A comprehensive review of dynamic anterior stabilization of the long head of the biceps

Quality Assessment

Although formal quality assessment tools designed for systematic reviews were not applied to this narrative review, the studies were evaluated for methodological rigor, including sample size adequacy, follow-up completeness, outcome measurement validity, and potential sources of bias. Particular attention was paid to studies with prospective designs, validated outcome measures, and adequate follow-up durations.

Biomechanical Rationale for DAS

One of the driving concepts behind DAS is the creation of a dynamic soft-tissue sling at the anterior shoulder to resist dislocation forces, analogous to the effect of the conjoined tendon in a Latarjet procedure [14]. In Latarjet, the transferred coracoid's conjoined tendon, which originates from the conjoint of the short head of the biceps and coracobrachialis, acts as a sling that stabilizes the joint, particularly when the arm is in abduction and external rotation. DAS seeks to replicate that dynamic restraint using the patient's LHB tendon instead of a bone block [15,16]. The LHB originates on the superior glenoid at the supraglenoid tubercle and superior labrum and normally runs through the bicipital groove to the elbow. By tenodesing or reattaching the LHB to the anteroinferior glenoid, it can serve as a restraint to anterior translation when taut.

Hammock Effect

The re-routed LHB tendon drapes over the front of the humeral head like a hammock. In early abduction and external rotation, the LHB exerts a downward force on the inferior subscapularis and anterior capsule, supporting the humeral head and resisting subluxation [15,17,18]. This effect helps center the head in the glenoid at the initial range of motion, functioning as a passive stabilizing cradle.

Sling Effect

As abduction and external rotation increase, the LHB tendon fixed to the glenoid stretches across the front of the joint, providing a posteriorly directed force that directly opposes forward movement of the humeral head [15,17,18]. This is analogous to the sling created by the conjoined tendon in a Latarjet—the LHB physically blocks anterior translation at the critical position of vulnerability when the arm is cocked back in abduction and external rotation [13,14]. This dynamic restraint is engaged particularly during the late cocking and early acceleration phase of throwing or similar positions of apprehension.

Tensioning or Labral Bumper Effect

By placing the LHB along the anterior rim, especially in the onlay fashion, as described below, the tendon also augments the labrum, effectively deepening the anterior glenoid concavity. This labroplasty effect increases the bumper effect and the congruent contact area between the humeral head and glenoid [12,17]. If the native labrum is deficient or attenuated from multiple dislocations, the laid-on biceps can act as a pseudo-labrum, improving stability through increased concavity compression.

These mechanisms work in concert as a triple soft-tissue block to anterior translation. Notably, DAS also addresses any associated superior labral or superior labrum anterior to posterior (SLAP) pathology by removing the diseased biceps anchor, which is the LHB origin, and securing the tendon elsewhere [13]. Many patients with recurrent instability have a SLAP lesion or biceps tendon fraying; DAS inherently includes a biceps tenodesis, which can treat biceps-related pain and pathology while stabilizing the shoulder [13].

Hammock Effect

Mehl et al. [15] specifically evaluated the hammock mechanism by measuring anterior translation forces at different shoulder positions in cadaveric specimens with 13% glenoid bone loss. Their findings demonstrated that DAS provided significant restraint to anterior translation in early abduction, from 0°–30°, where the hammock effect would be most prominent. The transferred LHB created a mechanical advantage by distributing forces across the anterior capsule and subscapularis, effectively supporting the humeral head during the initial arc of motion. Force measurements revealed a 23% reduction in anterior translation in the 0°–30° abduction range compared with a Bankart repair alone, directly validating the theoretical hammock mechanism [15].

Sling Effect

The same biomechanical study by Mehl et al. [15] provided the most direct evidence for the sling mechanism by measuring restraint forces specifically in the apprehension position at 90° abduction with maximum external rotation. In this critical position, where most dislocations occur, DAS demonstrated resistance to anterior translation that was superior to both an isolated Bankart repair and a Bankart repair with conjoined tendon transfer. They showed that the LHB transfer increased anterior stability by approximately 16% compared with a Bankart repair alone, and that the greatest protective effect occurred at 90° abduction and external rotation [15]. This finding correlates directly with the theoretical sling effect, in which the transferred tendon provides maximum restraint during the position of greatest instability risk.

Nicholson et al. [18] further validated the sling mechanism in their comparative biomechanical study of patients with 15% glenoid bone loss. They demonstrated that DAS combined with a Bankart repair provided significantly less anterior translation under load than an isolated Bankart repair across all tested positions, but it showed the most pronounced effect during simulated apprehension testing. Their study specifically noted that the dynamicity of the LHB sling allowed normal motion in mid-range positions while providing maximal restraint during end-range external rotation, confirming the position-dependent activation of the sling mechanism [18].

