Masterclass: AC joint reconstruction- Part II

Surgery for ACJ injuries

Type III injuries and type II injuries in the high-level throwing athlete are the start of the spectrum for the decision to operatively stabilize the ACJ. This is usually determined on a case-by-case basis, and the criteria for surgery vs. conservative management may be based on:

1. Previous injury to the ACJ that has rendered the joint a little degenerative (new on old injury).
2. For those in high-risk sports (contact sport, combat sports, motocross) where the risk for re-injury may be quite high, the initial preference is to treat the ACJ conservatively. If the ACJ is re-injured, this may then push the surgeon to consider surgical stabilization.
3. In throwing sports where this is the dominant arm, early surgery may be preferred to avoid any unwanted sensations of ACJ instability or clicking and popping in the ACJ due to the high biomechanical loads imposed on the joint.
4. Arm dominance. Injuries to the ACJ on the dominant side may be a determining factor in early surgery.
5. Degree of instability. Instability in the anteroposterior direction tends to do poorly with conservative management compared with the up-down type instabilities.

The decision to manage Type III injuries surgically versus non-surgically still remains controversial. Some researchers have found that the outcome following surgical versus non-surgical AJC injuries is quite similar⁽¹⁾.

If the decision is to delay surgery on a Type II and III ACJ injury, then the usual time frame is three months of conservative rehabilitation. If the athlete complains of residual pain, sensations of instability, or an inability to perform sport at previous levels of function, then surgery is then considered.

The more serious types IV, V, and VI, will always need surgery.

Types of Surgery

There are four basic types of surgical procedures that have been described for the treatment of ACJ injuries. These include:

1. Primary repair of the AC joint with pins, screws, plates, tension band wiring or rods.

This procedure involves an open repair of the ACJ using a host of fixating options. These may be done with or without CC ligament reconstruction. A comparative study performed by Sugathan and Dodenhoff (2012) found that tension band wiring, although preferable over a Weaver-Dunn procedure (see below) in terms of ACJ strength and functional outcome in acute ACJ injuries, had a greater risk of early postoperative complications compared to the Weaver-Dunn procedure and the need for future surgery to remove any metal work in and around the ACJ⁽²⁾. They recommended the Weaver-Dunn procedure, particularly in those with failed conservative management.

2. Distal clavicle excision with a soft tissue reconstruction (Weaver-Dunn).

This procedure involves resection of the distal clavicle followed by the release of the CC ligament from its attachment on the acromion. The detached end of the ligament is then attached to the distal clavicle to help hold it in a reduced position. Transfer of the conjoined tendon, where the lateral half of the tendon is transferred to the distal clavicle, has recently been described. Transfer of the conjoined tendon has been argued to be superior to the original Weaver–Dunn technique because the functioning CC ligament is left intact.

3. Anatomic coracoclavicular reconstruction (ACCR).

The ACCR procedure entails a diagnostic shoulder arthroscopy and arthroscopic distal clavicle excision. The AC ligament is detached from its acromial insertion and tied to the distal clavicle through two drill holes. An autograft (donor site being the gracilis or semitendinosus) or an allograft is then looped underneath the coracoid and through two drill holes in the clavicle. The graft is then tied to itself in a figure-of-eight fashion or fixed to the clavicle with interference screws. Several biomechanical studies have been completed which illustrate that ACCR more closely approximates the stiffness of the CC ligament complex and produces less anterior-to-posterior translation at the AC joint compared with the Weaver–Dunn procedure.

4. Arthroscopic suture fixation.

Two types of surgical techniques for restoring the CC ligaments without a graft exist. The first technique involves using two suture anchors through four drill holes in the clavicle for fixation. The suture anchors are fixed in the coracoid and tied over a bone bridge in the clavicle. As part of this procedure, the CC ligament is transferred as well. The second type of procedure involves using two tightrope devices to reconstruct the CC ligaments through two single tunnels in the clavicle and coracoid.

Post-operative rehabilitation

Irrespective of the surgical procedure used, the post-operative rehabilitation protocol will be similar for all surgical types. The major point of difference will be that if screw/plate fixation has been used, these will usually be removed at around eight weeks post-operatively.

Stage 1: protection and immobilization (0-6 weeks).

The majority of surgeons would request a conservative six-week period of complete sling immobilization to allow full tissue healing without any unwanted stretch on the reconstructed ligaments or augmentation devices. This differs greatly from other major shoulder surgeries, such as shoulder reconstructions and rotator cuff repairs, whereby the surgeon encourages pendulum-type exercises in these types of shoulder surgeries early in the rehabilitation phase. The concern with sling removal in the early stage is that the weight of the arm and scapular provide a significant traction force to the ACJ, and if this is allowed to occur in the early stages, then the ACJ may end up with excessive post-operative laxity. To avoid this, most surgeons will advocate no pendulum in the first six weeks and not allow the arm to be unsupported whilst in the upright position.

