Facial plastic surgery FPS 2004 Czerwinski.pdf

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Traumatic Arch Injury: Indications and anEndoscopic Method of RepairMarcin Czerwinski, M.D.1 and Chen Lee, M.D., M.Sc., F.R.C.S.C., F.A.C.S.1

ABSTRACT

The unique strategic position of the zygomatic arch makes it an important surgicallandmark in facial fracture repair. Because of the numerous negative sequelae associated

with the traditional coronal approach to the arch, it has frequently been omitted as a pointof reduction and fixation. Endoscope-assisted repair allows accurate zygomatic arch

restoration without the setbacks of coronal access. The indications for arch repair includemarkedly displaced isolated arch fractures, complex zygoma fractures with arch comminu-tion, and Le Fort III level fractures. In complex zygoma fractures, the arch helps accurately restore midface projection and width and serves as an additional stable anchor point. In LeFort III fractures, restoration and fixation of the arch are essential components of the repairnecessary to stabilize the maxillary dentition to the cranial base. Endoscopic arch repair is anovel, technically challenging procedure that requires a different set of surgical skills andconsiderable training. Implementation of appropriate teaching programs and furtheradvances in instrument development will overcome the steep learning curve associated

with this technique and encourage its use.

KEYWORDS: Zygomatic arch, endoscope, Le Fort III

REGIONAL ANATOMY

The zygomatic arch is a narrow, laterally positionedelement of the craniofacial skeleton that has aconsistent structure and symmetry. In the axial plane,the shape of the arch changes from a curved posteriorthird to straight middle and anterior thirds. In thesagittal plane the arch is parallel to the Frankforthorizontal.

The arch is strategically positioned joiningthe zygoma and the rest of midface to the stable

cranial base. Thus, it is a potentially importantlandmark in the restoration of normal facial anatomy following traumatic injury to the structures adjoiningit.1,2 The length and shape of the arch in the axialplane and its angulation from the sagittal plane can

be used to reestablish accurate projection and width of the face.

Thorough knowledge of the regional soft tissueanatomy and of its relationship with the frontal branchof the facial nerve is essential to avoid injury during archexposure. The nerve pierces the superficial musculoapo-neurotic system at the lower border of the zygomaticarch and courses superficially to the temporoparietalfascia in an anterosuperior direction.3 The coronal inci-sion has been used traditionally to reach the arch

(Fig. 1). The disadvantages associated with a coronalincision have discouraged many surgeons from archrepair. We introduce a novel endoscopic method of arch repair with low risk of transection to the frontalbranch of the facial nerve (cranial nerve [CN] VII).

Current Considerations in Endoscopic Facial Plastic and Reconstructive Surgery; Editors in Chief, Fred Fedok, M.D., Gilbert J. Nolst Trenite,M.D., Ph.D., Daniel G. Becker, M.D., Roberta Gausas, M.D.; Guest Editor, James C. Alex, M.D. Facial Plastic Surgery , Volume 20, Number 3,2004. Address for correspondence and reprint requests: Chen Lee, M.D., M.Sc., F.R.C.S.C., F.A.C.S., Chairman, Division of Plastic Surgery,Associate Professor, McGill University, Montreal General Hospital, D6.269, 1650 Cedar Avenue, Montreal (Quebec), Canada H3G 1A4.1Division of Plastic Surgery, Department of Surgery, McGill University Health Center, McGill University, Montreal, Quebec, Canada. Copyright# 2004 by Thieme Medical Publishers, Inc., 333 Seventh Avenue, New York, NY 10001 USA. Tel: +1(212) 584-4662. 0736-6825,p;2004,20,03,231,238,ftx,en;fps00518x.

