What is Sternal Fractures?
Sternal fractures, or breaks in the breastbone, often result from direct trauma to the front of the chest or severe deceleration injuries, like the ones sustained in car accidents—being found in 3% to 6.8% of these incidents. Other causes frequently include sports injuries, falls, and assaults. Doctors usually identify these fractures by conducting chest X-rays from the side or CT scans.
It’s important to note that sternal fractures significantly raise the chances of having other injuries too. The next steps in treating a person with sternal fracture depend on several factors. This includes the seriousness of other injuries they might have, existing health conditions, and whether their pain can be adequately managed.
What Causes Sternal Fractures?
Sternal fractures, or breaks in the breastbone, are seen in roughly 8% of people who experience severe chest injuries and about 18% of cases involving multiple injuries including to the chest. These fractures mainly occur from blunt force to the front of the chest or deceleration injuries, like those typically happen in car crashes, which account for 3% to 6.8% of such fractures. Other common causes are sports injuries, falls, and assaults. Most of the time, these fractures occur due to a direct hit to the front of the chest or sudden slowing down such as in a car crash. In fact, 68% of these fractures are caused by car crashes, followed by falls and motorcycle accidents making up 7.9% each, accidents where a pedestrian is hit by a car amounting to 3.4%, and bicycle accidents contributing 1.4%. Laws requiring seat belts and shoulder restraints in cars have actually led to an increase in these types of fractures.
Sternal fractures are often linked with a severe curving of the upper back, known as thoracic kyphosis, which typically results from multiple fractures of the vertebral bodies in the chest, especially in severe cases of porous bones or osteoporosis. The breastbone and ribs play a crucial role in providing structural support for the chest part of the spine. A displaced breastbone fracture can signal a significant flexing and stretching injury to the spine, increasing the risk of deformity. People with porous bones often have these vertebral body fractures that lead to thoracic kyphosis, which makes them more prone to breastbone fractures. People on long-term steroid treatment, postmenopausal women, and older patients are more at risk. Also, stress fractures of the breastbone can happen due to repetitive use of the upper body, like in weightlifting and golf.
Risk Factors and Frequency for Sternal Fractures
Sternal fractures, or breaks in the sternum (chest bone), occur in about 3% to 6.8% of car crashes. Interestingly, these fractures have actually become more common since the introduction of seat belts. This is likely because the chest hits the shoulder restraint in a collision. Additionally, doctors are finding more minor sternal fractures thanks to improved scanning technology known as CT scans, used during trauma assessment.
The health complications from these fractures often depend more on other injuries that happen at the same time and how the patient’s condition progresses, rather than the break itself. Sternal fractures that occur without other injuries usually have a lower risk of causing issues with the heart and lungs, and patients often have better scores for trauma assessment.
Sternal injuries are most often caused by the chest hitting the steering wheel, especially in older cars without airbags. These fractures happen a bit more often in women than men, and are more common in older people. This seems to be because their chest walls are less elastic than in young people. In contrast, younger patients are more likely to have injuries inside their chests since their sternums can’t absorb impact energy as effectively.
Signs and Symptoms of Sternal Fractures
Sternal fractures, or breaks in the breastbone, usually occur due to a strong impact to the chest, such as from car crashes, sports injuries, falls, or assaults. These fractures generally cause pain in the front of the chest. This pain can become worse when taking deep breaths or coughing. Around one in five people with a sternal fracture might also feel short of breath. Some fractures cause a more spread-out pain and can feel similar to other serious health issues, especially if there’s no obvious injury.
Upon examining the patient, a doctor might feel tenderness in the location of the fracture on the sternum. Other signs could include swelling, bruises, or an unusual shape over the area. Sometimes, a crunching sound or feeling (crepitus) is noticeable when touching the injury. It’s also important for doctors to check for other potential injuries related to the chest, which include:
- Rib fractures
- Flail chest (several broken ribs in more than one place)
- Sternoclavicular dislocation (the collarbone separates from the sternum)
- Pneumothorax (collapsed lung)
- Hemothorax (blood in the space between the lungs and chest wall)
- Cardiac tamponade (fluid build-up in the sac around the heart)
- Myocardial contusion (bruising of the heart muscle)
- Pulmonary contusion (bruising of the lung)
- Injuries inside the abdomen
- Spinal compression fractures (broken vertebrae)
- Other traumatic injuries
Testing for Sternal Fractures
For people suspected of having a chest bone injury, chest X-rays are often the first step. However, the regular front-facing chest X-ray only has a 50% chance of detecting a fractured chest bone. A side view chest X-ray is more accurate for diagnosing this type of injury, as most chest bone fractures are across the bone, and any shifts or movements occur from front-to-back.
A chest CT scan is another method for diagnosing suspected chest bone fractures. Straight-on CT scans could potentially be less accurate than standard X-rays as they may overlook fractures that run across the chest bone. In contrast, Spiral CT scans are more likely to spot these fractures, even though there’s no recognised best method. Chest CT scans also have the added benefit of ruling out other injuries often seen with chest bone fractures. Ultrasounds can identify chest bone fractures with the same or better accuracy than a regular X-ray. Bedside ultrasounds may speed up the diagnosis process, but you have to take into account variables like differences between operators.
