INTRODUCTION
Recurrent anterior shoulder instability is a common challenge in orthopedics, often resulting from traumatic anterior dislocations and associated Bankart lesions involving avulsion of the anteroinferior labrum. Traditional surgical solutions include soft-tissue repairs (such as the Bankart repair) and bone-block procedures (such as Latarjet), which are generally chosen based on patient factors and the extent of glenoid bone loss. In cases of significant bone loss, classically exceeding 20%–25% of the glenoid width, bony augmentation is recommended to restore stability [1,2]. However, the management of subcritical bone loss of 13.5%–20%, remains controversial [3]. In patients with bone loss, isolated Bankart repairs have higher failure rates—systematic reviews show a 3-fold higher risk of recurrence—than bone-block procedures such as Latarjet [4,5]. On the other hand, although Latarjet is very effective at preventing recurrence, it carries a notable complication profile, with reported overall complication rates of 15%–30%, including graft nonunion, hardware issues, neurovascular injury, and long-term arthropathy [6]. This trade-off has prompted the development of alternative techniques to bridge the gap between soft-tissue repairs and bony reconstructions.
Remplissage has emerged as an important tool in managing these bipolar lesions [7]. Studies have shown that remplissage effectively converts off-track lesions to on-track, reducing engagement and improving stability when combined with Bankart repair [8]. The procedure offers several advantages: it is arthroscopic, avoids the complications associated with bone grafting, and can be combined with anterior stabilization procedures. Clinical outcomes demonstrate recurrence rates of 5%–15% when remplissage is appropriately indicated, with most patients maintaining satisfactory range of motion despite some expected loss of external rotation [9]. However, remplissage also has limitations. It primarily addresses humeral-sided pathology and might not provide adequate stability in patients with significant glenoid bone loss. The procedure results in predictable loss of external rotation, typically 5°–15°, which can be problematic for overhead athletes [10]. Additionally, remplissage effectiveness depends on the size and location of Hill-Sachs lesions—very large or medially located defects might not be adequately addressed [11]. In cases with both significant glenoid bone loss and large Hill-Sachs lesions, combined procedures involving remplissage plus bone augmentation or alternative approaches are sometimes necessary.
During the past decade, dynamic anterior stabilization (DAS) has emerged as an innovative solution for anteroinferior shoulder instability, particularly in patients with subcritical bone loss. First described by Collin and Lädermann [12] in the mid-2010s, DAS combines a standard Bankart repair with dynamic reinforcement: the transfer of the long head of the biceps tendon (LHB) to the anterior glenoid. By re-routing the patient LHB across the joint as a sling, DAS aims to recreate the stabilizing sling effect of a Latarjet procedure without a bone graft [12,13]. In essence, it is an augmented Bankart repair—the labrum and capsule are repaired, and the LHB tendon is tenodesed to the anterior glenoid rim through a subscapularis split, creating an extra checkrein against anterior translation [12,13]. Early biomechanical and clinical evidence suggests that this dynamic sling can improve stability in ways not achievable with a static soft-tissue repair alone, while potentially avoiding the morbidity of open bone transfer surgery [12,13].
METHODS
Since their introduction, DAS techniques have developed to include all-arthroscopic methods, and clinical data have accumulated. This narrative review examines the biomechanical rationale underpinning DAS, describes the surgical technique and its variations, summarizes clinical outcomes (particularly recurrence rates, return to sport, and complications), discusses appropriate indications/contraindications, and compares the effectiveness of DAS to the conventional Bankart and Latarjet procedures. This review comprehensively evaluates the biomechanical rationale, surgical variations, clinical outcomes, and comparative effectiveness of LHB-based DAS.
A comprehensive literature search was conducted to identify all relevant studies on LHB-based DAS for shoulder instability. The search was performed across the PubMed/MEDLINE, Embase, Cochrane, and Google Scholar electronic databases from January 2014 through May 2025. The search timeframe was selected because the earliest comprehensive reports on DAS techniques were published around 2014.
The inclusion criteria were as follows: (1) studies describing LHB-based DAS techniques for anterior shoulder instability; (2) clinical studies reporting the outcomes of DAS procedures, including case series, cohort studies, and comparative studies; (3) biomechanical studies evaluating LHB transfer for shoulder stabilization; (4) technical notes and surgical technique descriptions for LHB-based DAS; (5) studies including patients with subcritical glenoid bone loss, typically 10%–25%; (6) minimum follow-up of 12 months for clinical outcome studies; (7) studies published in the English language; (8) peer-reviewed articles.
