDT is useful in determining whether
dysmotility is restrictive or paralytic.
In blow out fracture with inferior rectus entrapment FDT is ‘positive’
indicating mechanical cause.
 Force Generation Test (FGT): In testing force generation, the muscle
insertion is grasped and the patient is asked to look into the muscle’s field
of action. A paretic muscle will feel weak when compared with the fellow
eye.
 Diplopia charting: With red green glass, diplopia charting with streak
light shows diplopia worsening in upgaze
 Hess screen or Lee screen test can be done.

19. Imaging
 Plain X-rays:. Water’s view for detecting an orbital floor
fracture .
 X ray shows bony discontinuity in orbital floor with
herniation of soft tissue in maxillary antrum seen as
‘hanging drop’ sign
 CT gives detailed visualization of bony and soft tissue
injury where entrapment of muscle can be appreciated.
 Coronal sections are particularly useful .
 MRI Can be utilized when there is need for greater soft
tissue evaluation
 . MRI is insufficient in assessing the bony structures and
therefore needs to be combined with CT.

21. complications
 cerebral and ocular damage,
 severe epistaxis due to avulsion of the anterior ethmoidal artery
 orbital hematoma,
 Csf rhinorrhea,
 Damage to the lacrimal drainage system,
 lateral displacement of the medial canthus, and
 Associated fractures of the medial orbital waIl and fl oor.

22. Management
. Restriction in ocular movement and / or diplopia is caused
not only by entrapment of muscle
but soft tissue edema, hemorrhage and motor nerve palsy can
also be the cause.
A better evaluation can be made if time is allowed for clearing
of initial edema and hemorrhage.
It is generally accepted that a 2 week window of observation
can be allowed in absence of urgent surgical indications

23.  Observation:
• Minimal diplopia (not in primary or downgaze),
• Good ocular motility
• No significant enophthalmos or hypo-ophthalmos

24.  Medical treatment
 Consider broad-spectrum oral antibiotics (e.g., cephalexin 250 to 500
mg p.o. q.i.d.; or erythromycin 250 to 500 mg p.o. q.i.d; or doxycycline
100 mg po b.i.d.) for 7 days.
 Antibiotics may be considered if the patient has a history of chronic
sinusitis, diabetes, or is otherwise immunocompromised.
 Prophylactic antibiotics should not be considered mandatory in
patients with orbital fractures.
 Patient advised not to blow nose as it can worsen orbital emphysema.

25.  Nasal decongestants (e.g., oxymetazoline nasal spray b.i.d.) for 3
days. Use is limited to 3 days to minimize the chance of rebound
nasal congestion.
 Apply q1–2h ice packs for 20 minutes each hour to the eyelids for
the first 24 to 48 hours and 30-degree incline when at rest.
 Consider oral corticosteroids (e.g., Medrol dose pack) if extensive
swelling limits examination of ocular motility and globe position.
 Neurosurgical consultation is recommended for all fractures
involving the orbital roof, frontal sinus, or cribriform plate, and
for all fractures associated with intracranial hemorrhage.
 Otolaryngology or oral maxillofacial surgery consultation may be
useful for frontal sinus, midfacial, and mandibular fractures

26. Follow up
 At 1 and 2 weeks after trauma to be evaluated for persistent diplopia and/or
enophthalmos after the acute orbital edema has resolved.
 If sinusitis symptoms develop or were present prior to the injury, the patient
should be seen within a few days of the injury.
 fundus examination to assure there is no peripheral retinal damage.
 Depending on the level of associated ocular injury, patients should also be
monitored for the development of associated ocular injuries (e.g., orbital
cellulitis, angle-recession glaucoma, and retinal detachment).
 Gonioscopy of the AC angle and dilated retinal examination with scleral
depression is performed 3 to 4 weeks after trauma if a hyphema or
microhyphema was present.
 Warning symptoms of retinal detachment and orbital cellulitis are explained to
the patient

27.  Surgical technique
 . It is generally accepted that unresolved diplopia with soft tissue
entrapment, significant enophthalmos (2 mm or more), marked
hypo-ophthalmus, fracture more than 50% of the floor, or
trapdoor type fracture will require surgical intervention.
 Surgical principle in blow out fracture is to assess orbital floor,
release soft tissue and muscle entrapment and strengthen the
floor with use of implants.

