70.1 Goals of Procedure

Acromioclavicular (AC) joint injuries are found in approximately 9% of all shoulder girdle injuries and are associated with injuries occurring from a direct collision or axially directed force on the affected shoulder. Among AC joint injuries that are managed surgically, a number of key elements are essential to a successful postoperative outcome depending upon surgical technique utilized. These include anatomic reduction of the AC joint, direct repair or reconstruction of the coracoclavicular (CC) ligaments, protection of the CC ligament repair, or reconstruction with synthetic material to maintain AC joint stability during the acute phases of healing, repair of the deltoid and trapezial fascia, and distal clavicular resection in patients with evidence of AC osteoarthritis. ¹ Many open surgical techniques are currently employed to achieve these goals. Recent surgical advancements have led to the development of an arthroscopically assisted CC ligament reconstruction with free tendon grafts or synthetic material. ² Here we describe a technique for an all-arthroscopic CC ligament reconstruction utilizing a semitendinosus allograft and biocomposite tenodesis screws without disruption of the deltoid attachment onto the distal clavicle as seen with the open technique.

70.2 Advantages

This all-arthroscopic surgical technique minimizes soft-tissue dissection and reduces skin and wound complications in comparison to open CC ligament reconstruction. As a result, this technique leads to decreased patient morbidity and facilitates faster postoperative recovery with earlier return to work or sport. Additionally, the surgeon is able to address intra-articular shoulder pathology at the same time of the arthroscopic CC ligament reconstruction surgery. The portal location described and utilized with this technique, as well as its use of 30- and 70-degree arthroscopes, allows for proper visualization of all relevant anatomy and appropriate debridement of the coracoid base and distal clavicle. The use of tendon grafts (autograft or allograft) in CC ligament reconstruction is associated with lower rates of failure and early complications as compared to cortical fixation button (a commonly employed technique in modern arthroscopically assisted AC stabilization procedures for acute AC separations). ³ Moreover, AC joint reconstruction using a semitendinosus graft has been shown to achieve better Oxford Shoulder Score and Nottingham Score than the classic modified Weaver–Dunn procedure. ²

70.3 Indications

AC joint injuries are classified as types I to VI using the Rockwood system. This classification system is based on the extent of damage to the AC and CC ligaments as well as the displacement of the distal clavicle. ⁴ Type I and II injuries of the AC joint involve either sprain or tear of the AC ligament without tear of the CC ligaments and are managed nonsurgically with sling immobilization, early shoulder range of motion, and physical therapy. Type III, IV, V, and VI injuries all involve tears of both the AC and CC ligaments with varying displacements of the distal clavicle. Surgical management is indicated for patients with type IV, V, and VI AC joint injuries. The management of type III AC joint injury remains controversial; however, surgical intervention is typically considered in active patients with high functional demand on the shoulder. ⁵ It should be noted that the all-arthroscopic CC ligament reconstruction technique described here is significantly easier to perform on type V AC joint separation compared to type III due to the portal positions and the amount of the displacement of the distal clavicle.

70.4 Contraindications

All-arthroscopic CC ligament reconstruction is contraindicated if the distal clavicle is not reducible under general anesthesia. Advanced age is a relative contraindication to arthroscopic AC joint reconstruction due to poorer overall bone quality. This all-arthroscopic technique is very difficult to perform in patients with chronic type V AC joint separations who have calcification of the CC ligaments or heterotopic bone formation in the CC interval. The senior author (XL) recommends a mini-open approach for these cases.

70.5 Preoperative Preparation/Positioning

The patient is placed in the beach-chair position. The author prefers a semitendinosus allograft for this procedure; however, a semitendinosus autograft is also applicable for this technique. A no. 2 braided suture is used to prepare the graft via whip stitch across the entire length of the graft for augmentation. Additional no. 2 braided suture is passed on either end of the graft in a Krakow fashion in order to facilitate passage of the graft ( Fig. 70.1a). Graft thickness is measured to guide the size of the tunnel drilled on the distal clavicle.

70.6 Operative Technique

This all-arthroscopic technique utilizes four portals ( Fig. 70.1b): a medial portal (portal M—located just medial to the coracoid process), an anterolateral primary viewing portal (portal V), an accessory anterolateral portal (portal A—located 1 cm lateral to the anterolateral corner of the acromion), and an AC joint portal (portal B—located just lateral to the AC joint). A standard 30-degree arthroscope is utilized for the majority of the procedure. A 70-degree arthroscope is utilized for visualization of the coracoid and clavicular undersurfaces during the debridement and drilling of the distal clavicle.

Starting with the 30-degree arthroscope located in the standard posterior portal, a spinal needle is used to locate the rotator interval anteriorly. A radiofrequency (RF) device is then introduced through the rotator interval, and debridement of the rotator interval and coracoid base is subsequently performed. Adequate debridement of the coracoid base is essential for the success of this all-arthroscopic procedure. One trick is to establish the anterior portal slightly lateral in the rotator interval to be able to debride the top and bottom of the coracoid base. Alternatively, a 70-degree arthroscope can be used in the posterior viewing portal to facilitate this step if visualization of the coracoid base is difficult.

