Monteggia Fracture

A Monteggia fracture is defined as a fracture of the proximal ulna associated with dislocation of the radial head at the elbow. It represents a complex injury involving both bony and ligamentous structures, requiring prompt recognition and appropriate management to prevent long-term dysfunction.

Epidemiology

• Monteggia Fracture accounts for approximately 1–2% of all forearm fractures
• It’s more common in children than adults
• It’s frequently associated with high-energy trauma in adults and falls in children

Anatomy & Pathophysiology

The Monteggia Fracture injury involves disruption of the proximal ulna and the radiocapitellar joint. Stability of the radial head depends on:

• Annular ligament
• Interosseous membrane
• Alignment of the ulna

When the ulna is fractured and angulated, the radial head dislocates due to loss of normal forearm alignment.

See Also: Radial Head Fractures

Mechanism of Injury

Common mechanisms of Monteggia Fracture include:

• Fall on an outstretched hand (FOOSH) with forearm in pronation
• Direct trauma to the forearm
• Hyperpronation or hyperextension forces

Monteggia Fracture Classification (Bado Classification)

Type I (Most Common)

• Anterior dislocation of radial head
• Fracture of ulna with anterior angulation

Type II

• Posterior or posterolateral dislocation of radial head
• Ulna fracture with posterior angulation

Type III

• Lateral dislocation of radial head
• Metaphyseal fracture of ulna

Type IV

• Fractures of both radius and ulna
• Radial head dislocation

Clinical Presentation

• Pain and swelling in the forearm and elbow
• Visible deformity
• Limited range of motion at the elbow
• Tenderness over ulna and radial head
• Possible posterior interosseous nerve (PIN) palsy, presenting as:
  • Weak finger and thumb extension

See Also: Elbow Anatomy

Diagnosis

Clinical Examination

• Assess deformity and neurovascular status
• Always examine wrist and elbow

Imaging

• X-rays (AP and lateral views) of forearm including elbow and wrist
• Key diagnostic sign:
  • The radial head does not align with the capitellum on all views

Monteggia Fracture Treatment

General Principle

Restore ulnar alignment → radial head reduces spontaneously

In Children

• Closed reduction and casting is usually sufficient
• Ensure stable reduction of radial head

In Adults

• Surgical management is standard
• Open reduction and internal fixation (ORIF) of ulna
• Radial head usually reduces after ulnar fixation
• If not:
  • Check for soft tissue interposition
  • Annular ligament reconstruction may be required

Complications

• Missed radial head dislocation
• Chronic instability
• Limited range of motion
• Posterior interosseous nerve injury
• Malunion or nonunion of ulna

Prognosis

• Good outcomes with early diagnosis and proper treatment
• Delayed or missed diagnosis can lead to poor functional results

Key Clinical Pearls

• Always check radiocapitellar alignment in forearm fractures
• A proximal ulna fracture should raise suspicion for Monteggia injury
• Missing the radial head dislocation is a common and serious error

References & More

1. Johnson NP, Silberman M. Monteggia Fractures. [Updated 2023 Jul 31]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan-. Available from: Pubmed
2. Johnson NP, Silberman M. Monteggia Fractures. 2023 Jul 31. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan–. PMID: 29262187. Pubmed
3. Soderlund T, Zipperstein J, Athwal GS, Hoekzema N. Monteggia Fracture Dislocation. J Orthop Trauma. 2024 Sep 1;38(9S):S26-S30. doi: 10.1097/BOT.0000000000002854. PMID: 39150291. Pubmed
4. Egol KA. Handbook of fractures. 6th ed. Philadelphia: Lippincott Williams & Wilkins; 2019.