Bony Bankart Lesion: Understanding, Causes, Symptoms, Diagnosis, and Treatment

What is Bony Bankart?

A Bony Bankart lesion is a specific type of injury to the shoulder joint, characterized by an avulsion fracture of the anteroinferior glenoid rim of the shoulder blade, often occurring concurrently with a tear of the glenoid labrum, typically following an anterior shoulder dislocation.

Understanding the Shoulder Joint

The shoulder is a complex ball-and-socket joint, renowned for its exceptional range of motion. It comprises three main bones: the humerus (upper arm bone), the scapula (shoulder blade), and the clavicle (collarbone). The "socket" of this joint, known as the glenoid, is a shallow depression on the scapula. To deepen this shallow socket and provide greater stability, a ring of fibrous cartilage called the glenoid labrum encircles its rim. This intricate anatomical design, while allowing for extensive movement, also makes the shoulder inherently less stable and more susceptible to dislocation compared to other joints.

What is a Bankart Lesion?

A Bankart lesion refers specifically to a tear of the anteroinferior (front and bottom) portion of the glenoid labrum. This injury most commonly occurs when the humeral head (the "ball" of the shoulder joint) is forcefully dislocated forward and downward, tearing the labrum from its attachment to the glenoid bone. This tearing compromises the stability of the joint, making it prone to recurrent dislocations.

What Makes it "Bony"?

The distinguishing feature of a Bony Bankart lesion is the involvement of bone. While a standard Bankart lesion is a soft tissue injury (a tear of the labrum only), a Bony Bankart lesion includes an avulsion fracture – meaning a piece of bone is pulled away – from the anteroinferior rim of the glenoid. In essence, the labrum, instead of simply tearing, pulls a fragment of the glenoid bone with it during the dislocation event. This bone loss from the glenoid rim further reduces the effective depth of the shoulder socket, significantly increasing the risk of recurrent anterior shoulder instability and dislocation.

Causes and Risk Factors

The primary cause of a Bony Bankart lesion is a traumatic anterior shoulder dislocation. This typically happens due to:

• High-impact sports injuries: Common in contact sports like rugby, football, hockey, or sports involving overhead movements such as basketball or volleyball, particularly when falling on an outstretched arm.
• Falls: Landing directly on the shoulder or on an outstretched arm.
• Direct trauma: A direct blow to the shoulder.

Individuals who have experienced one anterior shoulder dislocation, especially younger, active individuals, are at a higher risk of developing a Bony Bankart lesion and experiencing recurrent dislocations.

Signs and Symptoms

Individuals with a Bony Bankart lesion will typically experience symptoms associated with shoulder instability and previous dislocation:

• Severe pain at the time of injury, often persisting as a deep ache.
• A feeling of instability or apprehension, especially when the arm is placed in an abducted (away from the body) and externally rotated (outward) position.
• Recurrent shoulder dislocations or subluxations (partial dislocations).
• Clicking, popping, or grinding sensations within the shoulder joint.
• Weakness in the shoulder and difficulty with overhead activities.
• Reduced range of motion due to pain or mechanical blockage.

Diagnosis

Accurate diagnosis of a Bony Bankart lesion involves a combination of clinical assessment and advanced imaging:

• Medical History and Physical Examination: The physician will inquire about the mechanism of injury, past dislocations, and current symptoms. Physical examination will assess range of motion, stability, and specific provocative tests (e.g., apprehension test, relocation test) to elicit instability.
• X-rays: Standard X-rays are crucial for identifying the avulsion fracture of the glenoid rim (the "bony" component) and assessing the overall bone structure. They can also reveal other associated fractures, such as a Hill-Sachs lesion (an impaction fracture on the posterior-superior aspect of the humeral head, often occurring during anterior dislocations).
• Magnetic Resonance Imaging (MRI) or MR Arthrography: While X-rays show bone, an MRI provides detailed images of soft tissues, including the labrum, ligaments, and rotator cuff. An MR arthrogram, which involves injecting a contrast dye into the joint before the MRI, enhances the visualization of labral tears and capsular injuries.
• Computed Tomography (CT) Scan: A CT scan provides excellent detail of bone structure and is particularly useful for precisely quantifying the amount of glenoid bone loss, which is critical for surgical planning.

