Orthopaedic Surgery - Radial Head Fracture

Basics

Radial head fractures involve the proximal:

2–3 cm of the radius

and are usually:

Intra-articular fractures of the radiocapitellar joint.

The radial head contributes importantly to:

Elbow stability

and acts as a secondary stabilizer against:

Valgus stress.

Because of its role in forearm and elbow stability, radial head fractures should always be assessed for associated:

Ligamentous

Forearm

and

Wrist injuries.

Mason Classification

The Mason classification, with commonly used modifications, divides radial head fractures according to:

Displacement

Amount of articular involvement

Comminution

and

Associated elbow dislocation.

Type I

Nondisplaced or minimally displaced fracture.

Historically, these fractures involve less than approximately:

30% of the articular surface

and have little or no displacement.

Type II

A partial radial head fracture involving a larger portion of the articular surface, typically:

More than approximately 30%

with displacement greater than approximately:

2 mm.

Type III

A:

Comminuted, displaced fracture involving most or all of the radial head.

These fractures are often unstable or associated with additional soft-tissue injury.

Type IV

A radial head fracture associated with:

Elbow dislocation.

Epidemiology

Radial head fractures are among the most common:

Adult elbow fractures.

They account for a substantial proportion of elbow fractures, historically:

Approximately 30–75%.

Incidence

Reported incidence has ranged from approximately:

29–55 cases per 100,000 persons per year.

They may occur in:

Any adult age group

and in both:

Men and women.

Mechanism of Injury

The classic mechanism is:

A fall onto an outstretched hand

with the forearm in:

Pronation.

Axial force is transmitted through the radius to the:

Capitellum

causing the radial head to fracture.

High-Energy Trauma

High-energy injury may also cause radial head fracture, particularly in:

Younger adults

and is more likely to produce:

Comminution

Elbow instability

Associated fractures

Associated Injuries

Radial head fractures may occur together with:

Elbow dislocation

Coronoid fracture

Olecranon fracture-dislocation

Radial head dislocation

Annular ligament injury

Wrist fracture

Carpal fracture

Distal radioulnar joint injury

Ligament Injuries

Associated ligament injuries may involve the:

Medial collateral ligament

Lateral ulnar collateral ligament

or both.

Posterolateral Rotatory Instability

Disruption of the:

Lateral ulnar collateral ligament

may cause:

Posterolateral rotatory instability of the elbow.

Essex–Lopresti Injury

A particularly important associated injury is the:

Essex–Lopresti lesion.

This consists of:

Radial head fracture

with disruption of the:

Interosseous membrane

and injury or dislocation of the:

Distal radioulnar joint.

Failure to recognize this injury can lead to:

Proximal migration of the radius

Chronic wrist pain

and severe forearm dysfunction.

Diagnosis

Diagnosis is based on:

History

Physical examination

and

Radiographs.

The examination should include the entire:

Elbow, forearm, wrist, and hand.

Signs and Symptoms

Typical findings include:

Lateral elbow pain

Swelling

Tenderness over the radial head

Painful elbow motion

Painful forearm rotation

Hemarthrosis

An intra-articular fracture commonly produces:

Elbow hemarthrosis.

This may contribute to:

Pain

and

Restricted motion.

Physical Examination

Neurovascular Examination

Document:

Motor function

Sensation

Distal perfusion

before and after treatment.

Tenderness

Identify the area of maximal tenderness.

Radial head fractures usually produce tenderness over the:

Lateral elbow

at the level of the radiocapitellar joint.

Elbow Motion

Assess:

Flexion

Extension

Pronation

Supination.

Forearm rotation is often particularly painful.

Mechanical Block

Determine whether loss of motion results from:

Pain

or from a true:

Mechanical block caused by a displaced fracture fragment.

This distinction can alter treatment.

Wrist and Forearm Examination

Because axial force travels through the entire forearm, examine for:

Wrist tenderness

Distal radioulnar joint instability

Interosseous membrane tenderness

Essex–Lopresti Evaluation

An Essex–Lopresti injury should be suspected when there is:

Radial head fracture

plus:

Wrist pain

DRUJ tenderness

or

Interosseous membrane tenderness.

