Orthopaedic Surgery - Elbow Dislocation

Basics

Elbow dislocation is usually the result of acute trauma, most often involving disruption of the ulnohumeral articulation.

Posterior dislocation is by far the most common pattern.

The injury occurs most frequently in younger patients, particularly those under 20 years of age, although it may also occur in older adults after a fall.

Approximately 26% of elbow dislocations are associated with a fracture.

Classification

Elbow dislocations are generally named according to the position of the ulna relative to the humerus after injury.

They may be classified as posterior, anterior, medial, lateral, or divergent.

Posterior and posterolateral patterns are the most frequently encountered.

Fracture-Dislocation

An elbow dislocation associated with fractures of the radial head and coronoid process is referred to as the terrible triad of the elbow.

This is a complex unstable injury with a substantially worse prognosis than an uncomplicated simple dislocation.

Coronoid Fracture Classification

Coronoid fractures have traditionally been divided into three types.

Type I is an avulsion fracture involving the tip of the coronoid.

Type II involves up to approximately 50% of the coronoid.

Type III involves more than 50% of the coronoid.

Larger coronoid fractures are more often associated with major anterior or posterior fracture-dislocations, while smaller transverse fragments are frequently seen in terrible-triad injuries.

Epidemiology

The highest incidence of elbow dislocation occurs in patients younger than 20 years of age.

Among children, elbow fractures and dislocations together account for approximately 3–6% of pediatric skeletal injuries.

Risk Factors

Participation in sports increases the risk of elbow dislocation.

Snowboarding has been associated with a greater risk of elbow dislocation than skiing, largely because falls onto an outstretched upper extremity are common.

Pathophysiology

Posterior elbow dislocation most often results from a fall onto an outstretched hand.

Axial loading and valgus or rotational forces transmitted through the forearm disrupt the stabilizing structures of the elbow.

Soft-Tissue Injury

The collateral ligaments are usually injured during a posterior dislocation.

The brachialis muscle and coronoid region may also be damaged.

The severity of ligament disruption determines post-reduction stability.

Associated Injuries

Elbow dislocation may occur with fractures of the radius, ulna, or distal humerus.

Neurologic and vascular injuries can also occur.

Nerve Injury

The ulnar and median nerves are particularly vulnerable.

The median nerve can become entrapped within the joint, including during reduction, so its function must be documented carefully before and after the procedure.

Brachial Artery Injury

The brachial artery may be stretched, compressed, disrupted, or trapped within the dislocated joint.

Vascular compromise is a limb-threatening problem and requires urgent surgical assessment.

Diagnosis

Signs and Symptoms

The typical patient presents after trauma with severe elbow pain, swelling, obvious deformity, and inability or unwillingness to move the elbow.

The normal contour of the elbow may be markedly distorted.

Physical Examination

Neurovascular Examination

A complete neurovascular assessment is essential before any attempt at reduction.

Motor and sensory function of the radial, median, and ulnar nerves should be documented.

Median Nerve

Median nerve function deserves particular attention because the nerve may become entrapped during the injury or during reduction.

A clearly documented pre-reduction examination is important for distinguishing traumatic injury from an iatrogenic change.

Ulnar and Radial Nerves

Ulnar and radial nerve motor and sensory function should also be evaluated carefully.

Any abnormality should be documented and reassessed after reduction.

Vascular Examination

The brachial artery and distal perfusion should be assessed before reduction.

The examination should include radial and ulnar pulses, capillary refill, skin temperature, and overall hand perfusion.

Vascular Injury

Loss of perfusion or evidence of arterial entrapment requires immediate orthopaedic and vascular surgical evaluation.

Examination for Associated Injury

The entire upper extremity should be inspected because associated injuries are common.

The clinician should specifically evaluate the shoulder, forearm, wrist, and distal radioulnar joint.

Monteggia Injury

A Monteggia fracture-dislocation should be excluded when forearm pain or deformity accompanies an apparent elbow injury.

Compartment Syndrome

The forearm should be palpated for increasing firmness, swelling, or pain suggestive of compartment syndrome.

Serial examination is particularly important in high-energy injuries.

Imaging

Plain Radiographs

AP and lateral radiographs of the elbow are generally sufficient to confirm the direction of the dislocation.

Whenever practical, imaging should be obtained without an obscuring splint so that associated fractures and subtle joint incongruity are not missed.

Post-Reduction Radiographs

Radiographs should also be obtained after reduction to confirm concentric joint alignment and identify associated fractures that may have been difficult to appreciate initially.

CT

CT is especially useful in fracture-dislocations.

It defines the size, location, and displacement of coronoid, radial head, and other articular fragments and assists with surgical planning.

MRI

MRI can demonstrate collateral ligament and other soft-tissue injuries.

It is not routinely required for uncomplicated acute dislocations but may be useful when persistent instability or associated soft-tissue pathology is suspected.

Differential Diagnosis

The main diagnostic concern is an associated fracture or fracture-dislocation rather than a separate condition.

Careful imaging is therefore required to identify coronoid, radial head, olecranon, distal humeral, or forearm fractures.

Initial Treatment

Emergency Measures

The injured arm should be immobilized, elevated, and treated with ice while urgent evaluation is arranged.

An acute elbow dislocation requires prompt emergency assessment.

Neurovascular Documentation

Neurovascular status must be recorded before and after reduction.

Any deterioration following reduction requires urgent reassessment.

Radiographic Evaluation

Radiographs are obtained to define the dislocation and identify associated fractures whenever the clinical condition permits.

