1 Preliminary remarks topenlarge
In cases with good bone quality, a noncomminuted palmar cortex and limited metaphyseal comminution, treatment with closed reduction and K-wire fixation may be chosen.
Advantages of closed reduction and K-wire fixation, compared to open surgery, are:
- Minimal surgical risk
- Minimal infrastructure required
- Lower cost treatment
- Plaster immobilization
- High rate of secondary displacement, leading to a less predictable outcome
- Risk of injury to the dorsal sensory branch of the radial nerve
- Risk of pin-track infection
2 Closed reduction top
Closed reduction of A3.1 fractures
The closed reduction technique will vary with the fracture pattern.
For A3.1 fractures, it is important to use traction to restore radial length. By definition, angular deformity is not present.
Closed reduction of A3.2 fractures
For A3.2 fractures, the following steps are necessary: As a principle, the first step in reduction is to disimpact the fragment by increasing the dorsal angulation (B). Then, with traction applied, the distal fragment is pushed distally, and flexed (C + D), in order to reduce the palmar cortex and restore palmar inclination. Any traction is then released.
Closed reduction of A3.3 fractures
For A3.3 fractures, longitudinal traction is essential to restore radial length, but attention also has to be paid to correcting any associated angular deformity – dorsal, palmar and/or radial. In very unstable A3.3 fractures, reduction can be achieved with the use of a temporary spanning external fixator. This will hold the reduction whilst the stabilizing K-wires are inserted, and in many cases, it can then be removed.
3 K-wire insertion top
There are numerous techniques of K-wire fixation (eg, two wires, three
wires, Kapandji-technique) for A3 fractures of the distal radius.
We describe a technique using three K-wires. Two are introduced from the tip of the radial styloid, one from the dorsoulnar aspect.
Insert the first K-wire
First, a 1 cm incision is made over the tip of the radial styloid. The
radial styloid is exposed by blunt dissection and taking great care is taken
not to injure the sensory branch of the radial nerve or the tendons of the
first and third extensor compartments.
The drill guide is introduced between the tips of the soft-tissue spreader.
After checking reduction and anticipated direction of the K-wire using image intensification, the K-wire is introduced carefully with a power drill.
The K-wire should just penetrate the medial cortex of the radial shaft.
A second K-wire is introduced through the radial styloid in the same manner, but in a divergent direction.
Third K-wire: Insertion from the dorsoulnar aspect
A second incision is made between the fourth and fifth extensor compartments. Blunt dissection to the bone is carried out. Under image intensifier control, the third K-wire is introduced from the dorsoulnar rim of the radius into the anterior cortex of the radial shaft.
Cut and bend K-wires
The K-wires are cut and bent 180º to avoid further migration into the bone. According to preference, the ends of the wires are placed underneath the skin, or the incisions may be left open.
4 Cast application topenlarge
Below elbow cast
A well padded cast is applied, using minimal cast material over the
percutaneous pin sites.
One option to consider is creating a window in the cast directly over the pin sites.
Because the reduction is stabilized with K-wires, a below elbow cast is preferred.
Split the cast
The cast should be split along the ulnar side to allow for postoperative swelling. When swelling has subsided, the cast is closed and repaired, usually after 5-10 days.
It is imperative that the cast permit full digital motion, especially metacarpophalangeal flexion.