Sternal fractures

Chest wall

Transverse body fracture, manubriosternal dislocation

See it in 3D on the real bones, displace and reduce it, with simulated X-ray and CT — free, in your browser.

Most sternal fractures are transverse fractures of the body or at the manubriosternal junction, from a direct blow to the front of the chest. In isolation they are usually benign, but they mark a high-energy impact: look for blunt cardiac injury, thoracic spine fractures and other chest injuries.

Displaced sternal fracture, lateral view. Arrow: step and overlap of the fragments in the sternal body, visible only on the lateral film. — James Heilman, MD, CC BY-SA 4.0, via Wikimedia Commons.

Mechanism

Steering wheel or seatbelt in frontal collisions, direct blows; flexion–compression injuries of the thoracic spine (indirect fracture); insufficiency fractures in osteoporotic, kyphotic patients.

Clinical findings

Anterior chest pain, tenderness, sometimes a palpable step or crepitus.
Screen for blunt cardiac injury: 12-lead ECG and troponin on arrival; normal both means significant cardiac injury is very unlikely. Echocardiography for arrhythmia, haemodynamic instability or abnormal results.
Examine and image the thoracic spine: a displaced sternal fracture with a flexion mechanism is often paired with a thoracic spine fracture.

Imaging

Lateral sternal view (the frontal chest film usually misses it).
CT chest with sagittal reformats in major trauma.
12-lead ECG and troponin for blunt cardiac injury; echocardiography if abnormal or unstable.

Lateral sternal view: the key radiograph (the fracture is often invisible on the frontal chest X-ray).
CT chest with sagittal reformats in major trauma; look for retrosternal haematoma and mediastinal injury (CT angiography if suspected).
Ultrasound can show a cortical step at the bedside.

Classification

Location: Manubrium, manubriosternal junction, body (most common), xiphoid.
Displacement: Undisplaced, or displaced with overlap of the fragments (usually the lower fragment in front of the upper).
Manubriosternal dislocation: Type 1: body displaced behind the manubrium (direct blow). Type 2: body in front of the manubrium (indirect, flexion–compression with a thoracic spine fracture).

Types shown in 3D

Undisplaced transverse (body): The commonest pattern: a transverse line through the upper body. Check ECG and troponin; analgesia.
Displaced transverse (body): The lower fragment is displaced forwards relative to the upper one. Look for a thoracic spine fracture and retrosternal haematoma; plate fixation if unstable or very painful.
Manubriosternal dislocation (type 1): The body is driven behind the manubrium by a direct blow. Usually reduced and fixed if displaced; rule out mediastinal injury.

Treatment

Non-operative (most): Analgesia, breathing exercises; patients with an isolated undisplaced fracture and normal ECG and troponin can usually go home.
Operative: Severe displacement with instability or deformity, intractable pain, respiratory compromise, an unstable "sternal flail", or painful non-union: open reduction and anterior locking plate fixation.

Aftercare

Symptoms settle over 6–12 weeks; no lifting > 5 kg and no contact sports for about 6 weeks after fixation.

Complications

Blunt cardiac injury (arrhythmia, contusion)
Non-union or painful malunion
Missed thoracic spine fracture
Retrosternal haematoma, rarely mediastinal vascular injury