Executive Editor: Marcelo Figari, Gregorio Sánchez Aniceto General Editor: Daniel Buchbinder

Authors: Ricardo Cienfuegos, Carl-Peter Cornelius, Edward Ellis III, George Kushner

Mandible - Condylar process, simple and complex - ORIF

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Glossary

1 Principles top

Condylar process fractures fixation enlarge

Plating considerations

At the time of surgery, the decision is made whether to place one or two plates. This decision is based on fracture morphology, the amount of bone available to hold plates and screws, and on surgeon preference.

Ideally, two miniplates should be applied in a triangular fashion with one plate below the sigmoid notch and one plate along the posterior border.


Endoscopically assisted condylar process fracture fixation enlarge

As an alternative way of achieving the same stability, a single heavier plate can be used where there is limited bone available for plating. This plate is placed along the long axis of the condylar process.


General considerations

With plate and screw systems, micromovement of condylar fracture fragments is minimized. Correct application along with good fracture reduction will lead to primary bone healing and subsequent bone formation along the fracture surface.

Depending on the fracture location in the condylar region, one or two plates are used. In high condylar fractures, due to bony limitations, only one plate can be placed. In most cases, a mandibular plate 2.0 with two screws on each side of the fracture line is sufficient.

Adequate mechanical stability is gained by use of two adaptation plates or one stronger plate.

Plate and screw fixation used in condylar fractures allows immediate postoperative function.


Anesthesia

In condylar fractures, muscle relaxation is crucial.

Several extraoral surgical approaches to the condylar region can involve the facial nerve. During the soft-tissue dissection, a nerve stimulator may be used to identify the facial nerve. Chemical muscle relaxation will interfere with the use of a nerve stimulator. However, once the bony fracture has been reached, muscle relaxation may help the surgeon reduce and stabilize the fracture.

Therefore, a sufficient dose of muscle relaxant is administered before the reduction maneuvers.


Use of MMF

When treating condylar fractures, the surgeon may use arch bars or another form of mandibulomaxillary fixation (MMF). However, reduction and manipulation of the fracture may be best accomplished with the jaw open. At some point during the plate and screw fixation, the patient should be placed into occlusion. This may be accomplished by an assistant holding the patient into occlusion while the fracture is being plated. This minimizes the risk of postoperative malocclusion.

Additionally, many surgeons prefer the use of training elastics in the postoperative period.


Alternative: endoscopically assisted ORIF

The endoscopic technique is an alternative treatment technique for condylar fractures.

The two most important advantages of the endoscopic technique are the avoidance of face scars and minimizing the risk of facial nerve injury. The disadvantages are the necessity of endoscopic/special equipment and the specialized training and experience required for this surgical technique.


Special considerations

Following special considerations may need to be taken into account:

Click on any subject for further detail.

2 Choice of implant and plate position – one plate top

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Choice of implant for one plate fixation

If only one plate can be used, the surgeon should opt for a thicker plate and bicortical screws if possible.

The plate used can either be a mandible plate 2.0or preferably a small/medium locking plate 2.0. A DCP 2.0 can also be used (for its strength but not for its compression) as well as a large profile locking plate 2.0 because of their increased rigidity.

In each side of the fracture line, a minimum of two screws have to be inserted. Plates with or without a center space can be used.


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Plate position and order of screw insertion

The plate should be positioned in the center of the condylar region or close to the posterior border. The numbers indicate the order of screw insertion.

3 Choice of implant – two plates top

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Choice of implants for two plate fixation

There are several options of plates that can be used with condylar fractures:

  1. Two mandible plates 2.0 (2-hole and 4-hole, or 4-hole and 4-hole)
  2. Combination of a mandible plate on the anterior border of the condyle and a compression plate 2.0 (4- or 5-hole DCP) without using the compression effect (screws in neutral position)
  3. Two locking plates 2.0 (small and small/medium profile).

Thicker plates are usually best fixed with bicortical screws.

Lastly, mandible and locking plates 2.0 are preferred over compression plates by many surgeons.

In the following procedure, a combination of a 2-hole with a 4-hole mandible plate 2.0 is shown.

4 Reduction top

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Reduction strategy

It is advantageous if the condylar fragment is already displaced laterally (lateral override). However, the most common displacement of the condylar fragment is medial, by pull of the lateral pterygoid muscle. If the fragment is displaced medially, the surgeon must manipulate it and convert it into a lateral override situation.

Then the plate can be applied and fixed with one screw to the condylar fragment while it is supported by the underlying mandibular ramus. Using the plate as a handle, the condylar fragment can be reduced anatomically.

