Arthroscopic-Assisted Acromioclavicular Joint Reconstruction Using the TightRope Device With Allograft Augmentation: Surgical Technique

Abstract

Surgical management of acromioclavicular (AC) joint separations remains challenging, especially in the revision setting. Most commonly, Rockwood type I and II injuries are managed nonoperatively whereas type IV, V, and VI injuries are managed with surgery. Type III separations are more controversial, with evidence supporting both nonoperative and operative treatment options. Multiple different arthroscopic techniques have been described; however, there is no current gold standard. AC joint reconstruction with the TightRope device (Arthrex, Naples, FL) with the patient in the lateral decubitus position is a method of restoring joint stability that allows for a minimally invasive, low-profile fixation construct using a single drill hole through the clavicle. Allograft augmentation of this fixation construct helps to eliminate the stress risers potentially created by this device while increasing overall repair construct stability. The purpose of this article is to describe the surgical technique for arthroscopic AC joint reconstruction using a TightRope device with allograft augmentation.

Restoration of the function of the acromioclavicular (AC) ligament, conoid ligament, and trapezoid ligament is critical to obtaining a successful outcome. Over 75 different surgical techniques have been described for AC joint reconstruction. Treatment options are variable but typically include one or more of several basic procedures, including primary AC ligament fixation with pins, screws, or rods; coracoacromial ligament transfer (Weaver-Dunn procedure) with or without distal clavicle excision; anatomic coracoclavicular (CC) ligament reconstruction; and arthroscopic CC ligament reconstruction or repair.¹ All techniques can be augmented with autograft or allograft tissue, as well as sutures or prosthetic materials (or both).

Arthroscopic-assisted AC joint reconstruction with the TightRope device (Arthrex, Naples, FL) with allograft augmentation and with the patient in the lateral decubitus position is a method of restoring joint stability using a single drill hole through the clavicle. The TightRope is a commercially available device that was originally designed for treatment of syndesmotic ankle injuries and has since been applied to multiple other bony and soft-tissue reconstruction procedures. The TightRope contains 2 titanium buttons (1 each for the clavicle and the coracoid process) joined by a loop of No. 5 FiberWire suture (Arthrex), and the device can be used for anatomic CC ligament reconstruction. One of the potential complications with this repair construct is suture failure by cutout through the coracoid or clavicle. Allograft augmentation of this fixation construct helps to eliminate the stress risers potentially created by this device while increasing overall repair construct stability. We describe the surgical technique for arthroscopic-assisted AC joint reconstruction with the TightRope device using hamstring allograft augmentation.

Surgical Technique

This technique is performed with the patient in the lateral decubitus position (Video 1). Both general endotracheal anesthesia and a supraclavicular regional blockade are used. An examination under anesthesia is performed, and the degree of AC joint instability, as well as feasibility of reduction, is documented. After routine skin preparation and draping, we establish a posterior viewing portal, as well as an anterior rotator interval portal, using an outside-in technique. A standard glenohumeral diagnostic arthroscopy is then performed with a standard 30° arthroscope. Next, a combination of an arthroscopic shaver and a radiofrequency device can be used to expose the base of the coracoid through the rotator interval. After initial dissection, the 70° arthroscope is then inserted through the posterior portal to improve visualization of the base of the coracoid. On the back table, both ends of the hamstring (semitendinosus) allograft are prepared with a No. 2 FiberWire by a whipstitch technique (Table 1). Care is taken to narrow one end of the graft to facilitate passage of this end of the allograft around the coracoid.

Table 1.

Summary of Surgical Steps

Hamstring allograft preparation (can occur at any time, on back table)

Whipstitch each end with No. 2 FiberWire

Narrow 1 end to facilitate graft passage

Examination of AC joint under anesthesia

Diagnostic arthroscopy in lateral decubitus position

Preparation of base of coracoid with shaver and RF device

Change to 70° arthroscope through posterior portal

Insert TightRope Guide through anterior portal, positioning tip just under base of coracoid

Make 1.5-cm incision transversely along distal aspect of clavicle

Dissect through deltotrapezial fascia to identify end of clavicle

Rasp anterior/posterior aspects of clavicle to create bleeding surface

Insert 2.4-mm guide pin through incision aimed toward base of coracoid

Drill guide pin through both clavicle and coracoid, visualizing arthroscopically

Remove drill sleeve, and leave guide pin in place

Drill 4-mm cannulated drill over pin through clavicle and coracoid

Remove guide pin

Advance nitinol wire through drill

Remove drill

Grasp wire with arthroscopic grasper; shuttle out through anterior portal

Place traction sutures (white) from TightRope through wire, and pull wire out of portal to shuttle TightRope into incision

