Bankart Lesion: Understanding Shoulder Anatomy, Causes, Symptoms, and Treatment

What is a Bankart Lesion in the Shoulder?

A Bankart lesion is a specific type of injury to the shoulder joint, characterized by the tearing of the anteroinferior (front and bottom) portion of the glenoid labrum, often accompanied by damage to the inferior glenohumeral ligament. This injury typically occurs following an anterior shoulder dislocation, compromising the stability of the joint.

Anatomy of the Shoulder Joint

To understand a Bankart lesion, it's crucial to first grasp the basic anatomy of the shoulder. The shoulder is a ball-and-socket joint, formed by the head of the humerus (upper arm bone) and the glenoid fossa, a shallow socket on the scapula (shoulder blade). This configuration allows for an impressive range of motion but inherently sacrifices stability.

Key structures contributing to shoulder stability include:

• Glenoid Labrum: A ring of fibrocartilage that encircles the glenoid fossa, deepening the socket and providing a stable attachment point for ligaments.
• Joint Capsule: A fibrous sac enclosing the joint.
• Glenohumeral Ligaments: Thickened bands within the joint capsule (superior, middle, and inferior) that reinforce the capsule and help prevent excessive motion. The inferior glenohumeral ligament (IGHL) is particularly important in preventing anterior and inferior dislocation.
• Rotator Cuff Muscles: A group of four muscles (supraspinatus, infraspinatus, teres minor, subscapularis) and their tendons that surround the joint, providing dynamic stability and facilitating movement.

Understanding the Bankart Lesion

A Bankart lesion is named after British surgeon Arthur Bankart, who first described it in 1923. It specifically refers to the avulsion (tearing away) of the anteroinferior labrum from the glenoid rim. This detachment can occur with or without an associated fracture of the glenoid bone.

Mechanism of Injury: The most common cause of a Bankart lesion is a traumatic anterior shoulder dislocation. When the humeral head is forced out of the glenoid socket in an anterior direction (forward), it can peel or tear the labrum and its attached ligaments from the front and bottom edge of the glenoid. This injury is particularly prevalent in athletes involved in contact sports or activities requiring overhead movements, or individuals who experience falls onto an outstretched arm.

Consequences of the Lesion: The integrity of the labrum and the inferior glenohumeral ligament are vital for maintaining anterior shoulder stability. Once a Bankart lesion occurs, the deepened socket effect of the labrum is lost, and the primary ligamentous restraint (IGHL) is compromised. This significantly increases the risk of recurrent anterior shoulder dislocations, often with less force required for subsequent dislocations.

Types of Bankart Lesions

While the classic Bankart lesion involves the anteroinferior labrum, variations exist based on the extent of the damage:

• Classic Bankart Lesion: Detachment of the anteroinferior labrum from the glenoid rim.
• Bony Bankart Lesion: A classic Bankart lesion that includes a fracture of a small piece of bone from the anteroinferior glenoid rim, pulled away along with the labrum. This is a more severe form as it involves bone loss from the socket.
• Perthes Lesion: A tear of the anteroinferior labrum where the periosteum (the fibrous membrane covering the bone) remains intact, but the labrum is displaced medially.
• ALPSA Lesion (Anterior Labroligamentous Periosteal Sleeve Avulsion): The anteroinferior labrum and joint capsule are avulsed from the glenoid and displaced medially, but the periosteum remains intact and acts as a sleeve, preventing the labrum from returning to its anatomical position.

Signs and Symptoms

Individuals with a Bankart lesion typically present with a history of shoulder dislocation and subsequent symptoms, which may include:

• Pain: Often localized to the front of the shoulder, especially with certain movements.
• Instability or Apprehension: A feeling that the shoulder might "pop out" again, particularly when the arm is abducted and externally rotated (e.g., throwing position).
• Recurrent Dislocations or Subluxations: The shoulder partially or fully dislocates repeatedly.
• Clicking, Popping, or Grinding Sensations: These sounds or feelings may occur during shoulder movement.
• Weakness: Difficulty with overhead movements or activities that stress the shoulder.
• Reduced Range of Motion: Especially in external rotation or abduction.

