Bristow Procedure: Understanding Shoulder Instability, Indications, and Recovery

What is the Bristow procedure?

The Bristow procedure is a surgical technique primarily used to treat recurrent anterior shoulder instability, particularly when there is significant bone loss from the glenoid (shoulder socket) or humerus. It involves transferring a portion of the coracoid process, along with its attached conjoined tendon, to the anterior aspect of the glenoid, providing both a bone block and a dynamic muscular sling to prevent further dislocations.

Understanding Shoulder Instability

The shoulder joint, or glenohumeral joint, is a highly mobile ball-and-socket joint. Its remarkable range of motion comes at the cost of inherent instability, primarily relying on soft tissues like the joint capsule, ligaments, and surrounding musculature (rotator cuff) for stability. When these stabilizers are compromised, the humeral head can dislocate from the glenoid.

Causes of Instability:

• Traumatic Injury: Often due to a fall or direct blow that forces the arm into an abducted and externally rotated position, tearing the labrum (a cartilage rim) and/or ligaments (e.g., Bankart lesion).
• Repetitive Overuse: Can stretch the joint capsule and ligaments over time.
• Ligamentous Laxity: Individuals with generalized joint hypermobility.

Types of Instability:

• Anterior Instability: The most common type, where the humeral head dislocates forward.
• Posterior Instability: Less common, dislocation backward.
• Multidirectional Instability: Dislocation in multiple directions.

Recurrent anterior instability, especially after a traumatic first dislocation, can lead to progressive damage, including bone loss from the anterior glenoid rim (glenoid bone loss) or a compression fracture on the posterior aspect of the humeral head (Hill-Sachs lesion). When significant bone loss occurs, soft tissue repairs alone may not be sufficient, necessitating a bone augmentation procedure like the Bristow.

The Bristow Procedure: A Detailed Overview

The Bristow procedure, first described by Arthur Bristow in 1905 and later popularized by Latarjet, is an open surgical technique (though arthroscopic variations exist). It addresses anterior shoulder instability through a combination of bony and muscular stabilization.

Core Principle: The essence of the Bristow procedure is the transfer of a small piece of bone – the tip of the coracoid process – from the scapula. This bone fragment, which has the conjoined tendon (comprising the short head of the biceps and coracobrachialis muscles) attached to it, is moved and fixed to the anterior inferior aspect of the glenoid.

Surgical Steps (Simplified):

1. An incision is made on the anterior aspect of the shoulder.
2. The deltopectoral interval is opened to expose the coracoid process.
3. The tip of the coracoid process, along with its attached conjoined tendon, is osteotomized (cut).
4. The subscapularis muscle (one of the rotator cuff muscles) may be split or retracted to access the joint.
5. The detached coracoid fragment is then transposed and affixed with screws to the anterior inferior glenoid rim, typically through the subscapularis muscle.

Mechanism of Action: The Bristow procedure provides stability through multiple mechanisms:

• Bone Block Effect: The transferred coracoid fragment acts as a physical "bumper" or buttress, extending the glenoid rim and preventing the humeral head from dislocating anteriorly.
• Conjoined Tendon Sling Effect: When the arm is externally rotated and abducted (a common position for anterior dislocation), the conjoined tendon, which now lies across the anterior capsule, becomes taut. This creates a dynamic sling effect that further resists anterior translation of the humeral head.
• Capsular Tensioning (Secondary): The transfer may also indirectly tension the anterior capsule, contributing to stability.

Indications for the Bristow Procedure

The Bristow procedure is not typically the first-line treatment for all shoulder dislocations. It is specifically indicated for:

• Recurrent Anterior Shoulder Instability: Especially after multiple dislocations.
• Significant Glenoid Bone Loss: When the repeated dislocations have caused erosion or fracture of the anterior glenoid rim, making soft tissue repairs less effective. This is often quantified as greater than 20-25% glenoid bone loss.
• Large Hill-Sachs Lesion: A compression fracture on the posterior humeral head that engages with the glenoid rim during abduction and external rotation.
• Failed Previous Soft Tissue Repairs: If a prior Bankart repair (a common soft tissue repair) has failed.
• High-Demand Individuals/Contact Athletes: For individuals involved in contact sports or occupations requiring overhead activities, where robust stability is paramount and recurrence rates must be minimized.

