Shoulder Dislocation: Causes of Pain, Long-Term Consequences, and Management

Why Does My Shoulder Hurt After Dislocation?

A shoulder dislocation causes immediate pain due to severe trauma to the joint, tearing of ligaments, tendons, and muscles, and potential damage to bone, nerves, and blood vessels, with persistent pain often stemming from ongoing instability, unaddressed tissue damage, or secondary conditions like arthritis.

Understanding Shoulder Dislocation: A Biomechanical Perspective

The shoulder is a complex ball-and-socket joint, the most mobile joint in the human body. This remarkable range of motion, however, comes at the cost of stability. The "ball" (head of the humerus, or upper arm bone) sits within a shallow "socket" (glenoid fossa of the scapula, or shoulder blade). Stability is primarily provided by a network of soft tissues: the joint capsule, glenohumeral ligaments, the labrum (a rim of cartilage deepening the socket), and the powerful rotator cuff muscles.

A shoulder dislocation occurs when the head of the humerus is forced completely out of the glenoid fossa. While dislocations can occur in various directions, an anterior dislocation (where the humerus moves forward and downward) is by far the most common, often resulting from a fall onto an outstretched arm or a direct blow to the shoulder. This violent separation of the joint surfaces inevitably causes significant trauma to the surrounding structures, leading directly to the intense pain experienced.

Immediate Causes of Pain Post-Dislocation

The acute pain following a shoulder dislocation is a direct consequence of the structural damage inflicted upon the joint and its surrounding tissues.

• Soft Tissue Damage:
  • Ligamentous Tears: The joint capsule and glenohumeral ligaments are stretched or torn, which are critical for joint stability. These tears are inherently painful due to the disruption of nerve endings within the ligaments.
  • Tendon and Muscle Injury: The powerful rotator cuff muscles (supraspinatus, infraspinatus, teres minor, subscapularis) and the long head of the biceps tendon can be stretched, strained, or torn as the humeral head displaces. These injuries cause pain with movement and at rest.
• Bone Bruising and Fractures:
  • Hill-Sachs Lesion: As the humeral head dislocates, it can impact the anterior rim of the glenoid, causing a compression fracture or "dent" on the posterolateral aspect of the humeral head. This bone bruise or defect is a source of pain and can contribute to recurrent instability.
  • Bankart Lesion: The anterior inferior labrum (cartilage rim) can tear away from the glenoid, often taking a piece of bone with it (a bony Bankart lesion). This is a significant source of pain and instability.
  • Greater Tuberosity Fracture: Less commonly, the greater tuberosity (a bony prominence on the humerus where rotator cuff tendons attach) can fracture during the dislocation, especially in older individuals.
• Nerve Damage: The axillary nerve, which supplies sensation to the deltoid region and controls deltoid and teres minor muscles, is particularly vulnerable to stretching or compression during an anterior dislocation. Nerve injury can cause immediate sharp, burning, or shooting pain, numbness, tingling, or weakness in the shoulder and upper arm.
• Blood Vessel Damage: While less common, severe dislocations can occasionally damage adjacent blood vessels, leading to bruising and swelling, which contribute to pain.
• Inflammation and Swelling: The body's natural response to trauma is an inflammatory cascade, leading to swelling, warmth, redness, and pain in the injured area. This protective mechanism, while vital for healing, significantly contributes to immediate discomfort.

Persistent Pain: Long-Term Consequences and Contributing Factors

Beyond the initial acute pain, many individuals experience lingering or recurrent pain after a shoulder dislocation. This is often due to unaddressed structural issues or secondary complications.

