Sternal fracture

Original Editor - Lieselot Vanderhoeven Top Contributors - Lucinda hampton, Lieselot Vanderhoeven, Kim Jackson, Naomi O'Reilly, Claire Knott, Wanda van Niekerk and Vaibhav Panchal

Introduction

Sternal fractures

• Most commonly caused by blunt, anterior chest-wall trauma and deceleration injuries, with a reported incidence of 3% to 6.8% in motor vehicle collisions.
• Athletic injuries, falls, and assaults are the frequent causes of the remaining cases.

Sternal fractures are frequently diagnosed using a lateral chest x-ray or CT scan of the chest.

Sternal fractures increase the risk of and are commonly associated with other injuries.

The disposition of patients with a sternal fracture is dependent upon several variables, including potentially significant associated injuries, comorbidities, and inadequate pain control

Clinically Relevant Anatomy

• The sternum is a flat bone, located in the center of the anterior thoracic wall. It consists of three segments; manubrium (uppermost part)
• body (middle part)
• xiphoid process (lowest part)

Etiology

Anterior, blunt chest trauma is the most frequent cause of sternal fractures.

• Cardiopulmonary resuscitation, athletic injuries, falls, and assaults result in the majority of the remaining traumatic cases.
• Patients with severe thoracic kyphosis, osteoporosis, or osteopenia can develop insufficiency fractures of the sternum.
• Patients on long-term steroid therapy, postmenopausal women, and elderly patients are at increased risk.
• Stress fractures of the sternum have also been reported secondary to repetitive upper body use in such sports as weightlifting and golf

Epidemiology

Sternal fractures are the result of motor vehicle collisions in 60% to 90% of cases.

This is typically the result of the chest striking the steering wheel with most injuries occurring in older vehicles with no airbag deployment.

• Fractures are slightly more prevalent in females than males.
• Sternal fractures are more common in older patients, and this is thought to be due to the more elastic chest wall of younger patients.
• Younger patients are more likely to incur intrathoracic injury because the energy of impact is not as like to be absorbed by the sternum.
• Sternal fracture occurrence has tripled with the use of vehicular shoulder restraints, likely secondary to the deceleration forces concentrated directly to the sternum

Clinical Presentation

Case studies report complaining of substernal chest pain that increases with inspiration shortness of breath, cough, or hemoptysis. There can be pain to palpation of the anterior chest wall over the sternum with slight bruising across the sternal area.

Most patients complain of violent localized sternal pain due to a direct trauma. There is tenderness, bruising and sometimes a stair-step palpable at the fracture line.

Patients with spontaneous fractures are a greater diagnostic challenge, because the symptoms often resemble other serious conditions. Their pain may be more diffuse. These fractures tend to occur in the elderly population, especially in postmenopausal women.

Dyspnea is present in 15-20% of these patients and may indicate associated cardiopulmonary contusion.

Palpitations may be noted only if dysrhythmia occurs, which is unusual in isolated sternal injury without associated cardiac contusion.

Differential Diagnosis

The differential diagnosis of acute sternal injury is broad. Some include (as well as other traumatic injuries that must be ruled out)

• Rib fractures
• Flail chest,
• Sternoclavicular dislocation/injury
• Pneumothoraces
• Hemothoraces
• Spinal compression fractures
• Costochondritis
• Aortic dissection

Diagnostic Procedures

Manubrial fractures may be associated with aortic and brachiocephalic vessels injuries, while the depresses sternal body fractures may determine myocardial effects in 1,5-6% of patients. So echocardiography, CT and other cardiac tests are recommended to rule out pericardial effusion or other signs of myocardial injury in case of depressed, displaced sternal fractures.

A CTscan is used most commonly to diagnose sternal fractures. But is less sensitive than plain radiography.

Sternal fractures need to be detected with lateral views or other special radiographic projections of the sternum. Sternal fractures can only be detected in a frontal chest plain film when it is associated with significant tansverse displacement. A CT scan identifies almost all sternal fractures, displacements, internal thoracic injuries and retrosternal haematomas.

Examination

A stair-step can be palpable at the fracture line of the sternal bone.

Medical Management

Most patients only need to be treated conservatively if the fracture is not displaced. They need to avoid provocative movement for four to six week.16

It is contraindicated to tape or splint sternal fractures, because it causes a restriction of normal chest expansion during respiration and can lead to atelectasis and pulmonary insufficiency. Encouragement of deep breathing decreases pulmonary complications during recovery. If this is to painful, analgesia need to be prescribed.

Surgical fixation for sternal fractures is generally unnecessary, although a recent study suggests that a more rapid recovery can be made if painful unstable fractures are fixated early rather than allowing them to heal over time.

Physical Therapy Management

Once serious conditions have been ruled out and the sternal fracture has been confirmed as minor and non-displaced, treatment can be commenced.

Overhead lifting, pushing, pulling, and lifting objects that weigh more than 2 to 3 kilograms and activities which place large amounts of stress through the sternum, particularly lying face down and applying direct pressure or impact to the chest, should be avoided until the fracture has healed.

The goal of rehabilitation is to decrease pain, prevent respiratory complications, and restore function. Local application of heat or cold may provide temporary relief of discomfort, in conjunction with pain relieving medication. The therapist will instruct patients in deep-breathing exercises to promote full lung expansion, relieve muscle spasm, and mobilize lung secretions. To relieve discomfort, promote chest expansion and functional shoulder mobility, and improve posture when the fracture is stable, shoulder and trunk stretching exercises may be used.

Once the fracture has healed, there can be a gradual return to normal activities, provided there is no increase in pain and other symptoms. This should take place over a period of weeks to months. Ignoring symptoms is likely to cause further damage and may slow healing or prevent healing of the sternal fracture altogether.9

To prevent stiffness and weakness, exercises to improve posture, flexibility and strength should also be performed

In the final stages of rehabilitation, a gradual return to activity or sport can occur as provided symptoms do not increase. When returning to contact sports or ball sports, the use of protective padding or chest guards may be required to prevent further injury.

Patients with more severe sternal fractures, particularly those which require surgical correction, or when other structures have been involved, will usually require a prolonged period of management over many months before recovery can take place.