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

Endoscopically assisted condylar process fracture fixation enlarge

Plating considerations

At the time of surgery, the surgeon will finally decided whether to place one or two plates. This decision is based upon fracture morphology, the amount of bone available to hold plates and screws and the surgeon’s personal 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 for reaching the same stability, a single heavier plate can be used when 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, micro movement of condylar fracture fragments is minimized. Their correct application along with good fracture reduction will lead to primary bone healing and subsequent bone formation along the fracture surface will occur.

Depending on the fracture location in the condylar region, one or two plates will be used. In high condylar fractures, due to bony limitations, only one plate can be placed. A 2.0 plate with two screws on each side of the fracture line in most of these cases 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 for immediate postoperative function.


Use of MMF

When treating condylar fractures, the surgeon may use arch bars or another form of maxillo-mandibular 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 chance of postoperative malocclusion.

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


General considerations for endoscopically assisted fixation

When considering an endoscopically assisted intraoral approach to a condylar process fracture, the two main advantages are:

  • Avoidance of injury to the facial nerve
  • Avoidance of incision scar.

The disadvantages are the necessity for endoscopic/special equipment and the specialized training and experience required for this surgical technique.


Anesthesia

In condylar fractures, muscle relaxation is crucial.

Since the facial nerve is not a risk during the intraoral approach with endoscopic assistance, muscle relaxors can be administered early in the surgical procedure.

A sufficient dose of muscle relaxant is administered before the reduction maneuvers.


Special considerations

Following special considerations may need to be taken into account:

Click on any subject for further detail.

2 Choice of implant – one plate top

Endoscopically assisted condylar process fracture fixation enlarge

Choice of implants for one plate fixation

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

The plate used can either be a 2.0 adaptation plate, a dynamic compression plate (2.0 DCP, used for its strength but not for its compression), or a 2.0 small locked plate. Lately, adaptation and locked plates are preferred over compression plates by many surgeons.

In each side of the fracture line, a minimum of 2 screws have to be inserted. Plates with or without a center space can be used.


Endoscopically assisted condylar process fracture fixation enlarge

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

Endoscopically assisted condylar process fracture fixation enlarge

Choice of implants for two plate fixation

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

  1. Two adaptation plates (2-hole and 4-hole, or 4-hole and 4-hole)
  2. Combination of an adaptation plate on the anterior border of the condyle and a 2.0 compression plate (4- or 5- hole DCP)
  3. Two locking plates

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

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

4 Reduction - one plate 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 medially by pull of the lateral pterygoid muscle.

Pearl: If the fragment is medially displaced, the surgeon must manipulate it and convert it into a lateral override situation. This is especially difficult when using an intraoral approach and could be a reason for selecting an elective external access or converting an intraoral approach to extraoral.

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.


Endoscopically assisted condylar process fracture fixation enlarge

Endoscopic image shows condylar fragment in a lateral override situation.


Endoscopically assisted condylar process fracture fixation enlarge

Pearl: threaded fragment manipulator

The threaded fragment manipulator is used when difficulty in manipulating the condylar fragment into correct position is encountered. The fragment manipulator should only be used in healthy bone to prevent further fracturing of the condylar fragment. The fracture manipulator acts as a “joy-stick” and can facilitate the three-dimensional reduction of the condylar fragment.

The threaded fragment manipulator is applied through a transcutaneous stab incision without a transbuccal sleeve.

The tip of the manipulator is self-drilling. This requires generally no predrilling but support of the fragment is required to withstand the pressure resulting from insertion of the instrument.


Endoscopically assisted condylar process fracture fixation enlarge

Transbuccal system

Insert the transbuccal system approximately over the palpated fracture line at the posterior border of the mandible. Use the drill guide with window to allow for endoscopic control of drilling and screw insertion.

See here for a detailed description of the use of the transbuccal system.

Note: no cheek retractor needed
No cheek retractor from the transbuccal set is required as the optical retractor used together with the endoscope takes the task of the cheek retractor.


Endoscopically assisted condylar process fracture fixation enlarge

Drill hole for the first screw in condylar fragment

Place the retractor over the fracture zone. Insert the drill guide of the transbuccal system (use the opening of the retractor). Next, insert the 1.5 mm diameter drill without drill stop into the drill guide.

The plate is applied over the midaxis of the condylar fragment.

Drill a first hole in the condylar fragment.

There is no drill bit with drill stop available for the transbuccal system. Therefore, drill carefully not to damage the maxillary artery.


Endoscopically assisted condylar process fracture fixation enlarge

Plate placement

Place the 4-hole plate and insert the screw manually without complete tightening. The purpose of not tightening the screw completely is to be able to apply traction to the fragments later in the procedure.


Endoscopically assisted condylar process fracture fixation enlarge

Manual traction

Reduction of the fracture is done under endoscopic assistance 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 plate prevents medial displacement of the condylar fragment during reduction.


Endoscopically assisted condylar process fracture fixation enlarge

Pearl: use of bite block

To maintain the open mouth and help the fracture reduction, after placement of the first screw in the anterior two-hole plate, a bite block is placed in the molar region. This results in posterior vertical lengthening and rotation of the mandible.


Endoscopically assisted condylar process fracture fixation enlarge

Alignment of posterior border

In order to align the posterior border, apply traction on the most distal hole of the plate with a clamp (as illustrated) or an angled hook.

The alignment of the posterior border is checked with the endoscope.

5 Reduction - two plate top

Endoscopically assisted condylar process fracture fixation enlarge

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 medially by pull of the lateral pterygoid muscle.