Diagnosis

Diagnosing a Bankart lesion involves a combination of clinical evaluation and imaging studies:

• Medical History and Physical Examination: A detailed history of the injury (mechanism, previous dislocations) is taken. The physical exam will assess for pain, range of motion, and stability, often including specific tests that provoke apprehension or instability (e.g., apprehension test, relocation test).
• X-rays: While X-rays primarily visualize bone, they can identify a Bony Bankart lesion (a fracture of the glenoid rim) or a Hill-Sachs lesion (a compression fracture on the posterior-superior aspect of the humeral head, which often occurs secondary to the humeral head impacting the glenoid rim during dislocation).
• Magnetic Resonance Imaging (MRI): An MRI is the gold standard for visualizing soft tissue injuries like labral tears. An MR Arthrogram, where a contrast dye is injected into the joint before the MRI, significantly enhances the visualization of the labrum and capsule, making Bankart lesions more apparent.

Treatment Options

Treatment for a Bankart lesion depends on several factors, including the patient's age, activity level, number of previous dislocations, and the presence of associated injuries like bony defects.

Conservative Management

For some individuals, particularly those with a first-time dislocation, conservative treatment may be attempted. This typically involves:

• Immobilization: Short-term use of a sling to allow initial healing.
• Pain and Inflammation Control: Rest, ice, compression, and elevation (RICE), along with non-steroidal anti-inflammatory drugs (NSAIDs).
• Physical Therapy: A structured rehabilitation program focusing on:
  • Restoring pain-free range of motion.
  • Strengthening the rotator cuff muscles and scapular stabilizers to improve dynamic shoulder stability.
  • Proprioceptive training to enhance joint awareness and control.
  • Gradual return to activity.

Conservative management may be less successful in preventing recurrent dislocations, especially in young, active individuals.

Surgical Repair

Surgical intervention is often recommended for Bankart lesions, particularly in cases of recurrent instability, significant labral detachment, or bony involvement. The most common procedure is an arthroscopic Bankart repair.

• Arthroscopic Bankart Repair: This minimally invasive procedure involves making small incisions around the shoulder. An arthroscope (a small camera) is inserted to visualize the joint. The torn labrum is reattached to the glenoid rim using small anchors (often bioabsorbable) with sutures. The joint capsule and ligaments are also tightened and re-tensioned as needed to restore stability.
• Open Bankart Repair: Less common now, but may be used in complex cases or revisions.

The goal of surgical repair is to restore the anatomical integrity of the labrum and ligaments, thereby improving shoulder stability and reducing the risk of future dislocations.

Rehabilitation and Return to Activity

Whether treated conservatively or surgically, a comprehensive rehabilitation program is critical for optimal recovery and return to function. This typically follows a phased approach:

• Phase 1: Protection and Early Motion (0-6 weeks post-injury/surgery): Focus on protecting the repair, managing pain and swelling, and initiating gentle, controlled range of motion exercises (often passive or assisted).
• Phase 2: Intermediate Strengthening (6-12 weeks): Gradual introduction of active range of motion, light isometric exercises, and early rotator cuff and scapular strengthening.
• Phase 3: Advanced Strengthening and Proprioception (12-20 weeks): Progression to more challenging strengthening exercises, resistance training, balance, and proprioceptive drills.
• Phase 4: Return to Activity/Sport (20+ weeks): Sport-specific drills, plyometrics, and functional training to prepare for full return to desired activities, guided by rehabilitation specialists.

Adherence to the prescribed rehabilitation protocol is paramount to ensure proper healing, regain strength, and minimize the risk of re-injury.

Prognosis and Long-Term Considerations

The prognosis after a Bankart lesion depends on several factors, including the type of lesion, the presence of bone loss, age at injury, and treatment method.

• Recurrence Risk: Without surgical stabilization, the risk of recurrent dislocation after a Bankart lesion is high, especially in young, active individuals. Surgical repair significantly reduces this risk, though it is not eliminated.
• Osteoarthritis: Long-term, repeated dislocations or significant joint instability can increase the risk of developing osteoarthritis in the shoulder joint due to chronic wear and tear.
• Importance of Rehabilitation: Even after successful surgery, a dedicated and complete rehabilitation program is essential for restoring full strength, stability, and function, and for maximizing long-term outcomes.

Understanding a Bankart lesion is crucial for anyone involved in fitness, sports, or health, as it represents a significant structural injury that can severely impact shoulder function and stability if not properly managed.