Elbow Dislocation

If the fracture occurs with an elbow dislocation, after reduction determine:

The range through which the elbow remains stable.

Imaging

Plain Radiographs

Initial radiographs should include:

AP

and

Lateral views of the elbow.

Occult Fracture

A nondisplaced radial head or neck fracture may not be directly visible.

Indirect findings include:

Posterior fat-pad sign

and

Anterior sail sign.

These indicate:

Elbow joint effusion or hemarthrosis

and should raise suspicion for an occult fracture.

Radiocapitellar View

A dedicated:

Radiocapitellar view

may improve visualization of:

Nondisplaced radial head fractures

and help characterize:

Displacement

Fragmentation

Internal Oblique View

An internal oblique view may help evaluate:

Lateral condyle injury

and other lateral elbow fractures.

CT

CT is particularly useful for:

Comminuted fractures

Complex articular injury

Surgical planning

Assessment of fragment number and position.

MRI

MRI is less commonly required for the fracture itself but may help evaluate:

Ligamentous injury

Interosseous membrane disruption

Occult associated soft-tissue injury.

Diagnostic Aspiration and Injection

Aspiration of an elbow hemarthrosis followed by local anesthetic injection has historically been used to:

Reduce pain

and help determine whether motion is limited by pain or by a:

True mechanical block.

Its routine diagnostic value remains uncertain.

Aspiration Landmark

A standard lateral approach uses the triangle formed by:

Radial head

Olecranon tip

and

Lateral epicondyle.

Differential Diagnosis

Important alternatives include:

Distal humerus fracture

Radial head dislocation

Radial neck fracture

Elbow ligament injury

Treatment

General Principles

Treatment depends on:

Displacement

Comminution

Mechanical block

Elbow stability

Associated injuries.

Type I Fractures

Nondisplaced or minimally displaced fractures are usually treated:

Nonoperatively.

Early Mobilization

The most important treatment principle for stable fractures is:

Early motion.

Prolonged immobilization should be avoided because the elbow develops stiffness rapidly.

Initial Splinting

A short period of sling or splint support may be used for approximately:

A few days

for pain control.

Historically, fractures involving less than one-third of the articular surface were immobilized for approximately:

3–5 days

followed by:

Protected range of motion.

Range of Motion

Active and gentle passive motion should usually begin within approximately:

1–5 days

as pain allows.

Type II Fractures

Moderately displaced fractures may be treated operatively when there is:

Mechanical block

Significant displacement

Loss of joint congruity

Instability

or important associated injury.

Not every displaced fracture requires surgery if motion remains functional and the elbow is stable.

Type III Fractures

Comminuted fractures may require:

Open reduction and internal fixation

or

Radial head arthroplasty

depending on:

Fragment number

Bone quality

Reconstructability

Associated instability.

Type IV Fractures

Radial head fracture associated with elbow dislocation requires restoration of:

Bony stability

and

Ligamentous stability

to permit early motion.

Physical Therapy

Elbow stiffness and weakness are common after injury.

Rehabilitation should therefore emphasize:

Early flexion and extension

Pronation and supination

Progressive strengthening

as stability allows.

Medication

Pain is usually treated with:

NSAIDs

or

Acetaminophen.

Short-term stronger analgesia may be required after:

Surgery

or severe trauma.

Surgery

Open Reduction and Internal Fixation

Moderately displaced reconstructable fractures may be fixed with:

Headless compression screws

or other low-profile fixation.

Comminuted Fracture Fixation

Comminuted fractures may also be reconstructed when:

Stable fixation

and restoration of:

Articular congruity

are achievable.

Number of Fragments

Fixation becomes more difficult when the radial head is divided into:

Multiple fragments.

Historically, outcomes have been less predictable when there are:

More than three major fragments.

Radial Head Excision

Isolated radial head excision is generally:

Avoided in acute unstable injuries

because shortening of the radial column can worsen:

Valgus instability

DRUJ instability

and

Proximal radial migration.

