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Zygomatic Complex Fracture (Tripod Fracture)

last modified on: Thu, 06/01/2017 - 08:55

Zygomaticomaxillary Complex Fracture (Tripod Fracture)

return to: Facial Fracture Management Handbook

see also: Case Example Zygomatic Complex Fracture (Tripod Fracture); Reconstructive Procedures Protocols

  1. GENERAL CONSIDERATIONS
    1. Consideration 1 (Indications)
      1. Second most common mid face fracture (nasal fracture is first), usually from lateral blunt force like a blow from a fist
      2. Fractures occur along the zygomaticofrontal and zygomaticomaxillary junctions, zygomaticotemporal attachment  and sphenoid - another term might by tetrapod fracture
      3. Pertinent anatomy:
        1. Buttresses: two major buttresses of the ZMC are the upper transverse maxillary (across the zygomaticomaxillary and zygomaticotemporal sutures) and the lateral vertical maxillary (across the zygomaticomaxillary and frontozygomatic sutures)
        2. The ZMC makes of a large portion of the inferior and lateral orbital walls
      4. Indications - generally aimed at realignment of mid face skeleton with restoration of relative symmetry including projection of malar eminence, as well as restoration of unrestricted motion of the globe and mandible.   
    2.  Contraindications
      1. Minimal displacement and/or no remediable functional deficits - the majority of patients will have varying degrees of V2 hypesthesia that may or may not recover depending on the original nerve injury and surgery should not be undertaken for the latter alone.  
  2. PREOPERATIVE PREPARATIONS
    1.  Exam (Evaluation)
      1. As always, consider ABCs first, including the need for surgical airway - cricothyrotomy or tracheostomy as conceivably the safest options bearing in mind that direct laryngoscopy may be hindered by either blood and/or possible cervical spine injury depending of severity of overall facial fractures. 
        1. In patients with multiple facial fractures it is imperative to rule out cervical spine injury that can occur in >5% of cases
        2. Complete visual exam including acuity testing and rule out of retrobulbar hematoma
        3. Assessment of facial nerve function
        4. Limited mouth opening may be present and is generally mild and is typically due to pain with masseteric pull given its attachment to the zygoma.  Severe displacement may cause direct impingement on the coronoid process, however, and trismus is more pronounced leading to interincisor distance of ~1cm.   
      2. Radiologic assessment
        1. Evaluation of orbits - to judge whether exploration of orbit is warranted and therefore involvement of oculoplastics
        2. Evaluation of the buttresses (see pertinent anatomy)
        3. Axial and coronal CT images are the most useful in determining location of severity of displacement of ZMC
           
    2. Consent for Surgery
      1. Consent should detail the planned approach including a maxillary vestibular approach (AKA sublabial or buccal sulcus), possible transconjunctival, subciliary, lateral brow, hemicoronal.  Each has a separate set of indications and risks involved and should be enumerated including the risk of ectropion with the transconjunctival and subciliary approaches.  The maxillary vestibular approach 
  3. NURSING CONSIDERATIONS
    1. Room Setup
    2. Instrumentation and Equipment
      1. oral retractor tray that should include Spandex retractor, McKesson bite block, 
    3. Medications (specific to nursing)
      1. dilute beta dine face prep
      2. 1% lidocaine with 1:100,00 epinephrine
      3. lacrilube for eye
      4. possible erythromycin ophthalmic ointment
    4. Prep and Drape
      1. Maintain full access to mouth and ipsilateral eye
    5. Drains and Dressings
      1. No drains usually required with the exception of if a coronal approach is required, then two 10 mm fully-perforated Jackson Pratt drains are used.
    6. Special Considerations
      1. Depending on degree of orbital involvement and manipulations would consider post operative vision checks
      2. soft diet (depending on whether isolated ZMC repaired) for one to two weeks
      3. Depending on degree of pre op trismus, may require re-expansion of inter incisor distance with TheraBite (Atos Medical) or similar device or incremental expansion with tongue blades 
  4. ANESTHESIA CONSIDERATIONS
    1. Airway management should be discussed with nursing, patient and anesthesia providers prior to the day of surgery, if possible.  
      1. In general, in an isolated ZMC oral intubation should be possible.  
        1. Deviation of the mandible to the side away from the injury can help improve extrusion of the jaw
    2. Be prepared for flexible endoscopic nasal and tracheostomy, especially in cases of cervical spine injury where exposure would be difficult
  5. OPERATIVE PROCEDURE
    1. Exposure of all fracture lines prior to plating is important (with exception of non- or minimally-displaced zygomatic arch that is typically not exposed) and the approach for each area follows this necessity 
      1. Maxillary vestibular (buccal sulcus or sublabial)
        1. Exposure afforded to anterolateral surfaces of the lower mid face including:
          • Entire anterior face of the maxilla
          • Zygomaticomaxillary buttress
          • Infraorbital rim
          • Zygomatic body, anterior portion of zygomatic arch
          • Piriform aperture
          • Anterior nasal spine and caudal nasal septum
        2. Incision can be either uni- or bilateral depending on required exposure
          1. Important to the leave a cuff of mobile gingiva of about 3-5 mm, incise with either needle cautery on cut or scalpel
          2. Care to not enter buccal fat pad posteriorly to avoid interference with exposure
          3. Carry incision down to periosteum of maxilla 
          4. dissection in subperiosteal plane, care to avoid injury to the V2 branch as dissection proceeds cephalad 
          5. Care to not enter the nasal cavity medially via the piriform aperture
    2. Rim and zygomaticofrontal exposure
      1. Transconjunctival approach
  6. POSTOPERATIVE CARE
  7. SUGGESTED READING
    1. Myers, Operative Otolaryngology, Head and Neck Surgery 2nd edition, Saunders Elsevier 2008
    2. Diagnosis of midface fractures with CT: what the surgeon needs to know.  Hopper RA, Salemy S, Sze RW.Radiographics. 2006 May-Jun;26(3):783-93. Review