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TRAUMATIC INJURY PATTERNS

OF THE ARCH

Fracture displacement of the arch is determined by thedirection of the traumatic force and pull of the attachedmasseter muscle. Three common patterns of arch injury

occur. First, a direct lateral impact fractures and displacesthe arch medially (Fig. 2). Second, posterior telescopingof the arch can result from a frontal impact to the malarprominence (Fig. 3). Third, lateral arch displacement isless common and results from an anterior force vector tothe malar prominence with the energy dissipated at thearch through an explosive burst with lateral displacementof the comminuted arch fracture segments (Fig. 4A).Recognition of this fracture pattern is important asreduction attempts with lateral force applied under thearch as described by Gillies and Keen further exacerbatethe degree of fracture displacement.

The clinical patterns of presentation include iso-lated fractures of the zygomatic arch with temporaldepression, especially in patients with a prominent pre-injury arch contour. A zygoma fracture results from

fracture disruption of all its normal bone attachmentsto the cranial base. Because arch disruption is a necessary component of a displaced zygomatic fracture, inclusionof arch repair may enhance reduction and stability of acomplex zygomatic fracture.4,5 The mobile maxilla of aLe Fort III level fracture is defined partially by thefracture separation of the maxilla from the cranial baseat the arch.6 Repair necessitates reduction and stabiliza-tion at this cranial buttress.

EFFECT OF ARCH REPAIR ON

TREATMENT OUTCOME

The arch has frequently been omitted as a point of reduction and fixation. In contradistinction, anatomicfracture repair using open methods of reduction andinternal rigid fixation are the accepted current standardsin the operative management of most facial fractures.

This general disregard for arch restoration may havearisen because of the disadvantages associated with thetraditional coronal approach to arch repair. An extensivescalp incision and dissection has been traditionally necessary with coronal arch repair. This exposure intro-duces risk of temporal hollowing, weakness or perma-nent paralysis of the frontal branch of the facial nerve,

alopecia, loss of sensation posterior to the incision,excessive blood loss, and a lengthy operative time.7

Thus, the potential role of the arch as a foundationlandmark has been neglected.

In isolated arch fractures, accurate visual reduc-tion reestablishes the preinjury contour of the lateralface. Stabilization prevents redisplacement due toreinjury or pull of the masseter muscle, an issue notaddressed by the often used Gillies approach. Anatomicrepair is especially important in patients with prominentarches, where the normal soft tissues may not hide theunderlying bone discrepancies.

Figure 1 Open reduction and rigid miniplate fixation of the arch

have traditionally required an extensive coronal scalp incision.

Figure 2 Three patterns of comminuted arch injury are com-

monly observed. Medial arch displacement often results from a

direct lateral impact.

Figure 3 Posterior telescoping of the arch occurs secondary to

an anterior impact to the malar prominence.

232 FACIAL PLASTIC SURGERY/VOLUME 20, NUMBER 3 2004



In complex zygoma fractures, restoration of original arch shape, length, and angulation facilitatesan accurate reestablishment of midfacial projectionand width. The arch serves a secondary role as a pointof added fracture stabilization.

In associated Le Fort III fractures, the arch rigidly suspends the mobile midface segment to the cranial baseand stabilizes the maxillary dentition. Here as well, thearch is important in restoration of accurate midfacialprojection and width.

To benefit from the advantages of arch repairand simultaneously minimize surgical stigmata of cor-onal exposure, we have developed an endoscope-assistedtechnique.

EVOLUTION OF ENDOSCOPIC

REPAIR OF THE ARCH

In the laboratory, we evaluated the effectiveness of theendoscope to reduce and fixate the arch precisely andavoid facial nerve injury on a cadaver fracture model.Using remote minimal access incisions, excellent fracturereduction and rigid miniplate stabilization were achievedby endoscopically assisted fracture repair in all cadaver

skulls. Dissections of the frontal branch of the facialnerve confirmed complete anatomic continuity in allspecimens.7

Subsequently, we have used the endoscopic ap-proach to zygomatic arch repair in 25 clinical cases.8 Of those, 3 were isolated arch fractures, 15 were associated

with zygoma fractures, and 7 involved Le Fort IIIfractures (Fig. 5). All patients demonstrated excellentreestablishment of facial width and projection, as con-firmed by facial computed tomography scans. No per-manent dysfunction of the frontal branch of CN VIIoccurred in our series. Temporary palsies, probably

caused by aggressive traction, were present in 4 of 7 LeFort III, 3 of 15 complex zygoma, and 1 of 3 isolatedzygomatic arch fractures. Operating times for endo-scope-assisted repairs were 2.0 hours for the isolatedarch, 4.9 hours with complex zygoma, and 9.7 hours forthe Le Fort III fractures (Fig. 6).