Intraoperative image shows angulation and lateral displacement of the condylar fragment.

One plate
If the use of only one plate is possible, the plate should be centered over the long axis of the condylar process.

Two plates
If two plates are being used, the anterior plate is used to reduce and initially stabilize the condylar fragment. The second plate is placed parallel to the posterior border of the ramus.

5 Reduction – one plate top

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Drill hole for the first screw in condylar fracture fragment

Drill a hole in the midaxis of the condylar fragment through the plate hole closest to the fracture line using the 1.5 mm diameter drill. The use of the drill guide is recommended to avoid injuries in the soft tissues.


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Plate placement

Place the plate and insert the screw manually without complete tightening. The aim of not tightening the screw completely is to be able to apply traction to the fragments later in the procedure.


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Manual traction

Reduction of the fracture is done under direct vision by aligning the posterior border of the ramus.

Pull the mandible inferior and anterior in order to restore the posterior height of the ramus and achieve reduction.

The lower end of the plate prevents the medial displacement of the condylar fragment during reduction.


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Clinical image shows the reduced fracture. The plate acts as stop during the reduction and prevents medial displacement of the condylar fragment.
In this clinical example a 5-hole locking plate without center space is used. The center hole is placed directly over the fracture line and left empty.


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Pearl: use of bite block

To keep the jaw open and aid fracture reduction, a bite block is placed in the molar region after placement of the first screw in the plate.

This results in posterior vertical distraction and rotation of the mandible.


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Alignment of posterior border

In order to align the posterior border, pull traction on most distal hole of the plate with a clamp.

6 Reduction – two plates top

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Drill hole for the first screw in condylar fragment

The first plate to be applied will simplify the fracture. In this case the anterior plate is applied first.

Drill a hole in the proximal fragment with the 6 mm drill stop drill bit of 1.5 mm diameter. The use of the drill guide is recommended to avoid injuries in the soft tissues.


Condylar process fractures fixation enlarge

Plate placement

Place the plate and insert the screw manually without complete tightening. The aim of not tightening the screw completely is to be able to apply traction to the fragments later in the procedure.


Condylar process fractures fixation enlarge

Manual traction

Reduction of the fracture is done under direct vision by aligning the posterior border of the ramus.

Pull the mandible inferior and anterior in order to restore the posterior height of the ramus and achieve reduction.

The lower end of the plate prevents medial displacement of the condylar fragment during reduction.


Condylar process fractures fixation enlarge

Pearl: use of bite block

To keep the jaw open and aid fracture reduction, a bite block is placed in the molar region after placement of the first screw in the anterior 2-hole plate

This results in posterior vertical distraction and rotation of the mandible.


Condylar process fractures fixation enlarge

Alignment of posterior border

In order to align the posterior border, pull traction on the small plate with a clamp (illustrated) or an angled hook.

7 Fixation – one plate top

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Fixation of the plate

Place the inferior screw of the plate while the patient is in occlusion.

Completely tighten both screws at this time.


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Insertion of additional screws

Fill the remaining screw holes in the order shown in the illustration with additional screws and fully tighten them.


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Completed osteosynthesis.


Condylar process fractures fixation enlarge

3-D CT reconstruction shows a one plate fixation using a large profile locking plate 2.0.


Condylar process fractures fixation enlarge

Case example.


Condylar process fractures fixation enlarge

Another case example.

8 Fixation – two plates top

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Fixation of anterior plate

Place the inferior screw of the anterior plate while the patient is in occlusion.

Completely tighten both screws at this time.


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Templating

Check the proper alignment of the posterior border. If it is properly aligned, adapt the plate. Sometimes, a template can be beneficial if the lateral pole of the condylar head is approached. However, use of a template is not always possible due to the size of the surgical approach and fracture morphology.


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Plate bending

In the condylar neck and subcondylar region, the plate does not require much bending. Bending is done using bending pliers.


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Posterior plate application

Drill the first screw hole in the condylar fragment close to the posterior border. It is recommended to drill the first hole without the plate applied.

Apply the plate and insert the first screw but do not completely tighten it.


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Place the plate parallel to the posterior border of the ramus.

Apply the second screw which is placed in the plate hole next to the fracture line and fully tighten it. Then fully tighten the first screw.


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Additional screw insertion

Fill the remaining screw holes with additional screws and fully tighten them.


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Completed osteosynthesis

Clinical image shows the completed osteosynthesis.

Option: plate without center space
As an option for the anterior plate, a 3-hole plate with empty center hole over the fracture is used.


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X-ray of the completed osteosynthesis.

v1.0 2008-12-01