Abstract
Background:
Posterior glenoid labrum lesions occur in only 2% to 10% of all cases of shoulder instability, yet these injuries may cause significant shoulder dysfunction in an athletic population. Moreover, these injuries frequently require surgical intervention and present a unique surgical challenge.
Indications:
Indications for arthroscopic posterior labral repair include symptomatic posterior labral tears identified on magnetic resonance imaging with or without contrast, that failed nonsurgical management (ie, lifestyle modification, nonsteroidal anti-inflammatory drug, and physical therapy). Patients may present with a positive posterior load and shift or positive posterior apprehension test.
Technique Description:
With the patient in the lateral decubitus position, use a standard posterior superior portal, an ancillary anterior superior portal, a posterior-inferior, and the portal of Wilmington. After portal placement and diagnostic arthroscopy, the torn labrum is debrided. The torn portion of the posterior labrum is then mobilized from approximately the 6 o’clock to 10 o’clock positions, and a curette and shaver are used to produce a bleeding margin for fixation. Two double-loaded 2.4-mm suture anchors are placed, passed, and tied; one at the 6:30 o’clock position and the other at the 8 o’clock position. A cinch stich configuration using a 2.9-mm pushlock anchor can be used at the 10 o’clock position. A polydioxanone suture is used to assist with capsular plication and to close the posterior portal.
Results:
The literature suggests that 90% to 94% of patients are able to return to their desired sport with 5% to 10% reporting recurrent instability by 2 years after operation. Two out of 3 patients report no limitations at 2 years.
Discussion/Conclusion:
Arthroscopic repair of posterior labral tears with suture anchors can be an effective surgical option for patients with reverse Bankart lesions. Using advanced imaging to identify concomitant pathologies, meticulous surgical technique, direct visualization of the anatomy and anchor placement, and a dedicated rehabilitation program, greater than 90% of patients can expect to return to sport.
This is a visual representation of the abstract.
Video Transcript
This video demonstrates our technique for an arthroscopic reverse Bankart repair.
These are our disclosures.
Approximately 5% to 10% of traumatic shoulder instability cases occur in the posterior direction, yet injuries of this etiology tend to require surgical intervention more commonly than anteriorly directed instability. Specifically, 25% of all operatively managed labral tears are posterior labral repairs. In addition, 40% of patients with posterior and combined instability are managed operatively.
Risk factors for posterior instability are generalized ligamentous laxity, young athletes, male gender, and bony abnormalities including glenoid hypoplasia and increased degree of glenoid retroversion.
Posterior dislocations can occur secondary to trauma, seizure, electric shock, or microtrauma. Traumatic dislocation classically occurs when the joint is in a flexed, adducted, and internally rotated position.
It is essential to compare the affected limb with the contralateral limb. Patients can present with gross deformity of the joint. They should also be asked if they are able to self-dislocate as this has been shown to effect outcomes.
In addition to the standard special tests, posterior stress and load and shift should be evaluated. Patients are often limited with external rotation and adduct/adduction/internal rotation likely secondary to pain. It is also important to evaluate for generalized hyperlaxity. A majority of patients present with pain rather than instability.
Diagnostic imaging includes standard radiographs with standard additional projection, lateral, axillary and scapular views, computed tomography can be helpful in chronic and recurrent dislocators and those with suspected concomitant pathology. Yet magnetic resonance imaging (MRI) is still the most valuable form of advanced imaging with the literature reporting a sensitivity 86% and 100% specificity. Kim lesions, which are defined as a concealed, nondisplaced crack of the posterior chondrolabral junction, can be diagnosed on MRI with a reported sensitivity of 86% and specificity of 75%.
During the workup phase and also during a surgical intervention, surgeons should be sure to identify and address the most common associated pathologies, which include avulsions of the posterior band of the inferior glenohumeral ligament, reverse Hill–Sachs lesions, posterior labral cyst, posterior glenoid rim fracture, lesser tuberosity fracture, large capsular pouch, and labral articular disruption. These pathologies may require alternative strategies for arthroscopic or open fixation; however, any capsulolabral plication should be titrated based on the extent of damage and individual level of laxity.
And now a case example. Our patient is a 29-year-old man with no significant past medical history presented to clinic with shoulder pain localized anterolaterally and posteriorly. A painful arc was noted, and subjective weakness was also described. He reported multiple instability events though no formal reductions were performed. He ultimately failed conservative treatment, although he received no steroid injections prior to surgery. On physical examination, he had full range of motion and positive Kim and Jerk testing. He had mild tenderness of the long head of the biceps and reported mild pain during palpation at the lateral outlet. He had a negative O’Brien’s test.
