Absolute fracture stability, achieved by interfragmentary compression, results in direct bone healing.Axial compression
If available, a partially threaded cortical lag screw (shaft screw) can be used to accomplish interfragmentary compression.
Reduce the fracture anatomically, using a reduction forceps on each main fragment. The use of blunt, as opposed to pointed, reduction forceps can be helpful, particularly if greater forces are required.
A small bone lever can be used to reduce transverse, or short oblique, fractures as illustrated.
A reduced transverse fracture can not be maintained with reduction forceps alone. However, transverse fractures are usually dentate and are intrinsically stable after anatomical reduction.
If not, fix the plate to the intermediate fragment and then reduce the displaced main fragment onto the plate, maintaining the position with a reduction forceps.
Short oblique fractures may be reduced and maintained using the plate. The plate should be primarily fixed to that fracture fragment with its apex on the opposite side to the plate. The aim of this maneuver is to create an “axilla” into which the other fragment can be locked and compressed, either with a compression screw or using a push-pull technique.
In order to maintain the reduction, using the same independent screw, preliminary axial compression can then be obtained by pulling the plate end towards the screw with a small Verbrugge clamp.
The holes of the plate are shaped like an angled cylinder. The spherical undersurface of the screw head slides down the inclined cylinder as the screw is tightened.
The horizontal movement of the head, as it impacts against the angled side of the hole, results in movement of the bone fragment relative to the plate, and leads to compression of the fracture.
To insert a load screw through an LC-DCP, the drill guide with the yellow (gold) collar is used. The arrow on the top of the drill guide must point towards the fracture to be compressed.
For inserting screws into the limited contact dynamic compression plate (LC-DCP), the Universal Drill Guide can be used as well. When this drill guide is pressed into the plate hole, the screw position will be neutral (A). When it is held against the end of the plate hole, without exerting downward pressure, the screw position will be eccentric (B).
After the plate has been contoured anatomically to the reduced bone surface, prebend it with the handheld bending pliers, or a pair of bending irons, as explained in the principles section.
In the following procedure, we demonstrate the plate positioned deep to the extensor carpi ulnaris muscle (A).
Insert a neutral screw through the plate into the main fragment near the fracture line.
Insert a load screw through the plate on the other side of the fracture line into the intermediate fragment, thereby applying axial compression.
Secure the intermediate fragment to the plate with a neutral screw near the unreduced fracture line.
Reduce the other main fragment onto the intermediate fragment by pushing it towards the plate using a pointed reduction forceps.
Alternatively, the push-pull technique can be used to distract, reduce,…
… and then preliminarily compress the second fracture.
Fix the second fracture line with a load screw in the main fragment applying the compression principle (as previously described).
After checking the reductions clinically and using image intensification, insert additional screws in order to complete the fixation. In longer oblique fractures, consider an interfragmentary lag screw either separate from, or through, the plate, depending on the fracture configuration.
Note: This is a biomechanically less desirable construct but may be necessary either because of a long intermediate fragment or nonavailability of a single plate of suitable length.
The reduction of the fracture is checked and held with a pointed reduction forceps. A load screw is inserted through the plate into the main fragment near the fracture line.
Insert an additional screw into the intermediate fragment …
… and then the remaining main fragment screws in order to secure the fixation of the first fracture.
Before starting the operation the uninjured side should be tested as a reference for the injured side.
After fixation, the distal radioulnar joint should be assessed for forearm rotation, as well as for stability. The forearm should be rotated completely to make certain there is no anatomical block.
The elbow is flexed 90° on the arm table and displacement in dorsal palmar direction is tested in a neutral rotation of the forearm with the wrist in neutral position.
This is repeated with the wrist in radial deviation, which stabilizes the DRUJ, if the ulnar collateral complex (TFCC) is not disrupted.
This is repeated with the wrist in full supination and full pronation.
In order to test the stability of the distal radioulnar joint, the ulna is compressed against the radius...
...while the forearm is passively put through full supination...
If there is a palpable “clunk”, then instability of the distal radioulnar joint should be considered. This would be an indication for internal fixation of an ulnar styloid fracture at its base. If the fracture is at the tip of the ulnar styloid consider TFCC stabilization.