What is Pectus Carinatum?
Also known as "pigeon chest" or "bird chest," pectus carinatum is a structural abnormality that causes the sternum (breastbone) and ribs to protrude outward. It is the opposite of pectus excavatum, where the chest appears sunken. Pectus carinatum typically results from an overgrowth of the cartilage that connects the ribs to the sternum. While it is a congenital condition, meaning it is present at birth, it often becomes more prominent during a child’s rapid growth spurt in adolescence, particularly between the ages of 11 and 15.
For many people, the condition is primarily an aesthetic issue and does not cause significant physical problems. However, its visible nature can lead to body image issues, reduced self-esteem, and social anxiety, especially in adolescents. In more severe cases, it can sometimes be associated with mild physical symptoms related to breathing and heart function.
Causes and Risk Factors
The exact cause of pectus carinatum is often unknown, though it is believed to be a disorder of the cartilage growth. Several factors are understood to contribute to its development.
The Role of Cartilage
At the core of pectus carinatum is the abnormal, excessive growth of the costal cartilages, which are the tough connective tissues that join the ribs to the sternum. When this cartilage grows at an accelerated rate compared to the surrounding bones, it pushes the breastbone forward. This is the most common form, known as idiopathic pectus carinatum.
Genetic Predisposition
Genetics play a significant role in chest wall deformities. Pectus carinatum often runs in families, with up to a third of people with the condition having a family member with a chest wall issue. It is also associated with a number of other genetic conditions and connective tissue disorders, including:
- Marfan syndrome
- Ehlers-Danlos syndrome
- Noonan syndrome
- Osteogenesis imperfecta
- Morquio syndrome
Growth Spurts
While some children may show signs at a younger age, the deformity typically becomes most obvious during the rapid growth associated with puberty. The accelerated bone and cartilage growth during this period can exacerbate the protrusion.
Other Associations
In some cases, pectus carinatum can be seen alongside other health issues, such as scoliosis (curvature of the spine), asthma, or bronchitis. It can also arise after open heart surgeries where the sternum has been split.
Signs and Symptoms
The most prominent sign of pectus carinatum is the visible outward protrusion of the chest wall. The bulge can be mild or severe, and it may be symmetrical or affect one side more than the other. Beyond the cosmetic appearance, some individuals may experience physical symptoms.
Potential Physical Symptoms
- Chest tenderness or mild discomfort
- Shortness of breath, especially during intense physical activity
- Fatigue and reduced stamina
- Fast heartbeat or heart palpitations
- Recurrent respiratory infections, in severe instances
Psychological and Emotional Impact
For many, the most significant impact is psychological. The visible chest deformity, particularly during the self-conscious adolescent years, can lead to:
- Low self-esteem
- Social anxiety
- Embarrassment, which may cause individuals to avoid activities like swimming or changing rooms
Diagnosis and Evaluation
If you or your child notices a protruding chest, a medical evaluation is recommended to confirm the diagnosis and rule out any associated conditions.
- Physical Exam: A doctor will perform a thorough physical examination and inquire about family history of chest wall deformities.
- Imaging Scans: To evaluate the severity of the protrusion and its effect on internal organs, a chest X-ray, CT scan, or MRI may be ordered.
- Heart and Lung Function Tests: In more severe cases, an electrocardiogram (EKG) or pulmonary function testing may be performed to ensure the heart and lungs are functioning properly.
Pectus Carinatum vs. Pectus Excavatum: A Comparison
It is important to distinguish between pectus carinatum and its counterpart, pectus excavatum, as they are treated differently.
| Feature | Pectus Carinatum | Pectus Excavatum |
|---|---|---|
| Appearance | Outward protrusion of the sternum | Sunken or concave chest wall |
| Commonality | Less common (approx. 1 in 1,500) | More common (approx. 1 in 400) |
| Physical Impact | Often cosmetic, less frequent heart/lung impact | Can be more severe, potentially affecting heart and lung function |
| Other Name | Pigeon Chest, Bird Chest | Funnel Chest, Sunken Chest |
| Treatment | Bracing (common), surgery | Bracing (less common), surgery (Nuss procedure) |
Treatment Options
For individuals whose pectus carinatum causes significant distress or symptoms, several treatment options are available.
Bracing (Non-Surgical)
Bracing is a highly effective, non-invasive method for correcting pectus carinatum, particularly in children and adolescents whose chests are still flexible. A custom-fitted brace applies gentle, constant pressure to the prominent area of the chest, gradually pushing the sternum back into a normal position. The brace is typically worn for up to 24 hours a day, with results often seen within months to a year, depending on severity and patient compliance.
Surgery
For severe cases, for older patients with stiffer chests, or for those who do not respond to bracing, surgical correction may be considered. The most common procedure, a modified Ravitch procedure, involves an incision to remove the excess cartilage that is causing the protrusion. The sternum is then repositioned and, in some cases, supported with a temporary metal strut. A more minimally invasive approach, similar to the Nuss procedure used for pectus excavatum, may also be used in some centers.
Exercise
While exercise alone cannot fix the underlying cartilage issue, specific exercises focusing on posture, core strength, and the chest muscles can sometimes help improve overall chest appearance. It is important to consult a healthcare provider or a physical therapist experienced with chest wall deformities before beginning an exercise program.
Conclusion
In most cases, the question of why does the middle of my chest go out is answered by understanding pectus carinatum, a common and often benign chest wall deformity. While it is predominantly a cosmetic concern, the availability of effective treatments like bracing and surgery means individuals can address both physical symptoms and the psychological impact associated with the condition. A consultation with a medical professional is the first step toward proper diagnosis and crafting an appropriate treatment plan.
For more detailed medical information on chest wall deformities, you can visit the Cleveland Clinic website.
