Fracture, Sternum

By admin Last updated Sep 20, 2023

Ovid: 5-Minute Sports Medicine Consult, The

Fracture, Sternum

Steven C. Cuff

Thomas L. Pommering

Basics

Description

Direct:
- Results from direct force applied to the sternum, most often from a blow to the body of the sternum in the lower part; usually from a motor vehicle accident (MVA)
- Fracture typically occurs near manubrium.
Indirect:
- Results from an indirect flexion-compression injury of the cervicothoracic spine, usually a forced flexion of the cervical spine that causes the upper 2 ribs to pull the manubrium posteriorly (downward and posterior force on the manubrium and upper 2 ribs)
- May be exacerbated by chin striking the manubrium
- Always involves the upper 2 segments of the sternum
Muscular:
- Results from violent muscular action that causes fracture through opposing muscle groups, ie, tetanus
- Extremely rare

Epidemiology

Very rare, especially in children and adolescents, due to elasticity of sternum and costal cartilage
Accounts for about 3–8% of all blunt trauma
More common in men (60–80%)

Etiology

In adults, most commonly related to automobile accidents, typically from a direct mechanism:
Striking the steering wheel or dashboard
Flexion of the sternum across the diagonal part of the seat belt, which acts as a fulcrum
While seatbelts decrease the risk of serious injury, they do not seem to decrease the risk of sternal fractures during MVAs; however they do decrease the risk of internal injury, likely because of the fracture mechanism.
In children, more likely related to a fall off a bicycle (direct) or from a height (indirect)

Commonly Associated Conditions

Vertebral fracture: Especially from indirect mechanism. Most commonly thoracic vertebrae, but also may occur in lower cervical or upper lumbar vertebrae.
Rib fracture: Most often associated with a direct mechanism. Can cause flail chest.
Trauma to heart, mediastinum, great vessels, tracheobronchial tree, lung parenchyma, or liver: Mediastinal injury much less common with an indirect mechanism. Always consider cardiac contusion, especially with double or comminuted fracture and in fracture involving the sternal angle.
Pneumothorax
Tamponade
Head injury
Limb fracture

Diagnosis

Chest posteroanterior and lateral radiographs postreduction

History

Direct blow to chest wall
Forced flexion of cervical spine (heavy blow to back of head or fall onto head or upper back)
Pain with inspiration
Crepitus with respiratory excursion
Dyspnea, usually transient. If persistent, consider more severe underlying injury.

Physical Exam

Pain
Tenderness
Bruising
Swelling
Deformity
Possible dyspnea
Localized tenderness
Palpable or visible step-off (deformity present with displaced fracture)
Palpable crepitus with respirations (more rare)
Edema, ecchymosis
Screen for associated rib fracture, clinical evidence of pulmonary contusion, vascular injury, pneumothorax, and pericardial friction rub.

Diagnostic Tests & Interpretation

Imaging

Care must be taken not to confuse nonossified intrasternal cartilage in young patients with fractures.
Chest posteroanterior (PA) and lateral radiographs (fracture missed in >80% of anteroposterior views): Possible pneumothorax or mediastinal injury. Widened mediastinum should not be attributed to hematoma, but instead to underlying vascular injury until ruled out. Sternal fracture displacement and sternal dislocation occur in the sagittal plane.
ECG: May see ECG changes in >50%, especially if from a direct mechanism. No single test is consistently reliable for diagnosis of myocardial contusion. If initial ECG is normal, consider repeat in 24 hr. May see ST or T-wave abnormalities or bundle branch block. May see major arrhythmia in 1st 24 hr (rare).
Cervical, thoracic, lumbar spine radiographs: Especially if from an indirect mechanism
Consider other modalities (echocardiogram, CT, aortography, serial creatine phosphokinase levels) if underlying injury is suspected.

Differential Diagnosis

Costochondral dislocation
Sternoclavicular dislocation
Sternal contusion
Costochondritis
Cardiac contusion
Cardiac ischemia

P.255

Treatment

Narcotics appropriate once associated injuries are ruled out
Consider hematoma block if reduction is necessary.
Most nondisplaced fractures are treated conservatively with rest and analgesia until symptoms subside.
Some displaced fractures can be reduced by having the patient lay supine and hyperextending the thoracic spine by placing a sandbag transversely under the shoulders, slightly below the level of the spines of the scapulae. Extension can be maintained by bracing or bed rest.
For simple displaced fractures, some authors recommend having the patient lay supine and simultaneously lifting the head and the extended lower extremities, thus separating the upper and lower parts of the sternum. Use thumb to place pressure on the anteriorly displaced fragment (should infiltrate with local anesthetic first).
Open reduction internal fixation: Primary indication is pain with respiration that limits respiratory excursion; also flail chest. If not stabilized, can have pseudoarthrosis that can be source of ongoing pain or instability.
Consider 24-hr inpatient observation and monitoring due to the relatively high likelihood of associated underlying injuries.
Immobilization typically is not necessary with nondisplaced fractures.
Short-term immobilization may be necessary after surgical repair.

Additional Treatment

Additional Therapies

Consider cardiac monitoring while performing reduction if available.
Avoid aggravating activities and contact sports.
May start general conditioning within the limits of discomfort

Surgery/Other Procedures

Surgical treatment for displaced fractures as above
Consider surgical repair if nonunion (rare).

Ongoing Care

Follow-Up Recommendations

Usually heals without any sequelae
Consider early orthopedic referral if displaced fracture, open fracture, or flail chest.
Early consultation as appropriate if there are associated underlying thoracic injuries (pneumothorax, cardiac contusion, etc.)

Additional Reading

Athanassiadi K, Gerazounis M, Moustardas M, et al. Sternal fractures: retrospective analysis of 100 cases. World J Surg. 2002;26:1243–1246.

Buckman R, Trooskin SZ, Flancbaum L, et al. The significance of stable patients with sternal fractures. Surg Gynecol Obstet. 1987;164:261–265.

Ferguson LP, Wilkinson AG, Beattie TF. Fracture of the sternum in children. Emerg Med J. 2003;20:518–520.

Jones HK, McBride GG, Mumby RC. Sternal fractures associated with spinal injury. J Trauma. 1989;29:360–364.

Kitchens J, Richardson JD. Open fixation of sternal fracture. Surg Gynecol Obstet. 1993;177:423–424.

Lyons FR, Rockwood CA. Orthopaedic sports medicine: principles and practice. Philadelphia: WB Saunders, 1994.

Mayba II. Sternal injuries. Orthop Rev. 1986;15:364–372.

Metaxas EK, Condilis N, Tzatzadakis N, et al. Sternal fracture with or without associated injuries. Assessment of the difference in the diagnosis, management and complications. Eighteen years of experience. Ann Ital Chir. 2006;77:379–383.

Recinos G, Inaba K, Dubose J, et al. Epidemiology of sternal fractures. Am Surg. 2009;75:401–404.

Santos GH. Treatment of displaced fractures of the sternum. Surg Gynecol Obstet. 1988;166:273–274.

Codes

ICD9

807.2 Closed fracture of sternum
807.3 Open fracture of sternum
807.4 Flail chest