Authors of section

Authors

Jonas Andermahr, Michael McKee, Diane Nam

Executive Editor

Joseph Schatzker

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ORIF - Hook plate

1. Introduction

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.

This is typically the case with an intra-articular fracture. Hook plate fixation is an attractive alternative when dealing with fixation of small intra-articular fracture fragments.

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.

orif hook plate

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

2. Patient preparation and approach

Patient preparation

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

Approach

For this procedure a superior approach is norally used.

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3. Verification of necessity of hook plate use

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

Typically, a displaced intra-articular fracture will result in disruption of part of or the entire acromioclavicular joint capsule and therefore the joint is usually readily apparent.

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4. Direct reduction and fixation

Reduction

Reduction can be performed with several different methods, depending on fracture configuration and surgeon’s preference.
Make certain that downward displacement of the arm is corrected.

Conventional direct reduction can be performed using fracture clamps while applying downward and anterior pressure on the shaft and a lifting and superior force on the distal fragment and attached shoulder girdle.

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

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Temporary fixation

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

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

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Incision for hook placement

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

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Plate selection

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

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Plate application

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.

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The hook plate is secured to the shaft fragment with cortical and cancellous screws (if possible) in the articular fragment to augment fixation.

Locking screws may be used if bone quality is poor.

K-wire is then removed.

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5. Indirect reduction and fixation

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.

complete lsss failure

Plate selection

A small incision is made at the posterior aspect of the acromioclavicular joint to allow sub-acromial placement of the hook. The hook portion of the trial hook plate trial is placed in the subacromial space at the posterior aspect of the joint, and the shaft portion of the trial hook plate is then used to lever the clavicle into place.

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At this point a trial and error method with the three different trial hook plate depths is used to determine the optimal hook depth for accurate reduction. Typically, the short four-hole hook plate will be adequate for most acromioclavicular joint dislocations.

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

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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.

lateral displaced fracture with cc disrupted articular

Case: Over reduction

This is an example of an intra-articular distal clavicle fracture with significant displacement.

Note the increased coracoclavicular distance.

complete lsss failure

Following hook plate fixation, over reduction of the clavicle is demonstrated with a decrease of the coracoclavicular distance compared to the normal side. This puts severe pressure on the acromion from the tip of the hook plate as can be seen in this postoperative radiograph.

complete lsss failure

Subsequent erosion of the hook through the acromion can occur as demonstrated in this illustration: acromial fracture can also occur. When hook plate mechanical failure occurs, over reduction is the most common contributing mechanism.

complete lsss failure

Avoidance of over-reduction

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
orif hook plate

Hook placement

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.

orif hook plate

Reduction and plate application

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...

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…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.

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

Alternative techniques for ligament repair can be found here:

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6. Check of osteosynthesis

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, and intraoperative radiograph should be taken for confirmation.

7. Aftercare

Wound care

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.

Implant removal

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.

Sleeping

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.


nonoperative treatment

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.


nonoperative treatment

Hygiene

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.


 
nonoperative treatment

Dressing

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.

diaphyseal multifragmentary fragmentary segmental

Progressive exercises

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.

nonoperative treatment

Phase I: Day one after surgery

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
nonoperative treatment

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

nonoperative treatment

  • Squeezing the shoulder blades together, while shoulders remain relaxed

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Phase II: Two to six weeks after surgery

Pendular exercises can be started when pain starts to subside.

nonoperative treatment

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

nonoperative treatment

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

nonoperative treatment

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.


nonoperative treatment

Phase III: Six to twelve weeks after surgery

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.


nonoperative treatment