• Chronic Instability and Recurrent Dislocation: If the initial ligamentous and labral injuries do not heal adequately, the shoulder can remain unstable, making it prone to re-dislocation. Each subsequent dislocation re-injures the tissues, perpetuating a cycle of pain and damage. Even without full dislocation, subluxation (partial dislocation) can cause pain and apprehension.
• Rotator Cuff Tears: Especially in older individuals (over 40), a significant rotator cuff tear can occur concurrently with a dislocation. If these tears are not identified and treated, they can lead to chronic pain, weakness, and limited range of motion.
• Labral Tears (Non-Bony Bankart and SLAP): Even without a bony component, a labral tear (e.g., a Bankart lesion where only the cartilage tears, or a SLAP tear involving the superior labrum from anterior to posterior) can cause persistent pain, clicking, catching, and instability.
• Adhesive Capsulitis (Frozen Shoulder): Following immobilization for a dislocation, some individuals, particularly those with a prolonged period of restricted movement, may develop adhesive capsulitis. This condition causes significant stiffness and pain due to thickening and contraction of the joint capsule.
• Post-Traumatic Osteoarthritis: Over time, the repeated trauma, cartilage damage, and altered biomechanics from an unstable shoulder can accelerate the degeneration of the joint cartilage, leading to post-traumatic osteoarthritis. This can result in chronic deep aching pain, stiffness, and crepitus (grinding sensation).
• Nerve Entrapment/Neuropathy: Residual nerve damage or scarring around the nerves can lead to chronic neuropathic pain, characterized by burning, tingling, or shooting sensations.
• Psychological Factors: Chronic pain can be influenced by psychological factors such as kinesiophobia (fear of movement due to fear of re-injury), anxiety, and depression. These can lower pain thresholds and make rehabilitation more challenging.

The Healing Process and Pain Management

Effective management of post-dislocation pain involves a multi-faceted approach, emphasizing both immediate relief and long-term joint health.

• Initial Management: This typically involves reduction of the dislocation (putting the joint back in place), followed by a period of immobilization (e.g., in a sling) to allow initial soft tissue healing. Pain relief is managed with RICE (Rest, Ice, Compression, Elevation) and over-the-counter or prescription pain medications (NSAIDs).
• Rehabilitation: This is the cornerstone of recovery. A structured physical therapy program is crucial to:
  • Restore range of motion.
  • Strengthen the rotator cuff and periscapular muscles to improve dynamic stability.
  • Improve proprioception (the body's awareness of joint position) to prevent recurrence.
  • Gradually return to activity.
• Pain Relief Strategies: Beyond medication, modalities like ice, heat, ultrasound, and electrical stimulation may be used in physical therapy. In some cases, corticosteroid injections may be considered for localized inflammation, though their use is debated due to potential effects on tissue healing.
• Surgical Intervention: Surgery may be recommended if conservative management fails, particularly in cases of recurrent instability, significant labral or rotator cuff tears, or large bony defects. Procedures like arthroscopic Bankart repair or Latarjet procedure aim to restore stability and alleviate pain by addressing the underlying structural damage.

When to Seek Professional Medical Attention

While some mild, improving pain is normal after a dislocation, it's crucial to seek medical advice if you experience:

• Persistent or Worsening Pain: If your pain doesn't improve with rest, medication, or therapy, or if it suddenly intensifies.
• Numbness, Tingling, or Weakness: Especially if new or worsening, as this could indicate nerve involvement.
• Inability to Move the Arm: Beyond what is expected during the early healing phase.
• Signs of Infection: Redness, warmth, pus, or fever around the joint (though rare after dislocation without surgery).
• Recurrent Dislocation or Subluxation: Any feeling of the shoulder "slipping out" or dislocating again.
• Clicking, Catching, or Grinding: Suggestive of labral tears or cartilage damage.

Conclusion: A Path to Recovery

Pain after a shoulder dislocation is a complex issue, arising from a cascade of immediate tissue damage and potential long-term complications. Understanding the underlying anatomical and biomechanical reasons for this pain is crucial for both patients and healthcare providers. While the initial trauma is significant, a diligent, evidence-based approach to recovery—involving appropriate medical assessment, effective pain management, and a comprehensive rehabilitation program—offers the best chance for restoring function, reducing persistent pain, and preventing future dislocations. Patience and adherence to professional guidance are paramount on the path to a strong, stable, and pain-free shoulder.