Pearl: If the fragment is medially displaced, the surgeon must manipulate it and convert it into a lateral override situation. This is especially difficult when using an intraoral approach and could be a reason for selecting an elective external access or converting an intraoral approach to extraoral.

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.


Endoscopically assisted condylar process fracture fixation enlarge

Endoscopic image shows condylar fragment in a lateral override situation.


Endoscopically assisted condylar process fracture fixation enlarge

Pearl: threaded fragment manipulator

The threaded fragment manipulator is used when difficulty in manipulating the condylar fragment into correct position is encountered. The fragment manipulator should only be used in healthy bone to prevent further fracturing of the condylar fragment. The fracture manipulator acts as a “joy-stick” and can facilitate the three-dimensional reduction of the condylar fragment.

The threaded fragment manipulator is applied through a transcutaneous stab incision without a transbuccal sleeve.

The tip of the manipulator is self-drilling. This requires generally no predrilling but support of the fragment is required to withstand the pressure resulting from insertion of the instrument.


Endoscopically assisted condylar process fracture fixation enlarge

Transbuccal system

Insert the transbuccal system approximately over the palpated fracture line at the posterior border of the mandible. Use the drill guide with window to allow for endoscopic control of drilling and screw insertion.

See here for a detailed description of the use of the transbuccal system.

Note: no cheek retractor needed
No cheek retractor from the transbuccal set is required as the optical retractor used together with the endoscope takes the task of the cheek retractor.


Endoscopically assisted condylar process fracture fixation enlarge

Drill hole for the first screw in condylar fragment

Place the retractor over the fracture zone. Insert the drill guide of the transbuccal system (use the opening of the retractor). Next, insert the 1.5 mm diameter drill without drill stop into the drill guide.

The first plate to be applied is the anterior plate. This will simplify the fracture.

Drill the first hole in the condylar fragment.

There is no drill bit with drill stop available for the transbuccal system. Therefore, drill carefully in order not to damage the maxillary artery.


Endoscopically assisted condylar process fracture fixation enlarge

Choice of implant

For the anterior plate, a 2-, 3- or 4-hole plate with or without center space is acceptable. Additional plate length allows for better manipulation with the angled hook during insertion of the second screw.

Plate insertion
Insert the plate through the intraoral incision. Forceps are used to keep it in position.


Endoscopically assisted condylar process fracture fixation enlarge

Insertion of first screw

Insert the screw manually without complete tightening. The purpose of not tightening the screw completely is to be able to apply traction to the fragments later in the procedure.


Endoscopically assisted condylar process fracture fixation enlarge

Manual traction

Reduction of the fracture is done under endoscopic control 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 plate prevents medial displacement of the condylar fragment during reduction.


Endoscopically assisted condylar process fracture fixation enlarge

Pearl: use of bite block

To maintain the open mouth and help the fracture reduction, after placement of the first screw in the anterior two-hole plate, a bite block is placed in the molar region. This results in posterior vertical lengthening and rotation of the mandible.


Endoscopically assisted condylar process fracture fixation enlarge

Alignment of posterior border

In order to align the posterior border, place traction on the small plate with an angled hook applied to an empty hole.

6 Fixation – one plate top

Endoscopically assisted condylar process fracture fixation enlarge

Fixation of the plate

Place the inferior screw of the anterior plate while the patient is in occlusion.
Completely tighten both screws at this time.


Endoscopically assisted condylar process fracture fixation enlarge

Endoscopic view of condylar fragment being manipulated into anatomic alignment.


Endoscopically assisted condylar process fracture fixation enlarge

Endoscopic view of screws being placed.


Endoscopically assisted condylar process fracture fixation enlarge

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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Check of final reduction

Check the final reduction endoscopically.


Endoscopically assisted condylar process fracture fixation enlarge

Completed osteosynthesis of a subcondylar fracture

X-rays show completed osteosynthesis of a subcondylar fracture.


Endoscopically assisted condylar process fracture fixation enlarge

X-ray of the same case (PA view).


Endoscopically assisted condylar process fracture fixation enlarge

X-ray shows endoscopically assisted single plate fixation of another subcondylar fracture.

7 Fixation – two plate top

Endoscopically assisted condylar process fracture fixation enlarge

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.


Endoscopically assisted condylar process fracture fixation enlarge

Posterior plate application

Using the endoscope, check the proper alignment of the posterior border. If it is properly aligned, insert the second plate.

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.


Endoscopically assisted condylar process fracture fixation enlarge

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

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

Note: patient is in occlusion while plate and screw fixation is completed.


Endoscopically assisted condylar process fracture fixation enlarge

Additional screw insertion

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

Inspect the reduction with the endoscope to assure anatomic alignment. Check for correct occlusion and undisturbed articulation.


Endoscopically assisted condylar process fracture fixation enlarge

X-ray shows completed osteosynthesis


Endoscopically assisted condylar process fracture fixation enlarge

Panoramic view postoperatively of two plate fixation technique for condylar process fracture.


Endoscopically assisted condylar process fracture fixation enlarge

PA view postoperatively of two plate fixation technique for condylar process fracture of the same case.

8 Alternative: angulated drill/screw driver top

Endoscopically assisted condylar process fracture fixation enlarge

A right-angled screw driver may be used for intraoral approaches to apply plate and screw fixation to condylar process fractures without any external incisions.

Endoscopic view of right-angled instrument used in intraoral approach to condylar process fractures fixed with a 5-hole DCP plate.

Click here for further details on the angled drill/screw driver.

v1.0 2008-12-01