Executive Editor: Steve Krikler

Authors: Renato Fricker, Jesse Jupiter, Matej Kastelec

Distal forearm 23-B2.3 ORIF

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Glossary

1 Preliminary remarks top

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B type fractures are partial articular fractures. These fractures demand accurate reduction since they involve the articular surface.

B2 fractures involve the dorsal rim of the distal radius. These fractures represent a spectrum of injuries, with variation in the size of the dorsal fragments. Large fragments may be suitable for plating or even lag screw fixation, while smaller fragments may require fixation with K-wires or suture anchors.

In some B2.3 fractures, the fracture of the dorsal rim is associated with a radial styloid fracture as well, and there is greater instability than in B2.2 fractures and dislocation of the carpus. These fractures usually require a dorsal plate to hold the dorsal fragments and a radial plate to hold the radial styloid.


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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 top

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Median nerve compression

If there is dense sensory loss, or other signs of median nerve compression, the median nerve should be decompressed.


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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.


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DRUJ/ulnar injuries

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 Initial assessment top

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Visualize dorsal components

Under direct vision, approach the radial styloid and dorsal lunate facet (dorsoulnar) fragment. Usually the dorsal capsule is torn, but if it is intact, a dorsal arthrotomy is made parallel to the dorsal rim to inspect the articular surface and look for any associated carpal injury.


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Decision Making

B2.3 fractures represent a spectrum of injuries, with variation in the size of the dorsal fragments. Large fragments may be suitable for plating or even lag screw fixation, while smaller fragments may require fixation with K-wires or suture anchors.

Reduce the carpus.
Fixation should be started with the less comminuted fracture fragment.

4 Dorsal fragment reduction and fixation top

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If the dorsal rim fragment(s) is(are) large enough, obtain  provisional fixation with K-wires.


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If they are too small they may be held with suture anchors or transosseous sutures.


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Provisional radial styloid fixation

The radial styloid fragments is reduced either under direct vision with a K-wire on the dorsoradial aspect or percutaneously.

In the latter case, in order not to injure the sensory branch of the radial nerve, make a small incision over the tip of the radial styloid and use a protective drill guide to insert two K-wires.

Confirm reduction using image intensification.


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Plate fixation

Many plates are available for this application, some with locking screws. The most recently designed plates have variable angle locking screws.


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Contouring

Because of the shape of the dorsal distal metaphysis, the plate may need to be contoured to fit the bone surface and the proximal limb may require some torsional adaptation.

If the distal transverse limb of the plate does not exert sufficient compression on the distal fragments, remove the plate and overbend the transverse distal limb.


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Pitfall: Screw hole distortion

Avoid contouring the plate through the locking holes, otherwise the locking head screw might not fit any more.


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Plate application

The plate should be applied as distally as possible over the dorsal rim fragment(s).


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If the provisional K-wire(s) conflict(s) with the optimal plate position, the plate can be slipped over the wire or the wire(s) can be repositioned.


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Insert a nonlocking, standard screw long enough to engage the opposite cortex through the oblong hole, but do not fully tighten it yet.

Confirm the reduction and plate position using image intensification. If necessary, adjust the plate position until it is as distal and as central as possible, then tighten the screw.


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Once the plate position is satisfactory, it should be secured with a (locking) screw in a proximal screw hole.


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Screws are inserted through the distal plate holes, before or after removal of the K-wire(s) as appropriate.


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Confirm screw position

With image intensification, confirm that the distal screws have not penetrated the articular surface. In order to have a view in line with the articular surface, the beam should be angled 20º from the true lateral.

5 Definitive radial styloid fixation top

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Depending on the size and configuration of the radial styloid fragment, K-wire fixation alone may be adequate.


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Alternatively, the fragment may be held with lag screws or may be supported with a buttress plate.


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Option 1: Lag screw fixation

Partially threaded cannulated screw(s) is(are) inserted over the guide wire(s) in the styloid, approximately perpendicular to the plane of the fracture.

In osteoporotic bone, washers should be used.


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Option 2: Radial column buttress plating

Dedicated radial column plates are available precontoured. However, some additional contouring may be necessary to accommodate the individual anatomy of some patients.


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Pitfall: Screw hole distortion

Avoid contouring the plate through the locking holes, otherwise the locking head screw might not fit any more.


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Variable angle locking plates enable precise positioning of the distal screws in desired directions in order to address the individual fracture patterns.


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Plate application

Apply the plate onto the radial column.
Ideally, the notch in the distal tip of the implant should be placed against the temporary K-wire.


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Pitfall: Inadequate buttressing

Placement of the plate on the dorsal aspect of the radial column is to be avoided as it will not buttress the reduction against shear forces.


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Plate fixation

Insert a conventional screw into the oblong plate hole, but do not tighten it yet.
Confirm plate position using image intensification. Adjust the plate position, if necessary, then tighten the screw.


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Insert first locking head screw

To prevent rotation of the plate during distal subchondral (locking) screw fixation it is recommended to secure the plate to the bone inserting the most proximal (locking) screw.


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Insert subchondral distal locking head screw(s)

Insert a locking head screw into the distal locking hole of the plate. Using variable angle screws allows optimal direction of fixation.

The position of the screw should be just under the subchondral bone.

Once the screw is inserted, the K-wire(s) may be removed.


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Pitfall: Penetration of sigmoid notch

Beware of the tip of the screw penetrating into the sigmoid notch. It is safer to leave the screw a little short and it should not be drilled into the opposite cortex.


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Confirm that the screw does not protrude into the joint under direct vision and using an image intensifier, with the beam angled 20º from the true lateral. This projection will profile the radial articular surface and visualize any encroachment of the screw into the joint.

6 Additional fixation top

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Additional palmar ligamentous avulsion reattachment

Dorsal carpal subluxation may be associated with avulsion of the palmar wrist capsule from the distal radius.
After dorsal fixation, check the carpal position and stability under image intensification. If there is carpal ulnar and/or palmar translation, consider an additional palmar approach to repair soft tissues.  The capsule can be reattached using multiple suture anchors or transosseous sutures.


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Additional external fixation

If the dorsal rim fragments are large enough, they may be held in place with a buttress plate.
If they are too small, K-wires may be the definitive fixation. In this case, a neutralization external fixation should be applied.

7 Assessment of Distal Radioulnar Joint 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.


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Method 1

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.


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This is repeated with the wrist in full supination and full pronation.


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Method 2

In order to test the stability of the distal radioulnar joint, the ulna is compressed against the radius...


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...while the forearm is passively put through full supination...


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...and pronation.

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.