Arthroscopic Double-Row Suture Anchor Repair of Acute Posterior Bony Bankart Lesion

Abstract

The treatment of anterior shoulder instability is well described with various techniques, including arthroscopic double-row repair, an alternative to open stabilization procedures in high-risk groups. The surgical management of posterior instability in high-risk and athletic populations is a less-explored entity. We describe our technique for an all arthroscopic double-row suture anchor repair of a large posterior bony Bankart lesion. We prefer this technique over percutaneous cannulated screw fixation because the double-row suture technique allows for incorporation of capsular plication with bony fixation in an effort to better restore normal anatomy for capsulolabral complex. Double-row repair capsulolabral repair or fixation of the bony Bankart is performed via a suture-bridge technique. Medial row anchors are placed down the glenoid neck and shuttled around the bony fragment and labrum. The lateral-row anchor is placed at the rim of the native glenoid. This repair technique has been shown to increase the surface area for healing and more closely reconstruct the native anatomic capsulolabral complex footprint, improve force distribution, and potentially impart enhanced posterior stability to the glenohumeral joint.

Posterior shoulder instability is a common presenting complaint in contact athletes. Labral pathology is common, with bony posterior Bankart lesions being less common. The posterior bony Bankart lesion requires special attention as successful surgical outcomes require stable osseous fixation to ensure timely healing. Also, the contribution of capsular laxity or associated labral injury must be appreciated (Table 1). We present the technique of double-row suture anchor repair of an acute posterior bony Bankart lesion. We prefer this technique over percutaneous cannulated screw fixation as we believe we can achieve better restoration of normal anatomy with both stable osseous fixation but also capsulolabral repair or plication as is necessary for each individual patient.

Table 1.

Patient Indications and Contradictions

Indications and contraindications: • Preoperative assessment of the bony fragment is imperative. Defects greater than 25% or 1 cm in total medial to lateral or anterior to posterior width may not be adequately reduced and/or compressed with suture anchor fixation alone. • Counsel patients as to the need for protected use of the arm for 6-8 weeks before more aggressive physical therapy ensues. • Apply this technique to acute, appropriately sized bony Bankart lesions. Be cautious of patients with chronic glenoid erosion and secondary calcification of labrum and/or capsule as this technique may not restore appropriate glenoid width in this setting.

Preoperative Planning

Plain radiographs, magnetic resonance imaging, and computed tomography are obtained on an individualized basis. Size and degree of displacement of the bony Bankart lesion are assessed. The magnetic resonance image is studied closely for associated pathology (rotator cuff, anterior or superior labrum) and an appropriate surgical plan is formulated (Table 2).

Table 2.

Pearls and Pitfalls

Pearls: • Ensure that the size and extent of the defect is fully appreciated prior to surgery. If plain radiographs and magnetic resonance imaging arthrogram are inadequate, obtain a computed tomography scan with 3-dimensional reconstruction. • Create the posterior portal in a far lateral position. • Perform diagnostic arthroscopy prior to addressing the bony Bankart. • Perform meticulous preparation of the native glenoid and fragment with rasp and burr as necessary. • Place medial-row anchors percutaneously and place as far apart from one another as possible. This will increase the surface area under compression when the knotless anchor is placed. • Use a suture passer with a more rigid filament (CHIA; Mitek) than a nitinol loop, which can be difficult to pass and retrieve without breakage around the large bony fragment. • Place 2 anchors at the proximal and distal extent of the defect. Tie these first to provide rotational control of the fragment • Verify appropriate tension before fully seating the final knotless suture anchor Pitfalls: • Avoid medial placement of the posterior portal. This will make it very difficult to adequately mobilize and reduce the bony fragment. • Avoid excessive resection of bone from the fragment. • Avoid lateralization of the bony fragment. • Avoid seating the final anchor prior to appropriate reduction and tensioning of the suture limbs.

Surgical Technique

Step 1: Patient Positioning

Interscalene nerve block performed preoperatively for postoperative pain control and the patient placed under general anesthesia. Examination under anesthesia revealed 3+ posterior instability, 2+ anterior instability, and 1+ inferior sulcus sign. Range of motion was normal and symmetric with contralateral side. The patient was positioned in lateral decubitus position on a beanbag and the operative arm hung in 10 pounds of lateral traction in 60° of abduction and 20° of forward flexion (Table 3).

Table 3.