Closed Reduction

Most simple elbow dislocations can be treated with closed reduction under appropriate analgesia, sedation, or anesthesia.

Posterior Dislocation Reduction

Posterior or posterolateral dislocations are commonly reduced using gentle longitudinal traction combined with gradual elbow flexion and directed pressure on the forearm or olecranon.

Forceful manipulation should be avoided.

Confirmation of Reduction

Successful reduction is suggested by restoration of elbow contour and improved motion.

Radiographic confirmation is required.

Post-Reduction Examination

Range of Motion

Following reduction, the elbow should be taken gently through flexion and extension to assess stability and determine the safe arc of motion.

Ligamentous Stability

Gentle valgus and varus stress testing may be performed to assess collateral ligament competence.

Gross instability after reduction raises concern for major ligament disruption or associated fracture.

Repeat Neurovascular Examination

Radial, median, and ulnar nerve function and distal vascular status must be rechecked immediately after reduction.

Immobilization

A posterior splint with the elbow at approximately 90° of flexion is commonly used initially.

The exact position may be modified according to stability and associated injury.

Duration

Immobilization is generally brief, often approximately 1 week in a stable simple dislocation.

Prolonged immobilization should be avoided because the elbow is highly prone to stiffness.

Immobilization beyond about 3 weeks substantially increases the risk of persistent motion loss.

Activity

After immobilization is discontinued, gradual active and passive motion should begin.

Heavy lifting should initially be avoided, with progression determined by pain, stability, and recovery.

Physical Therapy

Rehabilitation emphasizes restoration of range of motion followed by progressive strengthening.

Early controlled motion is one of the most important measures for minimizing post-dislocation elbow stiffness.

Surgery

Indications

Surgical treatment is indicated for irreducible dislocation, open dislocation, neurovascular entrapment, selected associated fractures, and unstable complex fracture-dislocations.

Irreducible Dislocation

Failure of closed reduction may result from soft-tissue interposition, an entrapped nerve, or an intra-articular fracture fragment.

Open reduction is then required.

Open Dislocation

Open elbow dislocations require urgent operative irrigation, debridement, reduction, and stabilization as appropriate.

Neurovascular Entrapment

Entrapment of the brachial artery, median nerve, or other critical structures is an indication for operative exploration.

Fracture Fixation

Open reduction and internal fixation may be required for associated displaced radial head fractures, olecranon fractures, distal humeral fractures, or other unstable osseous injuries.

Complex Fracture-Dislocations

The central objective in treating a complex fracture-dislocation is to restore the articular surface and recreate stable elbow mechanics.

Coronoid Repair

The coronoid should be repaired when necessary because it is an important anterior stabilizer of the elbow.

Radial Head Reconstruction

The radial head should be preserved and reconstructed when possible.

When the fracture is not reconstructable, radial head replacement may be required to restore stability.

Collateral Ligament Repair

Repair of the lateral and, when necessary, medial collateral ligament complexes may be needed to obtain a stable joint.

Terrible Triad Reconstruction

Management of the terrible triad commonly involves coronoid fixation, restoration or replacement of the radial head, and repair of the lateral collateral ligament complex, with additional procedures based on residual instability.

Total Elbow Arthroplasty

Total elbow arthroplasty may occasionally be considered for selected elderly patients with severe unreconstructable fracture-dislocations or neglected injuries.

It is generally reserved for low-demand patients because of postoperative lifting restrictions and implant-related complications.

Follow-Up

Prognosis

Most patients with a simple elbow dislocation treated with prompt closed reduction and early motion achieve a good functional outcome.

Residual Loss of Motion

The most frequent residual problem is loss of terminal extension.

A persistent deficit of approximately 10–15° of extension is common and often causes little functional impairment.

Instability

Persistent medial or valgus instability can predispose to chronic pain and secondary degenerative arthritis.

Role of Surgery in Simple Dislocation

Routine surgical repair has not generally been shown to improve outcomes in uncomplicated elbow dislocations without associated fracture or persistent instability.

Most such injuries are therefore managed nonoperatively.

Complex Injuries

Complex fracture-dislocations have a less favorable prognosis.

Aggressive reconstruction aimed at restoring stable anatomy and permitting early motion generally provides the best chance of functional recovery.

Complications

Loss of Motion

Elbow stiffness is the most common complication.

Loss of extension is more common than severe flexion loss.

Neurovascular Injury

Persistent nerve dysfunction or vascular injury may occur from the initial trauma, entrapment, swelling, or less commonly as a complication of reduction.

Chronic Pain

Some patients develop persistent pain because of residual instability, cartilage injury, heterotopic ossification, or post-traumatic arthritis.

Post-Traumatic Arthritis

Articular injury and chronic instability can lead to degenerative changes over time.

Recurrent or Persistent Instability

Failure of the collateral ligaments or inadequate healing may result in chronic valgus, varus, or posterolateral rotatory instability.

Heterotopic Ossification

Heterotopic bone formation can develop in the periarticular soft tissues after severe trauma.

It may contribute to pain and restriction of elbow motion.

Patient Monitoring

Follow-up frequency depends on injury severity and stability.

In a stable simple dislocation, immobilization is usually maintained for approximately 1 week, followed by early motion.

Immobilization should generally remain shorter than 3 weeks whenever stability permits.

During the first 12–24 hours, close monitoring should include neurovascular function, forearm compartment status, pain, swelling, and hand perfusion.

Subsequent follow-up should assess range of motion, stability, neurologic recovery, associated fracture healing, and development of heterotopic ossification or post-traumatic arthritis.