Type 4 Acromioclavicular Joint Separation Reconstruction With Suspensory Fixation,Allograft,and Suture Augmentation

Abstract

Background:

This is a case of surgical treatment of a type 4 acromioclavicular (AC) joint separation via an arthroscopically assisted approach and reconstruction with combined suspensory fixation, allograft ligament reconstruction, and suture augmentation. AC joint injuries are relatively common, representing approximately 9% of shoulder injuries and approximately 50% of sport-related shoulder injuries. Most AC joint injuries do well when treated conservatively. However, the literature supports surgical treatment for high-grade injuries, failed conservative treatment, and open injuries or those with threatened soft tissues, with good clinical outcomes.

Indications:

Given the patient's age (14 years), activity level as a multisport high school athlete, limited shoulder function, and type 4 AC joint separation, surgical intervention for AC joint reduction and reconstruction was recommended.

Technique Description:

The patient is positioned in the beach-chair position. Standard shoulder arthroscopy is performed to evaluate for intra-articular pathology. The rotator interval is opened, and the undersurface of the coracoid is identified and cleared. An incision is created along the distal clavicle in line with the AC joint. The distal clavicle is found tethered in the trapezius muscle and is freed, reduced to its AC joint position, and secured with a K-wire. The AC reconstruction guide is positioned 3 cm medial to the AC joint and hooked under the coracoid base. Using arthroscopic guidance and fluoroscopy for anatomic positioning, a tunnel is drilled. The suspensory fixation device is passed through this tunnel and secured under the coracoid. The ends of the semitendinosus allograft with suture augmentation are passed medially and laterally around the coracoid base through the anterior arthroscopic portal, respectively, and retrieved through the superior incision. The medial limb is shuttled through a 3-mm drill hole in the clavicle, 15 mm medial to the suspensory fixation device, with adequate spacing to decrease fracture risk. The superior button of the suspensory device is tightened, the allograft ends are tied and sutured together, and the suture augment is tied securely to complete the AC joint reconstruction construct.

Results:

The patient was able to resume his activities of daily living without pain, with a full range of motion, and returning strength at 5 months postoperatively. He began a sports-specific return-to-golf program for the upcoming season.

Conclusion:

Arthroscopic-assisted reconstruction of type 4 AC joint separations with combined suspensory fixation, allograft ligament reconstruction, and suture augmentation is an effective surgical method to return patients to painless functional use of the extremity.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

This is a presentation reviewing the treatment of a Type 4 acromioclavicular joint separation with reconstruction using suspensory fixation, allograft, and suture augmentation.

Background

The patient is a 14-year-old right-hand dominant male ice hockey player who was checked into the boards during play. He developed immediate pain and deformity of the shoulder and was unable to continue playing. He had limited shoulder motion. He was taken to the emergency department, where he was diagnosed with an acromioclavicular (AC) joint injury and was placed in a sling. He was seen in follow-up by orthopaedics 5 days after injury. He is a 9^th grader and competes in multiple sports—including ice hockey, baseball, and golf.

On examination, there was obvious posterosuperior prominence of the distal clavicle with moderate to severe tenderness to palpation around the AC joint and trapezius. No skin-threatening conditions were present, and the deformity was not reducible. His active and passive range of motion was severely limited due to pain. Distally, he was neurovascularly intact.

Radiographs in the clinic demonstrated open physes and approximately 100% cranial translation of the distal clavicle compared with the contralateral side. There was a widening of the coracoclavicular (CC) interval on bilateral anteroposterior (AP) and Zanca views. On axial view, posterior translation of the distal clavicle relative to the acromion was present, concerning for a type 4 AC joint separation. Bilateral AP and Zanca views can be helpful in better evaluating the AC joint and CC interval.