Here are the axial MRI images; the sagittal images; and, finally, coronal MRI images.
With the patient in the lateral decubitus position using dual-traction device, the shoulder is prepped and draped in a sterile fashion. Arthroscopic portals are then established. For this procedure, we recommend using a standard posterior superior portal, an ancillary anterior superior portal, a posterior-inferior, and portal of Wilmington.
We routinely establish our first portal approximately 1-cm inferior and 1-cm medial to the posterolateral corner of the acromion. The tissue is evaluated from the posterior and anterolateral portals to allow comprehensive assessment. An additional portal is created between 3 and 4-cm distal and lateral to this previous posterior portal, and this allows placement of anchors and suture shuttling.
A 7 o’clock portal may also be used to access between the 5:00 to 7:00 region on the glenoid clock face. This is typically established with a percutaneous access kit for the 2.4-mm double-loaded anchor.
The procedure begins with a diagnostic arthroscopy. With the camera through the posterior-inferior viewing portal, a probe is placed through the anterior portal. The labrum is probed circumferentially and viewed as tension is placed on the long head of the biceps. It is essential to assess all portions of the labrum, looking for any bony lesions or cartilage defects.
There were soft tissue fibrillations about the posterior glenoid that were debrided gently with the arthroscopic shaver through a low anterior portal.
At this time, a liberator was used until the posterior labrum was adequately mobilized. This was carried around from about 6 o’clock position to about the 10 o’clock position. We then proceeded to shave and curette to obtain a bleeding margin. At this point in time, we then proceeded to fixation.
Through an additional 7 o’clock portal, we placed a 2.4-mm double-loaded anchor. This was placed at about the 6:30 position, and excellent purchase was obtained. Once the sutures are placed, a 90° straight suture lasso shuttling device is used. Capsular entry of the lasso is aimed inferior and peripheral to the anchor. In general, this occurs at approximately “1 hour” lower on the clock face and at least 1-cm peripheral to the glenoid in the capsule to ensure appropriate capsulolabral plication.
Once the mattress sutures are passed and tied, these suture limbs are cut and the process is reproduced with a simple suture configuration in a “rip stop” configuration to further reinforce the capsulolabral plication.
Next, we moved to approximately the 8:00 o’clock position and a second 2.4-mm anchor was placed, passed, and then tied, again, in a double-loaded fashion.
Ultimately this posterior labral repair technique used 2 double-loaded anchors placed in the low position and then a cinch stitch with a knotless anchor placed more superiorly.
Moving up to approximately the 10 o’clock position, the tissue became slightly more attenuated, and as such, we elected to proceed with a cinch configuration using a 2.9-mm pushlock for knotless fixation.
A probe can now be used to assess the security of the established anchors.
A polydioxanone suture is then passed to close the posterior portal and also assist with capsular plication.
Adhering to a rigid rehabilitation protocol is essential. Until post operative week 4, the patient is kept in a 30° abduction brace with early focus on hand and wrist range of motion. During weeks 4 to 6, the patient is discharged from the brace, and shoulder range of motion is limited to 125° forward flexion and 90° abduction. After 12 weeks, the patient can begin strengthening gradually with light resistance. At this time, they can also begin transitioning into sports-specific activities.
The primary complications to be aware of are axillary nerve palsy and overtightening of the posterior capsule. The axillary nerve is at risk during suture passage at the posterior-inferior capsule. No studies have described the incidence of these complications in posterior repairs, but the anterior repair studies report injury of the axillary nerve in 0.3% of arthroscopic repairs. Meticulous technique combined with appreciation of the anatomy are key to avoiding this complication. Overtightening of the capsule can restrict post operative range of motion and cause both anterior subluxation and coracoid impingement.
Patient-reported outcome studies suggest that 90% to 94% of patients are able to return to their desired sport, with only 5% to 8% of patients reporting recurrent instability following repair at 2-year follow-up. Moreover, 2 out of 3 patients said they were able to return with no limitations.
A recent study from Chan and colleagues described an 83% return to duty at their preinjury level, with only 1 patient requiring revision repair in a 65-patient study examining an active military population.
Thank you for your attention!
Footnotes
Submitted May 12, 2021; accepted June 25, 2021.
The authors declared that they have no conflicts of interest in the authorship and publication of this contribution. AOSSM checks author disclosures against the Open Payments Database (OPD). AOSSM has not conducted an independent investigation on the OPD and disclaims any liability or responsibility relating thereto.