Orbitozygomatic osteotomy

The fractured zygomatic bone is usually displaced posteriorly, laterally and inferiorly in the acute situation.

Lack of adequate 3 dimensional reduction of a zygoma fracture is the most common etiology of residual orbitozygomatic deformities.

The illustration demonstrates a mal united posteriorly displaced zygoma with resulting facial widening at the level of the zygomatic arch.

Vertical globe malposition may be found in addition to enophthalmos (secondary to orbital volume enlargement) or exophthalmos (secondary to decrease of the orbital volume) depending on the resulting orbital volume.

This illustration demonstrates both vertical (hypophthalmos) and axial (enophthalmos) deformity.

Osteotomies are performed and the malpositioned bone segment is mobilized and repositioned to restore normal anatomy.

Additional onlay bone grafts and/or orbital wall reconstruction may be necessary.

Different malposition patterns lead to various clinical presentations. The fracture patterns will influence the design of the planned osteotomy.

Fracture patterns extending to the frontal bone are usually managed with a C-type osteotomy.

Fracture patterns extending to the infraorbital rim are managed with an L-type osteotomy.

Fracture patterns affecting the body of the zygoma and the external orbital wall may be managed with a standard osteotomy design.

High resolution CT-scan with fine cuts is obtained and the DICOM data processed in a suitable planning platform.

The non affected side is mirrored onto the affected side of a virtual 3D model...

...so that a prediction of the end result can be visualized.

Virtual osteotomies should be made through the existing fracture pattern. However, optimal osteotomies may not necessarily pass through every fracture plane depending on bone availability.

The virtual bone segment can then be moved into the desired position. The exact movements are recorded in mm in all 3 dimensions in order to replicate them during surgery.

Bone resection may be necessary to allow for the planned movements.

Additional bone grafting should also be planned if significant bone gaps are created.

If necessary, orbital wall reconstruction is also planned.

The coronal approach is used when significant deformity of the zygomatic arch requires correction, or associated central midface deformities. The coronal approach should be combined with a lower eyelid approach if access to the medial orbit or floor is needed.

The transconjunctival retroseptal approach is preferred by the author even when an eyelid transcutaneous approach was used initially.

If a coronal approach is not indicated, access can be achieved through a combination of a maxillary vestibular approach (used to get access to the zygomaticomaxillary buttress, infraorbital rim and zygomatic body) and upper blepharoplasty approach.

If additional access to the orbital floor is needed a transconjunctival approach is indicated.

The following pages provide general information regarding orbital anatomy and dissection

• Preoperative considerations
• Anatomy of the bony orbit
• Correlation of surface and cross sectional anatomy
• Introduction to periorbital dissection
• Orbital floor dissection
• Medial orbital wall dissection
• Lateral orbital wall dissection
• Orbital roof dissection
• Adjunctive access procedures (orbitotomies)
• Retrobulbar hemmorage

Subperiosteal dissection is performed to expose the zygoma including temporalis and masseter muscle attachments. Extensive circumferential orbital wall dissection may be indicated for the correction of globe malposition.

During the procedure, care is taken to protect the orbital contents.

The first osteotomy is performed in the lateral orbital wall usually at the level of the sphenoid zygomatic suture.

An ostectomy is performed when a superior repositioning of the zygoma is planned.

The osteotomy in the infraorbital rim is performed usually lateral to the infraorbital nerve, from the inferior orbital rim to the inferior orbital fissure.

The final osteotomy is made in the zygomatic arch as planned. To allow for a re-contouring of the zygomatic arch, several osteotomies or a bone graft may be necessary.

The zygoma is mobilized.

Masseter muscle fibers may need to be detached from the inferior border of the osteotomized zygoma to facilitate the movement.

The zygoma is then repositioned and fixed with miniplates and screws.

A four point fixation (including zygomatic arch) is performed when a coronal approach has been used. (More details on the fixation procedure can be found in the trauma section)

Three point fixation is performed when anterior approaches have been used. (More details on the fixation procedure can be found in the trauma section)

The medial infraorbital rim will often need additional remodeling and/or bone grafting to achieve the desired anatomical shape.

Any resulting significant gaps should be bone grafted.

If an orbital floor reconstruction is planned, it is performed at this time.

Resuspension of the cheek soft tissues to the infraorbital rim is performed at the end of the procedure using non resorbable sutures.

When a coronal approach is used, resuspension of the soft tissue is performed at the level of the temporalis fascia.

Additionally, navigation may serve for intraoperative control of implant position. Modern 3-D C-arm technology will further improve on intraoperative quality control of fracture reduction and implant positioning. Endoscopic modalities may also be helpful in confirming proper implant placement.

Preoperative frontal view.

Postoperative frontal view.

Preoperative basal view.

Postoperative basal view.

Preoperative frontal view.

Postoperative frontal view.

Preoperative basal view.

Postoperative basal view.

Evaluation of the patient's vision and pupillary response are performed as soon as awakened from anesthesia and then at regular intervals until they are discharged from the hospital.

Head of bed elevation may significantly reduce edema and pain.
A cooling mask may be used to further reduce edema.

To prevent orbital emphysema, nose-blowing should be avoided for at least 14 days following surgery.

The use of the following perioperative medication is controversial.

• Analgesia as necessary
• Antibiotics (many surgeons use perioperative antibiotics. There is no clear advantage of any one antibiotic, and the recommended duration of treatment is debatable.)
• Steroids may diminish postoperative edema. Some surgeons have noted increased complications with perioperative steroids.
• Ophthalmic ointment should follow local and approved protocol. This is not generally required in case of periorbital edema. Some surgeons prefer it. Some ointments have been found to cause significant conjunctival irritation.

The following signs and symptoms are usually evaluated:

• Visual acuity
• Extraocular motion (motility)
• Diplopia
• Globe position
• Lid position

Postoperative imaging has to be performed within the first days after surgery. 3-D imaging (CT, cone beam) is recommended.

Remove sutures from skin after approximately 5 days if non resorbable sutures have been used.
Avoid sun exposure and tanning to skin incisions for several months.

Clinical follow-up depends on the complexity of the surgery, and whether the patient has any postoperative problems. In most patients one week, four weeks, six months and one year follow up is recommended.
Additionally, ophthalmological, ENT, and neurological/neurosurgical examination may be necessary. A regular follow-up CT scan is recommended 3-6 months after surgery.
Travel in commercial airlines is permitted following orbital surgery. Commercial airlines pressurize their cabins. Mild pain on descent may be noticed. However, flying in non-pressurized aircrafts should be avoided for a minimum of six weeks.
No scuba diving should be permitted for at least six weeks.