1 Introduction topenlarge
These fractures are often caused by a direct blow. The direction of displacement depends on the direction of the blow.
The reduction and fixation should be performed under general anesthesia.
For fractures that are unstable after reduction, a single K-wire is normally sufficient to stabilize the fracture.
2 Reduction topenlarge
Indirect reduction by forearm rotation
Reduction maneuver is by forearm rotation and direct pressure over the distal ulna.
Posteriorly displaced fractures are reduced with forearm pronation.
Anteriorly displaced fractures are reduced with forearm supination.
Direct reduction using K-wire
In the presence of an intact radius, it is not possible to achieve reduction by hyperextension. If forearm rotation is unsuccessful, direct reduction using a percutaneous K-wire (inserted through a stab incision) is required.
3 Skin incision topenlarge
A small skin incision is made.
Care should be taken to avoid the dorsal sensory branch of the ulnar nerve.
The incision is deepened to the bone using a blunt artery forceps and a protective sleeve is inserted.
4 K-wire insertion topenlarge
A single smooth 1.6 mm K-wire is inserted through a protective sleeve into the ulnar styloid, through the physis, then engaging the lateral cortex of the ulnar diaphysis.
The wire should be inserted with an oscillating drill and cooled with saline solution to prevent thermal injury.
The wire may also be inserted by hand using a T-handle.
Ideally, wire insertion is monitored using image intensification in order to check the trajectory of the wire and to ensure engagement of far cortex without penetration of soft tissues.
The K-wire is left protruding through the skin, bent and cut. The skin is protected with sterile padding prior to the application of a cast.
The illustration demonstrates the use of a small section of plastic tubing over the cut end of the protruding wire. This adds further protection for the skin.
Note: Excessive pressure between dressing and skin should be avoided to prevent skin necrosis.
5 Long arm cast topenlarge
Once the fracture displacement has been reduced and fixed with a K-wire, the arm is splinted in a reduced position with a long arm cast to control forearm rotation.
The purpose of the cast is to maintain reduction by preventing forearm rotation and protect the fixation.
The long arm cast is applied according to standard procedure:
Splitting of the cast
If a complete cast is applied in the acute phase after injury, it should be split over the full length of the cast. The split of the cast must be full thickness and expose the underlying skin.