ORIF - Hook plate

Clavicle hook plate fixation is indicated when there is insufficient bone in the distal clavicular fragment for adequate fixation with a conventional or distal clavicle plate.

The decision to proceed with hook plate fixation can be made preoperatively or intraoperatively if unanticipated inadequate fixation is obtained in the distal fragment.

This makes hook plate fixation an attractive alternative when unexpected difficulties are encountered with fixation of the distal clavicular fragment.

One drawback of hook plate fixation is that, following solid healing of the fracture, plate removal is generally required to optimize shoulder range of motion and eliminate residual discomfort from the hardware.

AO teaching video: Lateral Clavicle—Dislocations and Fractures—The LCP Clavicle Hook Plate

This procedure is normally performed with the patient either in a beach chair or a supine position.

For this procedure a superior approach is normally used.

Following reflection of the deltoid the distal clavicle fracture site is identified and cleared of any hematoma or debris.

Pitfall: it important to preserve the integrity of the acromioclavicular joint capsule, as this contributes to stability of the small distal clavicular fragment.

A sterile 18-gauge needle is used to identify the acromioclavicular joint (this allows the surgeon a clear determination of the size and integrity of the distal clavicular fragment). Assessment is then performed whether conventional plate fixation is possible, or if hook plate use is required.

Reduction can be performed with several different methods, depending on fracture configuration and surgeon’s preference. Generally, reduction will be easier if the shoulder girdle is supported and prevented from sagging downwards.

Conventional direct reduction can be performed using fracture clamps on the proximal and distal fragments, with downward and anterior pressure on the proximal fragment and superior force on the distal fragment and attached shoulder girdle.

Alternatively, a ball-spiked pusher may be utilized to align the fragments.

Following accurate reduction, temporary fixation with a K-wire directed from anterior to posterior can be performed.

Alternatively (and preferentially), if fracture configuration permits, a lag screw can be placed at this point.

A small incision is made at the posterior aspect of the acromioclavicular joint to allow sub-acromial placement of the hook.

The trial hook plates are used to select the correct length of plate (to allow a minimum of 3 screws in the proximal fragment) and to determine the correct depth of the hook.

At this point, the definitive hook plate is applied to the fracture.

Correct placement of the hook portion posteriorly under the acromion aids in reduction and avoids rotator cuff impingement.

The hook portion of the plate resists downward and medial translation of the arm through its tip position under the acromion.

The fixation of the hook plate is completed with insertion of the cortical screws in the shaft fragment and cancellous screws in the distal fragment to augment fixation.

Locking screws may be used if bone quality is poor.

The K-wire is removed.

The hook plate is a powerful tool that can be used to provide an indirect reduction of a distal clavicle fracture.

This indirect reduction technique is useful for comminuted fractures or fractures with very small distal fragments in which conventional reduction and fixation is difficult.

A small incision is made on the posterior aspect of the acromioclavicular joint to allow subacromial hook placement.

With the hook portion of the trial hook plate in the subacromial space, the shaft portion of the hook plate is used to lever the shaft fragment in to place.

At this point a trial and error method with the three different trial hook plates depths is used to determine the optimal hook depth for accurate fracture reduction.

Pitfall: It is important not to over-reduce the clavicle. This is the most common technical error and occurs when the hook depth chosen is too small which leads to inferior displacement of the shaft fragment. This results in an excessive pressure exerted on the acromion by the hook portion of the plate: acromial erosion or fracture can occur.

There are a number of intraoperative maneuvers that will help avoid over-reduction. These include:

1. Selecting a hook depth that is appropriate for the individual case
2. It may be necessary to contour the shaft or hook portion of the plate with the hand held bending irons to optimize plate placement, as anatomy in this area may be quite variable. Care should be taken not to bend he plate or hook repeatedly as this might lead to material failure
3. Excessive downward pressure on the clavicle should be avoided as this often results in over-reduction
4. A superior bony prominence of the distal clavicle may be resected to provide a flat superior surface for plate placement: this will prevent over-reduction of the clavicle
5. In cases where reduction is uncertain, intraoperative imaging with a trial in place will clarify the degree of clavicular reduction and can aid in correction of any over-reduction

Pitfall: A too great hook depth will result in under-reduction, or residual superior displacement of the shaft fragment.

Pearl: It may be necessary to contour the shaft or hook portion of the plate with the hand held bending irons to optimize plate placement, as anatomy in this area may be quite variable. Care should be taken not to bend the plate or hook repeatedly as this might lead to material failure.

At this point, the definitive hook plate is applied to the fracture.

