Monteggia fracture

Anatomy: How the elbow and forearm work together

The elbow connects the upper arm (humerus) and forearm bones (ulna and radius). The flexion and extension movements occur predominantly in the humeroulnar joint. The rotation of the forearm (inward/outward rotation, pronation/supination) is primarily carried out by the proximal radioulnar joint - here the radial head at the elbow rotates against the ulna. This area is stabilized by a bony form fit, capsular structures and the annular ligament (annular ligament).

• Ulna (ulna): straight forearm bone, forms the “hinge side” at the elbow
• Radius (spoke): rotates at the elbow with the radius head in the annular ligament
• Annular ligament: holds the radial head in the socket
• Nearby nerves: the posterior interosseous nerve (posterior interosseous nerve) is particularly at risk

What is a Monteggia fracture?

By definition, there is a fracture of the ulna and at the same time the radial head at the elbow is dislocated (dislocated). Due to the disruption of the forearm length and axis, the radial head loses its guidance. Without restoration of the ulnar length/axis, the radial head often remains misaligned.

The Bado classification is often used for description. It assigns the direction of dislocation of the radial head to the ulnar injury.

Monteggia equivalents describe injury patterns that are functionally similar (e.g., ulnar fracture with radial soft tissue damage and unstable radial head).

Causes and accident mechanisms

Falls onto the outstretched or slightly bent hand as well as direct blows to the forearm are typical. Depending on the position of the arm, flexion, extension and rotation forces act, which lead to fracture and dislocation.

• Falling onto the hand with forced pronation (inward rotation) or supination (outward rotation)
• Direct trauma to the ulna (e.g. fall on edge, bicycle handlebars)
• Sports injuries (contact and fall sports), less often traffic accidents
• In children: often low-energy falls, with a high risk of overlooking the dislocation

Symptoms: How do I recognize a Monteggia fracture?

• Severe pain in the elbow and forearm, increasing with movement
• Swelling, hematoma, possibly visible deformity
• Restricted movement when bending/stretching and especially when rotating the forearm
• Snapping or locking sensation in the elbow
• Numbness or weakness in hand/fingers (indication of nerve irritation, e.g. posterior interosseous nerve)
• Tenderness along the ulna

Diagnostics: Examination and imaging

At the beginning there is an anamnesis and physical examination with a check of blood circulation, motor skills and sensitivity. It is important to assess the forearm length and axis as well as elbow stability.

• X-ray of the forearm including the elbow - in two planes
• Assessment of the axial relationship: The radial head should aim at the humeral head (capitulum) in every projection
• For complex or multi-fragmentary fractures: CT for surgical planning
• For chronic or ligament-related problems: if necessary, MRI for soft tissue assessment

Differential diagnoses include isolated ulnar fractures (e.g. “nightstick” fracture), both forearm bone fractures without dislocation, isolated radial head fractures, or pure elbow dislocations.

When is it an emergency?

• Severe, increasing pain with pronounced swelling/feeling of tension
• Numbness, tingling or signs of paralysis in the hand/fingers
• Cold, pale or blue wrist/hand
• Open fracture (visible bone/skin injury)
• Significant misalignment or locked elbow

If you see these signs, you should seek immediate emergency medical attention.

Conservative measures: what is possible without surgery?

The Monteggia fracture is often an indication for surgery, especially in adults, due to the combined instability. Nevertheless, initial conservative measures are always included - and in selected cases, closed reduction with plaster immobilization is possible in children.

• First aid: Immobilization in the upper arm plastic or plaster gap (splint), elevation, cooling, adequate pain therapy
• Repeat neurovascular checks (blood flow, sensitivity, motor function) serially
• Closed reduction in the emergency setting for dislocation - often successful, especially in children
• Definitely conservative, usually only if the fracture line is stable, the radial head is in the correct position and reliable follow-up (especially pediatric)

Limitations of conservative therapy: In adult orthopedics, an inadequately stable ulna often leads to further dislocation of the radial head. Then surgical stabilization makes sense to avoid incorrect healing and loss of function.