Labral Bumper Effect

Bokshan et al. [19] provided specific evidence for the bumper effect through their comparative biomechanical analysis. They measured glenoid track width and the effective glenoid arc before and after DAS procedures using both the onlay and inlay techniques. Their findings show that onlay LHB transfer effectively increased the anterior glenoid arc, by an average of 8°–12°, functionally widening the glenoid track and improving the on-track/off-track relationship for Hill-Sachs lesions [19]. This measurable increase in effective glenoid concavity directly supports the theoretical bumper effect, in which the LHB tendon provides soft-tissue labral augmentation.

Furthermore, the same study demonstrated that the bumper effect was most pronounced when the LHB was fixed in an onlay fashion rather than inlay, because the onlay technique positioned the tendon directly along the glenoid rim where it could most effectively augment the labral bumper [19]. Contact pressure measurements showed more uniform distribution of forces across the glenoid surface with onlay DAS than with an isolated labral repair, indicating improved concavity compression mechanics.

Patient Positioning and Portals

The patient is typically placed in the beach-chair position under general anesthesia, though lateral decubitus can also be used by experienced arthroscopists. Standard shoulder arthroscopy portals are established—usually a posterior viewing portal and an anterior working portal in the rotator interval [13,20]. An anterolateral portal can also be used for instrument access or suture passage [20]. Proper portal placement is crucial to allow access to the inferior glenoid and facilitate the biceps transfer; surgeons often mark the coracoid and intended split in the subscapularis on the skin surface as orientation [20].

Diagnostic Arthroscopy and Bankart Repair

A thorough inspection is performed. Any coexistent injuries, including Hill-Sachs lesions, rotator cuff tears, and biceps pulley lesions, are noted. Attention is first aimed at the Bankart lesion. The anteroinferior glenoid rim is prepared with scar tissue debridement and light bone decortication. Suture anchors, usually 2–3, are placed along the anterior glenoid, and the capsulolabral complex is reattached with appropriate tensioning, much like a standard Bankart repair [13,20]. If the labral tissue is deficient (minimal or chronically attenuated), the surgeon can plan to rely on subsequent biceps labroplasty for a bumper effect [17]. In some cases, a Bankart repair was not possible because the labrum was nonviable, and the biceps tendon alone was onlaid to act as the labral bumper [17]. Typically, at least a partial labral repair is performed.

Biceps Tenodesis and Mobilization

The LHB is identified in the joint; it is often frayed in chronic instability cases. A standard biceps tenodesis is performed: the LHB is tenotomized from its superior labral origin. Some techniques secure the proximal end immediately to the superior glenoid as a soft anchor to prevent it from retracting excessively, whereas others retrieve the free end out of the anterior portal. The biceps is then prepared by trimming away degenerative portions as needed. Notably, the distal attachment of the biceps at the elbow is untouched—the muscle remains connected to the forearm, maintaining continuity so it can contract and generate tension in the transposed tendon [20].

Subscapularis Split as an Approach to the Anterior Glenoid

Gaining access to the anterior glenoid neck requires passage of the tendon through or around the subscapularis muscle. The classic approach is to create a horizontal split in the subscapularis tendon approximately at the junction of its upper two-thirds and lower one-third, similar to the level used in an open Latarjet approach [20]. This split is usually performed bluntly from within the joint or via an anterior-superior capsulotomy, and care is taken to protect the axillary nerve, which lies distal to a safe zone in the upper subscapularis. Through the split, an instrument is passed to grasp the freed end of the biceps tendon and pull it out to the anterior aspect of the glenoid neck, which now lies extra-articularly between the split subscapularis edges. Alternatively, some surgeons have described passage under the subscapularis to route the tendon by retracting the entire subscapularis upward; however a controlled split yields a more anatomic path and preserves subscapularis function.

Fixation of the Biceps Tendon to the Anterior Glenoid

Once the LHB is positioned along the anterior glenoid, it must be securely fixed there so that it heals in place. Two main fixation strategies exist—inlay and onlay—based on seating of the tendon within a bone socket or laid on top of the glenoid rim (Fig. 3).

Fig. 3.