The goals, therefore at this stage are:

1. Allow healing of soft tissues;
2. Decrease pain/inflammation;
3. Early protected range of movement;
4. Retard muscle atrophy in scapular stabilizers.

For the first two weeks, the sling can be removed for hygiene purposes only. At two weeks post-op, the patient may start passive range of movement (therapist guided) or active-assisted (patient-guided) flexion and abduction movements whilst lying in supine. These flexion and abduction movements are slowly progressed to 70° from week two to six as pain allows. Usually internal and external rotation can be pushed to the limits as long as pain allows. Extension movements are avoided in this early stage as this movement produces the greatest amount of stress on the ACJ.

Soft tissue work to the pec major/ minor, the latissimus dorsi, and subscapularis, if the arm can be abducted comfortably away to expose these muscles, are usually also started early. Due to the restriction on pendulum exercises in the ACJ-reconstructed shoulders, the arm tends to ‘stick’ to the side quite easily due to soft tissue contracture and adhesive capsulitis in the shoulder joint. Therefore, if the therapist is able to access the shoulder comfortably, then gentle passive mobilizations of the shoulder joint (physiological as well as accessory) are allowed for the glenohumeral joint.

Gentle scapular setting exercises can be performed in a supported sitting position with the sling in situ. Only allow pain-free ranges of retraction and depression. These can be held as 10-second isometric contractions. This can be enhanced with muscle stimulators placed on the lower trapezius and the stimulator set to an ‘atrophy’ mode.

Similarly, muscle stimulators can be used on the deltoids and pec major in an ‘atrophy’ mode. In a supine lie, the patient may start gentle isometric shoulder abduction and rotation exercises at four weeks post operative.

Exit criteria for Stage 1

1. Minimal pain and inflammation in the ACJ.

Stage 2: regain range of movement (7-12 weeks).

The primary goals in this stage are:

1. Gradual increase in range of movement;
2. Gradual increase in isometric strength;
3. Maintain pain-free ACJ and minimal inflammation.

The sling is usually discarded at six weeks post-op. Due to the severe restrictions placed on movement in the first six weeks, the usual progression of movement is to allow active assisted flexion and abduction in weeks seven and eight, and then progress to active only in weeks nine through twelve. Rotation movements with the arm by the side can be progressed unrestricted early; however, extension is still avoided until 10 weeks post-op. It is expected that the patient will have achieved 90% of the range of movement into flexion, abduction, and hand behind the back by week 12 post-op.

Isometric deltoid, pec major and lat dorsi can be progressed at this stage in neutral and pain-free positions; rotation strength can be worked through range with therabands. More aggressive prone lying scapular retraction and depression drills can also be progressed early in this stage.

Scapular wall slides (start)

Scapular wall slides (finish)

As the patient achieves comfortable ranges of shoulder flexion, gentle wall slide exercises can be started to actively strengthen the serratus anterior. To perform a wall slide exercise (see image above), start with the forearms in contact with the wall. Gently slide the forearms up the wall above the head, slowly externally rotating the arms/forearms on the way up. This will create scapula upward rotation and protraction, a great exercise to activate the serratus anterior, a necessary muscle in the control of scapula movement.

For the athlete involved in a running sport, treadmill running with the affected arm holding onto the hand grip is allowed from week seven onwards. Due to the difficulty with this running technique, running velocities have to be limited to 12-14 km/hour. In weeks 9 and 10, on-field running is allowed with the arm kept locked in by the side to minimize excessive shoulder flexion and extension movements. Full running is allowed in weeks 11 and 12, and high speeds can be slowly progressed. It is difficult to reach top-end speeds in this stage due to the aggressive flexion and extension of the shoulder required in the arm drive phase. Therefore speeds can be curbed to 80% maximum.

Exit criteria for Stage 2

1. Range of movement achieves +90%.
2. No residual pain in ACJ one hour post-exercise.
3. No night pain in the ACJ.
4. Pain-free running at 80% speed.

Stage 3: strengthening phase (13-16 weeks).

The primary goals in this stage are:

1. Regain full range of movement.
2. Regain +90% pre-injury pulling strength.
3. Regain 70% pre-injury pushing strength.
4. Improve neuromuscular control.
5. Integrate skill components into rehabilitation.

Range of movement which should be close to +90% at 12 weeks post-operative, is now pushed into end-of-range positions. This can be done with a lot of athlete directed self-stretching for the global mobilizers such as pectoralis major/ minor and latissimus dorsi and local rotator cuff flexibility in infraspinatus. Furthermore, therapist-directed deep tissue myofascial releases to restricted muscles as well as more aggressive ACJ and glenohumeral joint mobilizations, can be used to improve arthrokinematics of the affected joints.