Pull on traction sutures, and aim oblong button vertically through drill holes in clavicle and coracoid; then pull sutures in turn to flip button horizontally along inferior surface of coracoid

Reduce AC joint

Pull traction sutures (blue) on free end of TightRope to tension round button onto superior aspect of clavicle; do not tie sutures yet

Advance curved graft passer around coracoid from medial to lateral through open incision

Advance suture-passing wire through graft passer; remove passer

Shuttle hamstring allograft (narrow end) through wire loop

Pass wire from medial to lateral around coracoid

Repeat steps with curved graft passer to pass allograft around clavicle

Release arm from arm holder, and maintain reduction of AC joint

Tie TightRope Sutures; do not cut limbs

Tie allograft limbs in figure-of-8 fashion; cut ends

Place several figure-of-8 stitches with No. 2 FiberWire through both limbs of allograft for added security; use 3-5 stitches in total

Tie TightRope suture limbs over allograft; cut limbs

Close in layers in standard fashion

AC, acromioclavicular; RF, radiofrequency.

A 1.5-cm incision is made transversely along the distal aspect of the clavicle. Dissection is carried through the deltotrapezial fascia, and the distal aspect of the clavicle is identified (Fig 1). A rasp is used along the anterior and posterior aspects of the clavicle to prepare the bony surface to stimulate healing in the area approximated by the hamstring allograft. If visualization is inadequate, the incision can be extended laterally to aid in exposure and reduction of the AC joint. Next, the AC joint TightRope Guide (Arthrex) is inserted through the anterior portal and is positioned such that the tip is just under the base of the center of the coracoid. The arm of the guide can be used to appropriately position the incision. The guide pin (2.4 mm) with the drill sleeve is placed through the incision, over the distal aspect of the clavicle (approximately 35 mm from the distal aspect in the center), and aimed toward the guide at the base of the coracoid. The surgeon then drills the guide pin through both the clavicle and the coracoid under direct visualization, stopping as the pin meets the tip of the drill guide. The drill sleeve is then removed, leaving the guide pin in place. A 4-mm cannulated drill is advanced over the pin, again through the clavicle and the coracoid. The pin is then removed, and a nitinol wire is advanced through the drill. The drill is removed, and the wire is grasped with an arthroscopic grasper and is shuttled out of the anterior portal. The white traction sutures from the oblong hole of the TightRope are then passed through the nitinol wire, and the wire is pulled out of the portal as the TightRope is shuttled into the incision. Under direct visualization through the arthroscope, the traction sutures are gently pulled to place the oblong button into a vertical position, allowing it to be passed through the drill holes in the clavicle and the coracoid. The oblong button is passed first through the clavicle and then through the coracoid drill hole; once it has passed completely through the coracoid drill hole, each of the sutures from the oblong hole is pulled, and the button is subsequently flipped onto the inferior aspect of the coracoid (Fig 2). The AC joint is then reduced by manual pressure on the distal aspect of the clavicle, performed under direct visualization through the incision. The blue traction sutures on the free end of the TightRope are pulled, tensioning the round button down to the superior surface of the clavicle.

Fig 1.

Intraoperative photographs of a right shoulder with the patient in the lateral decubitus position. (A) A 70° arthroscope is inserted into the posterior portal with the acromioclavicular joint reconstruction guide in the anterior rotator interval portal, with the drill sleeve positioned in the location of the planned incision. (B) The camera has been removed posteriorly, and the acromioclavicular joint reconstruction guide outrigger arm has been removed, allowing for incision and dissection of the incision for the allograft. (C) Dissection through subcutaneous tissue after creation of a 1.5-cm incision in Langer lines over distal clavicle. (D) Drill sleeve positioned in incision after dissection.

Fig 2.

Arthroscopic photographs of a right shoulder with the patient in the lateral decubitus position showing (A) TightRope button passage through the clavicle and coracoid drill holes, (B) flipping of the oblong button from the TightRope under the coracoid, and (C) allograft passage around the coracoid from medial to lateral (one should note the whipstitch sutures through the leading edge of the graft).

Through the open incision, digital palpation of the intended hamstring allograft pathway is confirmed medially and laterally to the coracoid. A curved graft passer is passed around the coracoid, from medial to lateral, through the open incision. A suture-passing wire is passed through the graft passer, and the graft passer is removed. The sutures from the narrowed end of the hamstring allograft are passed through the wire, and the wire is then passed from medial to lateral around the coracoid. The curved graft passer is used a second time to pass the graft around the clavicle, with the medial limb of the graft posterior to the clavicle.