Comparative schematic illustration of the inlay versus onlay dynamic anterior stabilization (DAS) techniques demonstrating the biomechanical differences in long head of the biceps tendon (LHB) fixation. (A) The inlay DAS technique, in which the LHB is transferred from its native superior glenoid origin and fixed within a surgically created bony socket on the anterior glenoid neck. This technique positions the tendon deeper within the bone, theoretically maximizing the hammock effect through close approximation to the glenoid while providing the sling effect during high-risk shoulder positions and contributing to overall joint stability through the tensioning effect. The inlay method might offer superior tendon-to-bone healing through increased contact area and protection within the bony trough, but it requires extensive bone preparation and carries potential risks of glenoid fracture during socket creation. (B) The onlay DAS technique, in which the LHB is fixed directly onto the anterior glenoid rim surface, positioned over the repaired labral tissue. This approach provides the same three stabilizing mechanisms as inlay DAS while additionally creating a pronounced labroplasty effect, whereby the tendon acts as soft-tissue augmentation for the anterior labrum to increase the effective glenoid concavity and improve the bumper effect against anterior translation. The onlay technique has gained favor due to its technical simplicity, avoidance of extensive bone drilling, and added benefit of labral augmentation in cases in which native labral tissue is deficient or attenuated by chronic instability. The two techniques achieve similar clinical outcomes in terms of stability and functional recovery, with the choice often depending on surgeon preference, bone quality, and concurrent labral pathology.

Inlay technique: a bone tunnel or socket is created in the anterior glenoid neck, and the biceps tendon end is placed into this trough and fixed; for example, with an interference screw or sutures through transosseous tunnels. This method, pioneered in some early descriptions [17], theoretically secures the tendon deeply and can maximize the hammock and sling effects by closely approximating the tendon to the glenoid. However, a large bone tunnel can weaken the glenoid, creating a potential fracture risk, and adds complexity.

Onlay technique: the tendon is laid flat against the anterior glenoid surface, essentially on top of the rim over the repaired labrum, and suture anchors are used to tie it in place against the bone. This is performed by passing multiple sutures through the tendon and tying them to anchors in the glenoid or via suture loops around the tendon itself. A popular method is the double double-pulley technique, which uses two anchors with sutures that are looped through the tendon in a pulley configuration to cinch the tendon securely [13,20]. Onlay fixation has come to be favored due to its technical simplicity and support of the aforementioned labroplasty effect by augmenting the anterior labrum [20]. Notably, healing rates of the tendon to bone have been similarly to those of other onlay and inlay fixation techniques [17], and onlay avoids the risk of glenoid fracture from drilling large holes.

Adjunct Procedures

If a significant Hill-Sachs lesion involving a posterolateral humeral head defect is present, the surgeon might combine DAS with remplissage, which is posterior capsulotenodesis of the infraspinatus into the defect. In fact, combining remplissage with DAS has been reported to engage off-track bipolar lesions and maximize stability in patients with high-risk lesions [17]. In the series by Khalil and Gad [17], for example, 12% of patients underwent concomitant remplissage for large Hill-Sachs lesions without issue. Thus, DAS can be part of a comprehensive approach to bipolar bone loss by addressing both sides of the joint. After biceps fixation, standard closure of the portals is performed.

Postoperative Protocol

After DAS, the shoulder is immobilized in a sling for a short period, typically 2–4 weeks, to allow the labrum and biceps tenodesis to initiate healing. Passive range of motion is started early, but external rotation is limited for approximately 6 weeks to protect the subscapularis split and biceps fixation [13,17]. Active biceps use is restricted for at least 6–8 weeks to allow tenodesis healing. Strengthening is introduced around 3 months, and return to full sports is usually allowed around 6 months postoperatively, once imaging or an exam confirms a stable healed construct [13,17].

Variations and Technical Pearls

In addition to the LHB, some surgeons have experimented with using the conjoined tendon from the coracoid for dynamic stabilization. An arthroscopic technique described by Wu et al. [21] involves detaching the conjoined tendon from the coracoid and securing it to the glenoid edge, akin to an arthroscopic Bristow without the coracoid bone. Another technical variant involves button fixation—using a cortical button device to secure the tendon on the far side of the glenoid cortex, similar to suspensory fixation in anterior cruciate ligament surgery [22]. Although those techniques are feasible, they are not often reported.

Surgeons performing DAS should be mindful of a few key points. First, ensure proper tension of the biceps tendon—it should be snug but not overtight—to avoid restricting external rotation or causing over-tension of the biceps muscle, a balance similar to that of tenodesis for biceps pathology. Second, protect the axillary nerve by remaining in the upper half of the subscapularis for the split; the nerve runs about 5 cm inferior to the top of the subscapularis insertion. Third, if using the onlay technique for a right shoulder, anchors are typically placed at the 5 and 3 o'clock positions on the glenoid to secure the tendon at the inferior and mid-anterior glenoid, corresponding to the typical Bankart anchor positions [13,20]. All-suture anchors are often used to minimize hardware and because they provide good fixation in glenoid bone while reducing the risk of collision with any later procedure, such as a potential bone block revision. Fourth, maintain subscapularis integrity—the split should be carefully closed or incorporated into the capsular repair to ensure that the subscapularis tendon heals without lengthening [12,13]; some techniques use a side-to-side stitch in the subscapularis after passing the biceps. If the subscapularis is inadvertently damaged, it should be repaired, as a deficient subscapularis could cause instability or weakness.

