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    RSA for Locked Anterior Shoulder Dislocation

    A 56-year-old female patient with a prior left humeral shaft fracture presents with pain and dysfunction following a fall on the same shoulder. Will a reverse shoulder arthroplasty provide pain relief and restore range of motion?

    Authors

    Bradley Schoch, MD, and Surena Namdari, MD

    Disclosures

    Dr. Schoch has no disclosures relevant to this article. Dr. Namdari has disclosed that he is a paid consultant and receives design royalties from DJO Surgical; is a paid consultant and receives research support from Integra Life Sciences; receives research support from Zimmer Biomet; and receives research support from DePuy Synthes.

    Case Presentation

    A 56-year-old, left hand-dominant female who fell from a standing height directly onto her left shoulder presented to the emergency department with left shoulder pain and dysfunction. Radiographs were reportedly negative and the patient was discharged home in a sling. She was instructed on home exercises, which aggravated her shoulder pain.

    Over the next 2 months, her range of motion failed to improve, and she remained in significant pain. She presented to our institution for a second opinion.

    Past Medical and Surgical History

    • Cardiovascular disease; taking clopidogrel (Plavix)
    • Previous left humeral shaft fracture with a varus malunion

    Physical Examination

    • Height: 5 feet, 4 inches; weight: 190 pounds; BMI: 32.6
    • Deformity at the anterior aspect of the shoulder, tender to palpation
    • Unable to resist internal or external rotation due to pain
    • Passive motion limited by guarding
    • No tenderness or pain at the elbow/forearm
    • Lateral arm sensation normal, positive deltoid activation
    • Intact sensation in median/radial/ulnar nerve distributions
    • Intact but limited elbow flexion/extension; intact wrist/finger extension and flexion
    • 2+ radial pulse

    Differential Diagnosis

    • Rotator cuff tear
    • Proximal humerus fracture
    • Glenohumeral dislocation
    • Dislocation with concurrent proximal humerus fracture
    • Dislocation with concurrent acute rotator cuff tear

    Imaging

    Radiographs

    • Chronic anterior dislocation of the shoulder with anterior glenoid bone loss seen on anteroposterior and axillary radiographs of the left shoulder (Figures 1a-b)

    MRI

    • Impaction of the humeral head with associated glenoid bone loss on MRI (Figures 1c-d)
    • Severe anterior subluxation of the humeral head on the glenoid with greater than 50% glenoid bone loss
    • Supraspinatus and the anterior portion of the infraspinatus appear torn and retracted to the glenohumeral joint
    • Grade 1 atrophy of the supraspinatus.

    CT scan

    • Not obtained on this patient
    • Should be done in cases in which the glenoid is not well visualized on MRI


    Figures 1a-d. Radiographs (top) and MRI (bottom) indicate shoulder pathology in a patient with a prior left humeral shaft fracture who has fallen on the same shoulder.

    Diagnosis

    • Chronic locked anterior shoulder dislocation with anterior glenoid bone loss

    Treatment Options

    Closed Reduction

    • Advantages: Least invasive
    • Disadvantages: Unlikely to be clinically possible; high likelihood of recurrent instability

    Open Reduction and Soft Tissue Repair

    • Advantages: Preserves native anatomy
    • Disadvantages: Will not correct the cartilage damage present on both sides of the glenohumeral joint; high likelihood of anterior subluxation or recurrent dislocation

    Hemiarthroplasty with Glenoid Reconstruction Using Structural Iliac Crest

    • Advantages: No weight-lifting restrictions; restoration of glenoid bone stock; pain relief
    • Disadvantages: Potentially incomplete pain relief; risk of anterior subluxation or recurrent dislocation

    Hemiarthroplasty with Latarjet

    • Advantages: No weight-lifting restrictions, pain relief
    • Disadvantages: Potentially incomplete pain relief; altered anatomy should a revision operation be required; coracoid bone graft may not be large enough to restore native glenoid width

    Reverse Shoulder Arthroplasty (RSA)

    • Advantages: Best chance for substantial pain relief (both sides of the joint replaced); semi-constrained implant minimizes risk of early instability; maintains motion and preserves shoulder function
    • Disadvantages: Unsupported by long-term clinical outcomes for this indication; long-term weight-lifting and weight-bearing restrictions

    Glenohumeral Fusion

    • Advantages: Definitive correction of shoulder instability; no weight-lifting restrictions following surgery; least likely to require multiple operations if able to achieve successful fusion
    • Disadvantages: Loss of glenohumeral motion in an otherwise active patient

    Procedure

    The patient agreed to undergo an RSA. After receiving a preoperative interscalene block, she was placed in the beach chair position at 45° of elevation, with the operative arm in a pneumatic arm-holder. She received general anesthesia for the procedure.