The exclusion criteria were: (1) studies focusing solely on other tendon transfers, such as conjoined tendon, without LHB data; (2) case reports with fewer than five patients; (3) studies on multidirectional instability without a clear anterior instability component; (4) non-English language publications without available translations; (5) studies with insufficient methodological detail or unclear patient populations; (6) duplicate publications or overlapping patient cohorts from a single institution.
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.
THEORETICAL STABILIZING EFFECTS OF DAS—THE TRIPLE EFFECT
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].
CADAVERIC BIOMECHANICAL VALIDATION OF THE TRIPLE EFFECT
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.
INTEGRATED BIOMECHANICAL EVIDENCE
The comprehensive study by Nicholson et al. [18] tested all three mechanisms simultaneously by comparing DAS with other stabilization procedures across multiple shoulder positions and loading conditions. Their key finding was that DAS provided position-dependent stability enhancement, with minimal restraint during mid-range motion, preserving normal kinematics, but significant restraint in at-risk positions. This behavior pattern directly supports the integration of all three mechanisms: (1) early motion stability through the hammock effect, with reduced translation in 0°–45° abduction; (2) end-range protection via the sling effect, with maximum restraint in the apprehension position; (3) overall concavity enhancement through the bumper effect, with improved stability across all positions due to increased effective glenoid depth.
MOTION PRESERVATION
Importantly, all cadaveric studies consistently demonstrated that DAS preserved external rotation range of motion compared with the intact shoulder [15,18]. Mehl et al. [15] specifically measured this parameter and found no significant loss of external rotation with DAS, whereas isolated Bankart repairs, especially under tension for bone loss, and Latarjet procedures tend to cause mild decreases in external rotation [13]. This finding supports the dynamicity of the LHB sling by providing restraint when needed but allows normal motion when the shoulder is in safe positions, distinguishing it from static constraints that can limit motion across all ranges.
MECHANISM SUMMARY AND CLINICAL IMPLICATIONS
The cadaveric evidence collectively validates the LHB-based DAS as a dynamic restraint system that acts through the proposed triple mechanism. The biomechanical data demonstrate that (1) the hammock effect provides early motion stability without restricting normal kinematics; (2) the sling effect delivers maximum protection in high-risk positions, where most dislocations occur; (3) the bumper effect enhances overall glenoid concavity and improves track relationships (Fig. 1).
These mechanisms work in concert as a triple soft-tissue block to anterior translation and offer the unique advantage of dynamic activation based on shoulder position and loading. This position-dependent activation explains why DAS can provide stability as well as bone-block procedures while preserving normal shoulder kinematics—effectively recruiting a dynamic stabilizer on demand while remaining relatively inert in safe positions. The biomechanical evidence supports the clinical rationale for using DAS as an intermediate option between simple soft-tissue repair and bone augmentation procedures, particularly in patients with subcritical bone loss who need enhanced stability but want to preserve their normal anatomy.
SURGICAL TECHNIQUE AND TECHNICAL CONSIDERATIONS
Several surgical techniques for DAS have been described, and their common principle is combining an anterior labral repair with a biceps tendon transfer. The procedure can be performed using an open approach, but arthroscopic surgery is more common. Arthroscopic DAS has been refined in recent years, allowing the entire procedure to be performed through a few small incisions, which is appealing to both patients and surgeons.
GENERAL STEPS OF ARTHROSCOPIC DAS USING THE LHB TRANSFER TECHNIQUE (Fig. 2)
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).
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 similar 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].
CLINICAL OUTCOMES OF DAS
Clinical results for DAS are emerging in the literature, with most studies reporting short- to mid-term outcomes ranging from 1–5 years. Overall, the data suggest that DAS can achieve stability rates comparable to those of bone-block procedures in properly selected patients, with good functional recovery and low complication rates, as shown in Fig. 4. Key findings from recent studies are summarized below.
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.
SUMMARY OF OUTCOMES
Across studies, the recurrent instability rates after DAS generally range from 0%–15% at early to mid-term follow-up, which is on par with reported recurrence rates for the Latarjet procedure in similar populations, 5%–10% in most series, and lower than the recurrence rates after isolated Bankart repairs in patients with even modest bone loss [13]. Functional scores, including Rowe, Western Ontario Shoulder Instability Index, and American Shoulder and Elbow Surgeons (ASES), consistently improve into the good-to-excellent range, and patients often regain full or near-full motion without the loss of external rotation that sometimes accompanies other procedures [13]. Return-to-sport rates are high, often greater than 85%–90%, including contact or overhead athletes, indicating the stability of the repair and the preservation of shoulder function [13].