In summary, the surgical techniques for DAS have developed from early open, transosseous methods to refined all-arthroscopic, anchor-based techniques. Mastery of shoulder arthroscopy and familiarity with biceps tenodesis principles are prerequisites. When executed properly, DAS adds minimal operative time to a Bankart repair and avoids the need for osteotomy or hardware fixation of a bone graft, which is a major advantage of this procedure [12].

de Campos Azevedo and Ângelo [20]—Onlay DAS Outcomes after a Minimum of 1 Year

This prospective series evaluated 18 patients who underwent all-arthroscopic onlay DAS using the double-pulley technique for ≤20% glenoid bone loss, and 15 of them were followed for a minimum of 1 year. Among the patients, 60% were recreational or competitive athletes, including participants in soccer, volleyball, rugby, and martial arts. At a mean follow-up of approximately 2 years, the shoulder function scores showed significant improvements, with the Western Ontario Shoulder Instability Index improving by approximately 959 points and the Rowe score improving by approximately 74 points. Range of motion was largely preserved, with small but significant gains in elevation and rotation, reflecting restoration of confidence in shoulder use. Return to play was high: 93% of patients returned to sports, with 60% at their pre-injury level. Importantly, only 1 of 15 patients (6.7%) experienced recurrence, a re-dislocation in a hyperlax individual. No other complications were reported, and follow-up magnetic resonance imaging confirmed successful healing of LHB tenodesis in all cases. These results demonstrate that, even at 1 year, DAS can provide robust stability with a low recurrence rate in cases of subcritical bone loss.

Collin et al. [23]—Arthroscopic DAS 2-Year Results

Collin et al. [23] reported on 22 patients with recurrent instability and subcritical glenoid bone loss (mean of approximately 13% loss) treated with arthroscopic Bankart repair plus LHB transfer, the DAS procedure. Although specific athletic participation rates were not detailed, the authors noted that their population included "active individuals" with high functional demands. After an average of 3.2 years, the Rowe score improved dramatically from 36 preoperatively to approximately 90 postoperatively (P<0.001), indicating excellent functional outcomes. Range of motion was maintained postoperatively, with no significant losses in external rotation. They reported a 13.6% recurrence rate, with 3 of 22 patients experiencing recurrent instability during this mid-term period. Two of those failures were managed with revision Latarjet procedures, and 1 was treated nonoperatively. Notably, no patient had a Popeye deformity or biceps muscle cramping complaints, indicating that the tenodesis held and the muscle adapted well. Furthermore, the only neurovascular complication or instance of postoperative stiffness required brief manipulation under anesthesia, as reported in a commentary. The authors concluded that DAS provided "satisfactory 2-year results" for patients with subcritical bone loss by effectively augmenting the Bankart repair and preserving motion without the typical complications of bone-block procedures.

Wu et al. [21]—DAS with LHB Versus Conjoined Tendon, ≥3-Year Outcomes

In the largest comparative series to date, Wu et al. [21] from China reported on 63 patients with <15% glenoid bone loss. Among them, 33 patients underwent arthroscopic DAS with LHB transfer, and the other 30 patients received arthroscopic DAS with a conjoined tendon transfer. Within the whole study population, 78% were classified as competitive athletes who participated in contact sports including rugby, American football, basketball, and martial arts. All patients suffered recurrent anterior dislocations and were followed for a minimum of 3 years. The results were excellent in both groups, with no significant differences between the LHB-DAS and conjoined-DAS groups. At the final follow-up, the Oxford Shoulder Instability Scores were approximately 15, which is very low (indicating minimal symptoms), in both groups, and Rowe scores averaged in the mid-90s of 100, reflecting near-normal shoulder function. Patients experienced very low pain, with visual analog scale scores of approximately 0.7. The return to sport rate was high: approximately 90% in the LHB group and 87% in the conjoined group, with 75%–79% returning to their previous competitive level. Most strikingly, no recurrent dislocations occurred in either group. The study recorded only subtle signs of instability in a few patients: one patient in the LHB group reported occasional subjective subluxations, and one patient in each group showed a positive apprehension test, but those signs did not progress to frank dislocations. The complication profile was minimal—only one patient in each group showed a positive apprehension test, but those signs did not progress to frank dislocations. The complication profile was minimal—only 1 patient in the conjoined group developed postoperative stiffness that required arthroscopic release. No hardware problems, nerve injuries, or biceps ruptures were noted. This study provides strong evidence that arthroscopic DAS with either tendon choice yields durable stability at >3 years, showing equivalent outcomes for the LHB and conjoined tendon techniques. It also reinforces the low recurrence rates achievable in patients with <15% bone loss when augmented repairs are performed.

