Summary
Isolated proximal ulna fractures are rare. Always examine for Monteggia fracture-dislocations.
Management
- All Monteggia fracture-dislocations require urgent orthopaedic consultation.
- Reduction of dislocation under sedation in ED or operating theatre within 6–8 hours.
- Adults: most require open reduction and internal fixation techniques.
- Paediatric: most are managed conservatively with closed reduction and long arm cast.
Follow-up care
- Consultation with the orthopaedic team after their reduction and stabilisation of the injury.
- Follow up with an x-ray in the fracture clinic in 7 days.
Classification
Giovanni Battista Monteggia first described the injury in 1814, which is now known as the Bado fracture. The Monteggia fracture-dislocation consists of dislocation of the radiohumeral joint, associated with a fracture of the ulna at various levels.
Bado classification
Type 1
Fracture of the proximal or middle third of the ulna with anterior dislocation of the radial head. This is the most common in children and young adults (up to 70%).
Type 2
Fracture of the proximal or middle third of the ulna with posterior dislocation of the radial head (70–80% of adult Monteggia fractures).
Type 3
Fracture of the ulnar metaphysis (distal to coronoid process) with lateral dislocation of the radial head.
Type 4
Fracture of the proximal or middle third of the ulna with dislocation of the radial head in any direction.
Epidemiology
Rare in adults. The predominant lesion in adults is the posterior Monteggia fracture associated with osteoporosis. Anterolateral diaphyseal proximal radioulnar joint fracture-dislocations are not commonly seen in adults.
This type of injury is more common in children with peak incidence between 4–10 years of age. It accounts for less than 5% of all forearm fractures with published literature supporting 1–2%.
Presentation
Primarily associated with falls on an outstretched hand with forced pronation (low energy). In some cases, a direct blow to the forearm or trauma, such as a motor vehicle collision (high energy), can result in similar injuries.
Symptoms
Elbow pain, swelling, crepitus and paraesthesia or numbness. May not have severe pain but limited elbow flexion and forearm rotation.
Physical exam
Inspection: may or may not be obvious dislocation at radiocapitellar joint and skin integrity should be evaluated.
Palpation: tenderness over radial head in an anterior, antero-lateral or postero-lateral location.
Range of motion (ROM) and instability: loss of ROM due to dislocation.
Neurovascular: posterior interosseous nerve neuropathy; radial deviation of hand and wrist extension; weakness of thumb extension; weakness of metacarpophalangeal (MCP) joint extension; and weakness or paralysis of extension in the fingers or thumb.
Imaging
- Radiography: AP and lateral (true) elbow, wrist and forearm.
- CT scan: helpful in fractures involving coronoid, olecranon and radial head.
Management options
Radial head dislocation should be reduced emergently. Closed reduction should be performed within 6–8 hours. This is usually achieved with supination of the forearm, but may require traction and direct pressure on the radial head.
If the closed reduction is unsuccessful, the patient should be taken to theatre within this same timeframe for open reduction. A delay in reduction of the radius may lead to permanent articular damage, further nerve damage or both. All management is aimed at maintaining length of ulna and alignment.
Most adult fractures require open reduction and internal fixation techniques; whereas most paediatric patterns can be managed conservatively with closed reduction and long arm casting.
All Monteggia fracture-dislocations should be splinted in a long arm cast and an on-call orthopaedic doctor should be consulted urgently.
Referral and follow-up requirements
Urgency: all require an urgent orthopaedic assessment.
Follow-up care: after reduction and stabilisation of the injury, either by non-operative or operative means, review within 7 days at the fracture clinic.
Potential complications
- Delayed diagnosis is the most frequent complication.
- Nerve injury: radial nerve and posterior interosseous nerve injury (10%) due to proximity to the radial head with neuropraxia. Common treatment involves observation for 2–3 months and usually spontaneously resolves. If no improvement, obtain nerve studies.
- Malunion with radial head dislocation: usually caused by failure to obtain anatomic alignment of ulna with treatment involving ulnar osteotomy and open reduction of the radial head.
- Compartment syndrome.
- Infection.
- Plate loosening is common in adults.
- Proximal radioulnar synostosis is common for posterior Monteggia injuries.
- Ulnohumeral instability.
- Recurrent radial head dislocation.
Patient advice
- Adults should be informed about the potential risk of functional deficits and the possible need for further surgery.
- Pain from the fracture and restriction of movement is usual for 2–3 weeks and will require regular analgesia, then analgesia as required.
- Care of temporary casts fact sheet
Resources
- Konrad GG, Kundel K, Kreuz PC, et al. Monteggia fractures in adults: long-term results and prognostic factors. J Bone Joint Surg Br. 2007;89(3):354-360. DOI:10.1302/0301-620X.89B3.18199
- Monteggia fractures
Source: Orthobullets - Monteggia fracture
Source: Medscape - Clinical practice guidelines: Monteggia fracture-dislocations – emergency department
Source: The Royal Children’s Hospital Melbourne
Accessed from the Emergency Care Institute website at https://aci.health.nsw.gov.au/networks/eci/clinical/tools/monteggia-fracture-dislocation