DAS APPROPRIATENESS FOR HIGH-DEMAND CONTACT/COLLISION ATHLETES
The DAS procedure can be appropriate for carefully selected high-demand athletes in contact and collision sports, though with more restrictive criteria than for the general population [21]. Wu et al. [21] provide the strongest supporting evidence: 78% of their cohort consisted of competitive athletes in contact sports, including rugby, American football, basketball, and martial arts, and they reported 0% recurrence at a minimum 3 years of follow-up, with 90% return to sport and 75% return to the same competitive level. However, success appears to be highly dependent on patient selection, with optimal candidates having subcritical bone loss <15%, age <30 years, and sports that require motion preservation rather than pure collision exposure [17,21]. The procedure might be most appropriate for skilled position players such as quarterbacks and guards and multi-directional athletes in basketball and volleyball, for whom the motion preservation advantages of DAS outweigh the proven long-term durability of bone-block procedures [13,21]. Factors of consideration include the dependence of DAS on soft tissue, which might be more vulnerable to acute high-energy trauma than bone, as evidenced by failures during high-impact activities in Khalil's series, and the lack of long-term data (beyond 3–5 years) in athletic populations [17]. Therefore, although DAS represents a promising option for young contact athletes with subcritical bone loss, it remains a developing procedure with a potential 8%–13% recurrence risk and the possible need for revision to Latarjet if it is unsuccessful. Thus, DAS is most appropriate as a first-line treatment for young athletes for whom motion preservation is critical and whose future surgical options can be preserved [17,21,23].
In terms of complications, DAS appears to have a favorable profile. The absence of hardware screws and bone grafting eliminates issues such as nonunion, graft lysis, and hardware irritation. The main potential unique issues are related to the biceps; for example, tendon failure or Popeye deformity, but they have not been a major problem in published series. Collin's 22 patients demonstrated 0 cases of Popeye deformity or biceps rupture [23], and other series similarly report that the tenodesis remained intact throughout follow-up, with imaging confirmation [17]. Transient stiffness can occur, as with any shoulder surgery, but persistent stiffness is uncommon and usually resolves with therapy or a minor scope lysis [21]. Infection rates are extremely low; infection from arthroscopic shoulder surgery occurs in <0.5% of cases. An area of long-term concern is the effect of the altered anatomy, with the biceps across the joint, on glenohumeral cartilage and arthritis. However, given that DAS aims to stabilize the joint by preventing further dislocations, which themselves cause arthropathy, it is expected to reduce rather than increase long-term arthritis risk. Long-term data for DAS (5–10 years) have yet to be published; thus, continued follow-up of these cohorts will be important to ensure that stability is maintained over time and that no late tendon-related issues arise, such as attenuation of the tenodesis or biceps muscle fatigue.
INDICATIONS AND CONTRAINDICATIONS
Proper patient selection is critical for the success of DAS. Based on the literature and clinical experience, the indications for DAS can be outlined as follows.
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
Stability and recurrence
The available data suggest similar recurrence rates between the procedures. Systematic reviews of Bankart with remplissage report recurrence rates of 5%–15% in appropriately selected patients [18,19], comparable to the 0%–13.6% reported for DAS series [13,17,21,23]. Both procedures demonstrate better stability than isolated Bankart repair in the subcritical bone loss population.
Functional outcomes
Both procedures achieve excellent functional scores, with Rowe scores typically exceeding 90 points [18,23]. However, the mechanisms of improvement differ. Remplissage patients can experience initial functional limitations from posterior tethering that improve with rehabilitation, whereas DAS patients typically regain their range of motion immediately [13,20].
Range of motion
This represents the most significant difference between the procedures. Bankart with remplissage consistently results in external rotation loss, with a mean of 8°–15° across studies, which can be functionally significant for overhead athletes [20,21]. The DAS procedure preserves or even improves external rotation in most series, representing a substantial advantage for patients who require full motion [13,23].
