1 Principles topenlarge
Triangle of stability
Stability of the distal humerus is based on a triangle of stability, comprising the medial and lateral columns, and the transverse condylar mass. In C-type fractures, all 3 columns have to be restored.
2 Reduction and provisional fixation topenlarge
Fixation of small articular fragments
Although the C2 fracture has , by definition, a simple articular fracture, in many instances, small articular fragments may be found.
In parallel plating it is customary to reduce and provisionally secure all of the fracture fragments, prior to plate application, using smooth K-wires.
3 Definitive plate and screw fixation topenlarge
Plate selection and contouring
Contoured 3.5 millimeter reconstruction plates, or precontoured plates, are selected for direct lateral positioning on the lateral column and direct medial positioning on the medial column.
These are usually placed slightly posteriorly and are always placed on top of the soft tissues—do NOT strip the medial and lateral columns.
The plates should extend distally enough to engage all fracture fragments and proximally enough so that 2 or 3 screws from each plate engage the proximal (shaft) fragment.
Drilling for distal screws
As many screws as possible are placed in each distal fragment.
Each screw goes through a plate hole.
Smooth K-wires the same size as the appropriate drill (e.g. 2.0 mm wire for 2.7 mm screw) can be manually inserted through the plate holes to ensure that the screws, once inserted, do not conflict: this also allows the drilling stage to be skipped.
The length of each of these K-wires must be known so that the appropriate screw length can be measured off the protruding wire, or the wire removed and the length of the pilot hole that it created measured using a standard depth gauge.
Distal screw application
Each of the smooth pilot K-wires is exchanged for its
4 Proximal plate fixation topenlarge
When there is solid bony contact across the articular and proximal fragments, compression is applied with pointed reduction forceps and eccentrically placed load screws, one column at a time.
Once the fixation is complete, all remaining K-wires are removed.
- When a column is comminuted it should be bridged and if necessary, because of missing bone fragments, bone grafted.
- When the reassembled condylar mass is short, and non-locking plates are used, long, distal-to-proximal, 3.5 mm column screws will enhance the stability of the fixation. These need to be inserted with great care in the presence of comminution of a column.
5 Osteosynthesis of the olecranon osteotomy topenlarge
Drill hole for wire
Using a 2.5 mm drill, make a coronal hole in the proximal ulna from ulnar to radial side, to pass the figure-of-eight wire.
Prepare a 0.8 mm wire by making a loop approximately one third along its length. Insert the shorter segment of the wire through this drill hole.
Reduction of the olecranon
Reduce the olecranon osteotomy with pointed reduction forceps.
Use the figure-of-eight tension band wiring technique to obtain stable fixation. Two K-wires are drilled parallel across the osteotomy.
The K-wires can be directed down the shaft of the ulna, or alternatively aimed anterior so that they engage the anterior ulnar cortex, just distal to the coronoid process: this may help to limit the potential for wire migration.
Obtain correct K-wire tension
The wire loop has to go underneath the triceps tendon.
Double twist the wire loop to obtain equal tension on both sides. The cut wire loops are then impacted firmly onto the bony cortex of the ulna.
Cut the wires to the appropriate length and bend them. Impact the bend K-wire tip into the olecranon, being sure to bury them beneath the triceps tendon.
Completed osteosynthesis of olecranon
The illustration shows the completed osteosynthesis of the olecranon.