Following debridement of the rotator interval and coracoid base, the 30-degree arthroscope is moved to portal V. This is performed with the assistance of a switching stick. Portal V serves as the primary viewing portal for this technique and provides an excellent view of the subscapularis tendon and coracoid base ( Fig. 70.2 ). The RF device is inserted through accessory portal A to perform further debridement of the superior and inferior aspects of the coracoid base ( Fig. 70.2 ). In order to locate a working portal medial to the coracoid base, a spinal needle is inserted to assist in establishing portal M ( Fig. 70.3a). Once direct visualization of the spinal needle is achieved, a trocar is placed to widen the tunnel and also to further debride the soft tissue on the medial side of the coracoid base. The RF device is then inserted through the M portal for thorough debridement of the medial aspect of the coracoid base and release of the pectoralis minor tendon ( Fig. 70.3b) to help facilitate with the graft passage. Debridement is complete once the RF can be passed from the medial to inferior aspect of the coracoid base.

A 90-degree suture passer is introduced into the M portal such that the tip of the passer can be visualized on the medial and inferior side of the coracoid base. The suture shuttle device is passed medially around the undersurface of the coracoid base and the suture passer is then deployed. Using a grasper inserted through portal A, the deployed suture is grasped ( Fig. 70.4a) and a no. 2 braided suture is subsequently shuttled around the base of the coracoid. The limbs of this suture are used in a future step to facilitate passage of the semitendinosus graft around the coracoid base.

Next, debridement of the inferior aspect of the clavicle is performed. The anterior and posterior borders of the clavicle are delineated using three spinal needles, which serve as reference guides for the anterior and posterior extents of the clavicle during subsequent debridement ( Fig. 70.4b). The undersurface of the distal clavicle is visualized via a 70-degree arthroscope inserted in portal V. The clavicle undersurface is debrided using the RF wand inserted through the accessory portal B. Thorough soft-tissue debridement past 4.5 cm from the distal clavicle is critical for accurate drill tunnel positioning for the conoid and the trapezoid tunnel position.

Following thorough debridement and complete visualization of the inferior clavicle, a 3-cm incision is made in line with and superior to the distal clavicle at the location of the conoid (4.5 cm from the distal clavicle) and trapezoid tunnels (3.0 cm from the distal clavicle). Two clavicular drill tunnels (for the conoid and trapezoid) are now prepared. The senior author (XL) prefers to use either a 5.0- or a 5.5-mm cannulated headed reamer over a drill bit for the two tunnels and 5.5 × 8 mm polyetheretherketone (PEEK) tenodesis screws for the fixation (Arthrex, Naples, FL). The senior author (X.L.) finds that semitendinosus grafts will fit perfectly into a 5.0- or 5.5-mm tunnel. The tunnel position for the conoid medially is located approximately 4.5 cm from the distal clavicle and slightly in the posterior aspect of the clavicle. The tunnel position for the trapezoid laterally is located around 3.0 cm from the distal clavicle (1.5 cm lateral to the conoid drill tunnel) and slightly anterior on the distal clavicle. The conoid and trapezoid drill tunnels are created over guide pins from the superior to the inferior direction. The two drill guide pins are visualized arthroscopically on the inferior aspect of the distal clavicle using the 70-degree arthroscope via portal V during this process. Once the guide pin is drilled, either a curette or an arthroscopic grasper can be used to hold the pins and protect the soft tissue from injury. Once the two tunnels are made, the RF wand is used to debride the tunnels superiorly and inferiorly.

Following preparation of the two clavicular drill tunnels, the 90-degree suture passer (Ideal Passer with Chia; DePuy-Mitek Sports Medicine, Raynham, MA) is introduced through the medial (conoid) drill tunnel. The lateral limb of the no. 2 braided suture that was previously looped around the coracoid base is now shuttled through the medial (conoid) drill tunnel using a grasper and the deployed suture passer via portal A ( Fig. 70.5a). This step results in the medial limb of the suture still exiting through portal M and the lateral limb of the suture now exiting through the medial (conoid) drill tunnel. In similar fashion to the previous step, the suture shuttle is next introduced through the lateral (trapezoid) drill tunnel and the suture passer is deployed. The medial limb of the suture is then shuttled through the lateral (trapezoid) drill tunnel with the use of a grasper inserted through portal A. The result of these steps is a crisscross pattern of the no. 2 braided suture around the coracoid base with the medial limb exiting through the lateral (trapezoid) drill tunnel and the lateral limb exiting through the medial (conoid) drill tunnel ( Fig. 70.5b).

Attention is now turned to preparation of the semitendinosus allograft for passage. Mineral oil is applied along the surface of the graft to facilitate passage through the drill tunnels. Using the no. 2 suture, the graft is passed through one drill tunnel, around the coracoid base, and out the opposite drill tunnel. Following this maneuver, the two ends of the graft will be visualized through the 3-cm superior incision at the distal end of the clavicle. A biocomposite screw is now inserted into the medial (conoid) drill tunnel to secure this limb of the graft. The AC joint is then reduced using a superiorly directed force on the ipsilateral upper extremity and an inferiorly directed force on the clavicle. While holding this reduction, a second biocomposite screw is inserted into the lateral (trapezoid) drill tunnel.

The residual two ends of the tendon graft are sutured upon themselves with a no. 2 braided suture ( Fig. 70.6a) and the final reconstruction is seen arthroscopically ( Fig. 70.6b). Currently, the senior author (X.L.) also prefers to augment the reconstruction with a FiberTape (2.0-mm thickness, Arthrex) hand tied over the top of the clavicle that is passed around the coracoid base. This is passed at the same time as the semitendinosus allograft.