1 Introduction topenlarge
These are intraarticular fractures and the adult principles of anatomical reduction and stable fixation are also relevant in children.
If closed reduction, with or without the assistance of a percutaneous K-wire, is unsuccessful, open reduction is required.
Impediments to closed reduction include pronator quadratus and/or periosteum in radial injuries and the ulnar nerve and adjacent tendons in ulnar injuries.
In younger children, fixation can be achieved using a K-wire. A lag screw, totally within the radial epiphysis, can be used as an alternative near skeletal maturity when the epiphysis is largely ossified.
Preoperative CT imaging is desirable to determine the exact anatomy of the fracture and, therefore, the correct orientation of any intraepiphyseal implant.
2 Open reduction topenlarge
Removal of impediments
Soft tissue impediments to reduction are removed.
After soft tissue impediments have been removed, the fracture will generally reduce directly using a small pointed reduction clamp.
Reduction with the help of a K-wire
A single K-wire can be inserted into the epiphyseal fragment and used as a joystick to facilitate reduction.
If this wire is inserted in the direction of the proposed definitive fixation, it can then be advanced across the fracture after reduction has been secured.
3 K-wire fixation topenlarge
A small skin incision is made for the K-wire insertion.
This incision is deepened to the bone using a blunt artery forceps and a protective sleeve is inserted.
Care should be taken to avoid the dorsal sensory branch of the radial nerve and the dorsal sensory branch of the ulnar nerve.
Insertion of the intraepiphyseal K-wire
A smooth 1.25-1.6 mm K-wire is inserted through the radial epiphysis in a direction determined by the fracture pattern. The K-wire should ideally cross the fracture plane as near to 90° as the fracture anatomy permits.
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, the K-wire is inserted using image intensifier control, in order to check the trajectory of the wire.
Alternative: Cannulated screw
In the child nearing skeletal maturity an intra epiphyseal lag screw can be inserted. Using the intraepiphyseal wire as a guide, a cannulated screw is inserted over the wire with the appropriate soft-tissue protection, provided the full instrumentation is available.
Insertion of a second K-wire
Occasionally a second wire is required to maintain the reduction.
This wire is inserted obliquely through the radial epiphysis, across the physis and engaging the medial cortex of the radial metaphysis.
Stabilization of the ulna
An oblique wire is used to stabilize the ulna using similar principles.
Confirmation of reduction
Ideally, reduction should be confirmed using image intensification, or arthrography.
The K-wires are 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 ends 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.
4 Short arm cast topenlarge
The purpose of the cast is protective and for pain relief, as stability is provided by the K-wire(s).
The short arm cast is applied according to standard procedure:
Note: In young, small, or noncompliant patients, it is safer to apply a long arm cast.
Splitting of 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.