Return to sport
Both procedures demonstrate high return-to-sport rates of 85%–95% overall, but DAS can offer advantages for return to the same competitive level, particularly in overhead sports for which motion preservation is critical [13,21]. Remplissage studies show more variable same-level return rates of 60%–85%, potentially related to motion restrictions [18,19] (Fig. 4).
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.
Failed isolated Bankart repair with moderate bone loss progression
Patients who have failed a prior Bankart stabilization and present with recurrence plus bone erosion from repeated dislocations are good candidates for DAS as a revision strategy. A traditional revision would often be an open Latarjet; however, if the bone loss remains in the subcritical range, arthroscopic DAS can be an attractive second-line option. It allows the use of remaining tissue plus augmentation without needing to resort to a bone graft when bone loss is not yet severe. Essentially, DAS can be used as a salvage technique for a failed Bankart in the presence of moderate bone loss or poor capsulolabral tissue quality.
Young, high-demand athletes with risk factors for recurrence
Even as a primary procedure, DAS might be preferred in a young athlete engaged in a high-impact sport and who has relatively minor or no measurable loss but high risk factors such as an engaging Hill-Sachs lesion or ligamentous laxity. The added sling effect could confer extra protection in collision sports, potentially avoiding recurrence compared with Bankart alone [13]. If an athlete has any sign of subcritical bone loss, DAS can be considered to support the repair, given the high failure rates of Bankart in that setting. For example, a 20-year-old contact athlete with 15% glenoid bone loss and a Hill-Sachs lesion would be a prototypical DAS candidate to maximize stability while preserving joint anatomy.
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].
Presence of SLAP lesions or biceps pathology alongside instability
Because DAS inherently involves biceps tenodesis, it is particularly indicated if the patient also has a type II SLAP tear or biceps tendinopathy due to instability episodes. Rather than performing biceps tenodesis and stabilization separately, DAS accomplishes both in one procedure [13]. Patients with chronic anterior instability often have superior labral damage that could cause pain or micro-instability; transferring the biceps addresses that pathology and uses the tendon for stabilization—a dual benefit.
Patient preference to avoid bone graft surgery
Some patients wish to avoid the potential complications of a bone block procedure. For those with borderline indications for Latarjet (15%–20% bone loss), DAS is an alternative that is less invasive (all-arthroscopic), requires no bone harvest or graft, and is potentially reversible because a Latarjet can be performed later should the DAS fail. Patients who prioritize a shorter recovery and less surgical morbidity might also opt for DAS if it is deemed appropriate by the surgeon. On the other hand, there are clear contraindications and cautionary scenarios for DAS.
Critical glenoid bone loss exceeding 20%–25%
When anterior bone loss is greater than the subcritical threshold—commonly cited around 20%—a bony reconstruction including Latarjet, an iliac crest graft, or distal tibia allograft is generally indicated [6,25,26]. DAS alone is unlikely to compensate for such large deficits in glenoid track width. In fact, DAS in a situation of severe bone loss could result in persistent instability or early failure because the soft-tissue sling cannot fully substitute for the missing bone. In those cases, bone augmentation, possibly combined with a dynamic procedure (some have combined a bone graft with DAS), is needed. Thus, DAS is contraindicated in cases of critical bone loss, where static stabilization via bone graft is required as the foundation.
Engaging Hill-Sachs lesions without a glenoid track or off-track lesions unless addressed
A large Hill-Sachs lesion that engages the anterior rim or is off-track demands additional procedures, such as remplissage or bone transfer, for stability. Though DAS by itself provides anterior stabilization, if the humeral defect is large, remplissage should be added or a different approach used. If remplissage is not performed for a large off-track lesion, DAS alone might not prevent engagement-related dislocations. So, either DAS should be combined with remplissage for off-track lesions or an alternative should be considered, such as a bone block that addresses both sides of the joint. In other words, DAS is not a standalone solution for large bipolar bone loss; it deals mainly with the glenoid side.
Multidirectional instability or gross ligamentous laxity
Patients with multidirectional instability or significant hyperlaxity, such as patients with connective tissue disorders or bilateral instability, are generally not ideal for DAS. Their instability is not due to a discrete Bankart lesion that can be resolved with a sling, but to generalized capsular redundancy. A capsular shift or plication is the appropriate treatment for multidirectional instability. In the series by de Campos Azevedo and Ângelo [20], the only failure was in a patient with hyperlaxity, indicating the insufficiency of DAS in such patients.
Contraindication
Multidirectional instability or hyperlax shoulders without well-defined Bankart lesions should be treated by other means; DAS is designed for traumatic unidirectional instability.