More traditional strength work is now started or progressed if started earlier. As a rule of thumb, regaining gym-based strength in an ACJ is quite similar to regaining strength in a glenohumeral joint. It should progress based on movement directions. The order of movements directions that can be safely progressed, and a new direction added weekly are:

1. Horizontal pulling (for example, seated rows, prone flyes, prone pulls, 1 arm rows).
2. Vertical pulling (close grip pulldowns, 1 arm pulldowns, lat pulldowns, chin up variations).
3. Horizontal pushing (push-up variations, bench/dumbbell/cable presses, incline bench).
4. Vertical pushing (dumbbell/barbell shoulder press, lateral/front raises).
5. PNF diagonal patterns (flexion/ abduction/external rotation to extension/ adduction/internal rotation).

It is expected that by the end of week 16, most of the movement directions have been re-introduced however, the strength of the pushing movements will only be around 70% of pre-injury levels. Furthermore, any heavy traction movements to the shoulder, such as deadlifts, are also avoided at this stage. Lighter deadlifts with the scapular held in retracted positions may be started. However, most of the posterior chain strength work will need to be performed away from deadlifts.

Medium to high-level proprioceptive work can also be integrated into this stage with exercises such as:

1. Swiss ball arm wrestle.
2. Push-ups on unstable surfaces.
3. Bodyblade-type shoulder exercises.

For the contact sport athlete involved in hand-ball type sports such as rugby, AFL, and basketball, skills can now commence in non-contact situations.

Exit criteria for Stage 3

1. Full painless range of movement.
2. Pain-free scarf test.
3. Pulling strength 90% pre-injury.
4. Pushing strength 70% pre-injury.
5. Pain-free running at full speed.

Stage 4: return to sport phase (16-24 weeks).

The primary goals in this stage are:

1. Maintain painless full range of movement.
2. Regain +90% pre-injury strength.
3. Integrate back into full training/contact training.

This phase is a continuation of phase 3 in that the athlete is still progressing back to full shoulder strength whilst in parallel increasing return to full training. Pushing movements can be really progressed in this stage to regain 90+% of pre-injury strength. The athlete should have full painless range of shoulder flexion, extension, abduction, hand behind back and horizontal flexion (scarf test).

If the athlete is involved in a contact sport such as rugby, American Football, AFL, MMA/wrestling then the decision to start controlled contact is also a decision based on certain criteria. Prior to starting full contact, the athlete should be able to perform:

1. Pain-free clap push-ups;
2. Pain-free bench dip.

These two movements impose a high tensile and compressive force on the ACJ therefore, they are good screening movements to ascertain if the ACJ has fully recovered from injury and surgery.

Exit criteria for Stage 4

1. Full painless range of movement.
2. Pain-free scarf test/clap push-up/ bench dip
3. Pulling strength close to 100% pre-injury.
4. Pushing strength 90%+ pre-injury. 5. Completed full contact training.

Return to contact training.

Staging an ACJ-injured athlete back to full competitive training situations requires a stepwise progression of drills and skills that resemble the demands of the competition whilst still allowing appropriate protection of the shoulder/ ACJ at critical stages of recovery. A logical way to prepare the athlete to develop match readiness is to modify the training environment from safe and controlled situations initially to more advanced game-specific events as they progress. For example, starting in kneeling positions and then progressing to standing, walking, and running positions allows the athlete to confidently practice contact components without fear of further ACJ injury.

Table 1: Example of how an ACJ-injured athlete would progress contact situations for a combative sport such as rugby.

Conclusion

Returning an athlete back from a surgically reconstructed ACJ is similar in content and time frame to other shoulder surgeries except for a few key differences. Firstly, the initial six-week protection stage is far more important to adhere to in the ACJ-repaired athlete as early movement out of the sling may lead to traction on the joint which may render the ACJ hypermobile in the early postoperative stage. Furthermore, the progression of functional range of movement is also different to other shoulder surgery in that rotation movements are allowed early; however, extension is avoided for the first 10 weeks. Following these slight differences, the remainder of the rehabilitation process is quite similar in content to other shoulder surgeries in the development of range of movement, strength, and also return to sports guidelines, especially contact in training.

The later stages of rehabilitation will be highly dependent on the sport chosen. For the throwing athlete, appropriate interval throwing has to be woven into the last stages of rehabilitation, similarly with the pitching, tennis, golf, and swimming. The contact sports athlete has a host of other complicating integrations that are not an issue with non-contact athletes. Most of the ACJ-repaired athletes can return to full sports participation within six months of surgery depending on the sport played. Some non-contact sports may be back competing at 14-16 weeks postoperative. Power athletes may take much longer and sometimes up to nine months post-operatively.