Anterior Elbow Dislocation: Complications, Management, and Long-Term Effects

What are the complications of anterior elbow dislocation?

Anterior elbow dislocation, while less common than posterior dislocation, can lead to a range of significant complications affecting joint stability, range of motion, and neurovascular integrity. These issues can manifest immediately following the injury or develop over time, underscoring the importance of prompt and accurate management.

Understanding Anterior Elbow Dislocation

The elbow joint, a complex hinge formed by the humerus, radius, and ulna, is inherently stable due to its bony congruence and strong ligamentous support (medial and lateral collateral ligaments) and the joint capsule. An anterior elbow dislocation occurs when the ulna and radius displace anteriorly (forward) relative to the humerus. This typically results from a direct blow to the posterior elbow or a fall onto an outstretched hand with the elbow in flexion, driving the forearm bones forward. While relatively rare compared to posterior dislocations, anterior dislocations are often associated with severe soft tissue and bony injuries, leading to a unique set of complications.

Immediate Complications

Complications that arise at the time of injury or shortly thereafter are often the most critical and require immediate attention.

• Neurovascular Injury: This is arguably the most severe immediate complication.
  • Brachial Artery Injury: The brachial artery runs anterior to the elbow joint. It can be stretched, compressed, or lacerated during dislocation, potentially leading to acute limb ischemia if not promptly recognized and treated. Signs include absent pulses, pallor, paresthesia, paralysis, and pain (the "5 Ps").
  • Median Nerve Injury: The median nerve also passes anterior to the elbow. It can be stretched or entrapped, resulting in sensory deficits (thumb, index, middle, and radial half of ring finger) and motor weakness (flexors of the forearm, pronators, thenar muscles).
  • Ulnar Nerve Injury: Less commonly, the ulnar nerve (which runs posterior to the medial epicondyle) can be affected, particularly with significant valgus stress or associated fractures. This can lead to sensory loss in the little finger and ulnar half of the ring finger, and weakness of intrinsic hand muscles.
• Associated Fractures: The force required to cause an anterior dislocation often leads to concomitant fractures.
  • Olecranon Fracture: This is the most common associated fracture, occurring as the olecranon process (part of the ulna) is forced against the posterior humerus.
  • Coronoid Process Fracture: The coronoid process of the ulna can fracture as it impacts the anterior humerus during the dislocation. These fractures can compromise elbow stability.
  • Radial Head Fracture: Less common but possible, often due to axial loading during the fall.
  • Epicondyle Fractures: Fractures of the medial or lateral epicondyles of the humerus.
• Extensive Ligamentous and Capsular Disruption:
  • Anterior dislocations involve significant tearing of the posterior joint capsule and posterior collateral ligaments.
  • The medial (ulnar) collateral ligament (MCL) and lateral (radial) collateral ligament (LCL) complexes may also be severely damaged, contributing to post-reduction instability.

Early and Intermediate Complications

These complications typically manifest within weeks to months after the injury.

• Recurrent Instability: Due to significant ligamentous and capsular damage, the elbow may remain unstable even after reduction. This can lead to:
  • Chronic Subluxation/Dislocation: The joint repeatedly displaces or partially displaces, often with specific movements.
  • Functional Instability: A subjective feeling of the elbow "giving way" or being unreliable during activity.
• Elbow Stiffness and Loss of Range of Motion (ROM): This is a very common complication following any severe elbow injury.
  • Post-Traumatic Swelling and Scarring: Edema, hematoma formation, and subsequent fibrotic scarring can restrict joint movement.
  • Prolonged Immobilization: While necessary initially, extended periods of immobilization can lead to capsular contractures and muscle atrophy, severely limiting flexion and extension.
  • Heterotopic Ossification (HO): The abnormal formation of new bone in soft tissues around the joint, particularly in the anterior capsule or brachialis muscle. HO can severely restrict ROM and cause pain. It is more common after severe trauma, particularly with delayed reduction, repeated manipulations, or associated head injuries.
• Post-Traumatic Arthritis: Over time, the damage to articular cartilage during the dislocation, combined with any associated fractures or chronic instability, can lead to degenerative changes in the joint. This can cause:
  • Chronic pain.
  • Persistent stiffness.
  • Crepitus (grinding sensation).
  • Progressive loss of function.

Long-Term Complications

These issues can persist or develop years after the initial injury.

• Chronic Pain: Persistent discomfort, often exacerbated by activity or weather changes, stemming from nerve damage, arthritis, or ongoing instability.
• Persistent ROM Deficits: Despite rehabilitation, some degree of elbow stiffness, particularly in extension, may remain. This can significantly impact daily activities and occupational demands.
• Nerve Entrapment Syndromes: While initial nerve injury may recover, scarring or heterotopic ossification can lead to chronic compression of nerves, particularly the ulnar nerve in the cubital tunnel. This can result in:
  • Ongoing numbness and tingling in the hand.
  • Progressive weakness and atrophy of intrinsic hand muscles.
• Deformity: Severe cases, especially those with unreduced dislocations or significant malunion of fractures, can result in visible or palpable deformity of the elbow joint.
• Functional Limitations: The cumulative effect of pain, stiffness, instability, and nerve issues can lead to significant long-term functional impairment, affecting activities of daily living, sports, and work.

Factors Influencing Complications

Several factors can influence the likelihood and severity of complications:

• Severity of Initial Injury: High-energy trauma and extensive soft tissue damage increase the risk.
• Associated Fractures: The presence and type of concomitant fractures significantly elevate complication rates.
• Timeliness and Quality of Reduction: Prompt and gentle reduction of the dislocation is crucial to minimize further soft tissue and neurovascular damage.
• Post-Reduction Stability: If the elbow remains unstable after reduction, re-dislocation and chronic instability are more likely.
• Rehabilitation Adherence: A structured, progressive rehabilitation program is vital for restoring range of motion, strength, and function, and for mitigating stiffness and instability.

In conclusion, anterior elbow dislocation is a serious injury with a potential for significant and varied complications. A thorough initial assessment, prompt and appropriate management, and dedicated rehabilitation are essential to minimize adverse outcomes and optimize long-term functional recovery.