Indications

Nonoperative management is usually the preferred initial treatment for Rockwood types I and II injuries. Treatment of type III has historically been controversial; however, a new subclassification provides evidence supporting nonoperative treatment of Rockwood type IIIA (horizontally stable) and surgical reconstruction of type IIIB (horizontally unstable) ( ). Acute and chronic Rockwood type IV through VI injuries should also be treated surgically, as should symptomatic type IIIA injuries for which conservative management has failed ( ).

Patient Positioning and Anesthesia

Following induction of general endotracheal anesthesia, the patient is placed in the beach-chair position. Intraoperative fluoroscopy is positioned with the x-ray tube anterior to the patient’s shoulder; this positioning permits utilization of fluoroscopy throughout the procedure to assist with visualization of the bony structures, confirmation of AC joint reduction, and placement of hardware. The patient and fluoroscopy machine are then prepared and draped in sterile fashion with the operative extremity placed in a pneumatic arm holder. Single-shot intravenous antibiotics are administered prior to the incision.

Operative Technique

See Video 12A.1 .

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  Video 12A.1 Operative technique demonstrating coracoclavicular ligament fixation for the treatment of acromioclavicular joint injuries.

  
  

  (From Tahal DS, Katthagen JC, Millett PJ. arthroscopic acromioclavicular joint reconstruction using knotless coracoclavicular fixation and soft-tissue anatomic coracoclavicular ligament reconstruction. Arthrosc Techn. 6(1);2017:e37-42.)

Allograft Coracoclavicular Ligament Reconstruction

Augmentation of the knotless CC fixation may be performed with an 8-mm double-diameter tibialis anterior or hamstring allograft. This is typically added in the patient who has a chronic acromioclavicular joint injury, in whom there is a lot of force on the reduction, or in whom there is considerable anteroposterior translation even after the CC ligaments have been reconstructed to reduce postoperative re-dislocations.

A switching stick is used to bluntly create two soft tissue tunnels from clavicle to coracoid. The first tunnel is created posterior to the clavicle and medial to the coracoid process under direct arthroscopic visualization; this recreates the anatomic orientation of the conoid ligament. A soft-tissue dilator (Arthrex) is placed over the switching stick, and the switching stick is removed. Subsequently, a rigid shuttling suture (Fiberstick, Arthrex) is passed through the dilator from superior to inferior and retrieved out the AIL portal. The process is repeated for the second tunnel, beginning anterior to the clavicle and exiting lateral to the coracoid process. This maneuver recreates the anatomic orientation of the trapezoid ligament. Next, the shuttling sutures are used to pass the allograft around both the clavicle and coracoid. The graft is first passed posterior to the clavicle, enters the subcoracoid space medial to the coracoid, and is retrieved out the AIL portal, thus re-creating the conoid ligament. With the second shuttling suture, the graft is next shuttled from inferior to superior; it is passed under the coracoid process and through the soft tissue lateral to the coracoid, and exits anterior to the clavicle ( Fig. 12A.3 ), thus re-creating the trapezoid ligament.

( A ) The superior hardware of the knotless fixation device. ( B ) View of the superior knotless fixation device on the superior aspect of the clavicle; the ends of the tibialis anterior allograft have been successfully passed around the coracoid process.

At this point, both the graft and the CC fixation device are secured. The knotless CC fixation device can be retensioned, and an inferior force may be applied to the clavicle to ensure its reduction into anatomic position. The CC fixation device contains a self-locking mechanism, so no knots are required on the top of the clavicle; thus minimizing soft-tissue irritation for the patient. Next, the ends of the graft are placed over the superior aspect of the clavicle and secured with a simple overhand throw stitch using nonabsorbable sutures. The free ends of the graft are sharply cut. This completes the repair, and wound closure is performed to finish the surgery ( Fig. 12A.4 ).

Postoperative radiography of previous Rockwood type V AC joint dislocation now fixed in anatomic position; (A) anteroposterior view, (B) axillary view.

Precautions

Precautions after AC joint reconstruction surgery include avoidance of passive and active traction to the shoulder girdle, of downward force on the repair for 6 weeks, and of heavy lifting or carrying for 12 weeks. Physical therapists and patients should avoid internal rotation behind the back and horizontal adduction for 8 weeks. AC joint mobilizations should not be performed for 8 weeks, and then only as indicated. Patients are not allowed to begin bench presses or full pushups until 12 weeks postoperatively.

