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January 16, 2019
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A 56-year-old woman with shoulder instability

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A 56-year-old right-hand-dominant woman sustained two dislocations to her right shoulder, the first of which occurred about 18 days prior to presentation when she slipped and fell onto her bent arm. The fall resulted in an anterior shoulder dislocation that was reduced at the local ED (Figure 1). Post-reduction radiography was normal, and the patient was discharged in a simple sling (Figure 2). Fourteen days later, when lying in bed, she reached across her body and caused a subsequent dislocation. This dislocation also required a reduction performed at the ED and placement into an abduction sling. Again, post-reduction radiographs were negative for fracture. The patient was initially referred to a nonoperative sports medicine specialist for rehabilitation.

The patient denied any history of prior trauma, prior shoulder dislocations or prior surgery to the right shoulder. She also denied any history of joint hypermobility. The patient’s past medical history was notable for systemic lupus erythematosus and Sjogren’s syndrome for which she chronically takes Prednisone 5 mg twice daily.

On physical exam, the patient’s vital signs were normal with no evidence of previous incisions about the shoulder. She was neurovascularly intact proximally and distally without signs of motor or sensory deficits. Motion was limited secondary to pain. The sling was maintained, and non-arthrogram MRI was obtained (Figure 3).

Radiogrpah and MRI of right shoulder
Figure 1. Shown is a modified axillary radiograph of the right shoulder, which demonstrates an anterior shoulder dislocation.
Figure 2. The post-reduction AP radiograph of the right shoulder demonstrates a reduced glenohumeral joint.
Figure 3. Shown is a T2-weighted axial MRI of the right shoulder.

Source: Adam B. Yanke, MD, PhD

What is your diagnosis?

See answer on next page.

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Small Hill-Sachs lesion and Bankart lesion

Review of the non-arthrogram MRI revealed a small Hill-Sachs lesion and anterior-inferior labral damage possibly consistent with a Bankart lesion. Conservative treatment was attempted in the form of continued sling use with intermittent discontinuation to perform elbow, wrist and hand range of motion. At the 6-week follow-up visit, the patient’s pain had largely subsided. Physical exam revealed forward flexion to 155° compared to 165° on the contralateral side, and external rotation with the arm adducted to 80° bilaterally. With the shoulder abducted to 90°, external rotation was 85° and internal rotation was 60°. The patient demonstrated minimal or no apprehension in all positions, and 5/5 rotator cuff strength bilaterally.

Given the patient’s progression and resolution of pain, physical therapy in the form of range of motion and rotator cuff strengthening was recommended for the next 6 weeks.

At 2 months after her initial dislocation, she dislocated a third time while reaching in an abducted and externally rotated position while lying down. She required a third reduction with sedation in the ED. Post-reduction films also showed no abnormalities. The patient was then referred to an orthopedic surgeon for re-evaluation. Motion was limited secondary to pain and apprehension.

What new imaging should be obtained?

We performed a repeat non-arthrogram right shoulder MRI (Figure 4) and CT with 3-D reconstruction (Figures 5 and 6).

What is your diagnosis now?

 posterolateral Hill-Sachs and Bankart lesion
Figure 4. The original MRI showed the patient has a small posterolateral Hill-Sachs and Bankart lesion. This repeat T2-weighted coronal MRI of the right shoulder demonstrates a glenoid avulsion of the glenohumeral ligament.
Figure 5. There are no bony abnormalities as seen in the axial CT of the right shoulder.
Figure 6. A 3-D reconstruction of the right shoulder also demonstrates no bony abnormalities.
Figure 7. Shown in the arthroscopic view from the posterior portal is significant synovitis and degenerative labral tearing of the superior glenoid.
Figure 8. The arthroscopic view from the posterior portal also demonstrates significant synovitis and degenerative labral tearing of the inferior glenoid.
Figure 9. In the arthroscopic view from the posterior portal, a horizontal split of the anterior and inferior capsule held open by an arthroscopic shaver can be seen, as well as the subscapularis muscle in the background.
Figure 10. The arthroscopic view from the posterior portal demonstrates a vertical split of the anterior and inferior capsule.
Figure 11. In a closer view, the vertical split with the axillary nerve is shown (black arrow).
Figure 12. The arthroscopic view from the posterior portal indicates two double-loaded anchors are placed through the trans-subscapular portal at the 4 o’clock and 5 o’clock position.

