Posterior Elbow Dislocation: Complications, Management, and Recovery

What are the complications of a posterior elbow dislocation?

A posterior elbow dislocation, a significant traumatic injury, can lead to a range of immediate and long-term complications, primarily involving neurovascular compromise, associated fractures, persistent instability, and chronic functional deficits such as stiffness and post-traumatic arthritis.

Understanding Posterior Elbow Dislocation

The elbow joint, a critical hinge joint formed by the humerus, ulna, and radius, is inherently stable due to its bony configuration and robust ligamentous support. A posterior elbow dislocation occurs when the ulna and radius are displaced backward relative to the humerus, typically resulting from a fall onto an outstretched arm. While prompt reduction is crucial, the high-energy nature of the injury often leads to significant soft tissue and potential bony damage, predisposing individuals to various complications.

Immediate (Acute) Complications

Complications encountered at the time of injury or shortly after reduction are critical and demand immediate attention.

• Neurovascular Compromise: This is one of the most serious immediate concerns. The brachial artery and median, ulnar, and radial nerves pass close to the elbow joint. Dislocation can stretch, compress, or even tear these structures, leading to:
  • Vascular Injury: Diminished or absent pulse, pallor, coolness, or paresthesia distal to the elbow, indicating compromised blood flow. This is a surgical emergency.
  • Nerve Damage: Numbness, tingling, or weakness in the hand or forearm, specific to the distribution of the affected nerve. The ulnar nerve is most commonly affected due to its superficial position behind the medial epicondyle.
• Associated Fractures: The forces involved in a dislocation often cause concomitant fractures, significantly complicating treatment and prognosis. Common fracture patterns include:
  • Coronoid Process Fractures: A fracture of the coronoid process of the ulna, critical for elbow stability, especially against posterior displacement.
  • Radial Head Fractures: Fractures of the radial head can impair forearm rotation and contribute to instability.
  • Medial or Lateral Epicondyle Fractures: Avulsion fractures where ligaments or muscles attach.
  • Olecranon Fractures: Less common but can occur with severe trauma.
• Ligamentous Instability: While some degree of ligamentous injury is inherent to any dislocation, severe tears can lead to persistent instability.
  • Ulnar Collateral Ligament (UCL) Tears: The primary stabilizer against valgus stress; severe tears can result in chronic instability.
  • Lateral Collateral Ligament (LCL) Complex Tears: Often involved in posterolateral rotatory instability.
  • Annular Ligament Tears: Can lead to radial head subluxation or dislocation, particularly in children.
• Capsular Damage: The joint capsule is invariably torn during a dislocation, and its healing can contribute to stiffness or instability.
• Muscle and Tendon Injuries: While less common than ligamentous or bony injuries, severe strains or tears of muscles and tendons around the elbow can occur.

Early (Subacute) Complications

These complications typically manifest in the weeks to months following the injury and reduction.

• Redislocation/Recurrent Instability: Inadequate healing of ligaments, particularly the UCL, or the presence of unaddressed fractures (e.g., coronoid process) can lead to recurrent dislocations or chronic instability, especially during specific movements.
• Stiffness and Loss of Range of Motion (ROM): This is perhaps the most common complication. It can result from:
  • Capsular Contracture: Thickening and shortening of the joint capsule due to inflammation and scar tissue formation.
  • Heterotopic Ossification (HO): The abnormal formation of bone in soft tissues around the joint, particularly in the brachialis muscle, which can severely limit elbow flexion and extension.
  • Prolonged Immobilization: While necessary initially, excessive or prolonged immobilization can worsen stiffness.
• Persistent Pain: Chronic pain can arise from incomplete healing, nerve irritation, early arthritic changes, or ongoing instability.

Long-Term (Chronic) Complications

These complications can persist for years after the initial injury and significantly impact long-term function and quality of life.

• Post-Traumatic Arthritis (Osteoarthritis): Damage to the articular cartilage during the dislocation, combined with potential instability or malunion of fractures, can accelerate degenerative changes in the joint, leading to chronic pain, stiffness, and crepitus.
• Chronic Pain and Weakness: Even without significant arthritis, individuals may experience chronic pain and reduced strength due to residual soft tissue damage, nerve irritation, or muscle atrophy from disuse.
• Nerve Entrapment Syndromes: Scar tissue formation, heterotopic ossification, or chronic inflammation can entrap nerves, most commonly the ulnar nerve at the cubital tunnel (cubital tunnel syndrome), leading to chronic paresthesia, weakness, and muscle wasting in its distribution.
• Myositis Ossificans: This is a severe form of heterotopic ossification where mature bone forms within muscle tissue, most commonly the brachialis. It can cause significant pain and severely restrict elbow motion, often requiring surgical excision.
• Deformity: Malunion of associated fractures or severe capsular contracture can lead to visible deformities of the elbow, which may also impair function.

Factors Influencing Complication Risk

Several factors can increase the likelihood and severity of complications:

• Severity of Initial Injury: High-energy trauma, greater displacement, and the presence of gross instability after reduction.
• Presence of Associated Fractures: Fractures, especially of the coronoid process or radial head, significantly increase complexity and risk of poor outcomes.
• Timeliness and Quality of Reduction: Delayed reduction or multiple attempts can increase soft tissue damage and neurovascular risk.
• Rehabilitation Adherence: Non-compliance with prescribed rehabilitation protocols can lead to stiffness, weakness, or recurrent instability.
• Individual Factors: Age, bone quality, pre-existing conditions, and genetic predispositions (e.g., for heterotopic ossification) can also play a role.

Prevention and Management Strategies

Minimizing complications relies on a multi-faceted approach:

• Prompt and Proper Reduction: Immediate, gentle, and accurate closed reduction of the dislocation is paramount.
• Thorough Assessment: Comprehensive evaluation for neurovascular compromise and associated fractures post-reduction.
• Controlled Rehabilitation: A carefully structured rehabilitation program that balances early, controlled motion to prevent stiffness with adequate protection for healing ligaments and bones.
• Addressing Underlying Instability: Surgical intervention may be necessary for significant ligamentous tears or unstable fractures to restore joint stability.
• Monitoring for Complications: Close follow-up to identify and manage complications like stiffness, nerve issues, or heterotopic ossification early.

Conclusion

Posterior elbow dislocation is a complex injury with a broad spectrum of potential complications, ranging from acute neurovascular emergencies to chronic pain, stiffness, and arthritis. A deep understanding of these risks, combined with prompt diagnosis, meticulous reduction, and a structured, individualized rehabilitation program, is essential to optimize patient outcomes and restore maximal elbow function. For fitness professionals and enthusiasts, recognizing the severity of this injury underscores the importance of proper technique to prevent falls and the necessity of expert medical guidance should such an injury occur.