Poor or absent LHB due to prior tenodesis or rupture
Obviously, if the LHB tendon is not intact, it cannot be used for DAS. Patients who have had a prior biceps tenodesis or tenotomy for other reasons are not candidates for the LHB transfer version of DAS. In theory, conjoined tendon transfer could be used in such cases, but that becomes essentially an arthroscopic Bristow and entails a different set of considerations. Absence of a usable LHB is a contraindication to the standard DAS. Likewise, if the LHB is present but of very poor quality, such as attenuated or frayed to an extent that it might not hold sutures, caution is needed; however, even a somewhat frayed tendon can usually be trimmed and used.
Insufficient surgical expertise or resources
If a surgeon does not have experience with arthroscopic shoulder stabilization or is not comfortable with subscapularis splitting and tendon transfers, they should not attempt DAS without proper training. Moreover, the technique requires specific tools such as suture anchors and high-quality arthroscopy equipment. In the absence of required tools, an open bone-block could be safer. In summary, surgeon factors play a role in indication, and the procedure should be performed only by those experienced in shoulder arthroscopy and soft tissue reconstruction.
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.
Recurrence and stability
As perhaps the most critical metric, recurrence rate illustrates the effectiveness of each procedure in preventing further dislocations.
Bankart repair
For patients with minimal bone loss, isolated arthroscopic Bankart repair demonstrates low recurrence, often <10%. However, multiple studies have shown significantly higher failure rates for Bankart repair in patients with modest glenoid bone loss exceeding 10%–15%. Shaha et al. [1] found that outcomes "worsen with subcritical bone loss," those with approximately 13.5% loss had notably more numerous recurrences than those without bone loss. A recent meta-analysis of 4,584 shoulders confirmed that bony lesions are significant risk factors for recurrence following arthroscopic Bankart repair [27]. Military patients and contact athletes also have high failure rates with Bankart alone [28,29]. In short, Bankart repair is less forgiving in high-risk scenarios [30,31]. Reported re-dislocation rates in cases of subcritical bone loss were up to 75% in the absence of augmentation [32].
Latarjet
The open Latarjet is considered the gold standard for significant bone loss or failed prior stabilization. Recurrence rates after Latarjet are consistently low—often in the 0%–5% range in experienced hands over mid- to long-term follow-up [33]. For example, in large series, instability recurrence was 2%–5% at 5–10 years [34]. In comparative studies, Latarjet typically outperforms Bankart repairs in bone loss cases [35-37]. In addition, Latarjet has shown excellent stability, for which it is favored for collision sport athletes or revision cases [38]. Thus, in terms of raw efficacy in preventing dislocation, Latarjet is very robust. However, some failures occur, often due to trauma or extreme laxity or if the procedure is improperly indicated or executed.
DAS
Emerging data suggest that DAS approaches the stability of Latarjet in the short- to mid-term for patients with subcritical bone loss. Wu et al. [21] reported 0 dislocations in 63 DAS patients at 3 years, comparable to the best Latarjet outcomes. Other series report recurrence of 5%–7% at 1–2 years [17,23] and approximately 13% at >3 years [18], which are similar to many Latarjet series, with recurrence rates of 0%–5% in most contemporary meta-analyses [4,5]. Notably, in the subset of patients with subcritical bone loss ≤20%, DAS has superior stability to Bankart alone, effectively reducing the failure rate by more than half in such a scenario [13,23]. Although direct randomized trials of DAS versus Latarjet are lacking, the indirect comparisons are promising. An editorial in 2023 concluded that "DAS is an efficient and well-established glenohumeral stabilization technique, offering an arthroscopic alternative to Latarjet," with similar low recurrence rates in carefully selected cases [25]. The important factor is careful selection of patients without massive bone loss, in whom DAS performs very well.
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.
Bankart repair
Most complications of such repair are related to recurrence or failure, as well as general surgical risks such as infection and stiffness. Neurologic injury is very rare in Bankart repairs. Arthritis can develop if instability persists [40]. Overall, Bankart is a low-complication procedure, aside from the risk of failure in certain settings.
