Long head of biceps transfer to augment Bankart repair in chronic anterior shoulder instability with and without subcritical bone loss: a biomechanical study

Biomechanical Analysis Reveals Shoulder Instability With Bipolar Bone Loss Is Best Treated With Dynamic Anterior Stabilization for On-Track Lesions and With Remplissage for Off-Track Lesions

PURPOSE

To compare the biomechanical effects of augmenting Bankart repair (BR) with either remplissage or dynamic anterior stabilization (DAS) in the treatment of anterior shoulder instability with on-track or off-track bipolar bone loss.

METHODS

Eight fresh-frozen cadaveric shoulders were tested at 60° of glenohumeral abduction in the intact, injury, and repair conditions. Injury conditions included 15% glenoid bone loss with an on-track or off-track Hill-Sachs lesion as previously recommended. Repair conditions included isolated BR, BR with remplissage, and BR with DAS (long head of biceps transfer). The glenohumeral stability was assessed by measuring the anterior translation under 0, 10, 20, 30, 40, 50 N load and maximum load without causing instability at mid-range (60°) and end-range (90°) external rotation (ER). Maximum range of motion (ROM) was measured by applying a 2.2-N·m torque in passive ER and internal rotation.

RESULTS

Isolated BR failed to restore native glenohumeral stability in both on-track and off-track bipolar bone loss models. Both remplissage and DAS significantly decreased the anterior instability in the bipolar bone loss models, showing better restoration than the isolated BR. In the on-track lesions, DAS successfully restored native glenohumeral stability and mobility, whereas remplissage significantly decreased anterior translation without load (-2.12 ± 1.07 mm at 90° ER, P = .003; -1.98 ± 1.23 mm at 60° ER, P = .015). In the off-track lesions, remplissage restored native glenohumeral stability but led to significant ROM limitation (-8.6° ± 2.3° for internal rotation, P < .001; -13.9° ± 6.2° for ER, P = .003), whereas DAS failed to restore native stability at 90° ER regarding the increased anterior translation under 50 N (4.10 ± 1.53 mm, P < .001) and decreased maximum load (-13.8 ± 9.2 N, P = .021).

CONCLUSIONS

At time-zero, both remplissage and DAS significantly reduced residual anterior instability compared with isolated BR in the bipolar bone loss models and restored the native glenohumeral stability under most translational loads. However, remplissage could decrease the anterior translation without load for on-track lesions and may restrict ROM for off-track lesions, whereas DAS failed to restore native stability under high translational loads for off-track lesions.

CLINICAL RELEVANCE

DAS could be recommended to treat on-track bipolar bone loss with less biomechanical adverse effects, whereas remplissage might be the preferred procedure to address off-track bipolar bone loss for better stability.

Editorial Commentary: Arthroscopic Subscapular Sling Procedure for Anterior Glenohumeral Instability Has Limitations: Dynamic Anterior Stabilization Using Long Head of the Biceps Tendon May Represent a More Favorable Alternative

Anterior shoulder instability is common. Cases of mild glenoid bone loss are typically addressed with conventional arthroscopic Bankart repair procedures, whereas more critical glenoid bone loss often necessitates more invasive, bone-blocking procedures. Recently, for cases that fall between the need for arthroscopic repair and open procedures, surgeons have developed methods for using soft tissue grafts to create a "sling" effect and augment glenoid labral repair. The subscapular sling procedure aims to restore stability by introducing a semitendinosus autograft into the glenohumeral joint to reconstruct the torn labrum; the graft is wrapped around the subscapularis to create a suspensory sling. Limitations include harvest site morbidity; increased surgical time; subscapularis split, which can compromise the tendon integrity, resulting in loss of internal rotation; and a persistently positive apprehension test. Finally, the technique is complex, and similar alternatives with fewer limitations may include a dynamic anterior stabilization technique using the long head of the biceps tendon, which creates a stabilizing sling effect without graft harvest from the leg and has positive reported outcomes.