Khalil and Gad [17]—Onlay DAS 2-Year Outcomes

A prospective study from 2024 looked at 25 patients with a mean age of approximately 22.7 years and subcritical bone loss averaging approximately 22.5% glenoid loss (the higher end of subcritical) who were treated with onlay DAS involving LHB transfer. Although overall athletic participation was not specified, the authors noted that both recurrence failures occurred during "high-impact sports" involving handball and trauma from a fall, suggesting an active patient population. At a minimum of 2 years of follow-up, significant functional improvements were observed: the Rowe score improved from a mean of 21 preoperatively, indicating poor function, to 92.5 postoperatively. Likewise, the Quick Disabilities of the Arm, Shoulder and Hand score improved from 34.6, indicating substantial disability, to 14.6, indicating minimal disability. Those changes were both statistically and clinically significant. Magnetic resonance imaging at 6 months confirmed 100% healing of the biceps tenodesis to the glenoid in all patients. In terms of stability, two patients (8%) experienced a re-dislocation during high-impact sports about 9 months after surgery. Both had been on the higher end of bone loss (12% and 16% glenoid loss, respectively) and sustained traumatic re-injuries, one in handball and one in a fall, suggesting that, although DAS is robust, new trauma can still cause failure. Those two cases were successfully converted to Latarjet procedures. No other complications such as biceps issues or nerve injuries were reported in this cohort. The authors noted that patients with subcritical bone loss achieved "satisfactory 2-year results" with DAS, echoing high success rates with careful patient selection and treatment of any concurrent lesions (they performed remplissage in 3 patients with off-track Hill-Sachs lesions).

Other Studies and Follow-ups

Additional smaller case reports and technical case series; for example, a case report of a professional athlete returning to sport after DAS and a series combining distal tibia allograft with DAS to treat large bone loss, further support DAS as a safe and effective procedure. For instance, one report combined a free bone block for significant bone loss with a biceps transfer in select cases, reporting successful healing of both the graft and tendon [21]. Although those are specialized scenarios, they indicate the versatility of the DAS concept in a broader treatment algorithm.

Recurrent Anterior Shoulder Instability with Subcritical Glenoid Bone Loss

The DAS procedure is primarily indicated in patients with major soft-tissue injury involving a labral tear, capsule laxity, and some degree of anterior glenoid bone loss that might compromise a Bankart repair, but not enough bone loss to require a bony reconstruction. Subcritical bone loss is often defined as 13.5%–20% of lost glenoid width [1,3,24]. In practical terms, it might correspond to an inverted-pear glenoid on arthroscopy or a fragment size that is insufficient for screw fixation. If bone loss is mild (<10%), a Bankart repair alone usually suffices; if bone loss is critical (>20%–25%), a Latarjet or bone graft is recommended [1]. The DAS fills the niche for bone loss in the intermediate range of 10%–20%, where extra stability is needed but patients and clinicians hope to avoid a bone block procedure [13,17,23]. Indeed, the consensus is that the "best indication for DAS is anteroinferior instability with limited anterior bone loss" [25].

DAS Versus Bankart Repair with Remplissage

A particularly relevant clinical comparison is between LHB-based DAS and the combination of Bankart repair with remplissage. Both are arthroscopic approaches for managing subcritical bone loss with concurrent bipolar pathology. Although no direct comparative studies have been conducted, analysis of the available data reveals important distinctions in approach, indications, and outcomes.

Procedural Similarities and Differences

The two procedures share several characteristics: they are entirely arthroscopic, preserve native joint anatomy without bone grafting, and can be performed with lower morbidity than open bone-block procedures [14,18,20]. However, LHB-based DAS and the combination of Bankart repair with remplissage address instability through fundamentally different mechanisms. Bankart repair with remplissage focuses on restoring labral anatomy while converting off-track Hill-Sachs lesions to on-track through posterior capsulotenodesis [16,17]. In contrast, DAS emphasizes dynamic anterior augmentation through biceps transfer while treating Hill-Sachs lesions secondarily, if at all [13,23].

Indications and Patient Selection

The primary indication for Bankart with remplissage is subcritical glenoid bone loss, typically 10%–20%, combined with engaging or off-track Hill-Sachs lesions [16,19]. The procedure is specifically designed for bipolar bone loss in which the humeral defect contributes significantly to the instability risk. In comparison, DAS is indicated primarily for glenoid-sided pathology with subcritical bone loss, regardless of the presence of Hill-Sachs lesions, though it can be combined with remplissage for severe bipolar lesions [17,20].

The patient selection criteria also differ. Remplissage might be unsuitable for overhead athletes due to predictable external rotation loss, typically 5°–15°, and DAS is preferable for throwing athletes or those who require full range of motion [20,21]. Conversely, patients with large or off-track Hill-Sachs lesions might experience greater success from the targeted approach of remplissage than from anterior repair.

