What is Pectus Carinatum?
Pectus carinatum, also known as “keel chest,” is a condition present at birth that affects the front of the chest wall. This condition causes the breastbone or rib cage to stick outwards. Sometimes, this condition is referred to as “pigeon breast,” when the upper part of the breastbone sticks out prominently. On the other hand, when the main part of the breastbone sticks out, it’s often called “chicken breast.”
These deformities can be symmetrical (seen on both sides of the chest) or located more on one side, often towards the right. Unlike pectus excavatum, a similar condition that’s noticed soon after birth, pectus carinatum is typically not recognized until the teen years when rapid growth happens. Signs of this condition can appear as early as age 10, and most commonly show up around age 16 for girls and 18 for boys.
Most often, people with this condition don’t experience any symptoms and only seek treatment to improve the look of their chest. However, when symptoms do occur, they are usually just a feeling of tenderness where the breastbone sticks out. In more severe cases, other symptoms could include difficulty breathing, rapid breathing with exertion, and decreased stamina due to the chest’s reduced flexibility.
What Causes Pectus Carinatum?
Despite extensive research, it’s not clear exactly why pectus carinatum, a condition that results in a protruding chest wall, develops. Most experts think it could be due to a problem with how the costal cartilage, which connect the ribs to the sternum or breastbone, grows too much.
Other studies have noticed a link between how the sternum grows and pectus carinatum, especially when the upper part of the sternum, known as the chondromanubrial area, becomes deformed.
There might also be a genetic link, as many people with pectus carinatum have a family member with a similar chest wall issue. In fact, estimates suggest that between 25 to 33% of people with pectus carinatum have a family history of such a condition.
Risk Factors and Frequency for Pectus Carinatum
Pectus carinatum, also known as “pigeon chest,” is a rare condition that affects about 0.06% of all newborns, which equates to roughly 1 in every 1,000 teenagers. With the help of advanced imaging technologies like computed tomography (CT), it’s believed that milder forms of pectus carinatum might actually be present in up to 5% of the population. This condition occurs more frequently in males, who outnumber affected females by nearly four to one.
- Pectus carinatum affects approximately 0.06% of newborns, or about 1 in 1,000 teenagers.
- With the use of advanced imaging like CT scans, it’s suspected that milder forms of the condition may be found in up to 5% of people.
- The condition is more common in males, with a male to female ratio of nearly 4:1.
Signs and Symptoms of Pectus Carinatum
Pectus carinatum is a condition where there’s a noticeable protrusion of the sternum and ribs, often without any symptoms. However, some people might feel tenderness at the spot where the chest juts out, get tired easily during physical activities, or breathe rapidly during exertion. There are other signs of this condition, too. For some individuals, they may have a family history of chest wall deformities. In other cases, the condition may occur alongside certain medical conditions.
- Tenderness in the area of the chest that’s protruding
- Decreased endurance or getting tired easily during physical activities
- Rapid breathing during physical activities
- The chest protrusion could exist on both or just one side
- Family history of chest wall deformities
- Co-occurrence with certain conditions like scoliosis, Marfan syndrome, mitral valve prolapse, Homocystinuria, Morquio syndrome, Noonan syndrome, or osteogenesis imperfecta.
- Potential association with conditions like asthma or chronic bronchitis
Testing for Pectus Carinatum
Pectus carinatum, also known as ‘pigeon chest’, is a condition where the breastbone is pushed outward. The diagnosis is made just by looking at the chest, but sometimes, more details might be needed. This is done through a side view X-ray or a computed tomography (CT) scan of the chest.
The severity of the deformity is usually measured through what is called a Haller index. This is the ratio of the width of the chest to the highest front-to-back diameter. It’s calculated using X-rays or a CT scan.
Research suggests that simple chest X-rays are just as effective as CT scans in calculating the Haller index. An added advantage of using X-rays instead of a CT scan is that they expose the patient to less radiation.
The Haller index is not only used to grade the severity or seriousness of the pectus carinatum but also to measure the progress of the treatment.