Phase I: Protection

The patient is immobilized in a sling with abduction pillow for 4 to 6 weeks positioned in the scapular plane to unload the reconstructed AC joint. Full passive range of motion (PROM) of the glenohumeral joint is initiated postoperative day 1; it is not uncommon to restrict PROM forward elevation and abduction to 90 degrees for the first 2 postoperative weeks. The patient may also begin full active range of motion (AROM) of the cervical spine, elbow, wrist, and hand as well as neuromuscular re-education scapular exercises on postoperative day 1.

Phase II: Muscular Endurance

Active assisted range of motion (AAROM) and active range of motion (AROM) are initiated between 4 and 6 weeks postoperatively; PROM should be continued during this phase until full ROM is achieved. AAROM and AROM exercises focusing on the glenohumeral and scapulothoracic joint musculature are initiated with the patient in supine, prone, and sidelying positions in order to reduce load on the AC reconstruction. It is paramount to establish normal scapulohumeral rhythm throughout full AROM in all planes during this phase prior to progression to initial strengthening in phase III.

Phase III: Muscular Strength

The rehabilitation goals of phase III consist of advancing muscular strength by means of resisted initial open and closed kinetic chain exercises, generally introduced at weeks 8 and 10, respectively. Introduced first are isotonic exercises to strengthen the rotator cuff and periscapular musculature ( Figs. 12A.5 and 12A.6 ) using light band or dumbbell resistance with emphasis on controlled eccentric and concentric motion. Closed kinetic chain exercises are initiated in positions of low-load weight bearing through the upper extremities in a fixed position. Once scapular stability and strength of the involved upper extremity has improved to 90% of that of the uninvolved upper extremity in all planes, transition to phase IV is appropriate.

Scapular stabilization exercises on ball in kneeling or full plank position. Right shoulder is the operative side. (A) A: Middle and lower trapezius activation in conjunction with glenohumeral external rotation and extension. (B) T: Middle trapezius and rhomboid activation in conjunction with glenohumeral horizontal abduction. (C) W: Middle trapezius and rhomboid activation in conjunction with glenohumeral external rotation and horizontal abduction. (D) Single Arm Y: Lower trapezius and serratus anterior activation in conjunction with glenohumeral forward elevation.

Forearm wallslide for serratus anterior. ( A ) Start position with resistance band at wrists to facilitate glenohumeral external rotation. ( B ) Slide arms up wall to facilitate combined activation of lower trapezius and serratus anterior to stabilize the scapula with glenohumeral forward elevation with external rotation.

Phase IV and Phase V: Muscular Power and Return To Sport

The rehabilitation goals of phase IV consist of establishing muscular power to return to high-level occupations or athletics, generally introduced at week 16. Supervised throwing progressions and sport-specific training are also incorporated at this time. Patients are allowed to return to sport between 16 and 20 weeks postoperatively if they have achieved full restoration of strength and stability as assessed by functional testing and have received physician approval.

Anatomy and Biomechanics

The primary static stabilizers of the AC joint include the AC ligaments and coracoclavicular ligaments. The AC ligaments are the primary restraints to horizontal instability of the distal clavicle, with the superior ligament providing 56% of the resistance to posterior translation and the posterior ligament contributing 25%. The coracoclavicular ligaments are the primary restraint to vertical instability, with the conoid ligament specifically providing 60% of the resistance to superior translation of the clavicle ( ). The trapezoid and conoid ligaments both originate posterior to the pectoralis minor insertion on the coracoid and traverse the coracoclavicular interspace. The conoid inserts onto the posteroinferior clavicle approximately 46 mm medial to the AC joint. The trapezoid inserts 26 mm medially to the AC joint and more centrally in the anteroposterior dimension ( ).

The author’s preferred technique for treatment of operative AC joint injuries is the ACCR. This surgical technique attempts to reconstruct the appropriate anatomy and biomechanics of the AC joint and coracoclavicular space, with the goal of restoring both vertical and horizontal stability to the AC joint. In the ACCR, the conoid and trapezoid ligaments are reconstructed using autograft or allograft tendon tissue, with reconstruction of the AC joint capsular ligaments. Fixation of the graft to the clavicle is performed using interference screws, but fixation of the graft to the coracoid can be performed one of two ways. The tendon graft may be passed around the coracoid base with the loop technique, or it may be fixed to the coracoid with an interference screw in the tenodesis technique. The tendon graft is supplemented with nonbiologic fixation in the form of high-strength nonabsorbable suture (no. 2 FiberWire, Arthrex). The biomechanical advantage of the anatomic coracoclavicular ligament reconstruction has been demonstrated in multiple studies. found that anatomic CC reconstruction with allograft had a significantly higher load to failure than modified Weaver-Dunn, anatomic suture, nonanatomic allograft, and GraftRope techniques. Although the ACCR can be performed via an arthroscopic approach ( ), the open approach using a loop technique is the author’s preference and will be described here.