Comparative Clinical Outcomes

Clinical Decision-Making Algorithm

The choice between DAS and Bankart with remplissage should be individualized based on several key clinical factors and patient characteristics. DAS is typically favored in patients with primarily glenoid-side bone loss and minimal Hill-Sachs pathology, in whom the anterior augmentation provided by the biceps transfer can directly address the primary pathology. This approach is particularly beneficial for overhead athletes who require preservation of full external rotation; DAS maintains or even improves range of motion, whereas remplissage sacrifices external rotation. Additionally, DAS is an optimal choice when concurrent SLAP lesions require biceps management because it inherently addresses both instability and superior labral pathology through the tenodesis component. Patient preference for motion preservation over specific repair of Hill-Sachs lesions could also guide selection toward DAS in borderline cases.

Conversely, Bankart repair with remplissage is the preferred approach when significant bipolar bone loss exists with engaging or off-track Hill-Sachs lesions because it specifically targets the humeral-side contribution to instability. This technique is particularly indicated when the Hill-Sachs lesion is the primary contributor to recurrent instability, where targeted posterior capsulotenodesis is essential for stability restoration. Patients whose functional demands allow acceptable motion loss, typically non-overhead athletes, might benefit more from the specific bipolar approach of remplissage combined with anterior repair. Surgeon expertise and comfort level with the remplissage technique can also influence the decision in patients for whom either approach can be considered.

A combined approach incorporating both DAS and remplissage should be considered in cases of severe bipolar bone loss requiring both glenoid augmentation and Hill-Sachs management, particularly in high-risk athletes with significant defects on both sides of the joint. This comprehensive strategy might also benefit patients who have failed with prior single-procedure approaches, in whom addressing all potential contributors to instability is paramount. The combined technique requires careful consideration of the complexity and potential for overtightening, but it can provide optimal stability in the most challenging cases.

Future Research Directions

Direct comparative studies between DAS and Bankart with remplissage are needed to guide evidence-based decisions. Research priorities include randomized trials in overhead athletes, cost-effectiveness analyses, and long-term comparative outcomes. Additionally, studies evaluating combined DAS and remplissage procedures could help define optimal approaches for severe bipolar bone loss. In summary, both DAS and Bankart with remplissage are valuable arthroscopic options for patients with subcritical bone loss, and the choice between them depends on the relative contribution of glenoid versus humeral pathology, patient activity demands, and acceptable trade-offs between stability enhancement and motion preservation.

Biceps Strength Concerns in High-Demand Athletes

A critical consideration for DAS in high-demand athletes is the potential impact on biceps muscle function, given that the procedure fundamentally alters the anatomical course and length–tension relationship of the LHB. This concern is particularly relevant for athletes whose performance depends heavily on maximal biceps strength, such as weightlifters, gymnasts, rock climbers, and combat sport athletes [25,26].

Theoretical Biomechanical Concerns

The transfer of the LHB from its native superior glenoid origin to the anterior glenoid rim creates several theoretical disadvantages for biceps function. First, the muscle-tendon unit is effectively shortened by 2–4 cm, potentially altering the length–tension relationship and reducing peak force generation capacity [27]. Second, the vector of force application changes from a primarily superior–inferior direction to an anterior–posterior orientation, which can reduce mechanical efficiency for traditional biceps functions such as elbow flexion and forearm supination [28]. Additionally, the biceps muscle must now function in a constrained environment in which the tendon is fixed to the anterior glenoid rather than sliding through the bicipital groove. This alteration could theoretically reduce the muscle's ability to generate maximum exertion and power, particularly during dynamic movements that require rapid acceleration or high-load lifting [27,28].

Clinical Evidence for Biceps Function

Despite those theoretical concerns, the available clinical data suggest that functionally significant biceps weakness is uncommon following DAS. Wu et al. [21] specifically evaluated biceps strength using manual muscle testing and reported no clinically detectable weakness in either their LHB transfer group of 33 patients or conjoined tendon transfer group of 30 patients after a minimum 3 years of follow-up. Similarly, Collin et al. [23] noted no patient complaints of biceps cramping, fatigue, or functional weakness in their 22-patient series at 3.2 years of follow-up.

Khalil and Gad [17] performed detailed strength assessment using dynamometric testing in a subset of their patients, comparing the operated and contralateral shoulders of each. They found no significant differences in biceps strength between sides, though they acknowledged that subtle strength deficits might not be detected by their testing protocol. Importantly, no patients in their series reported subjective weakness or inability to perform desired activities [17].

