Authors of section

Authors

Renato Fricker, Jesse Jupiter, Matej Kastelec

Executive Editors

Steve Krikler, Chris Colton

Open all credits

ORIF - Hook plate

1. Preliminary remarks

Multifragmentary fractures of the distal ulna usually occur in combination with distal radial fractures.

In multifragmentary ulnar fractures, there is instability and shortening, so the distal ulnar hook plate may be useful to hold distal multifragmentary fractures.

Attention should be paid to restoring correct rotation and correct length in relation to the radius.

Complete dislocation of the radiocarpal joint is often associated with disruption of the distal radioulnar joint (DRUJ).

orif hook plate

Teaching video

AO teaching video: Ulna, distal—Subcapital with diaphyseal comminution and styloid fracture. Fixation with a 2.0 LCP Distal Ulna plate

2. Patient preparation and approach

Patient preparation

This procedure is normally performed with the patient in a supine position for distal ulnar fractures.

orif palmar plate

Approach

For this procedure an ulnar approach is normally used.

ulnar approach to the distal ulna

3. Open reduction

Under direct visualization, the ulnar head is reduced to the ulnar shaft using a small periosteal elevator or a dental pick. In multifragmentary subcapital fractures, correct alignment and correct rotational alignment of the head is verified.

A reduction forceps is usually not applicable due to the small fragments and the soft bone quality at this level.

orif hook plate

Temporary stabilization with a small K-wire may be helpful, especially if there is a separate ulnar styloid fragment.

extraarticular multifragmentary fracture of the ulna

4. Internal fixation

Hook plate

The distal ulna hook plate is a precontoured plate that fits to the surface of the distal ulna and allows grasping of the ulnar styloid with the pointed hooks.

orif hook plate

Plate application

The pointed hooks are placed around the tip of the ulnar styloid and the plate is aligned on the ulnar shaft.

orif hook plate

Handling of the plate may be facilitated using the LCP drill sleeve inserted in one of the LCP plate holes.

Image intensification may be used to verify correct plate position.

orif hook plate

Screw insertion

An LCP drill sleeve is used to drill a hole for a locking screw in the ulnar head. Avoid drilling through the opposite cortex, as the screw tip would penetrate the distal radioulnar joint.

Screw length is measured pushing the hook of the depth gauge against the opposite cortex. A slightly shorter screw is then chosen.

orif hook plate

The first locking head screw is inserted into the ulnar head.

orif hook plate

A standard screw is inserted through the oblong plate hole to reduce the shaft fragment to the plate.

At this point reduction is verified under image intensification and unrestricted pronation and supination is checked.

orif hook plate

Additional locking head screws are inserted into the ulnar head and fixation at the shaft fragment is completed using standard or locking head screws.

orif hook plate

Option

A 1.5 mm screw may be inserted between the pointed hooks of the plate to provide additional stability to the fixation of the ulnar styloid fragment.

In this case, the most distal locking head screw cannot be inserted.

orif hook plate

Pearl: Retaining the K-wire

If a K-wire has been used for the fixation of the ulnar styloid, the K- wire may be left in place, if it enters the ulnar styloid between the pointed hooks. The K-wire is then bent and cut short.

orif hook plate

Pitfall: First locking head screw too long

If the screw penetrates the opposite cortex of the ulnar head, the screw tip will damage the cartilage of the radioulnar joint.

orif hook plate

5. Aftercare

Functional exercises

Immediately postoperatively, the patient should be encouraged to elevate the limb and mobilize the digits, elbow and shoulder.

joint spanning external fixation temporary or definitive

Some surgeons may prefer to immobilize the wrist for 7-10 days before starting active wrist and forearm motion. In those patients, the wrist will remain in the dressing applied at the time of surgery.

orif palmar plate

Wrist and forearm motion can be initiated when the patient is comfortable and there is no need for immobilization of the wrist after suture removal.

Resisted exercises can be started about 6 weeks after surgery depending on the radiographic appearance.

If necessary, functional exercises can be under the supervision of a hand therapist.

orif palmar plate

Follow up

See patient 7-10 days after surgery for a wound check and suture removal. X-rays are taken to check the reduction.

Implant removal

Implant removal is purely elective but may be needed in cases of soft-tissue irritation, especially tendon irritation to prevent late rupture. This is particularly a problem with dorsal or radial plates. These plates should be removed between nine and twelve months.