December 08, 2017
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Arthroscopic repair of posterior bony Bankart lesion addresses glenoid, capsulolabral pathology

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Posterior instability is less common than anterior shoulder instability, encompassing approximately 10% of all shoulder instability in young active patients. The etiology of posterior instability is most commonly traumatic dislocation or subluxation that damages the posterior labrum, posterior inferior glenohumeral ligament, and/or the bony glenoid rim (posterior bony Bankart lesion). Traumatic posterior shoulder instability or dislocation is typically seen when a posteriorly directed force is applied to a flexed adducted and internally rotated limb, which forces the humeral head posteriorly. Atraumatic chronic posterior instability is found notably in patients who frequently perform activities with repetitive posterior-directed forces, such as weight lifters or football linemen.

Posterior glenohumeral bone defects, usually caused by trauma or recurrent posterior instability, frequently lead to recurrent instability due to disruption of glenohumeral joint bony congruency. Surgical intervention is traditionally pursued in patients with acute posterior bony Bankart lesions or those with recurrent instability and posterior glenoid bone loss due to the high risk of recurrent instability with nonoperative management, occurring in 17.7% of patients. Although surgical repair of posterior bony Bankart lesions to restore the articular anatomy is commonly accepted, a variety of techniques have been described. Techniques including open reduction with internal fixation, posterior iliac crest or distal tibia allograft glenoid bone block, or arthroscopic bony and labral repair are all currently performed. Existing literature supports the efficacy of arthroscopic repair of anterior bony glenohumeral lesions, but a paucity of evidence exists in support of arthroscopic management of posterior glenoid rim bone defects.

The purpose of this article is to describe our technique of arthroscopic stabilization for posterior shoulder instability in the setting of a posterior bony Bankart lesion. Our patient had a single traumatic posterior dislocation, which resulted in a 10% posterior bony Bankart lesion. This technique is performed entirely arthroscopically to avoid the associated morbidity of an open procedure while addressing the posterior glenoid bone and capsulolabral pathology.

Preoperative history, imaging

The patient is a 22-year-old man who presented with left shoulder recurrent instability and reports having recurrent left shoulder subluxation for 2 years to 3 years and one incident of frank dislocation while playing basketball. The patient endorses posterior shoulder pain with pushups and bench pressing. Preoperative MRI and CT display a fractured segment of posterior glenoid that measures 2 cm in craniocaudal extent, which is consistent with a left shoulder posterior bony Bankart lesion and posterior subluxation of the humeral head (Figure 1).

Interscalene nerve block is performed preoperatively for control of postoperative pain. Patients are then placed under general anesthesia and examination under anesthesia is performed to evaluate posterior translation, anterior translation, inferior sulcus sign and range of motion (ROM). This patient had full motion, normal anterior translation, negative sulcus sign and grade 3 posterior translation. The senior author’s preference is to perform all instability procedures in the lateral decubitus position with gentle traction with the operative arm in 60° abduction and 20° forward flexion, which improves visualization of and access to the posteroinferior glenoid (Figure 2).

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Surgical technique

Accurate portal placement is critical to visualization, correct instrumentation and capsulolabral manipulation. A standard posterior viewing portal is established 2-cm inferior and 1-cm to 2-cm medial to the posterolateral corner of the acromion. A standard anterior rotator interval portal is then established low in the rotator interval and right above the subscapularis tendon via spinal needle localization. An 8.2-mm cannula is placed in the anterior portal. Next, a 7 o’clock portal is placed about 3-cm distal and 1-cm lateral to the posterolateral acromion via spinal needle localization and subsequently an 8.2-mm cannula is placed. The 7 o’clock portal allows access to the posterior and inferior glenoid for suture passage and anchor placement.

Complete diagnostic arthroscopy is performed, including evaluation of the labrum, rotator cuff and biceps tendon, as well as evaluation of the humeral head for bone loss. Arthroscopic examination in this patient revealed a posterior labral tear and acute posterior bony Bankart rim fracture that encompassed roughly 10% of the glenoid (Figure 3). The rotator cuff and biceps tendons were intact.

While viewing from the posterior portal, the bony lesion is gently prepared to generate a good bony healing surface using a 4-mm bone cutting shaver from the 7 o’clock portal (Figure 4). Care is taken to avoid excessive bone removal. A Bankart elevator is additionally used to gently mobilize the bony fragment. The capsulolabral complex is well fixed to the glenoid bony fragment. The bony fragment can then be reduced with a probe.