The absence of Popeye deformities across all major DAS series [13,17,21,23] suggests that the tenodesis remains structurally intact and continues to function as an active muscle-tendon unit rather than a passive restraint. This finding contrasts with some biceps tenodesis procedures in which cosmetic deformity indicates a loss of muscle function.

Comparison to Standard Biceps Tenodesis Outcomes

The biceps strength outcomes after DAS appear to be comparable to those reported for standard biceps tenodesis procedures performed for biceps pathology. Systematic reviews of subpectoral and arthroscopic biceps tenodesis show that 85%–95% of patients maintain normal or near-normal biceps strength, with only 5%–15% reporting subjective weakness [29,30]. Given that DAS is essentially a form of biceps tenodesis to an alternative location, similar functional outcomes might be expected. However, the anterior glenoid location in DAS could provide some biomechanical advantages over traditional tenodesis sites. The tendon remains relatively proximal, closer to the original insertion than with subpectoral tenodesis, potentially preserving more of the native length–tension relationship [27].

High-Risk Athletic Populations

Certain athletic populations could be at higher than normal risk for functionally significant biceps strength loss following DAS. Powerlifters and Olympic weightlifters who perform maximum-effort biceps-dependent movements such as heavy curls and clean and jerk are likely the most vulnerable to subtle strength deficits that could affect their performance [26]. The altered biomechanics could be particularly problematic during rapid, explosive movements for which optimal length–tension relationships are critical. Gymnasts and rock climbers who rely on sustained biceps strength for hanging and pulling movements could experience endurance limitations even if peak strength is preserved [25]. The constrained tendon position could theoretically reduce the muscle's ability to function efficiently during prolonged isometric contractions.

Combat sport athletes such as those involved in wrestling, judo, or Brazilian jiu-jitsu who frequently perform grappling movements requiring maximal biceps strength in various shoulder positions could find that the altered vector of biceps force application reduces their effectiveness in sport-specific movements [26].

Clinical Assessment and Patient Counseling

Preoperative assessment of high-demand athletes should include a detailed evaluation of biceps-dependent activities and discussion of potential strength implications. Objective strength testing using dynamometry, when available, can provide baseline measurements for postoperative comparisons [31]. Patient counseling should include an honest explanation that, although major biceps weakness is uncommon, subtle strength changes remain possible and have not been systematically studied in high-demand athletic populations. Postoperative rehabilitation protocols should emphasize progressive biceps strengthening once tenodesis healing is complete, typically after 3–4 months. Sport-specific training should be gradually reintroduced, with attention to any subjective changes in biceps function or endurance [17,23].

Alternative Considerations for High-demand Athletes

For athletes whose livelihood or competitive success depends critically on maximal biceps function, several alternative stabilization procedures merit consideration, depending on the specific clinical scenario and risk–benefit analysis. The Latarjet procedure preserves native biceps anatomy and provides excellent stability through bony augmentation. However, it carries a higher complication risk profile than the arthroscopic alternatives, including potential graft nonunion, hardware issues, and neurologic injury, that must be weighed against the biceps preservation benefit. Bankart repair combined with remplissage is another option for addressing bipolar pathology without biceps alteration, but this approach sacrifices external rotation and might not be suitable for throwing athletes who require full overhead motion. Pure soft-tissue augmentation techniques using alternative donor tissues, such as a semitendinosus allograft for anterior reinforcement, are another approach to stability enhancement that preserves native biceps function, but they are less well-established and carry risks related to allograft incorporation and immune response. Each of these alternatives requires careful discussion with the athlete about the specific demands of their sport, the relative importance of biceps strength versus stability, and acceptable trade-offs in terms of motion, complications, and recovery time. The decision-making process should incorporate objective preoperative strength testing (when possible), detailed analysis of sport-specific biceps requirements, and an honest discussion about the current limitations in understanding biceps functioning after DAS in high-demand athletic populations.

Research Gaps and Future Directions

Critical research needs include objective strength testing via isokinetic dynamometry in DAS patients, particularly athletes. Sport-specific functional testing and performance metrics would better define any subtle deficits missed in standard clinical examinations. Additionally, long-term studies evaluating biceps muscle adaptation and potential compensation mechanisms are needed. Until more definitive data are available, surgeons should engage in shared decision-making with high-demand athletes, acknowledging both the theoretical concerns and the currently reassuring clinical evidence about biceps function after DAS [25,26].

Comparative Effectiveness: DAS Versus Bankart Repair Versus Latarjet

A central issue is comparison of DAS against the well-established traditional Bankart and Latarjet procedures. Each approach has advantages and disadvantages, and the choice often hinges on situation-specific factors such as bone loss, patient activity level, and surgeon expertise.

