1 Principles top
Considerations related to dental occlusion render nasotracheal intubation necessary. If it is not feasible change of intubation or primary submental/submandibular intubation should be considered. Depending on the patient’s general condition, a tracheostomy might be the appropriate choice.
The aim of successful reconstruction of midface fractures is reestablishing the midfacial buttresses. These pillars can serve an even more important role in patients who lack dentition (partial or completely edentulous patients).
A principle in all Le Fort fractures is to reestablish the premorbid dental occlusion. Portions of the pterygoid plates and associated musculature are still attached to the posterior portion of the maxilla, so passive mobilization of the fracture can be difficult. Without passive mobilization, Class III tendency occurs often in the postoperative period. The reason for this is that when patients are placed into MMF during the surgery, the soft-tissue tension from the attached musculature distalizers the mandibular condyles in the glenoid fossae. When the MMF is removed, the condyles re-seat themselves into their normal position, bringing the mandibular dentition forward, creating a Class III malocclusion. In order to properly achieve a passive position of the maxilla, the maxilla requires strong mobilization forces using various instrumentation: Rowe’s disimpaction forceps, “Stromeyer” hook, Tessier retromaxillary mobilizers, etc.
The goal is to achieve an anatomical correct repositioning by means of 3-D reconstruction. If available, dental cast, stereolithographic models, and/or premorbid photographs may be useful guides for treatment.
As a general principle, all fractures should be exposed and reduced before plating.
Choice of implant
It is difficult to have absolute guidelines as to the strength of the plates that would be used at the three key points of fixation for a Le Fort II fracture:
- The plate placed for the fixation of the fracture at the zygomaticomaxillary buttress is generally a larger plate. The highest forces of mastication are in this area. Depending on the fracture pattern a L-plate or a straight plate can be considered.
- If a plate is used along the infraorbital rim, it must be a low-profile plate. The forces in this area are smaller, and patients may complain of being able to palpate the implant if a larger plate is placed.
- If a plate is used at the nasofrontal area, there are several options, including one or two straight plates, or various configurations of Y or X plates. In many cases with adequate fixation at one or both of the other two sites, plate placement at the zygomaticofrontal area may not be necessary.
There is considerable variation as to how unstable or comminuted the fractures may be. Furthermore, the majority of Le Fort II fractures are associated with a multitude of other midface fractures which influence the size and strength of the plate that must be used. Finally, in many cases of Le Fort II fractures with other panfacial trauma, many surgeons may choose to leave the patient in MMF for a period of time postoperatively. This has a further impact in deciding whether a larger or smaller plate is adequate.
Click here for a description of implant options.
A Le Fort II fracture involves a fracture of the orbital floor and possibly the medial orbital wall. If significant, these fractures are to be treated in the same way as other orbital fractures in this location. Click here for further details on the reconstruction of combined medial wall and orbital floor fractures.
AO Teaching video on fixation of a complex midface fracture
2 Approaches top
The following approaches are relevant for this procedure:
3 Reduction topenlarge
First, arch bars are secured to the dentition. Click here for a detailed description of mandibulomaxillary fixation.
After exposure of the fracture segments through a maxillary vestibular approach, the fracture has to be mobilized to enable reduction and fixation.
Reduction instruments - Use of Rowe disimpaction forceps
The Rowe disimpaction forces are side specific. They allow precise 3-D movement of fracture fragments of the centrally impacted midface or maxilla.
Note: Special attention has to be given to the patient’s individual fracture pattern so that the use of these instruments does not result in significant shearing at the skull base or orbit. Otherwise, severe complications such as blindness can occur.
Special attention has to be paid regarding the correct placement of the Rowe
disimpaction forceps so that the upper anterior dentition is not harmed.
The maxillary fracture is completely mobilized and an attempt should be made to make the fragment as passive as possible. This may require an up-down and side-to-side movement of the forceps.
Reduction instruments - Use of bone hooks
According to regional preferences and various schools of teaching, different bone hooks are used for fracture reduction in the lateral midfacial area.
Reduction hook (Stromeyer hook)
The Stromeyer hook (Georg Friederich Louis Stromeyer, Hannover, Germany, 1804-1876) is very versatile for transoral and transcutaneous reduction of lateral midfacial fractures. Its main indication is to reduce zygoma or zygomatic arch fractures.
In selected cases the Stromeyer hook can also be used for manipulating the Le Fort complex by hooking the tip of the instrument inside the piriform aperture and pulling downwards and anteriorly. This technique is called downfracture procedure in Le Fort osteotomies.
Placing the patient into MMF
After the fracture has been adequately mobilized, the patient is placed into MMF. Click here for a detailed description of various MMF techniques.
