1 Preliminary remarks topenlarge
Fracture assessment and decision making
C1 fractures are complete articular fractures with both simple articular and metaphyseal components. They may involve a dorsoulnar (posteromedial) articular fragment, or a sagittal or frontal articular fracture line.
Anatomical reduction and stabilization of these fractures are also essential because of the functional implications of the involvement of the distal radioulnar joint.
Once reduced, the fragments may all be held sufficiently with a palmar locking plate.
Advances in plate design have provided angular stable fixation. This allows enhanced stability and ease of application, even in the presence of osteoporotic bone. Plates with variable angle locking screw options may be useful.
Provisional reduction in displaced fractures
Reduction is achieved by applying longitudinal traction either manually or using Chinese finger traps.
The reduction is maintained by a temporary splint.
If definitive surgery is planned, but cannot be performed within a reasonable time scale, a temporary external fixator may be helpful.
2 Associated injuries topenlarge
Median nerve compression
If there is dense sensory loss, or other signs of median nerve compression, the median nerve should be decompressed.
Associated carpal injuries
These injuries may be associated with shearing injuries of the articular cartilage, scaphoid fracture and rupture of the scapholunate ligament (SL). Every patient should be assessed for this injury. If present, see carpal bones of the Hand module.
These injuries may be accompanied by avulsion of the ulnar styloid and/or disruption of the DRUJ. If there is gross instability after the fixation of the radial fracture, it is recommended that the styloid and/or the triangular fibrocartilaginous disc (TFC) is reattached (see A1.1). This is not common in simple fractures, but may occur with some high energy injuries.
The uninjured side should be tested as a reference for the injured side.
It may not be possible to assess DRUJ stability until the fracture has been stabilized (as described below).
3 Open Reduction topenlarge
Anatomical reduction may be achieved by direct manipulation, using a dental pick or similar hook.
A smooth K-wire is placed through the radial styloid across the fracture site into the opposite radial cortex to secure the reduction.
Further K-wires may be inserted to reduce and hold the remaining articular fragments.
Accurate anatomic reduction of the articular surface must be confirmed, before the plate is applied.
4 Plate fixation topenlarge
Apply the plate to the bone. The distal end of the plate should end at the anatomic watershed zone of the distal radius.
Insert a screw through the oblong plate hole in the proximal radial fragment. Select a screw which is long enough to engage both cortices.
Insert the screw. Before fully tightening it, check the plate position using intraoperative imaging, adjusting the position of the plate as necessary.
The initial distal screw should be placed through the ulnar sided screw hole.
The reason for this is that if the initial screw is placed on the radial side it will block accurate imaging of the ulnar screw placement.
A sagittal image with the angle of the X-ray beam directed 20° obliquely to the radius in order to confirm that the screw is not penetrating the radiocarpal joint.
Insert remaining screws
Insert distal locking head screws. Ideally each fragment should have at least two screws, but this is not always practical.
Then insert at least two more proximal screws.
Remove the K-wires.
5 Assessment of Distal Radioulnar Joint (DRUJ) top
Before starting the operation the uninjured side should be tested as a reference for the injured side.
After fixation, the distal radioulnar joint should be assessed for forearm rotation, as well as for stability. The forearm should be rotated completely to make certain there is no anatomical block.
The elbow is flexed 90° on the arm table and displacement in dorsal palmar direction is tested in a neutral rotation of the forearm with the wrist in neutral position.
This is repeated with the wrist in radial deviation, which stabilizes the DRUJ, if the ulnar collateral complex (TFCC) is not disrupted.
This is repeated with the wrist in full supination and full pronation.
In order to test the stability of the distal radioulnar joint, the ulna is compressed against the radius...
...while the forearm is passively put through full supination...
If there is a palpable “clunk”, then instability of the distal radioulnar joint should be considered. This would be an indication for internal fixation of an ulnar styloid fracture at its base. If the fracture is at the tip of the ulnar styloid consider TFCC stabilization.