Surgical treatment: goals and procedures

The aim of the operation is to anatomically restore the ulna length and axis. As a rule, the radial head centers spontaneously after correct ulna osteosynthesis. If the dislocation persists, soft tissues (e.g. annular ligament) are also addressed.

• Open reduction and internal fixation (ORIF) of the ulna, usually with an angle-stable plate and screws
• Intraoperative fluoroscopy to check joint centration
• If instability remains: ligament suture/reconstruction (annular ligament), if necessary temporary wire fixation
• Rare: Treatment of additional fractures (e.g. radius) according to Bado IV

Risks and possible complications are weighed individually. These include infection, secondary bleeding, nerve irritation (especially posterior interosseous nerve), delayed bone healing, malposition, new dislocation, joint stiffness or heterotopic ossifications.

Inpatient stay and form of anesthesia depend on the pattern of injury, general condition and accompanying injuries. Follow-up treatment is based on intraoperative stability.

Follow-up treatment, physiotherapy and everyday life

Structured rehabilitation is crucial to safely regain mobility and strength. The exact protocol depends on stability, pain and soft tissue situation.

• Short-term immobilization (e.g. upper arm splint for 1-2 weeks) to reduce pain and protect soft tissue
• Early functional mobilization in low-pain areas after medical clearance
• Physiotherapy with a focus on flexion/extension movements and gradual rotation exercises
• Scar care, lymphatic drainage and swelling management
• Build up your load gradually: everyday activities first, strength and coordination later

The periods mentioned are guidelines and do not replace individual therapy planning.

Healing process and prognosis

The prognosis is usually good if a Monteggia fracture is detected early and adequately stabilized. The decisive factors are the exact restoration of the ulnar geometry, stable centering of the radial head and early, guided mobilization.

• Better results with timely care in the acute stage
• Children often benefit from conservative reduction procedures and heal quickly
• Delayed diagnosis increases the risk of chronic dislocations and restricted mobility
• Ability to work and play sports depends on the severity of the injury, job/sport and quality of rehabilitation

Possible complications and accompanying injuries

• Nerve involvement: Irritation/lesion of the posterior interosseous nerve with weakness in finger extension
• Vascular involvement (rare), compartment syndrome
• Malunion or failure to heal (pseudarthrosis) of the ulna
• Persistent or renewed dislocation of the radial head
• Elbow stiffness, painful restriction of movement
• Heterotopic ossifications (ossifications in soft tissues)
• Post-traumatic osteoarthritis with joint involvement/chronic instability

Special features for children and young people

In childhood, Monteggia injuries are often caused by low-energy falls. Accurate X-ray diagnosis is important because dislocation of the radial head is easily overlooked. If the diagnosis is made quickly, a closed reduction with plaster immobilization is often sufficient.

• Conservative therapy with stable reduction with close monitoring
• Surgery in the event of instability, misalignment or failure of reduction
• Regular follow-up checks to protect growth plates and avoid misalignments

Prevention and self-help

• Fall prevention: safe footwear, lighting, balance and coordination training
• Sport: protective measures, technical training and adequate training control
• Bone health: Vitamin D, calcium, if necessary, osteoporosis clarification if there are risk factors
• After injury: pain-adapted activity, no forced self-reposition

Individual decision making

Whether conservative or surgical treatment is used depends on the fracture pattern, stability of the reduction, age, activity level and comorbidities. The aim is always to ensure safe joint function with as few restrictions as possible in everyday life. We explain options, risks and realistic expectations transparently and based on evidence.

Related Elbow Injuries

Depending on the mechanism of the accident, combined injuries occur. Also find out about common fractures around the elbow.

• Radial head fracture
• Olecranon fracture
• Humeral condyle fracture
• Dislocation combined with fracture
• Stress fractures due to overuse