The arm is taken out of the balance suspension arm holder, and the assistant reduces the AC joint with blunt palpation on the distal aspect of the clavicle as the TightRope is tied. The FiberWire suture limbs of the TightRope are left intact, and the hamstring tendon is then tied over the FiberWire sutures using half-hitches with the graft itself, creating a figure-of-8 construct over the TightRope repair. Next, a No. 2 FiberWire is used to tie interrupted figure-of-8 stitches through both limbs of the allograft; approximately 3 to 5 stitches are placed (Fig 3). Finally, the blue suture tails from the clavicle button are tied by the arthroscopic knot-tying technique of choice over the allograft. The deltotrapezial fascia, subcutaneous tissue, skin, and portal incisions are closed in standard fashion. Our postoperative protocol is provided in Table 2.

Fig 3.

Intraoperative photographs of a right shoulder with the patient in the lateral decubitus position showing (A) tying of the hamstring allograft with a half-hitch over the TightRope button and sutures and (B) final fixation construct after completion of tying of the TightRope sutures over the allograft and interrupted No. 2 FiberWire sutures through both limbs of the allograft.

Table 2.

Postoperative Protocol After Arthroscopic-Assisted Acromioclavicular Joint Reconstruction Using TightRope Device With Allograft Augmentation

Postoperative Period	Rehabilitation Process
Immediately	The patient is immobilized in a sling with an abduction and derotation pillow.
0-6 wk	Use of the sling and pillow continues; elbow, wrist, and hand range-of-motion exercises are permitted.
6-8 wk	Use of the sling is discontinued; active-assisted range of motion is begun.
8-16 wk	The patient begins isometric rotator cuff strengthening, progressing as tolerated.
16-24 wk	Sports-specific training is performed.
≥24 wk	The patient returns to full activity.

Discussion

Dozens of surgical techniques for AC joint reconstruction have been described; however, there is no current gold standard. Many of the described repair options offer biomechanically robust reconstructions; however, they often require multiple drill holes through the clavicle, which can create stress risers or result in suture cutout (or both). The TightRope device has been described both biomechanically2, 3, 4, 5 and clinically6, 7, 8 as a viable reconstruction option requiring only a single drill hole through the clavicle; however, concerns over suture failure through bony cutout remain. Allograft augmentation of this fixation construct helps to eliminate the stress risers potentially created by the device while increasing overall repair construct stability. In addition, performing this procedure with the patient in the lateral decubitus position, as opposed to the more traditional beach-chair position, facilitates treatment of concomitant intra-articular pathology.⁹

Several authors have evaluated the biomechanical properties of the TightRope system for AC joint reconstruction.2, 3, 4, 5 Most often, these studies have reported high vertical stiffness loads with the TightRope construct but more physiological axial stiffness with other techniques such as hook plates, bone anchors, and cerclage wires.2, 4 Similarly, clinical investigations have examined the clinical application of the TightRope device for AC joint reconstruction, with encouraging outcomes.6, 7, 8 Of note, none of these studies has evaluated the incorporation of allograft augmentation of a TightRope construct, and thus the findings of these studies cannot necessarily be applied to the technique described in this report. Arguably, the stiffness of a given TightRope repair construct would increase with allograft augmentation; however, this has not yet been described in the literature.

This type of repair construct is not without limitations (Table 3). Recently, Motta et al.¹⁰ reported on 20 patients undergoing arthroscopic AC joint reconstruction with the TightRope device, with loss of joint reduction due to rupture of the sutures across the buttons in 4 patients (20%). In addition, supraphysiological stiffness of the repair construct has been shown biomechanically³; however, the clinical relevance of this is as yet undetermined. Furthermore, the use of allograft has inherent limitations not related to the AC joint, including cost, availability, and risk of disease transmission and infection.

Table 3.

Advantages and Risks of Surgery

Advantages

Minimally invasive

Low profile

Biological augmentation that reduces stress risers

Single drill hole through clavicle

Arthroscopic assisted

Risks/limitations

Risks of allograft use

Risk of suture cut-through with FiberWire

Risk of neurovascular injury

Cost of implant and allograft

Unknown long-term clinical results

Overall, for appropriately indicated patients, AC joint reconstruction with the TightRope device with allograft augmentation is an arthroscopic method of restoring joint stability that allows for a minimally invasive, low-profile fixation construct with excellent biomechanical stability. Allograft supplementation helps to eliminate the stress risers potentially created by this device while increasing overall repair construct stability. Additional studies are needed to determine the short- and long-term outcomes of this technique.

Supplementary Data

Video 1

Arthroscopic acromioclavicular joint reconstruction using a TightRope device in a right shoulder with the patient in the lateral decubitus position.