SURGICAL TECHNIQUE

Endoscopic Equipment

The endoscope used at this center is a 4-mm-diameter,30-degree angle scope (Karl Storz, Germany). To

Figure 4 (A) Lateral arch displacement is the least common fracture pattern described. However, its recognition is important as most

techniques of fracture reduction employ a lateral force to the displaced arch segment. Application of such lateralizing techniques of arch

repair to an already laterally displaced arch only exacerbates the degree of fracture displacement. (B) Anatomic repair of the lateralized

arch wassuccessfully accomplished with endoscopic assistance. Refer to Figure 8 to see associated clinical photographs of this patient.

Figure 5 The arch components of fractures were repaired

endoscopically in isolated arch, complex zygoma, and Le Fort III

injuries.

TRAUMATIC ARCH INJURY/CZERWINSKI, LEE 233



maintain an optical cavity and stabilize the orientation of the endoscope simultaneously, a 4-mm endoscope-mounted retractor (Isse Dissector Retractor, Karl Storz,Germany) is required. The Olympus Video System(Olympus America, Lake Success, N.Y.) is used to pro-

ject the endoscopic image to a video display.

Exposure

A preauricular incision at the anterior margin of thehelical crus, extending superiorly 2 cm above the auricle,is made. This incision is carried through the skin andthe temporoparietal fascia to expose the deep temporalfascia. To create an adequate optical cavity, a periostealelevator is used to dissect superficial to the deep temporalfascia. To avoid injury to the frontal branch of thefacial nerve, the nonendoscopic component of the dis-section does not extend below an imaginary line joiningthe helical crus and the superior orbital rim. Followingdissection of the optical cavity, the retractor-mountedendoscope is inserted in the plane superficial to the deeptemporal fascia and visualized dissection is performeddown to the zygomatic arch (Fig. 7A, B). Temporalhollowing is avoided by maintaining the integrity of

the deep temporal fascia. Once the arch is reached, theperiosteum is incised and the dissection is carried in thesubperiosteal plane to expose the entire zygomatic archand identify all sites of fracture.

ReductionCommonly, reduction of the arch is performed in situ.

The fracture segments are aligned, according to thefragmentation pattern, to restore the preinjury form of the arch. When the comminution is severe and results ina highly unstable pattern, the fracture segments can be

removed from the operative field, stripped of attachedsoft tissues, and reduced on a side table. The lattermethod, however, suffers from an increased rate of postoperative bone resorption because of the interrup-tion of the periosteal blood supply.9

FixationA short miniplate (in isolated zygomatic arch fractures)or a long miniadaptation plate (in associated midfacefractures) is plated onto the arch in situ or on a side table.

The long miniadaptation plate extends onto the lateralorbital rim, restoring and rigidly fixing midface anatomy.Following confirmation of accurate alignment at allfracture sites and accurate arch positioning, the plate isanchored, under endoscopic guidance, with screw fixa-tion (Fig. 7C).

SEQUENCING OF COMPLEX REPAIRS With complex facial fractures, multiple sites of fracturerepair may be necessary to achieve accurate restoration of preinjury facial form. When arch restitution is an im-portant component of the repair, we have found thefollowing sequences of fracture reduction and fixation tobe most accurate and expedient.

Complex Zygoma

Anatomic repair of complex zygomatic fractures may require reduction and fixation at all the major fractureinterfaces. This includes the zygomaticofrontal suture,infraorbital rim, zygomaticomaxillary buttress, and thezygomatic arch. We have found repair most facile

when the zygomaticofrontal suture and infraorbital rimare reduced and fixated first. This serves to restore theexternal skeletal frame of the orbit. Next, accurateprojection of the orbital frame is achieved by repairingthe arch. Last, the fracture at the zygomaticomaxillary buttress is addressed.

