- Transolecranon approach
Make a straight incision beginning level with the junction of the middle and distal thirds of, and centered on, the humeral shaft. Some surgeons make a straight incision, whereas others prefer to curve the incision around the olecranon to the radial side. The incision ends over the ulnar diaphysis.
An ulnar-based subcutaneous flap is developed.
The ulnar nerve is identified proximally along the medial border of the triceps.
It is then released from the cubital tunnel distally, through the flexor pronator aponeurosis to the level of its first anterior motor branch.
Whenever possible, care should be taken to preserve the perineural vessels.
A vessel loop is placed around the ulnar nerve, which is protected throughout the entire procedure.
This intraoperative view shows the ulnar nerve freed and tagged with a vessel loop.
Incise the fascia over the flexor carpi ulnaris muscle at the border of the ulnar bone, as the first step in the preparation of the extensor apparatus flap.
Preparation for osteotomy
Determine the site of the osteotomy by incising either the medial capsule, after retracting the ulnar nerve, or the lateral capsule, after elevating part of the anconeus muscle and finding the center of the trochlear notch.
Clear the bone with a small elevator at the site of the planned osteotomy.
Mark a chevron osteotomy with a distal apex.
Chevron osteotomy with the apex distal
Alternative: Chevron osteotomy with the apex proximal (reversed chevron)
Sometimes the fracture configuration is such that a reversed chevron osteotomy is preferable.
Because of the shape of the olecranon, use a fine oscillating saw to divide only up to three quarters of the depth of the bone.
Use a chisel on the last part of the bone, but only just short of the subchondral bone. Remember that the central ridge of the olecranon, which is very strong, will need to be divided deeper, using a very narrow bladed chisel.
The subchondral bone is then fractured by levering the osteotomy apart.
Some surgeons prefer to perform the entire osteotomy with chisels, rather than with a power saw.
The chevron osteotomy is preferred to give a better and more stable bony contact during the repair of the olecranon reduction. The larger surface improves bone healing, and the shape improves rotational stability.
Reduction and fixation of the olecranon
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.
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.
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 olecranon, being sure to bury them beneath the triceps tendon.
The image shows the completed osteosynthesis of the olecranon.