Positioning

The importance of proper patient positioning should not be overlooked because it is a crucial step in this surgery. The patient is placed in the beach-chair position, with the torso and operative extremity brought to the edge of the surgical table ( Fig. 12B.1 ). A small radiolucent bump placed at the medial border of the scapula will serve to stabilize the scapula and elevate the coracoid anteriorly. The patient’s head should be secured in the beach-chair position, but it should not be firmly taped to the table as repositioning of the head is occasionally necessary during drilling of the medial clavicular bone tunnel. Before prepping and draping, the mini-C-arm should be trialed to ensure appropriate biplanar fluoroscopic imaging of the clavicle can be obtained. The operative arm is draped free to allow for easy maneuverability and reduction of the AC joint.

Patient positioned in a beach-chair position with additional scapular support, the head is turned medial to improve clavicle tunnel drilling. Surgical approach and anatomical landmarks are marked.

Surgical Exposure

Beginning laterally at the posterior clavicle and gently angling toward the coracoid process, a curvilinear skin incision is made along the Langer lines and centered approximately 3 cm medial to the AC joint. Full-thickness cutaneous flaps are elevated to expose the underlying deltotrapezial fascia ( Fig. 12B.2 ). The raphe between the clavicular attachments of the deltoid and trapezius provides a relatively avascular plane for dissection. Deltotrapezial fascioperiosteal flaps are then elevated posteriorly and anteriorly from the midline of the clavicle to circumferentially expose the lateral end of the clavicle and the AC joint laterally. It is important to elevate the entirety of the deltoid origin circumferential from the clavicle, including the inferior aspect, to allow for a full-thickness robust repair at the time of wound closure. Tagging sutures may be placed during the approach to allow for retraction during dissection and effective soft tissue coverage over the repair upon closure.

After curvilinear skin incision is made, full-thickness cutaneous flaps are elevated to expose the underlying deltotrapezial fascia. Deltotrapezial fascioperiosteal flaps are then elevated posteriorly and anteriorly from the midline of the clavicle to circumferentially expose the lateral end of the clavicle and the acromioclavicular joint laterally. Tagging sutures are placed during the approach to allow for retraction during dissection and effective soft tissue coverage over the repair upon closure.

Graft Selection and Preparation

An allograft (typically peroneus longus) or autograft (typically semitendinosus or gracilis) tendon can be used for this procedure. A standard tendon sizer is used to size the tendon, which is usually 5 mm in size. The graft size determines the size of the drill holes. The tendon graft should be prepared with as much length as possible to allow for later reconstruction of the AC capsule–ligament complex. The free tendon ends are then bulleted, and a whip stitch is placed to allow for a tight passage through the bone tunnels.

Coracoid Preparation

As mentioned earlier, the tendon graft can be secured to the coracoid by either looping the graft around the base of the coracoid (loop technique) or by a tenodesis technique with the graft secured to the base of the coracoid with an interference screw. The loop technique is described here because it is our preferred technique. The coracoid process is first exposed with soft tissue dissection, with clear delineation of its medial and lateral margins ( Fig. 12B.3 ). Importantly, the surgeon should not dissect too far into the posterior direction on the coracoid base because the suprascapular nerve is in close relationship. A Stanitsky aortic cross-clamp, or alternatively, a suture-passing device, is then passed in a medial to lateral direction around the coracoid process. A suture is fed around the base of the coracoid, and a loop is created at one of its free ends. The suture loop is then used to shuttle the prepared tendon graft, along with a supplemental collagen coated no. 2 FiberWire suture, around the base of the coracoid.

The coracoid process is first exposed with soft tissue dissection, with clear delineation of its medial and lateral margins. Loop the graft around the base of the coracoid with a Stanitsky aortic cross-clamp, or alternatively, a suture-passing device. The graft should be passed in a medial to lateral direction around the base of the coracoid process. A suture is fed around the base of the coracoid, and a loop is created at one of its free ends. The suture loop is then used to shuttle the tendon graft, along with a supplemental collagen coated no. 2 FiberWire suture, around the base of the coracoid.