Glenoid avulsion of glenohumeral ligament

The CT scan and 3-D reconstruction revealed no acute bony abnormality. Non-arthrogram shoulder MRI revealed a globular appearance of the labrum with degeneration. Additionally, extensive capsular edema was present which may have been due to glenoid avulsion of the glenohumeral ligament or possible midsubstance anterior-inferior glenohumeral ligament tear. The rotator cuff was otherwise intact.

Given these findings and the patient’s multiple instability events, she underwent right shoulder arthroscopy to address her anterior instability.

The patient was placed in the lateral decubitus position. Examination under anesthesia revealed a 3+ anterior load and shift with grade 1 posterior shift and negative sulcus sign. Intraoperatively, a standard posterior viewing portal was placed. Upon entering the joint, significant synovitis with degenerative labral tearing was seen (Figures 7 and 8). Evaluation of the anterior-inferior labrum revealed tearing and delamination from the glenoid. However, deep to the elevated labrum was a void that was due to tearing of the anterior and inferior capsule from the 3 o’clock to 5 o’clock position with a vertical split creating an L-shaped tear consistent with a glenoid avulsion of the glenohumeral ligament (GAGL) (Figures 9 and 10). An anterior portal was made just above the rolled border of the subscapularis. Investigation of the GAGL further revealed the subscapularis muscle belly deep to the horizontal component and the axillary nerve passing through the vertical limb of the L-shaped tear, which was in continuity (Figure 11). Two more portals were placed, including an anterior trans-subscapular portal and a 7 o’clock portal. Using a Bankart elevator, the axillary nerve was carefully released and mobilized from the capsular limbs for later repair. The Bankart elevator was used to elevate the labrum which was then debrided using a shaver. Two double-loaded anchors were placed through the trans-subscapular portal at the 4 o’clock and 5 o’clock positions (Figure 12). A suture passer was used to then grab the avulsed glenohumeral ligament, as well as capture a portion of the labrum in a simple fashion (Figure 13). One of the sutures at the 5 o’clock position was tied in a simple fashion to re-approximate the appropriate tension on the glenohumeral ligament (Figure 14). At this point, two margin convergence stitches were passed through the vertical tear to visualize the axillary nerve and keep it away from the passed sutures (Figure 15). The remaining sutures at the anchors were then tied, followed by the margin convergence stitches. Lastly, a knotless suture anchor was applied at the 3 o’clock position, which incorporated the capsule at this level and completed the repair (Figure 16).

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Postoperatively, the patient was placed in an abduction sling and remained in the sling until her 1-week postoperative visit. Her incisions were clean, dry and intact. She was neurovascularly intact throughout her arm including special assessment of her axillary nerve function. Physical therapy was prescribed for the first 4 weeks postoperatively. This included progressive passive, active-assisted and active range of motion with forward flexion to 90°, abduction to 45°, external rotation at her side to 20° and internal rotation to stomach. Shoulder isometric contraction in sling was done with heat before and ice after therapy. Cross-arm adduction was withheld until 6 weeks postoperatively.

Arthroscopic view of repair
Figure 13. The arthroscopic view from the posterior portal depicts a suture passer piercing the avulsed glenohumeral ligament and capturing a portion of the labrum in a simple fashion.
Figure 14. The arthroscopic view from the posterior portal shows a simple knot being tied at the 5 o’clock position and re-approximating the appropriate tension on the glenohumeral ligament.
Figure 15. Seen in the arthroscopic view from the posterior portal is passage of the first (a) and second (b) margin convergence stitches through the vertical tear.
Figure 16. The completed repair is seen in the arthroscopic view from the posterior (a) and anterior (b) portal.

Although soft tissue abnormalities almost always accompany glenohumeral dislocations, the presence of a GAGL is exceedingly rare. These avulsions are a rare variant that involve injury to the glenohumeral capsulolabral complex and there are few reported cases in the literature. The major indication for performing arthroscopic GAGL repair includes a history of traumatic shoulder dislocation and continued instability. Intraoperative evaluation is key. Any evidence of glenoid or humeral bony deficiency is a contraindication to surgery and would mean that a more invasive bony stabilization procedure, like a Latarjet procedure, is required.

Key points to consider with this surgical technique are the following:

  • Surgical set-up and instrumentation are essentially the same as what is commonly used when performing a standard Bankart repair;
  • Preparation and mobilization of the capsule, in addition to the labrum, is key for adequate visualization and repair; and
  • Be mindful of the proximity of the axillary nerve during suture passage through the capsular tissue.

Disclosures: Cancienne, Dempsey, Verma and Yanke report no relevant financial disclosures.