Treatment Options

Treatment for a Bony Bankart lesion depends on several factors, including the patient's age, activity level, the size of the bone fragment, the degree of bone loss, and the frequency of dislocations.

Conservative Management

For some individuals, especially those with minimal bone loss, older patients, or those with low activity demands, non-surgical options may be considered initially:

• Immobilization: A brief period of sling immobilization (usually 2-4 weeks) to allow initial healing.
• Pain and Inflammation Control: Rest, ice, and 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.

Conservative management aims to improve shoulder function and reduce the risk of future dislocations, but it may not be sufficient for significant bony lesions or recurrent instability.

Surgical Intervention

Surgery is often recommended for Bony Bankart lesions, particularly in young, active individuals, those with significant glenoid bone loss, or those experiencing recurrent dislocations. The goal is to restore the normal anatomy and stability of the shoulder joint.

• Arthroscopic Bankart Repair: In many cases, the surgery can be performed arthroscopically (minimally invasive, using small incisions and a camera). The detached labrum and bone fragment are reattached to the glenoid rim using small anchors and sutures.
• Open Bankart Repair: In some complex cases or revisions, an open surgical approach may be necessary.
• Latarjet Procedure: For patients with significant glenoid bone loss (typically >20-25%), a standard Bankart repair may not be sufficient. The Latarjet procedure involves transferring a piece of bone from the coracoid process (a part of the scapula) to the anterior glenoid. This effectively extends the glenoid and provides a bony block to prevent further dislocations, while also transferring attached muscles that act as a sling.

Rehabilitation After Surgery

Post-surgical rehabilitation is crucial for a successful outcome. It typically follows a phased protocol:

• Phase 1: Immobilization and Protection (0-6 weeks): The arm is kept in a sling to protect the repair. Passive range of motion exercises may begin under guidance.
• Phase 2: Early Motion and Gentle Strengthening (6-12 weeks): Gradual increase in active range of motion, followed by gentle isometric and light resistance exercises for the rotator cuff and scapular muscles.
• Phase 3: Progressive Strengthening (12-24 weeks): Increased resistance training, proprioceptive drills, and functional exercises to prepare for more demanding activities.
• Phase 4: Return to Activity/Sport (6+ months): Sport-specific drills and gradual return to full activity, depending on individual progress and the demands of their sport or occupation.

Adherence to the physical therapy program is paramount to regain strength, stability, and full function, and to minimize the risk of re-injury.

Prognosis and Long-Term Outlook

The prognosis for a Bony Bankart lesion treated appropriately is generally good, with a high success rate in restoring shoulder stability. However, the long-term outlook can be influenced by:

• Extent of bone loss: Greater bone loss typically requires more involved surgical procedures (e.g., Latarjet) and may have a slightly different recovery profile.
• Adherence to rehabilitation: Crucial for optimal recovery and preventing re-dislocation.
• Activity level: High-demand athletes may face a higher risk of re-injury if return to sport is too aggressive or if underlying biomechanical issues are not addressed.
• Potential for arthritis: Over many years, recurrent instability or previous dislocations can increase the risk of developing osteoarthritis in the shoulder joint.

Prevention

While not all shoulder dislocations can be prevented, especially those from traumatic accidents, certain measures can help reduce the risk of initial or recurrent injuries:

• Strengthening Exercises: Focus on strengthening the rotator cuff muscles and scapular stabilizers to enhance dynamic shoulder stability.
• Proprioceptive Training: Exercises that improve joint awareness and control can help the body react quickly to destabilizing forces.
• Proper Technique: In sports and daily activities, using correct body mechanics can minimize stress on the shoulder joint.
• Addressing Instability Early: If you experience symptoms of shoulder instability, seek medical attention promptly to prevent recurrent dislocations and potentially more severe injuries like a Bony Bankart lesion.