Advantages and Disadvantages

Like any surgical intervention, the Bristow procedure has specific benefits and potential drawbacks.

Advantages:

• High Success Rate: Particularly effective in preventing recurrent anterior dislocations, especially in cases with significant bone loss.
• Addresses Bone Loss: Directly compensates for glenoid bone defects, which is crucial for long-term stability.
• Robust Stabilization: Provides a strong, durable repair suitable for high-demand individuals.
• Low Recurrence Rate: Studies generally show very low rates of re-dislocation after a successful Bristow procedure.

Disadvantages:

• Invasive Procedure: Traditionally an open surgery, leading to a larger incision and potentially more soft tissue disruption compared to arthroscopic soft tissue repairs.
• Potential for Complications:
  • Nerve Injury: Risk to nearby nerves (e.g., musculocutaneous nerve, axillary nerve).
  • Non-Union/Malunion: Failure of the transferred bone fragment to heal properly.
  • Hardware-Related Issues: Screw loosening or impingement.
  • Stiffness/Loss of External Rotation: A common side effect, often a trade-off for increased stability.
  • Arthritis: Long-term risk of glenohumeral arthritis, though often related to pre-existing damage.
  • Coracoid Fracture: Rare, but can occur during osteotomy.
• Cosmetic: Larger scar compared to arthroscopic procedures.

Recovery and Rehabilitation

Post-operative rehabilitation is critical for optimizing the outcome of a Bristow procedure. It is a structured, progressive process guided by a physical therapist.

General Phases of Rehabilitation:

• Phase 1: Protection and Pain Management (Weeks 0-6):
  • Immobilization in a sling to protect the surgical site and allow bone healing.
  • Focus on pain and swelling control.
  • Gentle passive range of motion (ROM) for the elbow, wrist, and hand.
  • Avoid active shoulder movement, particularly external rotation and abduction.
• Phase 2: Gradual Range of Motion and Gentle Strengthening (Weeks 6-12):
  • Gradual progression from passive to active-assisted, then active ROM.
  • Initiation of gentle isometric exercises for the rotator cuff and scapular stabilizers.
  • Focus on restoring functional movement patterns without stressing the repair.
• Phase 3: Progressive Strengthening and Functional Return (Months 3-6):
  • Introduction of resistance exercises, gradually increasing load.
  • Focus on improving shoulder strength, endurance, and proprioception.
  • Begin sport-specific or activity-specific drills, ensuring proper form.
• Phase 4: Sport-Specific Training and Full Return (Months 6-12+):
  • Advanced strength and conditioning.
  • High-level agility and sport-specific drills.
  • Gradual return to full activity and competitive sports, often requiring specific criteria to be met (e.g., strength, ROM, functional tests).

Full recovery and return to demanding activities can take anywhere from 6 to 12 months, or even longer, depending on the individual, the extent of the initial injury, and adherence to the rehabilitation protocol. Close collaboration with the surgeon and physical therapist is paramount throughout this process.

Comparison with Other Procedures

The most common alternative to the Bristow procedure for shoulder instability is a Bankart repair.

• Bankart Repair: This is a soft tissue repair, typically performed arthroscopically, where the torn labrum and stretched capsule are reattached to the glenoid rim. It is the preferred procedure for shoulder instability without significant bone loss.
• Bristow Procedure: As discussed, the Bristow is chosen when there is considerable bone loss or when a Bankart repair has failed, as it provides a more robust, bone-based solution.

The choice between these procedures is highly individualized, based on the specific pathology, patient age, activity level, and surgeon's preference.

Conclusion

The Bristow procedure stands as a highly effective and durable surgical solution for recurrent anterior shoulder instability, particularly in challenging cases involving significant glenoid bone loss or failed prior soft tissue repairs. By combining a structural bone block with a dynamic muscular sling, it offers superior stability for patients, including high-demand athletes. While it involves a more invasive approach and a dedicated rehabilitation period, its proven success in preventing re-dislocation makes it a valuable option for carefully selected individuals. Anyone experiencing recurrent shoulder instability should consult with an orthopedic surgeon to determine the most appropriate course of treatment based on their specific condition.