Long head of the biceps tendon versatility in reconstructive shoulder surgery: a narrative review of arthroscopic techniques and their biomechanical principles with video presentation

The management of the long head of the biceps tendon (LHBT) during shoulder arthroscopy has been a subject of controversy for many years, with evolving discussions and trends. Despite long-standing debate, the nature of the surgical indication regarding how to treat concomitent LHBT injuries has undergone changes in recent years. It now extends beyond the timing of tenotomy to encompass considerations of alternative methods for preserving the LHBT, along with an ongoing exploration of how it can be effectively utilized in reconstructive shoulder surgery. Recent techniques describe approaches to using LHBT in a wide range of procedures, from shoulder instability to rotator cuff tears. Additionally, LHBT-based reconstructive techniques have surfaced for addressing what were formerly denoted as irreparable rotator cuff tears. While current literature provides detailed anatomical descriptions of the LHBT and many reports of novel, advanced techniques, there is still much debate regarding the decision-making process in each case. Because of the growing number of emerging techniques and the escalating debate in the subsequent paper, a decision has been made to present the current literature review concerning the potential utilization of LHBT in shoulder arthroscopy. In a dedicated video, we demonstrate the main arthroscopic techniques employed by the authors in their daily practice.

Biomechanical comparison of open Bankart repair vs. conjoint tendon transfer in a 10% anterior glenoid bone loss shoulder instability model

BACKGROUND

The treatment of shoulder instability in patients with subcritical glenoid bone loss poses a difficult problem for surgeons as new evidence supports a higher failure rate when a standard arthroscopic Bankart repair is used. The purpose of this study was to compare a conjoint tendon transfer (soft-tissue Bristow) to an open Bankart repair in a cadaveric instability model of 10% glenoid bone loss.

METHODS

Eight cadaveric shoulders were tested using a custom testing system that allows for a 6-degree-of-freedom positioning of the glenohumeral joint. The rotator cuff muscles were loaded to simulate physiologic muscle conditions. Four conditions were tested: (1) intact, (2) Bankart lesion with 10% bone loss, (3) conjoint tendon transfer, and (4) open Bankart repair. Range of motion, glenohumeral kinematics, and anterior-inferior translation at 60° of external rotation with 20 N, 30 N, and 40 N were measured in the scapular and coronal planes. Glenohumeral joint translational stiffness was calculated as the linear fit of the translational force-displacement curve. Force to anterior-inferior dislocation was also measured in the coronal plane. Repeated measures analysis of variance with a Bonferroni correction was used for statistical analysis.

RESULTS

A Bankart lesion with 10% bone loss increased the range of motion in both the scapular (P = .001) and coronal planes (P = .001). The conjoint tendon transfer had a minimal effect on the range of motion (vs. intact P = .019, .002), but the Bankart repair decreased the range of motion to intact (P = .9, .4). There was a significant decrease in glenohumeral joint translational stiffness for the Bankart lesion compared with intact in the coronal plane (P = .021). The conjoint tendon transfer significantly increased stiffness in the scapular plane (P = .034), and the Bankart repair increased stiffness in the coronal plane (P = .037) compared with the Bankart lesion. The conjoint tendon transfer shifted the humeral head posteriorly at 60° and 90° of external rotation in the scapular plane. The Bankart repair shifted the head posteriorly in maximum external rotation in the coronal plane. There was no significant difference in force to dislocation between the Bankart repair (75.8 ± 6.6 N) and the conjoint tendon transfer (66.5 ± 4.4 N) (P = .151).

CONCLUSION

In the setting of subcritical bone loss, both the open Bankart repair and conjoint tendon transfer are biomechanically viable options for the treatment of anterior shoulder instability; further studies are needed to extrapolate these data to the clinical setting.

