December 2, 2010

Fracture Plates for Condylar Neck and Base

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Fig 1a (left) Trapezoidal plate & Fig 1b (right) Lambda plates, left and right.

Fractures in the condylar region of the mandible present a specific challenge, ie, it can be difficult to access the region surgically due to the presence of the main stem of the facial nerve within the overlying soft tissue.

The most common solution for fractures in the neck and base region of the mandible is either closed treatment or various linear plating approaches, such as adaptation plates. When internal fixation is used a two-plate technique offers better stability than a one-plate technique. In response to a growing number of requests for improved treatment in this region, a series of plates have been developed with specific designs to treat such fractures and if possible to overcome such issues. The first two plates are now available.

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Fig 2 Trapezoidal Plate

Trapezoidal Plate

The trapezoidal plate is designed to fit the region of the condylar base and provides improved strength and stability over previous single-bar plate designs, thereby eliminating the need to place two plates. It is precontoured to account for the curvature in the transition zone between the base of the condylar process and the adjacent neck. The location of screw holes enables plates to straddle the mandibular foramen and the adjacent canal inlet, thereby avoiding accidental nerve injury. The trapezoidal plate can be applied using external and transoral surgical approaches. If required a transbuccal cannula can be centered in the countersunk screw holes for proper drilling alignment.

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Fig 3 Lambda Plate
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Fig 4 Subregions of the condylar process.
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Fig 5 Ideal position for placement of the lambda plate.

Lambda Plate

The lambda plate comes in a left and right version. It emulates a two-plate technique as its specific shape and 7-hole design with the width of a single plate at the top segment allows the surgeon to advance the lambda plate high up into the very narrow zone of the condylar neck just below the head. The fixation arms straddle the mandibular canal to avoid injury risk of the inferior alveolar nerve.

The lambda plate can be placed using retromandibular or submandibular surgical approaches. For positioning, the straight 5-hole segment is placed parallel to the posterior ramus border aligned with the condylar head. If required the anterior arm may be bent to fit the bony surface below the sigmoid notch.

Both plates are based on the matrix mandible system platform. Therefore, they are compatible with the existing matrix instrumentation and use the established color-coding for easy identification in the operating room. Both are 1.0 mm thick and malleable (green-grey color coding) and manufactured from commercially pure titanium.

Case 1

Case provided by Celso Palmieri, Shreveport, LA, USA

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Fig 1ab Endoscopic fixation of trapezoidal (a) and lambda (b) plates.

Case 2

Case provided by Michael Rasse, Innsbruck, Austria

 

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Fig 1ab Fixation of trapezoidal plate.

Case 3 

Case provided by Carl-Peter Cornelius, Mnchen, Germany

 

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Fig 1ab Fixation of fractures in the low condylar neck region using the lambda plates.

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