    • Make an incision from the coracoid toward the deltoid tuberosity and access the deltopectoral interval. Be sure stay lateral and protect the cephalic vein.
    • Incise 1 cm of the superior pectoralis major tendon to improve visualization.
    • Tenodese the biceps to the pectoralis major with 2 braided sutures. At this point, the patients supraspinatus and infraspinatus were noted to be torn. The subscapularis was intact.
    • Release the capsular attachments to the subscapularis, taking care to protect the axillary nerve.
    • Release the inferior capsular attachments to the humeral neck and reduce the shoulder.
    • Cut the humerus in 0 degrees of retroversion.
    • Place deep glenoid retractors and release the coracohumeral ligament and the superior, middle, and inferior glenohumeral ligaments while protecting the axillary nerve.
    • Remove the remnant labrum and biceps stump. 
    • The glenoid was evaluated and noted to be deficient in the anterior one third (Figure 2).
    • Prepare the incised humeral head on the back table in a manner that will fill the anterior glenoid defect, taking care to slightly oversize the graft (Figure 3).
    • Burr the anterior glenoid to bleeding bone and then secure the graft in place with a 2.0 K-wire (Figure 4).
    • Place two 2.0-mm cortical screws from anterior to posterior in lag mode to secure the graft.
    • Place the glenoid guide and drill a bicortical hole into the vault, followed by placement of a tap.
    • Prepare the glenoid by reaming over the tap and creating a flush surface between the graft and the glenoid.
    • Place a standard, central-screw glenoid base plate.
    • Leave the anterior screw hole unfilled to avoid fracturing the bone graft.
    • Place the 32-mm glenosphere with 10 mm of lateralization
    • Broach to an appropriately sized humeral stem. This patient’s stem was undersized due to her varus malunion.
    • Place the trial baseplate and humeral stem. Perform a trial reduction and assess stability.
    • Insert and cement the final humeral components.
    • Irrigate the wound and then close it in a standard layered technique.

    Figure 2. After glenoid exposure, the anterior third was noted to be deficient (suction tip pointing at anterior glenoid rim).

    Figure 3. The humeral head is prepared on the back table.

    Figure 4. The anterior glenoid rim is burred and the graft is positioned in a manner to overhang the glenoid rim by approximately 2 mm to account for reaming.

    Postoperative Management

    • 0-3 weeks: The patient is maintained in a sling with a small abduction pillow and is kept non-weight-bearing.
    • 3-6 weeks: The patient is out of the sling for light activities of daily living. Gentle active assisted range-of-motion exercises and pulley exercises are initiated. No weight-bearing.
    • Beyond 6 weeks: Home exercises are continued and the patient is allowed to progress activities as tolerated.

    Patient Course

    Postoperative radiographs are seen in Figure 5.

    Figure 5. Postoperative radiographs (AP and axillary) of the cemented reverse shoulder arthroplasty with bulk autograft supplementation of the anterior glenoid.

    Two weeks following surgery, the patient’s incision was healing well and her deltoid muscle was firing appropriately. At 6 weeks, she reported occasional numbness and tingling in her left hand. Her passive range of motion was:

    • Elevation 150°
    • Abduction 120°
    • External rotation 50°

    At 12 weeks, she denied significant pain and noted that the numbness and tingling had resolved. Radiographs demonstrated unchanged position of the reverse arthroplasty and healed bone graft. Her active range of motion was:

    • Elevation 165°
    • Abduction 120°
    • External rotation 30°

    At 6 months, she continued to do well and had returned to all activities with no further complaints.

    Author Information

    Bradley Schoch, MD, is a fellow in shoulder and elbow surgery at The Rothman Institute, Philadelphia, Pennsylvania. Surena Namdari, MD, is a board-certified shoulder and elbow surgeon with The Rothman Institute and an assistant professor of orthopaedic surgery at Thomas Jefferson University, Philadelphia, Pennsylvania.

    Shoulder Reconstruction Section Editor, Rothman Institute Grand Rounds

    Luke S. Austin, MD