1 Introduction topenlarge
These fractures are usually posteriorly angulated (apex anterior) and whilst they can generally be reduced closed, occasionally impediments to reduction include periosteum and/or pronator quadratus.
Anteriorly angulated (apex posterior) fractures are less common and are also generally reduced closed, but the extensor tendons occasionally impede reduction.
If closed reduction is unsuccessful, open reduction is indicated.
2 Open reduction top
As the majority of these fractures are posteriorly displaced, open reduction is most commonly performed via the anterior approach.
A posterior approach may occasionally be necessary for irreducible anterior displacement.
Removal of impediments
Soft tissue impediments to reduction are removed, eg, pronator quadratus as in the illustration.
Once the soft tissue impediments have been removed, the fracture can be reduced under direct vision.
Direct reduction using a K-wire
In multifragmentary fractures, direct K-wire leverage is not appropriate. In these fractures, direct open reduction via an anterior approach is undertaken prior to K-wire fixation.
Traction on the distal fragment via a hook assisted by a K-wire joystick in the intermediate fragment will usually facilitate anatomical reduction.
3 Plate fixation topenlarge
For anteriorly displaced fractures, a simple buttress technique is used confining screw insertion to the proximal fragment.
The plate acts as a buttress against further anterior displacement and is usually sufficient.
As the majority of these patients are approaching skeletal maturity, if additional stability is required screws may be inserted into the distal fragment, if necessary crossing the physis.
For posteriorly displaced fractures, distal fixation is required with screws engaging the epiphyseal segment.
Provisional K-wire fixation
The fracture is provisionally fixed using a single, or two crossed, smooth 1.6 mm K-wires through the radial metaphysis avoiding the growth plate and the perichondrial ring, if possible.
Application of distal radial plate
The longitudinal portion of the plate is applied to the bone. The distal end of the plate should end just proximal to the edge of the radial articular surface.
Smaller implants are available for younger children.
If in doubt, the position of the articular surface can be demonstrated with an arthrogram.
Insertion of the first screw
A screw is inserted through the most distal plate hole overlying the proximal radial fragment.
The plate position is checked using intraoperative imaging and/or arthrogram, and the screw is then tightened.
Insertion of additional screws
For unstable, posteriorly displaced fractures, the distal fragment is secured with screws through the transverse portion of the plate.
Once the plate fixation is complete, the provisional K-wires are removed.
4 K-wire stabilization of the ulna topenlarge
If ulnar stabilization is required, this can be achieved using a K-wire through the ulnar styloid or ulnar metaphysis if the fragment is sufficiently large..
An additional small skin incision may be required.
Care should be taken to avoid the dorsal sensory branch of the ulnar nerve.
The wires should be inserted with an oscillating drill and cooled with saline solution to prevent thermal injury.
The wires may also be inserted by hand using a T-handle.
The K-wire is left protruding through the skin, bent and cut. The skin is protected with sterile padding prior to 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 Short arm cast topenlarge
The purpose of the cast is protective as stability is provided by the internal fixation device.
The short arm cast is applied according to standard procedure:
Splitting the cast
If a complete cast is applied in the acute phase after injury, it is safer to split the cast down to skin over its full length.