Le Fort IIILe Fort III level fracture requires reduction and fixation

of the midface to the cranial base to provide a stableplatform for dental occlusion. Repair is most expeditiousif the cranio-orbital and maxillomandibular units arerestored separately and then joined at the Le Fort I level.

The cranio-orbital unit is repaired by reduction andfixation at the frontozygomatic suture and infraorbitalrim to recreate the orbital frame. Accurate projection of the orbital frame is established through arch repair. Themaxillomandibular unit is restored using maxilloman-dibular fixation. Last, the cranio-orbital and maxillo-mandibular units are joined by rigid fixation of theanterior buttresses of the maxilla.

Figure 6 Mean operative times of endoscope-assisted repair of

facial fractures involving the zygomatic arch. The length of

surgery correlates well with the complexity of injury.




CASE PRESENTATIONS

Complex Zygoma

A young male was a driver in a motor vehicle accident. The force of the collision resulted in his face striking thesteering wheel. He suffered a left lateral orbital lacera-tion. In addition, he complained of numbness in the leftinfraorbital nerve distribution and flatness and pain inthe affected cheek. Radiographic imaging demonstrateda complex left zygomatic fracture with lateral displace-ment of a comminuted arch. Access for fracture repair

was preauricular (endoscopic arch fixation), upper buccalsulcus (zygomaticomaxillary buttress and inferior orbitalrim), and lateral orbital laceration (zygomaticofrontalbuttress). The highly comminuted laterally displaced

arch was dissected as a free graft and rigidly plated ona side table, then repositioned anatomically as the archcomponent of the four-point zygomatic fracture repair

(Figs. 4 and 8).

Le Fort IIIA young male was assaulted with a baseball bat. Hecomplained of left facial flattening as well as mobility of his maxilla and malocclusion. Radiographic imagingdemonstrated left Le Fort III and right Le Fort II facialfractures. The patient’s preinjury occlusion was restoredusing maxillomandibular fixation. Access for fracturerepair was achieved using preauricular (endoscopicarch fixation), upper buccal sulcus (zygomaticomaxillary

Figure 7 The technique of endoscopic arch repair utilizes remote minimal access portals to effect repair. (A) The endoscope-mounted

retractor is inserted through a preauricular incision, in a plane superficial to the deep temporal fascia, to reach the zygomatic arch. (B)

Endoscopic view of the medially displaced, fractured arch fragments. (C) This endoscopic view demonstrates the arch to be

anatomically repositioned and fixated.




buttress and inferior orbital rim), and lateral orbitalupper blepharoplasty incisions (zygomaticofrontal but-tress). The left arch component of the Le Fort IIIfracture was dissected as a free graft and rigidly platedon a side table, then repositioned anatomically as thearch component of the midface fracture repair (Figs. 9and 10).

DISCUSSION

The zygomatic arch has a consistent shape and sym-metry. Its strategic position makes it a key surgicallandmark in facial fracture repair.1,2 In isolated archfractures, its reduction restores the contour of the lateralface. In complex zygoma fractures, it helps accurately reduce midfacial projection and width and recreate

Figure 8 (A) Preoperative photograph of a patient who sustained a complex zygomatic fracture demonstrates reduced malar

projection and increased facial width. The increase in facial width has resulted from a laterally displaced arch. (B) This 5-month

postoperative photograph demonstrates correction of the facial deformities following four-point reduction and fixation of the zygoma.

The arch component of the repair was achieved using endoscopic assistance. Refer to Figure 4 to see pre- and postoperative

radiographic images of this patient.

Figure 9 (A) Preoperative photograph of a patient with a left Le Fort III and right Le Fort II facial fractures, showing facial flattening and

unstable maxillary dentition. (B) Photograph several months following the surgery. The right central incisor was electively extracted

because of preexisting periodontal disease.