Clavicle Preparation and Tunnel Placement

Next, attention is turned to creating bone tunnels in the clavicle for fixation of the tendon graft to recreate the anatomic location of the conoid and trapezoid ligaments. A guide pin is drilled approximately 45 mm medial from the distal end of the clavicle ( Fig. 12B.4 ). The conoid tubercle on the inferior surface of the lateral third clavicle marks the attachment of the conoid ligament and can serve as an anatomic landmark during guide pin placement. The guide pin should be placed posteriorly in the clavicle to recreate anatomy, but care should be taken to avoid disruption of the posterior cortical rim during subsequent reaming. A 5-mm cannulated reamer (assuming a 5-mm tendon graft) is used on power over the guide pin to create the bone tunnel for the conoid graft limb. The reamer is removed from the bone tunnel by hand to ensure the tunnel remains a perfect circle and is not widened by eccentric reaming. After reaming, a hand-powered tap 0.5 mm wider than the drill is introduced. The depth of the tunnel is measured for appropriate tenodesis screw length placement. The trapezoid ligament reconstruction bone tunnel is then created by placing a guide pin approximately 15 to 20 mm lateral to the conoid tunnel and centered in the clavicle in the anterior-to-posterior plane. The trapezoid bone tunnel should be 25 to 30 mm medial to the AC joint, and it is drilled and measured in an identical fashion to the conoid tunnel. We have demonstrated in our laboratory that the bone mineral density of the distal clavicle decreases more laterally, which can negatively affect the fixation strength and graft pullout.

A Measuring the distance from the distal clavicle end to planned anatomic coracoclavicular reconstruction tunnels. B A guide pin is drilled approximately 45 mm medial from the distal end of the clavicle. C A cannulated reamer is used over the guide pins. D After reaming, a hand-powered tap is introduced.

Graft Fixation

The free limbs of the graft can be passed through the bone tunnels in a crossed (figure of eight) or a noncrossed fashion (U loop). In our technique, the noncrossed U-loop graft is passed through the tunnels if there is predominantly posterior displacement of the clavicle, and the crossed figure-of-eight configuration is used if there is just superior displacement. An end of the nonabsorbable suture (no. 2 FiberWire) accompanies each limb of the tendon graft through the bone tunnels ( Fig. 12B.5 ). Reduction of the AC joint is then performed by applying an upward force to the elbow or arm. In addition to the superior-inferior reduction, care should be taken to adequately reduce the distal clavicle in the anteroposterior direction as well. The reduction is held using a large pointed reduction forceps placed between the coracoid process and the clavicle. Fluoroscopy is used to confirm anatomic reduction of the AC joint as well as the visualization of the exposed AC joint. The conoid limb of the graft is secured first. The graft is positioned so that the graft tail is left 2 cm proud from the superior aspect of the clavicle. The long tail of the graft exits the trapezoid tunnel laterally and is later used to augment the AC joint repair. A nonabsorbable radiolucent screw of the appropriate size and length (usually a 5.5-mm × 10- to 12-mm PEEK interference screw) is placed in the conoid tunnel. While holding reduction of the AC joint and traction on the graft, a second nonabsorbable radiolucent (5.5-mm PEEK) screw is placed in the lateral trapezoid bone tunnel anterior to the tendon graft. With the graft secure, the no. 2 FiberWire ends are tied over the top of the clavicle to provide nonbiologic augmentation of the repair. The pointed reduction forceps can then be removed and fluoroscopic images taken to confirm reduction of the AC joint.

AB The free limbs of the graft together with a no. 2 FiberWire can be shuttled through the prepared clavicle tunnels. C Reduction of the acromioclavicular (AC) joint is then performed, and a large pointed reduction forceps is placed between the coracoid process and the clavicle. The conoid limb of the graft is secured first. The long tail of the graft exits the trapezoid tunnel laterally and is later used to augment the AC joint repair. D The long limb of the graft is looped on top of the AC joint to augment the capsule repair. Meticulous closure of the deltotrapezial fascia is then performed.

Acromioclavicular Joint Repair and Closure

An AC joint repair is performed in the setting of acute AC joint dislocations. A no. 0 nonabsorbable suture is used in simple or figure-of-eight fashion to repair the AC joint capsule and ligaments primarily. The posterior and superior AC ligaments are crucial to the repair because they contribute significantly to resisting posterior and superior displacement of the clavicle. The long limb of the graft exiting the trapezoid tunnel is then taken laterally and looped on top of the AC joint to augment the capsule repair. The 2-cm graft tail exiting the conoid tunnel is folded lateral and sutured into the base of the graft exiting the trapezoid tunnel.

In chronic dislocations, the AC joint can also be repaired as described earlier.

After the AC joint repair is completed, the excess tendon graft is trimmed. Meticulous closure of the deltotrapezial fascia is performed using interrupted nonabsorbable sutures followed by 3-0 Monocryl subcutaneous closure and running subcuticular closure.

