What is the step by step procedure for treating AC (acromioclavicular) joint dislocation using anchor sutures and CC (coracoclavicular) screw?

Surgical Management of AC Joint Dislocation Using Anchor Sutures and CC Screw

The optimal surgical approach for AC joint dislocation involves anatomic reconstruction of both coracoclavicular and acromioclavicular ligaments using anchor sutures and coracoclavicular screw fixation to ensure both vertical and horizontal stability. 1

Preoperative Considerations

• Early reconstruction is preferred (within 3 months of injury) to minimize risk of additional soft tissue damage 1
• Proper imaging (radiographs, potentially CT or MRI) to assess grade of dislocation and rule out associated injuries
• Patient positioning: beach chair position with the affected shoulder exposed

Step-by-Step Surgical Procedure

1. Anesthesia and Positioning

• General anesthesia
• Beach chair position with the affected arm draped free
• Ensure fluoroscopy access for intraoperative imaging

2. Initial Approach and Exposure

• Make a superior incision (5-7 cm) centered over the AC joint
• Develop full-thickness skin flaps
• Identify and protect the deltotrapezial fascia
• Expose the distal clavicle, AC joint, and coracoid process

3. Coracoid Process Preparation

• Dissect the coracoid process carefully
• Expose the lateral border of the conjoint tendon 2
• If using an endoscopic-assisted approach, perform medial pectoralis minor tenotomy with brachial plexus identification and protection 2

4. Clavicle and AC Joint Preparation

• Dissect both inferior and superior surfaces of the clavicle
• Maintain continuity between deltotrapezoid fascia and AC ligaments 2
• Identify and tag the torn CC ligaments (conoid and trapezoid) 2
• Prepare the distal clavicle and undersurface for reduction

5. Anchor Suture Placement for CC Ligament Reconstruction

• Place drill holes in the clavicle corresponding to the anatomic footprints of the conoid and trapezoid ligaments
• Insert suture anchors into the base of the coracoid process
• Pass suture tapes from the anchors through the clavicular drill holes
• Use at least 2 suture tapes with dog bone buttons for secure fixation 2

6. AC Joint Reduction

• Manually reduce the AC joint under direct visualization
• Confirm reduction with fluoroscopy
• Maintain reduction while securing the suture constructs

7. CC Screw Placement

• Drill a guide hole from the superior clavicle to the coracoid base
• Measure appropriate screw length
• Insert the CC screw through the clavicle into the coracoid
• The screw provides rigid fixation to protect the biological healing of the reconstructed ligaments 3

8. AC Ligament Repair/Reconstruction

• Place additional suture anchors at the acromion
• Repair the superior AC ligament, which is often torn from the clavicular side in a peeling fashion 4
• This step is crucial for horizontal stability of the AC joint 4

9. Closure

• Repair the deltotrapezial fascia over the clavicle
• Close subcutaneous tissue and skin in layers
• Apply sterile dressing

Postoperative Management

• Shoulder brace immobilization for 6 weeks 1, 2
• Limited range of motion exercises starting at 2-3 weeks 1
• Progressive rehabilitation protocol beginning at 6 weeks 1
• Return to sports activities typically at 6 months postoperatively 1, 5

Important Considerations and Potential Pitfalls

• Screw Complications: The CC screw provides rigid fixation but may lead to complications such as screw breakage or loosening 3. Consider planned removal at 8-12 weeks.
• Horizontal Stability: Ensure proper repair of AC ligaments in addition to CC ligament reconstruction to prevent horizontal instability 4.
• Overtightening: Avoid excessive tension on the construct which can lead to erosion of the coracoid or clavicle.
• Professional Athletes: For high-demand patients, anatomic fixation of both CC and AC ligaments is essential for optimal return to pre-injury performance levels 5.
• Biological Healing: The surgical construct aims to maintain reduction while allowing for biological healing of the native ligaments.

This technique provides both vertical stability (through CC reconstruction) and horizontal stability (through AC ligament repair), addressing the complete pathoanatomy of AC joint dislocations for optimal functional outcomes.