Acromioclavicular joint stabilization using autologous biceps for horizontal neutralization technique in the revision setting of acromioclavicular joint stabilization using autologous biceps

Complication rates of acromioclavicular joint (ACJ) stabilization vary severely (5%-88.9%) and are highly dependent on the primary technique.⁶ Due to altered and weakened anatomical relationships, revision surgery poses significant challenges. Only limited evidence exists on the preferred treatment method among a multitude of options for failed ACJ reconstruction.^1,9,10,18,21 There is a trend toward a hybrid technique, combining primary pulley-system coracoclavicular (CC) stabilization with biological graft augmentation.^6,10,17 When deciding on graft choice, the availability, high costs, and increased potential of graft failure of allografts must be considered.¹² Typical autografts, like the autologous hamstrings, require a second draped surgical field, possibly increasing infection rates and adding avoidable donor-site morbidity like hematoma, muscle weakness, or cramping.^2,13,19 In a revision context, another tendon harvesting may be denied by the patient or surgeon for this reason. A local autograft in the form of the coracoacromial ligament (CAL) has been used in the past but showed weaker biomechanical properties when used as a CC substitute in form of a modified Weaver–Dunn procedure compared to CC reconstruction.¹¹ Lately, the long head of the biceps (LHB) tendon has been discussed as an alternative autograft.^14,15 The autologous biceps offers distinct advantages, with cost-effective on-site availability, biological qualities, and the absence of additional donor-site morbidity.^4,21 A new technique using the autologous biceps for acromioclavicular (AC) and horizontal neutralization acromioclavicular joint stabilization using autologous biceps for horizontal neutralization [AutoBAHN] has been recently reported. It involves a transcoracoidal–transclavicular pulley-system fixation and transclavicular–supraacromioclavicular rerouting of the LHB tendon.

We present a technique for revision surgery of recurrent bidirectional ACJ instability. This arthroscopically assisted restabilization AutoBAHN revision technique (Fig. 1).

Figure 1.

(A) Schematic illustration of a right shoulder with implant loosening after primary surgery of acromioclavicular joint stabilization. (B) Illustration of the AutoBAHN revision technique. The LHB tendon is tenodesed in an onlay fashion and tenotomized near the musculotendinous junction. The LHB tendon is rerouted transarticularly and passed through the clavicula, The tendon is secured with an interference screw. The distal portion of the LHB tendon spans across the acromioclavicular joint and is anchored in the lateral central acromion. LHB, long head of the biceps; AutoBAHN, acromioclavicular joint stabilization using autologous biceps for horizontal neutralization.

Technique

The procedure was performed and developed in accordance with the ethical principles of the Declaration of Helsinki, and written informed consent for surgery and publication was obtained from the patient. For the implementation of the AutoBAHN revision technique, a clinical and radiographic work-up including anteroposterior stress views and Alexander views is required (Figs. 2 and 3).¹⁵ The work-up must also ensure that the LHB tendon is still present and intact. Computer tomography may further aid in estimating the precise position and extent of tunnels from the primary surgery.

Figure 2.

Anteroposterior stress views of a surgical progress: (A) pre-operatively, (B) 3 months after the primary acromioclavicular stabilization, and (C) after 7 months of the index surgery.

Figure 3.

Alexander views of the same patient as in Figure 1, depicting the surgical progress: (A) pre-operatively, (B) 3 months after the primary acromioclavicular stabilization, and (C) after 7 months of the index surgery.

In case of recurrent bidirectional ACJ instability after failed primary surgery, the CC stabilization is first re-established with a pulley system device.¹⁰ To achieve biological augmentation and horizontal stabilization, the LHB tendon is tenodesed and tenotomized proximal to the musculotendinous junction. While the proximal insertion of the LHB tendon is preserved, the distal portion of the LHB tendon is retracted intra-articularly and rerouted through the clavicle and over the ACJ, achieving additional vertical and horizontal stability (Video 1).

Surgical technique

Long head of the biceps tendon assessment and preparation

To rule out superior labrum anterior and posterior (SLAP) lesions and to assess the quality of the LHB tendon, a diagnostic glenohumeral arthroscopy is performed (Fig. 4A). The patient is placed in the beach-chair position, draped in sterile fashion and a posterior portal is created.

