1 Principles topenlarge
In some situations a surgeon may have a simple noncomminuted zygomatic-complex fracture which with open manipulation snaps into a perfect reduction. This has often been achieved with a maxillary vestibular approach. This approach allows visualization of both the lateral maxillary buttress and the infraorbital rim. Particularly in patients where CT has revealed no separation at the fracture of the zygomaticofrontal suture, and with good intraoperative visualization, and reduction of the lateral maxillary buttress and the inferior orbital rim, 1-point fixation with a plate between the maxilla and zygoma may be adequate.
Correct anatomical reduction is required to reproduce the original structure of the zygomaticomaxillary complex and the proper alignment of the orbital walls. In order to achieve proper reduction of the lateral orbital wall the greater wing of the sphenoid and the zygoma must be properly aligned.
The aim is to restore the proper orbital volume and to restore proper width, AP projection, and height of the midface. Proper reduction of the zygoma addresses the issues of AP projection of the width of the midface.
It is possible that the periorbital contents may have been affected by the reduction of the zygomatic-complex fracture. Forced duction tests should be performed before and after reduction of the zygoma to make sure that the patient does not have entrapment of the soft tissues. Pre- and postoperative ophthalmologic exams should be considered in all patients who have sustained periorbital trauma.
For the purpose of this discussion of the 1-point fixation technique for the zygomatic complex, the plate has been placed on the zygomaticomaxillary buttress.
2 Zygoma reduction methods topenlarge
The first step is to obtain proper 3-D reduction of the zygoma using an elevator, hook, screw, or Carroll-Girard type device to mobilize the zygoma into its proper position.
Illustration shows reduction being performed via a transoral (Keen) approach placed through the maxillary vestibular incision using an elevator …
… or using a hook.
Threaded reduction tool
A threaded reduction tool (Carroll-Girard screw) is inserted into the zygoma through the lower eyelid incision or directly through the skin of the face and used for reduction.
3 Placement and fixation topenlarge
Looking through the maxillary vestibular approach, the fracture of the
zygomaticomaxillary buttress is aligned. A larger L-shaped plate is ideal for
the fixation of this fracture. This is the most difficult plate to properly
adapt in a zygoma fracture. It is important that the leg of the L-plate be
placed on the most lateral portion of the lateral maxillary buttress, where the
bone is fairly thick.
It is similarly important that the foot of the L-plate is placed along the alveolar bone in a manner that the screws will not be placed into the dental roots. A common problem with this third plate is failure to properly adapt the L-plate, resulting in screw placement into the thin wall of the anterior maxillary sinus. It is not uncommon for the lateral maxillary buttress to be comminuted. In this instance using a longer L-plate with multiple screw holes may be ideal.
A stronger plate is recommended for the zygomaticomaxillary buttress.