Closed Reduction of ZMC (Zygomaticomaxillary Complex) Fracture

Definition and Concept

Indications for Closed Reduction

• The fracture is minimally displaced or non-comminuted (Zingg type A - isolated zygomatic arch, or type B - non-comminuted ZMC)
• The fractured segments are inherently stable once reduced (impacted or greenstick pattern; bone locks in position)
• There is no significant orbital floor blowout requiring repair
• The malar eminence is depressed but contours of the cheek are relatively preserved
• Early presentation (within 10-14 days; before fibrous union)
• Trismus from coronoid impingement by a depressed arch (urgent indication)

• Fracture is comminuted or unstable (tends to re-displace)
• Significant orbital floor involvement (enophthalmos, diplopia)
• Severe displacement with disruption of orbital volume
• Delayed presentation (> 2-3 weeks; fibrosis locks the bone)

Approaches for Closed Reduction

1. Gillies Temporal Approach (most widely used)

"Gillies' approach is performed from above. Incision within the temporal hair. Taken through the temporalis fascia. Elevation between fascia and muscle allows access to the arch medially since the fascia inserts on the arch and the muscle continues to the coronoid process of the mandible."

1. 2.5 cm incision made within the temporal hairline, angled ~45° to the zygomatic arch
2. Dissection carried through skin and superficial fascia
3. A plane is created deep to the deep temporalis fascia but superficial to the temporalis muscle - this is the key anatomical corridor; the deep fascia inserts on the outer lip of the zygomatic arch, so the instrument naturally passes under the arch
4. A Rowe's zygoma elevator (or Bristow's elevator) is passed through this tunnel
5. The elevator tip is positioned medial/deep to the depressed arch
6. The bone is elevated with a steady upward-outward levering force until a palpable "click" or "clunk" is felt, indicating reduction
7. Stability is assessed by pressing the malar area and releasing; if it re-displaces, fixation is needed

2. Keen's (Transoral / Intraoral) Approach

1. A small (~1 cm) incision in the gingivobuccal sulcus just below the zygomatic buttress of the maxilla
2. A periosteal elevator is passed upward, staying close to bone, posterior to the zygomatic buttress
3. The tip is advanced posteriorly along the medial surface of the zygomatic arch
4. Elevation is achieved by pushing outward and upward; a popping sound or sensation indicates reduction
5. The surgeon's free finger can palpate externally to confirm position

3. Percutaneous Hook Approach

• Two intersecting surface lines are drawn: one dropped vertically from the lateral canthus, one drawn horizontally from the alar base - their intersection marks the depressed arch segment
• A sharp bone hook is passed percutaneously through a tiny stab incision and hooked around or under the depressed arch segment
• Traction is applied laterally and outward to reduce the depressed fragment

Instruments Used

Post-Reduction Assessment and Protection

• Intraoperative CT is the gold standard for confirming reduction; a palpable "clunk" and restoration of malar contour are clinical surrogates
• Stability is tested by pressing on the malar eminence; an unstable fragment that re-displaces means open reduction and internal fixation (ORIF) is required
• A protective splint (e.g., bent aluminum finger splint or metal eye shield taped over the arch) is applied for 2-3 weeks post-reduction to prevent re-displacement from the weight of the head on a pillow or external pressure
• The zygoma typically "locks" in its new position due to periosteum and attached soft tissue

Key Anatomical Point for Gillies Approach

• Cummings Otolaryngology Head and Neck Surgery: "A simple arch fracture may be accessed via a Gillies incision, made within the temporal hairline and elevated beneath the temporalis fascia (over the temporalis muscle, because the fascia inserts on the arch, whereas the muscle passes beneath the arch); this allows an instrument to be passed with confidence beneath the arch for elevation."

Closed vs. Open Reduction - Decision Summary

• K.J. Lee's Essential Otolaryngology, p. 1110
• Cummings Otolaryngology Head and Neck Surgery, Middle Third section
• AO Surgery Reference - Closed treatment, zygomatic arch
• Mishra et al., PMC 2023 - Management of zygomatic fractures (150 patient study comparing Gillies vs. Keen approaches; three-point fixation showed best stability outcomes for unstable fractures)