Postoperative Protocol

Postoperatively, patients are placed in a platform brace (DonJoy Lerman Shoulder Orthosis or Hangar Gunslinger Shoulder Orthosis) and remain immobilized in the brace for approximately 8 weeks. The platform brace supports the arm and minimizes the gravity-induced stress on the AC joint reconstruction. With the arm unsupported, the surgical repair experiences a large amount of stress as the AC joint is the only link connecting the upper extremity to the thorax (via the clavicle). During the first 3 months after open ACCR, activities that increase the stress on the repair site should be avoided. This protocol is based on the fact that tendon graft in a bone tunnel requires up to 12 weeks before achieving strong union at the bone–tendon interface, so the strength of the construct is predominantly dependent on the biomechanical properties of the repair during this time. After 8 weeks of immobilization, patients are referred to formal physical therapy. The early focus (weeks 8–12) of physical therapy is restoring shoulder range of motion and scapular control. Closed-chain (limb-supported) exercises are initiated first, with a transition to open chain exercises as mobility improves. Caution is used with range of motion exercises that increase stress on the AC joint, such as internal rotation behind the back, cross-body adduction, and end-range forward elevation. Rehabilitation shifts from mobility to strengthening and control during weeks 12 to 18. Scapular strengthening exercises include low rowing, horizontal abduction with external rotation, and prone horizontal extension with the arm at 100 degrees abduction ( ). For athletes in particular, weight training may begin at 3 to 5 months postoperatively. Athletes are allowed to return to full contact sports at 6 months. Athletes should be counseled that it generally requires 9 to 12 months to regain peak strength, particularly with bench press and deadlift type exercises ( ).

Results

Although level 1 comparative studies and long-term outcomes data on ACCR are currently lacking from the literature, the open ACCR technique described earlier is thought to be a valuable addition to the treatment armamentarium for both acute and chronic AC dislocations. Short- and midterm clinical outcomes studies have demonstrated that the majority of patients experience significant relief of pain, return of normal strength and function, and negligible loss of motion. recently reviewed the clinical outcomes of 31 patients at a minimum of 2 years after primary ACCR with tendon grafts. The authors found excellent postoperative outcomes scores (American Shoulder and Elbow Surgeon [ASES], Single Assessment Numeric Evaluation score [SANE], quick Disabilities of the Arm, Shoulder and Hand score [quickDASH], and patient satisfaction) in the 20 patients available for follow-up beyond 2 years (mean, 3.5 years) who had not undergone revision surgery. In an analysis of 59 shoulders after ACCR, found construct survivorship rates of 86.2% and 83.2% at 12 and 24 months, respectively. In addition, they noted a significant improvement in the postoperative ASES and Short Form 12 physical component scores at a mean follow-up of 2.4 years. Several other smaller series demonstrate similar results with high patient satisfaction rates and significantly improved outcome scores ( ). Although most of these studies involved young active patients, there are no known studies investigating return to sport and patient outcomes specifically in athletes after ACCR.

Complications

As with any procedure, open ACCR presents risks that must be considered when discussing treatment options with patients. Complications after open ACCR have been reported with varying frequency in the literature. reported an 18% complication rate (3 of 17 patients), which included 1 infection, 1 radiographic loss of reduction, and 1 patient with chronic AC joint pain. In a retrospective analysis of 27 patients, reported a much higher complication rate of 52% (14 or 27 patients), including fractures of the clavicle and coracoid, infection, and adhesive capsulitis. The most common complication, however, was radiographic loss of reduction (43% of reported complications), and this was not correlated to clinical outcomes in the study. Thirteen complications (28%) occurred in a series of 46 patients with ACCR using tendon grafts by , including 4 graft ruptures, 2 clavicle fractures, and 2 cases of painful hardware. The remaining complications included individual cases of hardware failure, hypertrophic distal clavicle, suture granuloma, adhesive capsulitis, and axillary neuropathy. and more recently have found that medialization of the clavicular bone tunnels is a risk factor for radiographic loss of reduction. The risk of clavicle fracture after ACCR has been an area of specific interest. In their biomechanical study, demonstrated that large (6.0-mm) bone tunnels significantly reduce the strength of the clavicle and may contribute to postoperative clavicle fractures. Technical pearls for avoiding coracoid and clavicle fractures include using the loop technique for coracoid fixation, creating smaller (5-mm) clavicular bone tunnels, maintaining sufficient distance between bone tunnels, and avoiding bone tunnels in the lateral 15 mm of the clavicle ( ).