A fractured sternum, or broken breastbone, is an injury to the flat bone in the center of the chest. While the sternum is strong, a fracture itself rarely causes death. The primary concern stems from the significant force required to break it, indicating potential severe trauma to vital organs and structures behind it. The real danger lies in these associated internal injuries, which can be life-threatening.
The Sternum’s Structure and Purpose
The sternum is a flat, dagger-shaped bone positioned in the middle of the anterior chest wall. It consists of three main parts: the manubrium (uppermost portion), the body (largest middle section), and the xiphoid process (small, pointed bottom tip). This bone connects to the ribs via cartilage, forming the front of the rib cage. This arrangement provides a protective shield for the heart, lungs, and major blood vessels within the chest.
Understanding the Primary Risks
Fracturing the sternum requires substantial blunt force to the chest. Common causes include motor vehicle collisions (e.g., chest striking the steering wheel or seatbelt impact) and falls from significant heights. The sternum’s strength means that any force sufficient to break it can transmit considerable energy to underlying structures. Therefore, a sternal fracture often indicates severe, high-energy trauma. The immediate risk is not from bone fragments, which rarely cause direct damage, but from the force itself, which may injure the heart, lungs, or major blood vessels.
Life-Threatening Associated Injuries
The severe blunt trauma that leads to a sternal fracture can result in several life-threatening internal injuries. One such injury is a myocardial contusion, essentially a bruise to the heart muscle. This can disrupt the heart’s electrical activity, potentially leading to irregular heartbeats or reduced pumping efficiency. Another serious cardiac complication is cardiac tamponade, where blood or fluid accumulates in the sac surrounding the heart, compressing it and preventing it from filling properly. In rare but severe cases, the immense force can cause an aortic dissection or rupture, a tear in the body’s largest artery, leading to rapid, life-threatening internal bleeding.
Pulmonary injuries are also frequently observed. A pulmonary contusion, or bruised lung, can impair oxygen exchange and lead to respiratory distress. The force may also cause a pneumothorax, where air leaks into the space between the lung and chest wall, leading to a collapsed lung. Similarly, a hemothorax involves blood accumulating in this space, further compromising lung function. These conditions can severely impede breathing and require prompt medical intervention.
Damage to other major blood vessels within the chest, such as the vena cava, is also possible, resulting in significant hemorrhage. Less common but equally severe injuries include esophageal rupture, a tear in the food pipe, and diaphragmatic rupture, a tear in the muscle separating the chest and abdomen. These associated injuries, rather than the sternal fracture itself, account for the higher mortality rates (25-45%) in patients with sternal fractures.
Recognizing Symptoms and Seeking Care
Individuals with a sternal fracture experience severe chest pain over the breastbone, worsening with deep breathing, coughing, or sneezing. Other symptoms include tenderness, swelling, and bruising in the affected area. A cracking or grinding sensation (crepitus) may be felt with movement. Shortness of breath can also occur, sometimes due to pain limiting deep breaths or as a sign of underlying lung injury. Any suspicion of a sternal fracture or significant chest trauma warrants immediate medical attention. Prompt evaluation is essential to identify and address any potentially life-threatening associated internal injuries.
Medical Diagnosis and Management
Diagnosing a sternal fracture and associated injuries begins with imaging studies. While a chest X-ray may show a sternal fracture, a lateral view is often more effective, and X-rays can sometimes miss them. Computed tomography (CT) scans are the most effective diagnostic tool for sternal fractures and are particularly valuable for detecting associated internal thoracic injuries, such as retrosternal hematomas or lung contusions. For suspected heart injury, an echocardiogram may be performed to assess cardiac function and detect issues like fluid around the heart.
Treatment for a sternal fracture primarily focuses on managing pain and monitoring for, and treating, any associated internal injuries. Most sternal fractures heal without surgical intervention, with rest and pain medication. Adequate pain control is important to allow for deep breathing and coughing, which helps prevent pulmonary complications like pneumonia. Surgical fixation of the sternum is generally reserved for rare cases of severe displacement, instability, or chronic pain. Close medical observation is crucial to ensure that any complications are promptly identified and managed.