Figure 4.

(A) Arthroscopic views depicting the intact LHB tendon and the G. (B) After distal tenotomy, the tendon is grasped by its dLHB and retracted intra-articularly. The arthroscopic view further depicts the pLHB, the SSC tendon, and the H head. (C) The CB is exposed, and the previous implant is removed. (D) The previous drill hole is localized with a K-wire and débrided with a 3.5-mm drill (E). A new pulley system is introduced and tightly secured in place (F). LHB, long head of the biceps; G, glenoid; dLHB, distal long head of the biceps; pLHB, proximal long head of the biceps; SSC, subscapularis; H, humeral; CB, coracoid base.

Following diagnostic arthroscopy, the LHB tendon is exposed through a subpectoral approach. The tendon is armed with a nonresorbable suture (XBraid TT; Stryker, Kalamazoo, MI, USA) using a reinforced baseball-stitch configuration. A unicortical drill hole is created, and a 2.6-mm intramedullary button (Arthrex, Naples, FL, USA) is used for onlay tenodesis. Approximately 1 cm proximal to the musculotendinous junction, the tendon is carefully liberated from soft-tissue adhesions and tenotomized. The wound is irrigated thoroughly and closed in layers.

Arthroscopic setup and tendon management

The arthroscope is reintroduced into the glenohumeral joint. In addition to a standard anteroinferior portal, a transtendinous anterolateral viewing portal at the intra-articular site of the bicipital groove is created, supplemented by an additional anterolateral “parking” portal for tendon handling. The distal stump of the LHB tendon is mobilized intra-articularly, grasped through the parking portal, and exteriorized through the rotator interval (Fig. 4B). The tendon is reinforced in baseball-stitch fashion with a nonresorbable no. 2 suture, and its diameter is measured using a graft-sizing block. In most cases, a 5.0-mm diameter is appropriate for subsequent transclavicular tunnel preparation.

Implant management

A cranial incision in line with the clavicle is made approximately 3 cm medial to the ACJ. We recommend a singular incision, long enough for retraction of the failed pulley-system device and the exposure of a second drill hole for the later rerouted LHB tendon, lateral to the existing canal but medial to the ACJ. Subcutaneous and muscular layers are dissected to expose the superior surface of the clavicle. Arthroscopic dissection of the subcoracoid interval is performed with radiofrequency ablation to allow clear visualization of the coracoid base.

In revision settings, previously implanted pulley constructs must be carefully removed under arthroscopic and, if needed, fluoroscopic visualization (Fig. 5A). In case of remaining intact but loosened sutures, we recommend cutting them at the clavicle and retrieving them intra-articularly (Fig. 4C). The prior drill tunnel is inspected (Fig. 5B) and, if appropriately placed, should be reused for the new construct, in order to avoid unnecessary additional bone loss and to reduce additional fracture risk (Fig. 4D).

Figure 5.

Radiographic images depicting the transcoracoidal and transclavicular drilling and subsequent acromioclavicular joint stabilization. (A) The arthroscope is used to locate the old drill canal through the Cl and the CB. The previous drill canal is located with a 2-mm K-wire (B) and consequently over drilled with a 3.5-mm drill (C and D). After introduction of the new implants, the pulley system device is tightened using a suture tensioner (E). A slight over-reduction is achieved and desired (F). Cl, clavicle; CB, coracoid base; Ac, acromion.

Reconstruction of vertical acromioclavicular joint stability

The pre-existing transclavicular–transcoracoid drill tunnel is overdrilled and débrided with a 3.5-mm cannulated drill (Fig. 5C and D). A nitinol guidewire is advanced from the clavicle with the noneyelet end leading (Fig. 4E). A pulley-system device (ProCinch; Stryker, Kalamazoo, MI, USA) is shuttled through the tunnel and retrieved extra-articularly. A slotted concave 11-mm button (Stryker, Kalamazoo, MI, USA) is intertwined into the pulley system. The inferior button is positioned subcoracoidally and seated in a retrograde fashion by pulling the sutures superiorly until the button rests flush against the undersurface of the coracoid (Fig. 4F).