Anchorless Onlay Dynamic Anterior Stabilization of the Shoulder Using a Guided Posterior Double Endobutton Fixation

The treatment of shoulder instability in the presence of a subcritical glenoid defect poses challenges, as simple Bankart seems insufficient, and the Latarjet procedure may be excessive. Recently, a dynamic anterior stabilization technique involving anterior transposition of the long head of the biceps (LHB) through a subscapularis split was described for that purpose. Previously published results demonstrated good short-term results, but several technical pitfalls have also been mentioned. We describe an onlay, anchorless, and intra-articular knotless method of fixing the LHB into the anterior glenoid that provides the important stabilizing "sling effect" of the dynamic anterior stabilization while avoiding some of the pitfalls described by other techniques.

Modified Dynamic Anterior Stabilization and Labroplasty for Anterior Shoulder Instability With Concomitant SLAP Lesion

Several arthroscopic techniques to treat anterior shoulder instability have been described. Bankart repair may be insufficient in cases with some degree of bone loss, and arthroscopic Latarjet is technically challenging. It is not rare to find at the time of surgery a more extensive labral tear (SLAP lesion) or an insufficient anterior capsulolabral tissue. We describe for those cases a dynamic anterior stabilization where using the long head of the biceps we are treating the SLAP lesion and at the same time it provides the "sling effect" of a Latarjet procedure for the anterior instability.

How many anchors to use in arthroscopic Bankart repairs? A biomechanical study of postage-stamp glenoid fractures

BACKGROUND

Deciding how many anchors to use in a Bankart repair is challenging because of the desire to enhance stability while avoiding a postage-stamp fracture of the glenoid rim.

METHODS

This controlled laboratory study investigated load to fracture of the anterior glenoid rim after drilling holes of varying number and diameter and inserting anchors of 2 different types and sizes, with and without perforation of the medial cortex of the glenoid, creating postage-stamp fractures using a metallic humeral head that was compressed against the anterior glenoid rim. A destructive model with a servohydraulic load frame was used to test 46 synthetic scapulae with compressive strength and elastic modulus similar to that of a human glenoid. Load to fracture of the intact glenoid was compared with groups with a varying number of anchor holes of different diameters, with anchors of different sizes and types, and with anchors perforating or not perforating the glenoid medial cortex. The percentage of force to fracture an intact specimen was used to identify relative risk of fracture: low risk >75%, moderate risk 75%-50%, and high risk <50% of intact load.

RESULTS

The load to fracture of intact glenoids was 1276 ± 42 N. Loads decreased linearly as the number of holes drilled on the glenoid rim increased. Compared with the 1.6-mm group, the 3.0-mm group had significantly lower glenoid rim strength in specimens with 4, 5, and 7 holes (P = .013, .032, and .045, respectively). All-suture anchors in 1.6-mm holes did not alter the glenoid rim strength, and up to 5 anchors were associated with low risk of fracture. Load to fracture was significantly higher with 3.0-mm rigid core bioabsorbable anchors with 4 anchors (1081 ± 6 N) compared with the 4-hole condition (838 ± 107 N; P = .033). Perforating the glenoid medial cortex with five 1.6-mm anchors significantly weakened the glenoid rim to 58% of intact (P = .012). Perforating the medial cortex weakened the glenoid rim to 52% and 42% (P < .001 for both) of intact in the 3.0-mm 4-anchor and 5-anchor constructions, constituting moderate and high risk of fracture, respectively.

CONCLUSION

Up to five 1.6-mm all-suture anchors and four 3.0-mm bioabsorbable rigid-core anchors were associated with low risk of fracture of the glenoid rim. Smaller diameter all-suture anchors best preserved structural integrity of the glenoid rim, whereas tunnel enlargement and perforation of the glenoid medial cortex were associated with moderate or high risk of a postage-stamp fracture.

The long head of the biceps tendon: a valuable tool in shoulder surgery

ANATOMY AND FUNCTION

The long head of the biceps tendon (LHBT) has different properties and characteristics that render it a valuable tool in the hands of shoulder surgeons. Its accessibility, biomechanical strength, regenerative capabilities, and biocompatibility allow it to be a valuable autologous graft for repairing and augmenting ligamentous and muscular structures in the glenohumeral joint.