Latarjet
Latarjet has a known complication profile: graft nonunion in up to 2%–5% of cases, graft positioning problems (excessively medial or lateral) leading to instability or arthritis; hardware issues involving screw loosening or breakage requiring removal (approximately 5%); infection (slightly higher than scope procedures at 1%–2%); and neurological injury due to damage to the musculocutaneous and axillary nerves during coracoid harvest and drilling, along with the suprascapular nerve if the screws are too long. Fortunately, permanent nerve injuries are rare (<1%) for experienced surgeons [6]. Additionally, if the coracoid graft is not flush, it can cause contact arthritis over time by abrading the humeral head, contributing to the osteoarthritic changes noted in some Latarjet patients [17]. Another issue is scapular dyskinesis, in which the coracoid is detached with pectoralis minor insertion and alters the scapular kinetics; some patients experience anterior scapular tilt after Latarjet due to loss of tension of the pectoralis minor [12]. Even though that complication is often subclinical, it is a consideration. Overall, the complication rates for Latarjet in modern series are around 15%. A systematic review by Longo et al. [40] noted that Latarjet/Bristow had high success rates but also a relatively higher incidence of complications and reoperations than Bankart, and the Eden-Hybinette procedure involving an iliac crest graft had even higher recurrence and arthritis rates.
DAS
As discussed, DAS avoids many of the above issues. Absence of a bone graft avoids nonunion or graft malposition, and lack of metal screws prevents hardware complications. The neurologic injury risk is theoretically lower than with Latarjet because the coracoid and brachial plexus area is not dissected, and the axillary nerve is usually preserved if the subscapularis split is performed in the upper part of the muscle. Indeed, no published DAS study has reported nerve injuries or major vascular issues. In addition, infection risk is very low with arthroscopy. The unique concerns for DAS—integrity of the biceps and subscapularis—have largely been mitigated with improvements in the technique. In Collin's 22 patients, no biceps deformities or pain were noted, indicating reliable tendon healing and function [23]. The subscapularis in DAS is only split, not detached, and tends to heal well; persistent subscapularis weakness has not been reported as a major issue, unlike some older subscapularis augmentation procedures. One possible complication is re-dislocation requiring a salvage Latarjet—which occurs in a small percentage of cases; for example, 2 of the 25 patients in Khalil and Gad [17] required Latarjet after re-injury. If a DAS fails, the backup is usually a Latarjet, which tends to be more complex than usual due to scar tissue from the prior arthroscopy and the removal of anteriorly placed anchors or buttons. Nonetheless, Latarjet after failed DAS is feasible and has been achieved without major difficulty [17]. Another minor point is that the biceps muscle after DAS ends at the anterior glenoid instead of the supraglenoid, which is a shorter length, which could increase the risk of biceps fatigue or cramping during heavy lifting. However, in clinical follow-ups, patients have not voiced increased biceps issues, likely because the muscle adapts and the tenodesis is proximal, with only a few centimeters shift from the original anchor. In fact, removing the biceps from its intra-articular course could reduce anterior shoulder pain during activity.
In summary, DAS offers a compelling safety profile. First, it avoids the main complications of Latarjet because it involves no hardware, no bone block–related issues, and lower risk to nerves [12]. Second, its complication rates are low, mostly limited to occasional re-dislocation in high-risk scenarios. Bankart repair is also low risk, but it fails more often than DAS in suitable patients. Therefore, DAS combines the low complication rate of arthroscopic soft-tissue repair with the high stability of a bone-block procedure—at least in the short- to mid-term.
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].
CONCLUSIONS
The LHB-based DAS procedure is a promising arthroscopic alternative for managing anterior shoulder instability with subcritical glenoid bone loss. Current evidence demonstrates excellent short-term stability with recurrence rates of 0%–13.6%, excellent functional outcomes (Rowe scores >90), and better preserved range of motion than with bone-block procedures. The technique appears to bridge the efficacy gap between isolated Bankart repair and Latarjet procedures while maintaining the safety profile of soft-tissue reconstruction. Key clinical findings support DAS use in carefully selected patients with 10%–20% glenoid bone loss, in whom it provides enhanced stability without the complications associated with bone grafting. The procedure's ability to simultaneously address concurrent SLAP pathology through biceps tenodesis represents an additional therapeutic advantage.
Future research priorities must include randomized controlled trials that compare DAS directly to Bankart repair and Latarjet procedures, long-term follow-up studies extending beyond 5–10 years, and standardization of patient selection criteria. Until these evidence gaps are addressed, DAS should be considered a valuable but developing option in the surgical toolbox for anterior shoulder instability, requiring careful patient counseling about its investigational status and unknown long-term durability.
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