AC joint injuries are relatively common orthopaedic injuries, representing approximately 9% of shoulder injuries and approximately 50% sport-related shoulder injuries. They range in severity from simple sprains to more complex high-grade injuries. AC joint injuries are 5 times more likely to occur in men and typically occur in young active populations.^1,10 They are very common in contact sports or sports with a risk of anterior impact to the shoulder, such as skiing or cycling during a fall. These injuries represent 15%, 20%, and 41% of shoulder injuries in ice hockey, skiing, and American football, respectively.^1,8,10 AC joint injuries typically occur with direct contact over the superolateral border of the shoulder with an adducted humerus.^1,10

The AC joint is stabilized by both static stabilizers and dynamic stabilizers. The static stabilizers consist of the AC joint capsule, the AC ligaments, and the CC ligaments. The AC ligaments are the superior, inferior, anterior, and posterior components and control horizontal motion. The posterior and superior limbs are the strongest and most important for stability. The CC ligaments are made up of the conoid ligament and the trapezoid ligament and control vertical motion. The conoid ligament is positioned more medially and attaches approximately 4.5 cm medial to the lateral edge of the clavicle at the conoid tubercle. The trapezoid ligament is located more laterally and attaches approximately 3 cm medial to the lateral edge along the trapezoid line. It is the stronger of the 2 ligaments. Both attach along the superior base of the coracoid. The dynamic stabilizers of the AC joint include the trapezius and deltoid muscles.^1,11,12

Most AC joint injuries are treated conservatively and do well. Surgical treatment is often reserved for high-grade injuries, failed conservative treatment, and open injuries or those with threatened soft tissues. The Rockwood classification can help determine treatment based on injury severity. Type 4 injuries involve posterior displacement of the lateral clavicle, evident on an axial view radiograph, that is irreducible as it is buttonholed through the trapezius muscle belly.^2,3,7,9

Indications

Treatment options fall into 2 broad categories: nonoperative and operative treatment. Operative treatment is typically reserved for type 3, 4, 5, and 6 injuries. There are many techniques for AC joint reconstruction, and controversy exists over which to use as superiority has not panned out in the literature thus far. Surgeons can use open or arthroscopically assisted approaches. Reconstruction can be performed using implants such as hook plates, screws, suspensory fixation, K-wires, or suture augmentation versus biologic constructs made of autograft, allograft, or local ligament transfer, or a combination of techniques.^2,3,9,13 In this case, given the patient's age, activity level, and type 4 AC joint separation, he was recommended for operative intervention using a combined reconstructive technique of suspensory fixation with allograft reconstruction with suture augmentation.

Technique Description

The patient is placed in the beach-chair position using an arm holder. Incisions are marked for standard posterior, anterior mid glenoid, and anterolateral portals, as well as a superior incision to access the AC joint and distal clavicle. Diagnostic arthroscopy of the glenohumeral joint is performed to inspect the joint for other pathology. The rotator interval is opened using the ArthroCare device (ArthroCare Corp). The coracoid base is identified, and all soft tissues are released from the undersurface. Our skin incision over the clavicle is made, and dissection is carried down to the fascia. This is opened with electrocautery, and the clavicle periosteum is elevated to allow visualization of the posterior and anterior borders. The distal clavicle is noted to be posteriorly displaced, piercing the trapezius muscle belly. Scar tissue is cleared, and the distal clavicle is reduced to its anatomic position. This was temporarily fixed with a K-wire through the acromion and distal clavicle. The AC joint reconstruction aiming guide is placed under the coracoid, and positioning is verified using arthroscopic assistance. The trocar is positioned superiorly 3 cm medial to the AC joint for anatomic reconstruction of the CC ligaments; this more anatomically reconstructs the stronger trapezoid ligament. A 2.4-mm guidewire is passed through the clavicle and coracoid base through the guide. Arthroscopy is used to verify adequate placement of the guidewire, and fluoroscopy is utilized to confirm adequate reduction of the AC joint and CC interval. The guidewire is removed, and a shuttling suture is passed through the bone tunnels and retrieved arthroscopically through the anterior portal. A shuttling loop is pulled back through the tunnel. The suspensory fixation device is passed through the tunnel utilizing the shuttling loop and is pulled out of the anterior portal. The button is loaded on the distal sutures, and the construct is pulled back and positioned under the base of the coracoid. This is verified under arthroscopic guidance.