Radial Head Arthroplasty

If the radial head cannot be reconstructed, replacement with a:

Radial head prosthesis

is often preferred.

This is especially important when associated injuries compromise other stabilizers.

Indications for Replacement

Radial head replacement is particularly useful in:

Unreconstructable comminuted fracture

with:

Elbow instability

Coronoid fracture

Interosseous membrane injury

or

Collateral ligament disruption.

Essex–Lopresti Injury

In an Essex–Lopresti lesion, preserving or replacing the radial head is critical because the radial head helps maintain:

Longitudinal stability of the forearm.

Simple excision should be avoided.

Terrible Triad Injury

A complex elbow dislocation with:

Radial head fracture

Coronoid fracture

and ligament injury is commonly referred to as the:

Terrible triad of the elbow.

Management may require:

Radial head fixation or replacement

Coronoid repair

Lateral ligament repair

and other stabilization as needed.

Prosthesis Sizing

Accurate sizing of a radial head prosthesis is essential.

An excessively tall implant may:

Overstuff the radiocapitellar joint

and increase joint contact pressure.

Overstuffing

Overlengthening can cause:

Pain

Loss of motion

Capitellar wear

Altered elbow mechanics.

The prosthetic radial head should restore normal:

Radial length

without excessive proximal prominence.

Follow-Up

Patients should be monitored closely to ensure:

Maintenance of reduction or fixation

Elbow stability

Early restoration of motion

Prognosis

Nondisplaced fractures treated with early motion generally have a:

Good prognosis.

Factors Affecting Outcome

Outcome depends primarily on:

Degree of comminution

Articular damage

Associated ligament injury

Associated forearm injury

Duration of immobilization.

Displaced Fractures

Displaced fractures with only a few reconstructable fragments generally have:

Good long-term outcomes after stable fixation.

Radial Head Replacement

Radial head arthroplasty generally provides:

Good short- and medium-term results

when appropriately indicated.

Long-term outcomes depend on factors such as:

Implant design

Sizing

Cartilage wear

Associated ligament injury.

Pediatric Prognosis

Children generally have:

Good long-term outcomes

after appropriately treated radial head or neck injuries, although pediatric fracture patterns differ from those in adults.

Complications

Loss of Motion

The most common complication is:

Elbow stiffness.

Loss of:

Extension

and

Forearm rotation

is particularly common after prolonged immobilization.

Post-Traumatic Arthritis

Damage to the radiocapitellar joint may result in:

Degenerative arthritis.

Malunion

Malunion can alter:

Forearm rotation

Radiocapitellar mechanics

and

Elbow function.

Nonunion

Nonunion is uncommon but may occur, particularly in:

Severe fractures

or after compromised fixation.

Elbow Instability

Failure to recognize associated ligament injury may result in:

Persistent elbow instability.

Proximal Radial Migration

Loss of the radial head in the setting of interosseous membrane disruption may cause:

Proximal migration of the radius.

This can produce:

Chronic wrist pain

DRUJ dysfunction

and

Forearm shortening.

Capitellar Wear

After radial head replacement, long-term contact may contribute to:

Capitellar cartilage wear

or radiocapitellar arthritis.

Patient Monitoring

Document:

Neurovascular status

Elbow range of motion

Pronation and supination

before and after treatment.

Postoperative patients should be reviewed closely so that:

Elbow motion can begin as early as safely possible.

Physical or hand therapy may be required to prevent:

Persistent stiffness.

Key Principle

Radial head fractures are common intra-articular elbow fractures that may compromise both elbow valgus stability and longitudinal forearm stability.

The key management principles are:

Recognize associated injuries, especially Essex–Lopresti and elbow ligament injuries; avoid unnecessary immobilization; and restore a stable radiocapitellar articulation that permits early motion.

Stable nondisplaced fractures generally do well with:

Brief protection and early mobilization, whereas displaced, mechanically blocking, unstable, or severely comminuted injuries may require:

Fixation or radial head replacement.