Key Surgical Points

Patient positioning: • Position the arm in 60° of abduction and 20° of forward flexion with gentle traction. This will open up the posterior aspect of the shoulder for clear visualization of the bony fragment. Portal placement: • The posterior portal should be placed far lateral to allow one to work down toward the glenoid to mobilize and reduce the fragment. • The accessory posterior portal should be localized under direct visualization for planned medial-row anchor placement. Bony Bankart preparation • Using a combination of elevators and rasps in various angles to fully free and mobilize the fragment. • A small burr can be helpful to stimulate osseous bleeding. • View from the posterior portal to confirm that medial soft tissue has been fully mobilized. Suture anchor placement and fixation: • Place the medial-row anchors percutaneously. • Place 2 anchors at the proximal and distal extent of the defect. Pass these around the labrum and capsule and tie for provisional control. • Incorporate the capsule with the bony fragment if added plication is desired.

Step 2: Arthroscopic Portal Placement

Standard posterior portal was established 2 cm inferior to the posterolateral edge of the acromion and 1 cm medial to the posterolateral corner of the acromion directed anteriorly toward the tip of the coracoid process. The anterior portal was established via needle localization in the rotator interval just below the superior glenohumeral ligament. While viewing from the anterior portal, the posterior skin incision was extended and an 8.25-mm twist-in cannula (Arthrex, Naples, FL) was placed into the glenohumeral joint to function as the primary working portal for posterior repair.

Step 3: Diagnostic Arthroscopy

Diagnostic arthroscopy was performed from both the anterior and posterior portals (Table 3). The articular side of the rotator cuff, the proximal biceps, and the anterior and superior labrum were all normal (Fig 1). There was a 1.5 × 1.5–cm cartilaginous loose body found in the anterior rotator interval. Examination of the posterior labrum and glenoid confirmed the posterior glenoid rim fracture, posterior labral trauma, and mild cartilage loss all consistent with the patient's history and preoperative imaging (Fig 2).

Fig 1.

Arthroscopic view of left shoulder from the posterior viewing portal, which confirmed that rotator cuff, the proximal biceps, and the anterior and superior labrum were all normal.

Fig 2.

Arthroscopic view of left shoulder from a high posterior reveals posterior labral trauma, and mild cartilage loss consistent with the patient's history and preoperative imaging.

Step 4: Loose Body Removal and Evaluation and Reduction of Bony Bankart Lesion

The loose body was extracted through an extended anterior portal, and at that time the arthroscope was placed in the anterior portal to address the posterior bony Bankart lesion with the previously placed 8.25-mm twist-in cannula (Arthrex) in the posterior portal (Fig 1). A periosteal elevator was used to mobilize the bony fragment, which was partially healed with fibrous tissue (Video 1, Fig 3). A 4.0-mm barrel burr (Arthrex) was used to stimulate bleeding of the fragment and the native glenoid (Fig 4A). Care was taken so as not to remove excessive bone from the native glenoid or fragment. The fragment was manually reduced and evaluated using a rasp (Fig 4B). A decision was made to proceed with a double-row suture technique over percutaneous cannulated screw fixation. This would allow for incorporation of the capsular plication with bony fixation of the fragment across a large surface area (Table 3).

Fig 3.

Arthroscopic view of left shoulder from high anterior portal showing a periosteal elevator was used to mobilize the bony fragment.

Fig 4.

(A) Arthroscopic view of left shoulder from the high anterior portal showing the 4.0-mm barrel burr (Arthrex, Naples, FL) used to stimulate bleeding of the fragment and the native glenoid. (B) Arthroscopic view of left shoulder from the high anterior portal showing a rasp also being used to stimulate bleeding of the fragment and the native glenoid.

Step 5: Anchor Placement for Double-Row Suture Anchor Repair and Capsular Plication

A second incision was placed 2 cm distal to the first posterior portal, and two 2.4 × 12–mm BioComposite Suturetak Anchors (Arthrex) were percutaneously placed along the medial glenoid neck at the furthest extent of the fracture site to function as the medial-row anchors. The sutures were shuttled around the bony fragment using a straight-hook IDEAL Suture Shuttle with CHIA PercPasser (Mitek, Raynham, MA) (Fig 5). Two additional 2.4 × 12–mm BioComposite Suturetak Suture Anchors (Arthrex) were placed on the native intact glenoid at the distal and proximal extent of the fragment (Fig 6). The sutures from these anchors were passed around the posterior labrum and a 5- to 7-mm pleat of posterior capsule to provide a secondary plication affect using the straight-hook IDEAL Suture Shuttle with CHIA PercPasser (Mitek) (Fig 7). The sutures from these anchors were first tied to provide provisional fixation of the fragment via indirect reduction from the surrounding capsule. The sutures from the medial-row anchors were retrieved and brought up to the native glenoid in an inverted V configuration with a single 3.5 × 19.5–mm BioComposite PushLock Suture Anchor (Arthrex) (Fig 6). Appropriate tension of the sutures and stable reduction of the fragment are confirmed (Tables 1 and 3).

