Orbital Fracture

Fracture of one or more orbital walls. The orbital floor and medial wall are thinnest and fracture most often.

• Types:
  • Isolated blowout fracture (floor, medial wall) with an intact rim, from direct blow to the globe (a rise in intraorbital pressure transmitted to the weak walls).
  • Trapdoor fracture (linear, hinged) in children: orbital contents are trapped and the elastic bone springs back.
  • Zygomaticomaxillary complex (tripod) fracture: involves the lateral wall, floor, zygomatic arch and maxillary buttress.
  • Naso-orbito-ethmoidal and Le Fort fractures, orbital roof fracture (frontal sinus or skull), orbital apex fracture, blow in fracture.
• Complications: diplopia, enophthalmos, hypoglobus, infraorbital nerve hypoaesthesia, muscle entrapment with oculocardiac reflex, orbital emphysema, optic neuropathy, cerebrospinal fluid leak (roof), sinusitis.

• Periorbital bruising, oedema, subconjunctival haemorrhage, orbital emphysema (crepitus after nose blowing), epistaxis.
• Diplopia: vertical on upgaze or downgaze (inferior rectus entrapment, limited elevation more than depression), horizontal for medial wall (limited abduction and adduction).
• Infraorbital hypoaesthesia (cheek, upper lip, teeth), enophthalmos (appears after oedema settles), hypoglobus, orbital rim step, malar flattening, trismus (lateral wall and zygomatic arch).
• Trapdoor fracture in children: "white eyed blowout" with minimal soft tissue signs, severe restricted vertical movement, pain, nausea, vomiting, bradycardia (oculocardiac reflex), syncope.
• Roof fracture: brow haematoma, ptosis, proptosis (downward displaced), cerebrospinal fluid rhinorrhoea.
• Associated ocular injury in 20 to 30 percent: hyphaema, angle recession, retinal tear, commotio retinae, globe rupture, and optic neuropathy.

• CT orbits (fine axial and coronal cuts): defect size, herniation of fat or muscle into the sinus ("hanging drop" sign), herniation, haemosinus, fracture of the rim, muscle entrapment, orbital volume change; the trapdoor type may show a small linear fracture with tented muscle.
• Forced duction test (tests restriction): resistance indicates entrapment; confirm in the clinic or at surgery.
• Hess or Lees chart and field of binocular single vision; exophthalmometry (enophthalmos above 2 mm); infraorbital sensation; visual acuity, pupils, intraocular pressure and dilated fundus examination.
• Facial CT for associated fractures; ECG monitoring for bradycardia in children.

• Initial: ice packs, head elevation, avoid nose blowing for 2 to 3 weeks, nasal decongestants, antibiotics (amoxicillin clavulanate 625 mg three times daily for 5 to 7 days, or, if penicillin allergic, cefalexin 500 mg four times daily (if the allergy is not severe) or azithromycin 500 mg once daily for 3 days), analgesia, and a short oral steroid course (prednisolone 40 to 60 mg daily for 3 to 5 days) for orbital oedema in selected patients with significant swelling.
• Early (within 24 to 48 hours, ideally within 24 hours) surgery for trapdoor fracture with entrapment or oculocardiac reflex: urgent release of entrapped muscle (delay beyond 72 hours worsens muscle ischaemia and outcome).
• Surgical repair (within 7 to 14 days after swelling settles; before fibrosis at 2 to 3 weeks) is indicated for:
  • Persistent diplopia with positive forced duction and radiological evidence of entrapment.
  • Large defect (over 50 percent of the floor, or over 2 cm2) with expected enophthalmos or hypoglobus.
  • Enophthalmos above 2 mm or progressive.
  • Associated displaced zygomatic complex or other fracture requiring fixation.
• Technique: transconjunctival or subciliary approach, release of entrapped tissue, and reconstruction with an implant (porous polyethylene with titanium, titanium mesh, absorbable polydioxanone sheet, autologous bone graft, or silicone sheet); postoperative forced duction test; perioperative antibiotics.
• Conservative management when diplopia is mild or resolving, motility is good, and enophthalmos is minimal, with review at 1 and 2 weeks, 4 to 6 weeks and 3 months.
• Late complications: persistent diplopia (prisms, strabismus surgery), implant extrusion or infection, lower lid retraction, and enophthalmos.