SHOULDER SURGERY APPLICATIONS

Numerous applications of the LHBT have been described in the shoulder surgery literature, including augmentation of posterior-superior rotator cuff repair, augmentation of subscapularis peel repair, dynamic anterior stabilization, anterior capsule reconstruction, post-stroke stabilization, and superior capsular reconstruction. Some of these applications have been described meticulously in technical notes and case reports, whereas others may require additional research to confirm clinical benefit and efficacy.

CONCLUSION

This review examines the role of the LHBT as a source of local autograft, with biological and biomechanical properties, in aiding outcomes of complex primary and revision shoulder surgery procedures.

Shoulder Anteroinferior Glenoid Labrum Reconstruction With the Long Head of the Biceps Tendon Restores Glenohumeral Stability: A Cadaveric Biomechanical Study

PURPOSE

The purpose of this cadaveric study was to determine feasibility and assess biomechanical stability of glenoid labral reconstruction utilizing the long head of the biceps tendon (LHBT) as a local autograft for labral deficient shoulders.

METHODS

Ten cadaveric shoulders underwent resection of all soft tissue structures except the labrum and LHBT. The scapula and humerus were separately attached to a custom shoulder testing apparatus allowing for 22.5 N of compressive isotonic force across the joint. An Instron (Electroplus 1000) measured the peak force (N) as the humeral head was translated over the anteroinferior glenoid rim through 10 cycles. Shoulders were tested in 3 separate scenarios: intact labrum, resected labrum from 3- to 6-o'clock (for a right shoulder), and labral reconstruction with the LHBT. Reconstruction was performed by performing LHBT tenotomy at the level of the pectoralis major insertion. The proximal LHBT tendon, left attached to the supraglenoid tubercle, was then attached to the anteroinferior glenoid rim with suture anchors.

RESULTS

Mean (SD) length of the LHBT was 76.1 (12.9 mm) and the diameter was 5.9 (1.6) mm. Peak force for intact labrum was significantly greater than the deficient labrum state (14.06 vs 11.78 N; P = .012). Peak force for labral reconstruction (16.67 N) was significantly greater than both intact and deficient labral states (P < .001 and P = .011, respectively). In all specimens, the length for the LHBT to the pectoralis major insertion was sufficient for reconstruction of the labrum to the 6-o'clock position.

CONCLUSIONS

Glenoid labrum reconstruction with the LHBT is a feasible option to restore glenohumeral stability, with peak force to displacement significantly greater than the labral-intact and labral-deficient states.

CLINICAL RELEVANCE

This reconstruction may be an option for augmentation in the labral-deficient shoulder.

Arthroscopic Dynamic Anterior Stabilization Using Either Long Head of the Biceps or Conjoined Tendon Transfer for Anterior Shoulder Instability Results in a Similarly Low Recurrence Rate

PURPOSE

To compare the clinical outcomes of arthroscopic dynamic anterior stabilization (DAS) between transferring the long head of the biceps (DAS-LHB) and the conjoined tendon (DAS-CT) for anterior shoulder instability with <15% glenoid bone loss.

METHODS

From January 2016 to May 2019, a total of 63 patients who underwent DAS for recurrent anterior shoulder dislocation with <15% glenoid bone loss were included, comprising 33 patients in DAS-LHB group and 30 patients in DAS-CT group. Clinical outcomes were assessed preoperatively and at a minimum 3-year follow-up, including patient-reported outcomes, range of motion, and return to sports (RTS). Postoperative recurrent instability (including dislocation, subluxation, and subjective instability with a positive apprehension test), revisions and complications also were recorded.

