AtlasTraumaZygomatic Complex Fracture

Trauma

Zygomatic Complex Fracture

aka ZMC Fracture · Tripod Fracture · Quadripod Fracture

Fracture of the zygoma at its four articulations (frontal, temporal, maxillary, sphenoid) producing malar flattening, diplopia, infraorbital paraesthesia and trismus.

Articulations
4 (quadripod)
Imaging
CT face
Rx
ORIF 2–3 point

§ overviewOverview

Fracture of the zygomatic bone involving disruption at its articulations with the frontal, temporal, maxillary, and sphenoid bones (hence 'quadripod' rather than 'tripod').

§ etiologyEtiology

  • 01Assault, RTA, sports (esp cricket/hockey)

§ clinicalClinical Features

  • 01Flattening of malar prominence (masked by early oedema)
  • 02Periorbital ecchymosis, subconjunctival haemorrhage extending posteriorly
  • 03Infraorbital paraesthesia (V2)
  • 04Diplopia, enophthalmos, hypoglobus
  • 05Trismus (impingement on coronoid)
  • 06Step deformity at infraorbital rim, zygomatic buttress, frontozygomatic suture

§ investigationsInvestigations

  • 01CT face with coronal and 3D reconstruction (gold standard)
  • 02Ophthalmology assessment: visual acuity, pupils, motility, fundus
  • 03Occipitomental views if CT unavailable

§ classificationClassification

  • 01Knight & North (1961) — six groups based on displacement and rotation
  • 02Zingg (1992) — A (isolated), B (complete tetrapod), C (comminuted)

§ treatmentTreatment

  • 01Undisplaced/minimally displaced without functional deficit: conservative + soft diet 4–6 wk + avoid sleep on affected side
  • 02Displaced: open reduction with internal fixation via combined approaches: (1) frontozygomatic (upper eyelid or lateral brow), (2) infraorbital rim (subciliary/transconjunctival), (3) zygomaticomaxillary buttress (sublabial)
  • 03Fix at 2–3 points depending on stability; Gillies temporal approach for pure arch fractures
  • 04Orbital floor reconstruction if defect > 2 cm² or entrapment

§ complicationsComplications

  • 01Persistent infraorbital paraesthesia
  • 02Enophthalmos / diplopia
  • 03Malar flattening
  • 04Ectropion (subciliary approach)
  • 05Sinusitis, malunion

§ prognosisPrognosis

Good with anatomical reduction; delayed treatment produces malunion requiring osteotomy.

§ examKey Examination Points

  • 01Assess vision — retrobulbar haemorrhage is an emergency
  • 02Palpate all four articulations
  • 03Test V2 sensation

§ revisionQuick Revision Summary

  • 01Quadripod fracture · CT gold standard · ORIF at 2–3 points · watch V2 and eye

§ vivaBDS Viva Questions

  • 01Why is 'tetrapod' more accurate than 'tripod'?
  • 02Approaches for ORIF?
  • 03Indications for orbital floor reconstruction?

§ mcqsMCQs — Assessment (3)

Question 1

Zygoma articulates with all EXCEPT:

Question 2

Emergent complication requiring immediate decompression:

Question 3

Gillies approach is for:

References

  1. Ellis E. Oral & Maxillofacial Trauma 4e

Draft — pending faculty review. Educational use only; verify against current guidelines and primary sources before clinical application.