Using calibrated tensioning devices, the clavicle is reduced into a slightly overcorrected position relative to the acromion, which is desirable to account for later creep and relaxation (Fig. 5 E and F). The sutures are definitively tied over the clavicle and later reused for fascial and subcutaneous closure. This construct provides primary vertical stability of the ACJ.

Long head of the biceps rerouting and reconstruction of horizontal acromioclavicular joint stability

A second transclavicular tunnel is created lateral to the first and medial to the ACJ. A 2.0-mm K-wire is advanced and subsequently overdrilled to 5.5 mm (Fig. 6 A and B), enabling tendon passage (Fig. 7 A–C). A nitinol guidewire is introduced with the eyelet end leading (Fig. 7D). The LHB tendon, armed with sutures, is shuttled with the nitinol guidewire cranially and is rerouted through this tunnel (Fig. 7 E and F). Under maximal manual traction to ensure complete reduction and elimination of slack within the tendon, the tendon is secured intraosseously with a 5.5 × 10 mm interference screw. This provides rigid fixation and transforms the LHB tendon into a biological ligament substitute bridging the CC interval.

Figure 6.

Radiographic images depicting the Cl, CB, and the Ac. A second transclavicular tunnel is created with a 2-mm K-wire (A) and consequently overdrilled with a 5.5-mm drill (B). Once the tendon is rerouted through the Cl and spanned over the superior aspect of acromioclavicular joint, the distal aspect of the tendon is secured at the central aspect of the lateral Ac (C and D). Final images of the procedure are shown in (E) and (F). Cl, clavicle; CB, coracoid base; Ac, acromion.

Figure 7.

A K-wire is drilled through the clavicle (A) and gradually overdrilled with a 5.5-mm dill (B). A nitinol suture-passing wire is shuttled through the drill (C) and retracted with a suture grasper (D). After interlacing the distal suture of the LHB tendon with the nitinol Gw, the tendon is rerouted through the clavicle. (E) Depicts the pLHB, the SSC, and the shuttling maneuver with the Gw. The pLHB is successfully rerouted (F). LHB, long head of the biceps; pLHB, proximal portion long head of the biceps; SSC, subscapularis; Gw, guide wire; CB, coracoid base; G, glenoid.

To address horizontal instability, a transacromial drill hole for anchor placement is created under fluoroscopic control, with the drill trajectory carefully aligned to the center of the lateral acromion (Fig. 6C). An additional anterolateral portal may be necessary if the acromion cannot be accessed sufficiently, in order to place the lateral anchor in the middle part of the lateral acromion. The reinforcement sutures from the LHB tendon construct are retrieved subcutaneously and passed laterally to the acromial drill canal. They are secured with a knotless 4.75-mm Ω polyetheretherketone anchor (Stryker, Kalamazoo, MI, USA) and impacted intramedullarily into the acromion (Fig. 6D). This fixation not only anchors the tendon in an onlay fashion but also reconstructs the superior AC capsule, providing horizontal stability.

Finalization

The deltotrapezoid fascia is reconstructed with the remaining sutures of the pulley system, and the superior incision and the arthroscopic portals are closed in layers. Final fluoroscopic imaging confirms correct positioning of the pulley construct at the coracoid base, ACJ reduction, and secure anchor placement within the acromion (Fig. 6 E and F).

Discussion

Revision surgery for failed ACJ stabilization is a challenge. Multiple treatment and graft options have been described.^1,9,10,17,20 Recently, the autologous biceps has gained interest as a graft option for primary ACJ stabilization.14, 15, 16 We see particular value not only in the primary surgical setting but especially after failed ACJ stabilization, with emphasis on the benefits of a local biological graft choice.