28. Immediate repair
 If there is clinical evidence of muscle entrapment and
nonresolving bradycardia, heart block, nausea, vomiting, or
syncope.
 These may be present despite “negative” CT findings, WEBOF).
 Patients with WEBOF require urgent orbital exploration to
release any incarcerated muscle in the hope of decreasing the
chance of permanent restrictive strabismus from muscle ischemia
and fibrosis, as well as to alleviate the systemic symptoms from
the oculocardiac reflex.

29. Repair in 1-2 weeks
 Persistent, symptomatic diplopia in primary or downgaze that has not
improved over 1 week.
 CT may show muscle distortion or herniation around fractures. Forced
ductions may be useful in identifying bony restriction.
 Complex trauma involving the orbital rim, or displacement of the lateral
wall and/or the zygomatic arch.
 Complex fractures of the midface or skull base . Nasoethmoidal
complex fractures. Superior or superomedial orbital rim fractures
involving the frontal sinuses

30.  Large orbital floor fractures (>50%) or large combined medial
wall and orbital floor fractures that are likely to cause
cosmetically unacceptable enophthalmos over time
 . Enophthalmos and/or hypoglobus at initial presentation is
indicative of a large fracture
 . It is also reasonable to wait several months to see if
enophthalmos develops before offering repair.
 There is no clear evidence that early repair is more effective in
preventing or reversing globe malposition compared to delayed
repair.
 However, many surgeons prefer early repair simply because
dissection planes and abnormal (fractured) bony anatomy is
more easily discernable before post-traumatic fibrosis sets in

31. Delayed Repair
 Old fractures that have resulted in enophthalmos or
hypoglobus can be repaired at any later date.

32.  Subciliary approach
 Transconjunctival approach
 Transantral approach:.
 Endoscopic approach: With advances in endoscopic surgery,
transmaxillary and transnasal endoscopy has been described
which eliminate the need for eyelid incisions and gives
improved visualization of fractures.

33. Implants
 Surgeon should size the implant so as to cover the defect adequately and
to prevent displacement or extrusion later
 Membranous bone
 Cartilage
 Titanium mesh
 Porous polyethylene
 (Medpore)sheets
 Silicon sheet
 Silastic sheet (Teflon)

34. Complications of surgery
• Intra operative bleeding
• Residual or new onset diplopia
• Extra ocular muscle dysfunction
• Post operative neuralgia
• Residual enophthalmos
• Implant extrusion
• Possible loss of vision

35.  Treatment of persistent visually handicapping diplopia
 Few patients will have persistent diplopia even after adequate surgical
repair of floor fracture.
 Diplopia in primary gaze and in down gaze (functional gaze) are more
troublesome.
 Such cases will require muscle surgery. To correct diplopia in down gaze
‘Reverse Knapp procedure’ performed placing medial and lateral recti
behind inferior rectus muscle.
 Fresnel prisms can be employed in selective cases

36.  Late treatment of cosmetically unacceptable enophthalmos
 Resurgery with adequate size orbital implant if downward
sinking of eye along with enophthalmos is unacceptable to
patient.
 Correction of pseudoptosis done with mullerectomy which will
increase palpebral height.

37. Role of anticoagulants
 The role of anticoagulation in postoperative or post-trauma patients is
debatable. Anecdotal reports have described orbital hemorrhage in patients
with orbital and midfacial fractures who were anticoagulated for prophylaxis
against deep vein thrombosis (DVT).
 On the other hand, multiple large studies have also demonstrated an increased
risk of DVT and pulmonary embolism (PE) in postoperative patients who are
obtunded or cannot ambulate
 . At the very least, all in-patients with orbital fractures awaiting surgery and all
postoperative orbital fracture patients should be placed on intermittent
pneumatic compression (IPC) therapy and encouraged to ambulate.
 In patients at high risk for DVT, including those who are obtunded from
concomitant intracranial injury, a detailed discussion with the primary team
regarding anticoagulation should be documented, and the risks for and against
such therapy should be discussed in detail with the patient and family.

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