Treatment Options for Pectus Carinatum
Pectus carinatum, or a protruding chest wall, is typically treated in three ways: with non-surgical braces, surgery, or cosmetic methods to hide the condition. Wearing a chest brace is often the first line of treatment, as it can produce satisfactory results in many cases and doesn’t rule out the option of surgery if the brace isn’t effective. The braces are worn either on top of or under the clothes for around 14 to 24 hours a day, depending on how severe the chest wall protrusion is and the brace’s brand. This non-surgical method tends to work best when applied before the person undergoes a growth spurt, and is less effective after the age of 19 when the chest wall becomes less flexible. However, this method requires a long treatment period (often from several months to years), and the progress can be slow, so some people might not see it as a suitable option.
Surgical treatment for pectus carinatum has traditionally followed a technique from 1949, involving an incision in the front of the chest, lifting the big chest muscle (the pectoralis major), removing the deformed rib cage cartilage, and then fixing the correct shape of the chest wall. But this invasive method is now rarely used, as less invasive techniques have been developed. A minimal invasive method has been in use since 2006, which involves inserting a metal bar into a space just in front of the breastbone, and securing it to the ribs with metal plates. This bar is kept in place for approximately two years and then removed. This has become the preferred surgery, but it’s mostly used for a specific type of pectus carinatum where the chest wall is less flexible.
For those not seeking medical treatment to correct this condition, some have turned to bodybuilding as a way to build muscle around the chest deformity, making the protrusion less noticeable. This approach doesn’t correct the abnormality, but it can improve self-esteem and confidence. In women, breast augmentation has also been used to alter the physical appearance of the chest to make pectus carinatum less apparent.
What else can Pectus Carinatum be?
To diagnose pectus carinatum, or a protrusion of the chest bone, doctors usually only need to look at the chest, but sometimes they might use x-rays for confirmation. This condition usually occurs on its own, but it often shows up in people with certain other medical conditions, so a doctor might want to test for those conditions as well.
For example, Marfan syndrome, which is a disorder that affects how your body’s connective tissue works, is found in about 0.3% of all people. It’s common for people with Marfan syndrome to also have pectus carinatum. In fact, two-thirds of people with Marfan syndrome have a pectus deformity, and 12% of those people have pectus carinatum. So if someone has a pectus deformity, it could be a good idea to check if they have Marfan syndrome because over 5% of people with pectus carinatum or a related condition called pectus excavatum also have Marfan syndrome.
There’s another condition, called Morquio syndrome or mucopolysaccharidosis type IVA, that’s closely tied to pectus carinatum. This is a rare genetic disease that affects how the body breaks down a certain kind of molecule. It only happens in about 1 in 200,000 births and shows up with symptoms like scoliosis, shortness, very flexible joints, a bell-shaped chest, and heart problems. The severe form of Morquio syndrome shows up early in life with knock knees and a prominently protruding breastbone. A less severe form progresses more slowly and might not show symptoms until the teen years.
What to expect with Pectus Carinatum
The outlook for patients diagnosed with pectus carinatum, or a protruding chest, is generally very good. Without any treatment, patients may not experience any symptoms or long term negative effects on their health. Treatment is primarily aimed at improving physical appearance, and both external devices to reshape the chest and minor surgical techniques have shown success in enhancing the look of the chest wall.
Possible Complications When Diagnosed with Pectus Carinatum
People often overlook the emotional impact of pectus carinatum, a chest wall deformity. This condition often appears during the teenage years, a critical time for developing self-esteem and body image. Teens might use tactics to hide their chest such as wearing certain clothes or avoiding activities like team sports to dodge unwanted attention.
Some may even consider body-building for cosmetic reasons. However, it’s important to note that the American Academy of Pediatrics advises against intense physical activity in children, due to their still-developing bones.
- Pectus carinatum’s emotional impact
- Appearance during the critical teenage years
- Teens’ possible coping strategies such as wearing certain clothes or avoiding group activities
- Consideration of body-building for improved appearance
- The American Academy of Pediatrics’ advice against intense activity for developing children
Preventing Pectus Carinatum
It’s important that your healthcare provider gives you written information about pectus carinatum, which is a condition where the breastbone protrudes outward. You should feel free to ask any questions or express any concerns about your condition and the possible treatment options. If necessary, you may be referred to a specialist who can offer more detailed advice, better treatment, or further evaluations.