Note: In case of concomitant mandibular fractures, the integrity of the mandible should be restored as a first measure.
4 Fixation topenlarge
According to the quality and stability of the reduction, the final decision is made regarding the number of plates and screws, and the design of the plates.
Fixation usually starts at the most reliably reduced buttress, always considering any fracture line in all three dimensions. If reduction is satisfactory, the first plate can be fixed by filling an adequate number of screws into the plate holes. Due to the specific patient injury patterns, provisional fixation with a limited number of screws may be indicated (in special cases, even temporary wire fixation might be considered). Two screws per fracture side should be attempted.
The remaining buttresses are similarly addressed.
Complete reduction and fixation of the Le Fort fractures should take place before addressing the orbital wall fractures.
In the case shown, the first plate is applied to the left zygomaticomaxillary buttress. According to the particular fracture morphology, a plate of appropriate profile, shape, and length is selected and contoured using bending pliers. This is the most difficult plate to properly adapt.
The plate is positioned with appropriate instruments (eg, forceps, plate holders, gauze packer). The first hole is drilled (a drill bit with a stop can be used) next to the fracture line in the zygomatic complex and a screw is inserted.
A larger L-shaped plate is ideal for the fixation of this fracture. It is important that the leg of the L-plate be placed on the most lateral portion of the zygomaticomaxillary 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 are not placed into the dental roots. A common problem with this 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.
Second screw in first plate
After drilling, the second screw is inserted next to the fracture line on the opposite side. Care has to be taken not to damage the tooth roots.
Insertion of remaining screws
If reduction is satisfactory at the other fracture lines, the remaining screws are inserted (at least two screws per fracture fragment).
Plating the contralateral zygomatic buttress
In the illustrated case the contralateral alveolar zygomatic crest/buttress is fixed in the same manner.
A decision has to be made at this point whether or not the two plates at the zygomaticomaxillary buttress provide sufficient stability to the repositioned Le Fort II segment. If so, the MMF wires are removed and the occlusion is verified. If additional stability is required, plates at the infraorbital rim are applied next.
Plates at infraorbital rim
Two contoured plates of appropriate profile and length are selected, adapted, and applied to the infraorbital rim.
The first screw is inserted in the stable fragment (ie, the lateral fragment) next to the fracture line.
Additional screw and plate placement
The remaining screws of the first and second plate are applied accordingly.
A decision has to be made at this point whether or not the plates at the zygomaticomaxillary buttress and the infraorbital rims provide sufficient stability to the repositioned Le Fort II segment. If so, the MMF wires are removed and the occlusion is verified. If not, the frontonasal suture needs to be plated.
Depending on the fracture pattern appropriate plate(s) is/are selected. In the illustrated case, an inverted Y-plate is used for further reduction and stability of the nasal skeleton.
After internal fixation has been completed, MMF is released and the occlusion checked.
If an open bite and/or Class III tendency occurs when checking the occlusion, one or both mandibular condyles were malposed in posterior and/or inferior direction. In such cases, it is necessary to remove the bone plates, reapply MMF, and passively reposition the maxillomandibular complex again, assuring the condyles are properly seated. Bone plates are again applied and the occlusion verified.
The reason for a malocclusion may be the fact that the condylar heads were not positioned correctly in their respective glenoid fossae when securing MMF (as illustrated).
The illustration shows the subsequent malocclusion.
5 Comminuted fractures topenlarge
Le Fort II fractures can be comminuted. This is especially challenging if the buttresses are affected by the comminution zone. The appropriate fixation technique depends on the location of the comminution and the degree of comminution.
Comminution of buttresses
If the comminuted area affects the buttresses, the defects have to be bridged with plates of appropriate length and rigidity.
Comminution of the facial maxillary sinus wall
If the comminution affects the facial maxillary sinus wall, the first step is to reduce or even remove fragments compressing the infraorbital nerve.
Fracture fixation depends on the fracture morphology. If the fracture fragments can be reduced, one or more low profile plates are sufficient to keep the fragments in place.
Following a comminuted fracture of the anterior maxillary sinus, the most important structures to reconstruct are the framework of this portion of the midface which includes the following buttresses:
Paranasal (piriform) aperture
- Alveolar segment
If the above four structures are appropriately reduced, the skin stretches over these buttresses like a canvas on a frame. If there is a defect which remains in the center of these four buttresses, it is the equivalent of a Caldwell-Luc incision. Many surgeons feel that does not need to be treated. In both this illustration and the next, the surgeon has chosen to reconstruct the Caldwell-Luc defect. This may not always be necessary.
If there is a large defect of the facial maxillary sinus wall, the defect may be bridged by a mesh to reconstruct the original outer contour and thus support the overlying soft tissues.