Correct placement of the hook portion posteriorly under the acromion aids in reduction and avoids rotator cuff impingement.

The hook portion of the plate resists downward displacement of the arm through its position under the acromion.

To avoid excessive stress on any screw, insert first the screw closest to the fracture and tighten until appropriate resistance is felt. This may leave the plate proud but...

…sequential insertion of the following screws should approximate it to the shaft fragment and result in accurate fracture reduction. Note this can be done only if regular screws are used. Locking screws are contraindicated for such a maneuver.

If feasible, the coracoclavicular ligaments should be repaired with sutures.

Alternative techniques for ligament repair can be found here:

• Ligament repair

At the conclusion of fixation, the fracture site, plate and screws are carefully checked to ascertain accurate reduction, correct plate placement, and avoidance of any intra-articular screw placement. If any doubt remains regarding these findings, an intraoperative radiograph should be taken for confirmation.

Two days post-surgery the main surgical dressing may be removed and showers are permitted and a light dry dressing may be applied. Soaking in baths, hot tubs and swimming pools are not permitted until minimum two weeks after surgery when the wound is completely healed and the sutures and staples have been removed.

Plate removal from the clavicle is not routinely required or recommended. Symptomatic prominence and impingement of the clavicle plate can occur. After the fracture has completely healed, removal of the implant may be a consideration.

Athletes who return to contact sports should only have the plate removed if absolutely necessary and if so, done at the end of the season to allow maximal healing prior to return to sport.

Many patients who request hardware removal from local symptomatology 6-12 months after implantation find that symptoms diminish significantly by 2 years postoperatively and defer hardware removal indefinitely.

The patient should sleep wearing the sling on his/her back or on the non-injured side.

When sleeping on the side, a pillow can be placed across the chest to support the injured side.

When sleeping on the back, the injured side should be supported by placing a pillow underneath the arm.

It may be more comfortable sleeping in a sitting or semi reclined position.

A non-slip mat in the shower/bath tub will improve safety. The arm can hang gently at the patient's side while bathing. Axillary hygiene is important. If assistance is not available, a long-handled sponge can be used to wash the back and legs.

Loose fitting clothing and button-up shirts are ideal. The affected arm may be used for buttoning and unbuttoning. The affected arm is dressed first, then the non-affected arm. When undressing, start with the non-affected arm, then the affected arm.

Sling support should be provided until the patient is sufficiently comfortable to begin shoulder use, and/or the fracture shows early evidence of healing radiographically.

Once these goals have been achieved, rehabilitative exercises can begin to restore range of motion, strength, and function.
The phases of nonoperative treatment are thus:

• Temporary immobilization
• Passive/assisted range of motion
• Active range of motion
• Progressive resistance exercises

Usually immobilization is maintained for 1-2 weeks for comfort and wound healing purposes. The use of the sling is gradually decreased at this point.

This is followed by gentle range of motion exercises.

Non-weight-bearing of the affected upper limb is continued for approximately for 6 weeks or until radiographic and clinical evidence of progressive healing.

Resistance exercises can generally be started at 6 weeks. Isometric exercises may begin earlier, depending on the injury and patient symptoms.

After clavicular surgery, it is important to maintain full mobility of the unaffected joints to reduce arm swelling and to preserve joint motion. The following exercises are recommended:

• Straightening and flexion of the elbow
• Open and closure of the hand
• Squeezing of a soft ball

• Bending of the wrist forward, backwards and in a circular motion
• Movement of an open hand from side to side

• Squeezing the shoulder blades together, while shoulders remain relaxed

Pendular exercises can be started when pain starts to subside.

Gradual progression to passive and assisted range of motion exercises are started as tolerated. Scapular stabilization must be observed to restore normal kinetics to shoulder motion.

Activated assisted range of motion exercises are started with:

• External rotation
• Internal rotation

• Flexion with arms on table
• Flexion with ball on wall

Sub-maximal isometric exercises with:

• Internal rotation
• External rotation (1)
• Abduction (2)
• Extension

Note: Timing and progression of exercises are ultimately directed by the operating surgeon as factors such as bone quality, type of fracture and fixation may vary in individuals.

Pending clinical and radiographic review by the operating surgeon, weight-bearing may now be permitted and gradual resisted/strengthening exercises can begin.

Return to full activities and/or contact sports is permitted once the fracture is united and the extremity has regained full strength. Typically this takes around 6 months post injury. It may be sooner or later depending on the patient factors, progress of fracture healing and response to rehabilitation.

If there has been no progress on serial radiographs of fracture healing, at 3 months, then delayed or impaired healing may be present. If the fracture has not united after 9 months surgical intervention should be considered.