Long head of the biceps tendon as autologous graft choice

The LHB tendons is a cost-effective local graft choice combining favorable biomechanic and anatomical properties, with a mean suitable graft length of approximately 13.8 cm and a stiffness of the native insertion of 103 N/mm.^7,8,21 However, intra-articular variants (1.9%-7.4% of the time) and variations in the origin (40%-60% of the time the LHB tendon originates partially from the SLAP complex rather than solely from the supraglenoid tubercle), must be considered.^3,5,18 Biomechanical data suggests sound resistance of the SLAP complex against acute and repetitive loads; yet SLAP lesions may occur, potentially weakening the LHB stiffness.³

Practical considerations and tips

In the case of revision surgery for reconstructing ACJ stability, several challenges must be considered. Presence and integrity of the LHB tendon must be ensured. Scar tissue may alter the surgical anatomy, possibly complicating the removal of the previous implant. We recommend using the image intensifier and, in case of suture loosening and resulting loss of reduction, to locate the clavicular implant and create one single, slightly larger incision instead of two smaller incisions for AC stabilization and LHB tendon rerouting. This way the exposure of the previous implant can be improved, and bone thickness and quality and the distance to the ACJ can be better estimated. When removing the previous pulley system, cutting the cranial suture enables caudal and arthroscopically controlled retrieval of the suture system.

To reduce additional bone loss, wherever feasible, the previous clavicular drill hole can and should be used to reduce fracture risk.²² If the direction of the transclavicular–transcoracoidal-tunnel needs to be improved, a drill guide for anterior cruciate ligament reconstruction can be used to determine the exact vector. Tunnel placement may be limited by the previous tunnel and can be challenging in the context of placing two new tunnels.

When exposing and later rerouting the LHB tendon, particular care must be taken to free the tendon from surrounding tissue adhesions for unhindered retraction. For further tendon management, we recommend the usage of an additional anterolateral portal as a “parking portal.” Before rerouting the tendon through the clavicle, the diameter should be measured once again to recognize excessive tendon swelling and prevent damaging the tendon during the rerouting. Adhesions or loose ends of the tendon can be addressed with a scalpel. During fixation of the rerouted tendon, maximal manual tension must be applied to eliminate slack within the tendon. Towards the end of the procedure, the image intensifier should be repositioned, and an additional anterolateral portal can be created to sufficiently access the acromion for the placement of the lateral anchor in the middle part of the lateral acromion.

Strengths and limitations

Graft availability is one of the major advantages of this technique. Allografts may not be available universally and can produce higher failure rates.¹² Autografts like the hamstrings require different draping, a broader surgical skill set, and may come with donor-site morbidity such as infection, hematoma, or muscle-related complications.^2,13,19 Other local grafts like CAL may not biomechanically provide the support needed.¹¹ Using the autologous biceps enables a low-cost, on-site biological augmentation with potential for improved healing capacity. This can particularly occur at the LHB tendon–clavicle interface and at the LHB tendon–AC capsule interface. If implant loosening of the pulley system should occur in the later course, the inherent biological properties of the intact LHB tendon may continue to ensure sufficient biomechanical vertical and horizontal stability.

The obvious limitation for this technique is the availability of a healthy LHB tendon and no significant SLAP lesions. Furthermore, some anatomical configurations, such as smaller patient size, may prevent tunnel placement with a diameter large enough for the LHB tendon. Some patients might also be bothered by the slight palpable prominence of the LHB tendon over the ACJ compared to conventional ACJ stabilization. Due to the technical demands and the delicate balance between tendon preservation and the risk of excessive tendon swelling, this arthroscopically assisted technique can pose surgical challenges. Long- and mid-term clinical outcomes have yet to be evaluated and compared to conventional revision surgery using other graft options and techniques.

Conclusion

The AutoBAHN revision technique provides a possibility for revision surgery of failed ACJ stabilization, utilizing the LHB tendon as a cost-effective, local autograft choice that, due to reduced donor-site morbidity and potential biological advantages, may benefit patients as valuable option for revision ACJ restabilization. Further clinical studies are required.

Disclaimers:

Funding: No funding was disclosed by the authors.

Conflicts of interest: Markus Scheibel reports a relationship with Stryker that includes: consulting or advisory. The other authors, their immediate families, and any research foundation with which they are affiliated have not received any financial payments or other benefits from any commercial entity related to the subject of this article.