A sternal fracture is a break in the breastbone, the flat bone that runs down the center of your chest. It accounts for roughly 8% of all blunt chest trauma injuries and occurs in 3% to 6.8% of motor vehicle collisions. While a sternal fracture sounds alarming because of how close the bone sits to your heart and lungs, most cases heal on their own with pain management and rest.
Where the Sternum Sits and What It Protects
The sternum is made up of three segments: the manubrium at the top (where your collarbones meet), the body in the middle (the longest section), and the xiphoid process, a small piece of cartilage at the bottom. Together with the ribs, the sternum forms a protective cage around the heart, major blood vessels, and lungs. Most fractures happen in the manubrium or the body, where direct force is concentrated during an impact.
Common Causes
Car accidents are the leading cause by a wide margin, responsible for about 68% of sternal fractures. The typical scenario involves the chest striking the steering wheel, especially in older vehicles without airbag deployment. Interestingly, seatbelt shoulder restraints, while life-saving, have actually increased the rate of sternal fractures because the strap crosses directly over the bone during a sudden stop.
The remaining cases break down roughly as follows:
- Falls: about 7.9% of cases
- Motorcycle accidents: about 7.9%
- Pedestrian-versus-vehicle accidents: about 3.4%
- Cycling accidents: about 1.4%
- Sports injuries and assaults: making up most of the rest
In rare cases, a sternal fracture can develop not from a single impact but from repetitive stress. Athletes who do intense upper-body exercises, particularly rowers and weightlifters, can develop stress fractures of the sternum that show up as sudden chest pain after a period of heavy training.
What a Sternal Fracture Feels Like
The most obvious symptom is sharp pain at the front of the chest, right over the breastbone. This pain typically gets worse when you take a deep breath, cough, laugh, or twist your upper body. You may feel a grinding sensation or hear a clicking sound at the fracture site when you move, which is caused by the broken edges of bone shifting against each other. The area over the sternum is usually visibly bruised and tender to the touch. In displaced fractures, where the bone segments have shifted out of alignment, you may notice a deformity or a step-off in the chest wall that you can feel with your fingers.
Because it hurts to breathe deeply, many people instinctively take shallow breaths. This is worth paying attention to: shallow breathing over several days can raise the risk of chest infections, which is one reason proper pain control matters.
How It Is Diagnosed
A standard front-to-back chest X-ray is usually the first imaging test ordered, but it has low sensitivity for sternal fractures. The sternum overlaps with the spine on that view, making hairline cracks easy to miss. A lateral (side-view) X-ray does a better job, but CT scanning is considered the gold standard because it can show fracture lines, displacement, and any injuries to nearby structures with much greater detail. Even CT scans occasionally miss subtle fractures. In one documented case, both chest X-ray and CT initially failed to detect a sternal fracture in an older patient, and the break was ultimately identified with ultrasound.
Injuries That Can Occur Alongside It
The force required to break the sternum is significant, so doctors always check for damage to the organs behind it. The most concerning associated injury is blunt cardiac injury, essentially a bruise to the heart muscle. In one study of patients with sternal fractures, about 5% were diagnosed with blunt cardiac injury. Among those patients, 74% also had lung-related injuries, including bruised lung tissue, collapsed lung (pneumothorax), or bleeding into the chest cavity. Lung injuries turned out to be the strongest predictor that the heart was also affected.
Cardiac complications from an isolated sternal fracture (one with no other injuries) are uncommon. In a study of 129 patients with isolated sternal fractures, less than 1% experienced a heart-related complication such as an abnormal heart rhythm, and none required a cardiac procedure. About 2.3% had minor abnormalities on echocardiogram. This is reassuring if you have been told your sternal fracture is isolated, meaning no rib fractures, lung injuries, or other trauma were found alongside it.
Treatment and What to Expect
The vast majority of sternal fractures are treated without surgery. The core of treatment is pain control, which allows you to breathe deeply and cough effectively to keep your lungs clear. Ice over the area, rest, and avoiding heavy lifting or strenuous upper-body activity make up the standard approach for the first several weeks.
Breathing exercises are a key part of recovery. Because chest pain naturally discourages deep breaths, you may be instructed to practice slow, deliberate inhalations several times per hour. This helps prevent mucus from building up in your lungs and reduces the risk of pneumonia, especially if you are older or have pre-existing lung conditions.
Most sternal fractures heal within 8 to 12 weeks, following a similar timeline to other flat bone fractures. Pain tends to be most intense in the first two weeks and gradually improves. You can generally return to light daily activities within a few weeks, but high-impact exercise, contact sports, and heavy lifting usually need to wait until the bone has fully healed and you can move without pain.
When Surgery Is Needed
Surgical repair is reserved for a small subset of cases. The main reasons a surgeon would intervene include fractures where the bone segments have shifted, overlapped, or become impacted into each other; persistent instability of the chest wall; respiratory failure or dependence on a ventilator because the chest cannot expand properly; hunched posture and restricted trunk movement caused by the fracture; or pain that persists beyond seven days and does not respond to conservative treatment.
When surgery is performed, the bone is typically stabilized with locked titanium plates screwed into the sternum on either side of the break. In a review of surgical cases, this approach achieved bone healing in all 12 patients treated. For fractures that fail to heal on their own (called non-union), bone grafting combined with internal fixation is sometimes used. Non-union is uncommon but more likely when a fracture is significantly displaced and left untreated.