RESULTS

No significant demographic characteristics difference was detected between the DAS-LHB (26.3 ± 7.9 years) and DAS-CT groups (26.0 ± 6.7 years). At the latest follow-up, there were no significant differences between the 2 groups in functional scores: Oxford Shoulder Instability Score (14.8 ± 2.8 vs 15.2 ± 3.6), Rowe score (95.9 ± 6.5 vs 93.2 ± 10.2), visual analog scale for pain (0.8 ± 1.2 vs 0.7 ± 1.7), and American Shoulder and Elbow Surgeons (95 ± 8.8 vs 95.2 ± 9.1) (all P > .218). No significant difference was detected between groups in the rates of RTS (90.1% vs 86.7%, P = .700) and RTS at previous level (78.7% vs 73.3%, P = .258), respectively. No recurrent dislocation occurred in either group. One patient felt occasional subluxation in the DAS-LHB group, and one was positive for the apprehension test in each group. One patient presented with postoperative shoulder stiffness and underwent a secondary arthroscopic debridement in the DAS-CT group.

CONCLUSIONS

Comparable rates of recurrence, complication, return to sports, and subjective shoulder function were observed between DAS-LHB and DAS-CT groups.

LEVEL OF EVIDENCE

Ⅲ; retrospective comparative therapeutic trial.

Clinical and Radiological Outcomes in Patients With Anterior Shoulder Instability and Glenoid Bone Loss after Arthroscopic Free Bone Block Combined With Dynamic Anterior Stabilization

BACKGROUND

As an alternative to the Latarjet procedure, the arthroscopic free bone block (FBB) procedure combined with dynamic anterior stabilization (DAS) has been recently proposed to provide both glenoid augmentation and a tendon sling effect for treating anterior shoulder instability (ASI) with glenoid bone loss.

PURPOSE

To evaluate the clinical and radiological outcomes of FBB-DAS for ASI with glenoid bone loss.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

Patients who underwent arthroscopic FBB-DAS for ASI with >15% glenoid bone loss between February 2017 and March 2020 were screened and enrolled in this study. Clinical outcome measures were assessed preoperatively and at a minimum 2-year follow-up, including recurrence, complications, shoulder functional scores, range of motion, and return to sports. Postoperative computed tomography and magnetic resonance imaging were also performed.

RESULTS

Of a total of 65 patients with a mean follow-up of 46.1 ± 13.1 months, no patients experienced a recurrent dislocation or subluxation postoperatively, while 2 had a positive anterior apprehension test (3.1%). Additionally, 2 patients (3.1%) experienced complications of hematoma and shoulder stiffness, respectively. The mean visual analog scale score, American Shoulder and Elbow Surgeons score, Rowe score, and Oxford Shoulder Instability Score all improved significantly from 3.2 ± 2.4, 75.0 ± 18.9, 43.6 ± 27.3, and 33.8 ± 9.0 preoperatively to 1.3 ± 0.8, 95.1 ± 8.0, 95.5 ± 7.8, and 14.8 ± 3.5 at final follow-up, respectively (all P < .001). No difference was detected in range of motion except for 8.1° and 7.5° external rotation limitations in adduction and abduction, respectively. There were 62 patients (95.4%) who returned to sports, and 54 patients (83.1%) returned to the preinjury level. The transferred biceps tendon was intact in all 59 patients who completed radiological examination at the latest follow-up. Good bone healing was achieved in 98.3% of patients, and the glenoid bone defect decreased from 18.1% to 4.9%. Osseous and labral glenoids were significantly enlarged in width and depth on the latest magnetic resonance imaging (all P < .001).

CONCLUSION

Arthroscopic FBB-DAS provided satisfactory clinical and radiological outcomes for ASI with glenoid bone loss. Despite slight external rotation restrictions, it achieved low recurrence and complication rates, excellent shoulder functional scores, a high return-to-sports rate, and favorable graft healing and remodeling.

Early Treatment of Shoulder Pathology Is Necessary but Not Enough Is Being Performed

Delayed treatment of shoulder instability results in bone loss requiring more-complicated surgery, in turn resulting in less-optimal outcomes. Similarly, delayed treatment of repairable rotator cuff tears results in irreparable tears requiring more-complicated surgery and resulting in less-optimal outcomes. Delayed treatment of shoulder pathology is a problem. Solutions include education and research investigation.