Fig 5.

(A, B) Arthroscopic view of left shoulder from the anterior portal shows the sutures being shuttled around the bony fragment using a straight-hook IDEAL Suture Shuttle with CHIA PercPasser (Mitek, Raynham, MA).

Fig 6.

Arthroscopic view of left shoulder from the anterior portal shows two 2.4 × 12–mm BioComposite Suturetak Suture Anchors (Arthrex, Naples, FL) placed and tied at the proximal and distal extent of the fragment. A third 3.5 × 19.5–mm BioComposite PushLock Suture Anchor (Arthrex) is being placed at the edge of the glenoid, completing the double-row construct.

Fig 7.

Arthroscopic view of left shoulder from the anterior portal shows the final construct with the posterior labrum and capsule covering the bony Bankart lesion.

Step 6: Intraoperative Physical Exam and Posterior Capsule and Portal Closure

The shoulder was then taken through a full range of motion confirming that the humeral head was well centered and the fragment well reduced with a smooth transition from native glenoid to fragment. The rent in the posterior capsule of the working cannula was closed with No. 0 PDS suture and tied extra capsularly (Fig 8). Portals were closed in routine fashion, and the arm was placed in a postoperative sling in neutral rotation with 15° of abduction.

Fig 8.

(A, B) Arthroscopic view of left shoulder from the anterior portal showing the posterior capsular from the working cannula being closed with No. 0 polydioxanone (PDS) suture and tied extra-capsularly.

Postoperative Evaluation and Management

The patient's arm is placed in a sling, allowing wrist and elbow range of motion only for the first 2 weeks. Formal physical therapy is initiated at 2 weeks. The rehabilitation protocol includes avoidance of axial loading and posterior directed forces for 6 weeks as well as avoidance of cross body adduction and forced passive external rotation for 4 weeks. Range of motion is progressed as tolerated with a focus on scapular stabilization and initiation of resisted strengthening at 8 weeks postoperatively. Patients typically return to full activity including contact at 4 months.

Discussion

Posterior instability is less commonly encountered and treated than anterior shoulder instability. In turn, patients may not have gross instability as in this case. Full appreciation of both soft tissue (labral and capsular) injury and osseous injury is required when formulating an effective surgical plan. With more extensive injury, surgery is necessary to safely return the patient to high-demand activities.¹ Posterior Bankart lesions are described as detachment of the posterior capsule and labrum below the glenoid equator.² The need for surgical repair is greater in the contact and/or elite-level athlete with a confirmed posterior soft tissue Bankart lesion or bony involvement.³ The vast majority of patients can be successfully treated with arthroscopic posterior capsulolabral repair or plication alone. Open procedures are less common as arthroscopic techniques have shown excellent results.⁴

Anterior shoulder instability represents greater than 90% of traumatic shoulder dislocations.⁵ In turn, surgical approaches for anterior dislocation are well evolved, including arthroscopic double-row repair for both soft tissue and bony Bankart lesions.⁶

The double-row principle has been applied to anterior bony Bankart lesions by reducing the osseous fragment with the capsulolabral and ligamentous complex using 2 rows of suture anchors.⁴ Kim et al. describe a 3-point double-row repair in acute bony Bankart with more than 2-mm stepoff at the articular glenoid surface.⁴ However, Poehling-Monaghan et al. report poor results and high failure rates when only performing bony fixation of the fragment in absence of arthroscopic plication/stabilization.⁷

In a biomechanical analysis of single-versus double-row repair for bony Bankart lesions, Spiegl et al. showed that the double-row repair provided both improved stability and fracture reduction compared with single-row.⁸ We believe that similar application of these principles and findings to the treatment of posterior bony Bankart should provide increased stability, more stable reduction of the osseous fragment, and overall potential for improved fracture healing, restoration of normal articular surface, and improved long-term outcome with low surgical morbidity than open procedures. Poehling-Monaghan et al. have previously described favorable results with application of double-row technique in a similar clinical scenario. Their patient had full passive and active range of motion 2 to 3 months after surgery and initiated strengthening.⁷ Further studies are needed as there are limited data focused on the arthroscopic management of posterior bony lesions and instability.⁷ The described technique can provide excellent shoulder stability and favorable clinical outcomes when applied to appropriately selected patients. Successful implication of this technique requires thorough preoperative planning and a complete understanding of the extent and size of the involved lesion (Table 2).

Supplementary Data

Video 1

Surgical technique for arthroscopic double-row posterior bony Bankart repair performed in the lateral decubitus position on a left shoulder. The fragment is mobilized and medial- and lateral-row anchors are used to provide stable fixation of the bony fragment.