Figure 10 (A, B) Preoperative coronal and axial computed tomography images demonstrating left Le Fort III and right Le Fort II level

fractures with severe left zygomatic arch comminution. (C, D) Postoperative computed tomography images showing accurate

restoration of the arch and dental occlusion.




preinjury bony orbital volume to position the ocularglobe properly. In Le Fort III fractures, it principally stabilizes the midface and maxillary dentition through itsstable attachment to the cranial base. The usefulness of arch repair increases as does the complexity of facialinjury, being most important in Le Fort III fractures andleast so in isolated arch injuries. Nevertheless, the arch

has frequently been ignored in facial fracture repairbecause of the surgical access and undesirable sequelaeassociated with a coronal incision.7 Decreased scalpsensation, facial nerve injury, excessive bleeding, scar-ring, and alopecia have all been associated with thetraditional coronal access to repair the arch.

An endoscopic approach to the arch introducesnumerous advantages. The exposure involves small,

well-concealed incisions and direct visualized dissection.Reduction and fixation are also performed inside theoptical cavity using specialized endoscopic equipment.

This minimal access approach diminishes the problems

customarily associated with coronal arch repair.Endoscopic arch repair also suffers from severaldrawbacks. First, it requires a different set of surgicalskills. Tactile surgical feedback is impaired as all tech-nical aspects of the endoscopic intervention are remotely performed through limited access portals using specia-lized equipment. Perceived visual depth in the surgicalfield is absent as the endoscopic image is projected on atwo-dimensional monitor. Second, the purchase of thenecessary surgical instruments and electronic devicesrepresents a significant expense. Third, the learningcurve is steep with initial long operative times. However,

when rigid fixation is undertaken the operative times forthe endoscopic arch component of repair are similar tothose with coronal access.8

Traditional coronal access for arch repair is in-dicated for markedly displaced isolated arch fractures,

complex zygoma fractures with arch comminution, andLe Fort III level fractures. These are the same as theindications for endoscope-assisted zygomatic arch repair.

We believe endoscopic arch repair should be considered whenever traditional coronal access to the zygomaticarch is contemplated and we encourage its use. Theinitial steep learning curve can be overcome by the

institutionalization of appropriate training programsand further advances in instrument development. In-creased familiarity with the endoscopic procedure hasresulted in shorter and more efficient operative times.

REFERENCES

1. Gruss JS, Van Wyck L, Phillips JH, Antonyshyn O. Theimportance of the zygomatic arch in complex midfacial fracturerepair and correction of posttraumatic orbitozygomatic defor-mities. Plast Reconstr Surg 1990;85:878–890

2. Stanley RB Jr. The zygomatic arch as a guide to reconstruction

of comminuted malar fractures. Arch Otolaryngol Head Neck Surg 1989;115:1459–1462

3. Ellis EI, Zide MF. Surgical Approaches to the Facial Skeleton. Williams and Wilkins, 1995

4. Pearl RM. Prevention of enophthalmos: a hypothesis. AnnPlast Surg 1990;25:132–133

5. Pearl RM. Surgical management of volumetric changes in thebony orbit. Ann Plast Surg 1987;19:349–358

6. Lee C, Jacobovicz J, Mueller RV. Endoscopic repair of acomplex midfacial fracture. J Craniofac Surg 1997;8:170–175

7. Lee CH, Lee C, Trabulsy PP, Alexander JT, Lee K. A cadavericand clinical evaluation of endoscopically assisted zygomaticfracture repair. Plast Reconstr Surg 1998;101:333–345

8. Lee C, Stiebel M, Young DM. Cranial nerve VII region of the

traumatized facial skeleton: optimizing fracture repair with theendoscope. J Trauma 2000;48:423–430

9. Krimmel M, Cornelius CP, Reinert S. Endoscopically assistedzygomatic fracture reduction and osteosynthesis revisited. Int JOral Maxillofac Surg 2002;31:485–488


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