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.
§ figuresFigures (1)
Fig. 1CT brain bone window showing right zygomatic arch and anterior wall of right maxillary sinus fracture. Haemosinus is seen within the right maxillary sinus.
“CT brain bone window showing right zygomatic arch and anterior wall of right maxillary sinus fracture” · Cerevisae · CC BY-SA 4.0 · Wikimedia Commons
Verified open-access images only, reproduced for education under their stated licences · no AI-generated or illustrative artwork · Zygomatic Complex Fracture figures pending faculty review.
§ 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
- Ellis E. Oral & Maxillofacial Trauma 4e
Draft — pending faculty review. Educational use only; verify against current guidelines and primary sources before clinical application.