Range of Motion and Function

Bankart repairs usually preserve near-normal motion, with possible slight losses in extreme external rotation if the repair is overtight. They generally have good functional outcomes, assuming no recurrence, with high patient-reported scores in successful cases. Latarjet is more invasive and can affect motion. Some patients experience a small but significant loss of external rotation, commonly 5°–10°, due to the subscapularis split and tethering effect of the transferred coracoid [39]. However, meta-analyses have shown that, when performed well, the average external rotation loss is not dramatically different from that with Bankart repairs [40]. Still, in overhead athletes, such as throwers, even a slight loss of external rotation can be undesirable. Additionally, some Latarjet patients report subjective stiffness or tightness, and in a minority, abduction or rotation can be restricted, especially if they experienced concomitant capsule tightening.

DAS appears to preserve motion excellently. Cadaveric and clinical studies indicate no loss of external rotation with DAS compared with the intact shoulder [13]. Clinically, series have found maintained or even improved rotation postoperatively [23]. This is likely because the soft tissue sling is pliable and engages only at the end-range, and the arthroscopic technique limits muscle dissection. In Wu's study [21], for instance, both groups had a normal range of motion at follow-up, indistinguishable from the contralateral side in most cases. Patients also achieve high functional scores including Rowe and ASES comparable to Latarjet outcomes. One theoretical advantage for DAS is function: because it preserves the native anatomy without a bone block to alter contact pressures, it can lead to more natural shoulder kinematics. Moreover, by treating the biceps, it can alleviate any related pain, whereas Latarjet leaves the biceps intact to possibly develop biceps tendinitis after Latarjet if the bicipital groove is perturbed during the open approach. Overall, functional outcomes for DAS and Latarjet are both good.

Complications

Major differences between procedures are noted in their related complications.

Long-Term Considerations, Including Arthritis

The final comparison point is long-term outcomes such as arthritis or stability over decades. Stable Bankart repair patients can develop arthritis, especially those with many dislocations pre-surgery or with persistent slight translation. However, arthroscopic Bankart is generally tissue-preserving and does not inherently produce arthritis; long-term arthritis is more highly correlated with instability episodes.

Latarjet has a mixed legacy in terms of arthritis. Some long-term studies (15–20 years) have shown that a percentage of patients develop glenohumeral arthrosis; it is uncertain how much is due to the procedure versus the natural history of instability. If the Latarjet is conducted for someone with many prior dislocations, cartilage damage might already exist. An excessively large or poorly placed coracoid graft can cause cartilage wear. One long-term risk unique to Latarjet is hardware: screws can back out or cause mechanical irritation years later, sometimes requiring removal.

For DAS, only 10 years of data are available. However, the expectation is minimal degenerative changes if the shoulder remains stable, as it mimics a normal shoulder with an intact labrum. The biceps tendon itself, once healed in place, becomes an anatomic part of the joint; it is a soft tissue structure that likely will not cause erosion, as opposed to a bone block. Some theoretical concerns are degeneration of the transferred tendon over time, such as stretching or calcifying, but these remain speculative. Given the long-term success of biceps tenodesis elsewhere in the shoulder, such as subpectoral tenodesis, a well-healed biceps tenodesis to the glenoid is expected to endure.

Another consideration is revision options. After a failed Bankart, a patient can receive a Latarjet. After a failed Latarjet, revision is difficult as options are limited to allograft or arthrodesis. After a failed DAS, a patient can receive a Latarjet as salvage [17]. Thus, DAS does not limit options for future surgery as does Latarjet. This is one reason that DAS is an appealing intermediate step for young patients; it does not preclude later definitive bone-block if needed. In contrast, Latarjet cannot be followed by another procedure. Although DAS shows promising short- to mid-term recurrence rates, most evidence is derived from non-randomized, single-center studies. Direct comparative randomized controlled trials are lacking.

Limitations

Several important limitations must be acknowledged when interpreting the current evidence on LHB-based DAS. Most comparisons with established procedures, including Bankart repair and Latarjet, are indirect. No randomized controlled trials directly comparing DAS to these standard treatments have been published [1-5]. The available clinical studies are predominantly small, single-center case series representing level IV evidence, with sample sizes ranging from 15 to 33 patients and limited statistical power to detect meaningful differences in outcomes [13,17,21,23]. Follow-up periods remain relatively short at 1–5 years and might not capture late complications or failures that could emerge with longer observation periods.

Critical questions about long-term durability remain unanswered. The potential for biceps sling fatigue or attenuation over time has not been systematically evaluated beyond 5 years, and the biomechanical consequences of chronic loading on the transferred tendon are unknown [25]. Additionally, the effectiveness of DAS in truly high-risk patient populations, such as contact athletes with borderline bone loss of 18%–20% or patients with multiple previous failed procedures, requires further validation. Patient selection criteria vary across studies, hindering establishment of definitive indications or prediction of patients who will achieve optimal outcomes [13,17,21,23].