If you come to the emergency department with a chest bone fracture, you should expect to be given heart rate and blood oxygen level monitoring. You should also have an electrocardiogram, a simple test that checks your heart’s electrical activity, to look for signs of heart muscle injury. These signs could include irregular heartbeats, issues with the electrical signals traveling through the heart, a fast heart rate, or changes in parts of the electrocardiogram tracing. Blood tests for proteins that indicate heart muscle injury could also be useful, particularly if your troponin levels (a specific heart muscle protein) are raised. A type of ultrasound called an echocardiogram can help find heart muscle injuries by giving a direct view of any irregular wall movement in your heart.
Treatment Options for Sternal Fractures
Doctors should follow the Advanced Trauma Life Support guidelines when treating severe breastbone fractures. Initially, they check the patient’s airway, breathing, and blood circulation, and look for any immediate life-threatening conditions. They also check for related injuries like tension pneumothorax (excessive air pressure in the chest), hemothorax (the presence of blood in the chest), cardiac tamponade (pressure on the heart due to fluid build-up), and flail chest (a severe rib injury).
Once the patient is stable, doctors can then focus on treating chest injuries linked with the breastbone fracture. These can include broken ribs, lung bruising, and heart muscle injury.
In rare cases, surgery may be needed. If the patient experienced blunt trauma that injured the windpipe, esophagus, diaphragm, heart, or aorta, an operation is usually required. Patients with these types of injuries will have their heart activity monitored using electrocardiography. Patients showing heart muscle bruising or other chest injuries, patients who are unstable, or those with severe pain should be kept in the hospital for observation. Older patients are also closely monitored because they have a higher risk of breathing complications.
Pain management is the main treatment for isolated breastbone fractures. If doctors find no issues during the evaluation, the patient won’t need to be admitted to the hospital. The patient should check in with their primary care doctor within a day after leaving the hospital. Deep breathing exercises can help prevent complications involving the lungs. Surgery may be necessary if the fracture is severely displaced or unstable. However, most breastbone fractures will naturally heal after about ten weeks.
What else can Sternal Fractures be?
When a person injures their chest area, there could be various causes. Doctors have to consider and rule out all possibilities to accurately diagnose the issue. Here are some of these possibilities:
- Broken ribs
- “Flail chest” – a severe rib injury causing part of the chest to move separately from the rest
- Dislocated sternoclavicular joint (where the collarbone meets the breastbone)
- Pneumothorax – collapsed lung
- Hemothorax – when blood collects in the space between the chest wall and lung
- Cardiac tamponade – pressure on the heart due to fluid in the sac surrounding the heart
- Myocardial contusion – a bruise of the heart muscle
- Pulmonary contusion – a bruise of the lung
- Injuries within the abdomen
- Spinal compression fractures – small, hairline breaks in the spine bones
- Other injuries caused by trauma
These are all potential causes that the doctor may examine if someone has injured their chest. Ensure to provide all necessary information to your healthcare provider to facilitate accurate diagnosis.
What to expect with Sternal Fractures
The death rate for patients admitted to the hospital with a fracture in the breastbone is quite low, standing at 8% within 30 days after getting hurt. This supports other findings indicating that despite how serious the injury might be, the death rate is generally low. Fractures that only involve the breastbone have a very good chance of recovery, with a death rate of only 0.7%.
Most patients with only this type of injury get completely better within an average of 10 weeks. Surgery may be needed in rare situations for persistent breastbone pain or for a fracture that does not heal properly. However, up to two-thirds of breastbone fractures include injuries to other parts of the body as well, and death rates range from 25% to 45% in these instances.
Possible Complications When Diagnosed with Sternal Fractures
Sternal fractures, or breaks in the breastbone, can lead to a variety of complications, especially when linked with other injuries. If the fracture is displaced or unstable, it raises the risk of injuries to the lungs, fluid around the heart (pericardial effusions), broken ribs, and compressed spinal fractures. Chest pain might continue for 2-3 months after the injury, and this painful breathing could cause lung collapse (atelectasis), pneumonia, and other lung-related issues.
Some uncommon complications of sternal fractures include nonunion (where the bones do not heal properly), false joint formation (an abnormal connection between bones), and overlap deformities (where the fractured bones overlap). These issues may require surgery at a later date. Certain factors like being older, having osteoporosis, long term steroid use, and diabetes can increase the risk of delayed healing.
On rare occasions, complications such as bone infection (osteomyelitis), abscess in the sternum, and mediastinitis (inflammation of the tissues in the mid-chest) may occur. People who have a large bruise (hematoma), who use intravenous drugs, or who have concurrent staph infections are at a higher risk of these infectious complications.
Common Complications:
- Pulmonary (lung) injuries
- Pericardial effusions (fluid around the heart)
- Rib fractures (broken ribs)
- Spinal compression fractures
- Chest pain persisting for 2-3 months
- Atelectasis (lung collapse)
- Pneumonia
- Delayed surgical intervention due to nonunion, false joint formation, and overlap deformities
- Delayed healing especially in people of advanced age, with osteoporosis, prolonged steroid use, or with diabetes
- Rare complications such as osteomyelitis, sternal abscess, and mediastinitis
- Infectious complications associated with large hematoma formation, intravenous drug abuse, and concurrent staphylococcal infections
Preventing Sternal Fractures
It’s crucial for medical staff to help patients understand the nature and seriousness of their injuries. They should motivate patients to follow all instructions about medication and treatment, whether it’s before or after surgery. The staff should also provide advice on changes they might need to make in their daily lives, including how to sleep comfortably and what activities to limit. Additionally, patients need to know when they should reach out to the doctor’s office if they have any worries or issues.