A semitendinosus allograft is then prepared on the back table and is wrapped in a vancomycin-soaked Raytec sponge (Medline). An additional suture tape is added to the allograft to augment its strength. Through the superior incision, a curved hemostat is used to pass a shuttling suture under the coracoid base and is retrieved through the anterior portal. The medial limb of the allograft and suture augment is then retrieved through the anterior portal around the medial coracoid utilizing the shuttling stitch. A 3-mm drill is then used to create a tunnel through the clavicle 15 mm medial to our suspensory fixation with adequate spacing to decrease fracture risk. The medial limb of the graft is shuttled through the clavicle tunnel. The lateral limb of the graft and suture augment is then retrieved through the anterior portal along the lateral coracoid and pulled superiorly to the anterior clavicle, utilizing a passing stitch. The K-wire is then removed, and the clavicle is hyper-reduced. This is done to compensate for a small amount of loosening over time. The clavicle button of the suspensory fixation is cinched down to the bone. Fluoroscopic images are obtained to verify the appropriate reduction and placement of the suspensory fixation device. The 2 limbs of the allograft are then tied together over the clavicle and sutured together with a heavy Vicryl stitch (Ethicon). The suture tape is then tied overlying the allograft. Excess suture and graft are cut. The wound is filled with saline, and a Valsalva maneuver is performed to ensure no perforation of the lung. The incision is copiously irrigated, and hemostasis is obtained. The clavicle periosteum and trapezius/deltoid fascia are closed in separate layers. The remaining incision is then closed in a layered fashion. The patient is placed in a sling.

Here are postoperative images of the reconstruction construct. Suspensory fixation hardware is intact, and there is no evidence of fracture. These demonstrate a maintained reduction of the AC and CC intervals.

Postoperatively, patients are nonweightbearing in a sling for a minimum of 6 weeks. They are instructed to remove the sling for range of motion of the elbow, wrist, and hand to prevent stiffness of the remainder of the extremity, as well as pendulum exercises of the shoulder. We begin physical therapy at 2 weeks postoperatively, with an initial protocol focused on regaining full shoulder range of motion within 10 to 12 weeks. The sling is discontinued at 6 weeks, and patients can perform activities of daily living but are limited to lifting 1 to 2 pounds. Once the full range of motion has been achieved, at 12 weeks, strengthening exercises are initiated and patients are made full weightbearing as tolerated. Return to activity may occur from 5 to 8 months, depending on the sport or activity, and we may employ a specific return-to-sport program accordingly.

There are several considerations when performing this technique. First and foremost, know your anatomy. Multiple neurovascular structures lie in proximity to the coracoid.^4,5 Reducing the AC joint dislocation and maintaining this reduction is key in appropriately placing your suspensory fixation tunnel. K-wires from the acromion to the clavicle can be very helpful in maintaining reduction without the bulk of clamps that may get in the way of instrumentation. It is important to remember that the suspensory fixation and suture augment protect the reconstruction and provide stability while the allograft heals. This may ultimately allow for accelerated rehabilitation. Finally, complete and slight overreduction of the clavicle is necessary, as some minor loosening and stretching of the graft will occur in the short term.

Results and Conclusion

The management of AC joint injury has raised much controversy over the years. Surgical intervention is typically reserved for those who fail conservative treatment or for unstable type 3B, 4, 5, or 6 AC joint injuries. In 2024, Cleary et al ⁶ published the most encompassing systematic review on return to play after surgical treatment of AC joint injuries in the American Journal of Sports Medicine. They found that the overall return-to-play rate for all comers was 91.5%, with 85.6% returning to the preinjury level of play. Collision athletes demonstrated even higher return-to-play rates and return to the previous level of function. However, while overhead athletes also were found to have higher return-to-play rates, they incidentally had significantly lower rates of return to the previous level of play at 79.2%. When broken down by injury classification, types 3 and 5 injuries demonstrated excellent return-to-play rates. While type 4 injuries had significantly lower return-to-play rates, these rates were still comparable to those reported for rotator cuff repair and shoulder instability in the literature. Finally, they also found that the mean return to play time was around 5.7 months for recovery. Emerging techniques to repair or reconstruct the AC joint capsule are being more readily utilized to help control the horizontal stability of the AC/CC complex. However, there is conflicting evidence regarding the efficacy of these procedures, as some studies have found that while horizontal stability may be improved, this may not confer any clinical difference.

Our patient did very well postoperatively. He recovered full range of motion by 3 months out and had no pain. He returned to all activities of daily living by 3 months. His strength was returning. He began a return-to-sports program for golf at 5 months postoperatively. This case demonstrates that this is a safe and reproducible technique using modern devices and is a promising option for these high-grade injuries; however, larger and longer-term outcome studies are needed to determine the benefits of the procedure.