Figure 1. Preoperative imaging includes CT 3-D reconstruction (a), axial CT (b), sagittal CT (c), and T2 axial MRI (d) and it depicts a posterior Bankart lesion and bony fragment.
Figure 2. The patient is positioned in the right lateral decubitus position with the operative arm in 60° abduction and 20° forward flexion.
Figure 3. This arthroscopic intraoperative image of the left shoulder viewed from the posterior viewing portal shows the posterior bony Bankart lesion.
Figure 4. A bone-cutting shaver is shown being used to gently debride the bony edges at the fracture site through the 7 o’clock portal in an arthroscopic intraoperative image of the left shoulder viewed through the posterior portal.
Figure 5. Shown from the posterior arthroscopic portal is a knotless suture anchor being placed in the patient’s left shoulder through the 7 o’clock portal.
Figure 6. This arthroscopic intraoperative image of the left shoulder viewed through the posterior portal shows the completed capsulolabral repair.

Source: Brian J. Cole, MD, MBA

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Next, we proceed to repair the posterior bony Bankart and associated labrum. LabralTape (Arthrex) is passed around the bony piece and posterior labrum using a suture-passing device (Spectrum: Conmed; SutureLasso: Arthrex) from the 7 o’clock portal. The Spectrum device is used to pass a PDS (Ethicon) suture around the bony piece and posterior labrum, and the suture is shuttled out the anterior portal using an arthroscopic grasper. The PDS suture is used to shuttle labral tape. A second LabralTape, which is a polyethylene smooth low-profile suture, is passed around the bony piece and associated posterior labrum in similar fashion. Next, one low-profile suture is loaded into a knotless 2.9-mm PEEK PushLock knotless suture anchor (Arthrex). The anchor is placed from the 7 o’clock portal on the edge of the intact posteroinferior glenoid (Figure 5). A second anchor is loaded with the second low-profile suture and placed in a similar position to complete the repair of the posterior bony Bankart and labrum. The sutures are cut flush with an arthroscopic suture cutter to complete the knotless repair. Anchors are positioned at about the 6:30 o’clock position and the 8:30 o’clock position (Figure 6).

The patient is placed in a postoperative sling to immobilize the shoulder in neutral position and prevent internal rotation that would stress the repair. Rehabilitation involves no shoulder motion for 3 weeks, and gentle passive ROM begins at 3 weeks, including Codman’s. Motion is limited to 90° flexion, 45° internal rotation and 90° abduction until 6 weeks postoperatively, at which time patients begin active-assisted and active ROM with passive ROM to tolerance. Strengthening begins at 8 weeks for the rotator cuff, scapular stabilizers and deltoid. Gradual advancement of activity is performed until return to activity as tolerated occurs at about 5 months to 7 months postoperatively.

Discussion

Although it is less common than anterior shoulder instability, posterior instability with a bone fragment is important not to miss and can be managed arthroscopically. In a systematic review Delong and colleagues performed that included 53 publications, arthroscopic posterior stabilization procedures were shown to be an efficacious and dependable treatment for posterior glenohumeral instability when examining outcome scores, patient satisfaction and return to play. Additionally, the authors reported that arthroscopic repair provided superior outcomes to patients in regard to stability, recurrence of instability, patient satisfaction, return to sport and return to previous level of play compared to patients who underwent open repair procedures. Management of posterior instability in the setting of acute posterior bony Bankart lesion or chronic posterior glenoid bone loss can be challenging, with open and arthroscopic techniques described. The relative indications for posterior bone block augmentations, such as distal tibial allograft or iliac crest autograft, include chronic symptomatic instability with greater than 20% to 25% posterior glenoid bone loss, in addition to posterior erosion and loss of posterior glenoid bony height. In the setting of posterior bony Bankart lesions that are less than 20% to 25% of the glenoid width, we prefer an arthroscopic approach as described in this technique.

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Our arthroscopic technique utilizes the knotless suture anchor system. We prefer a knotless system to prevent intraarticular suture or tails that might cause mechanical irritation or articular cartilage damage. The low-profile labral suture is passed around the bony piece and the associated posterior capsulolabral complex to provide an anatomic repair and restore the articular surface, as well as any bony and soft tissue posterior stabilizing structures. It is important to re-establish the tension of the posterior inferior glenohumeral ligaments in all posterior shoulder stabilization procedures.

Disclosures: Cole reports he receives research support from Aesculap/B.Braun; he receives IP royalties from, is a paid consultant for and receives research support from Arthrex; he receives other financial or material support from Athletico; he receives other financial or material support from Ossur; he is a paid consultant for and receives stock or stock options from Regentis; he receives other financial or material support from Smith & Nephew; and he receives other financial or material support from Tornier. Christian, Cvetanovich, Frank and Redondo report no relevant financial disclosures.