Pectus carinatum (PC) is a chest wall deformity where the breastbone (sternum) and attached ribs protrude outward, often called “pigeon chest.” This condition arises from the abnormal overgrowth of the cartilage connecting the ribs to the sternum, forcing the breastbone forward. While it may be present at birth, PC is most frequently diagnosed in adolescence when the protrusion becomes more prominent during rapid growth.
The Natural Progression of Pectus Carinatum
Pectus carinatum rarely resolves on its own once the protrusion has developed. The underlying structural issue is an overgrowth of the costal cartilage, which does not simply shrink or remodel itself without external intervention. The condition often remains subtle or unnoticed in early childhood, even if present from birth.
The deformity typically becomes more noticeable and progresses rapidly during the adolescent growth spurt, generally between the ages of 11 and 14. This accelerated growth phase exacerbates the existing cartilage abnormality, causing the sternum to be pushed out further. The protrusion usually stabilizes once skeletal maturity is reached, typically around 18 years of age.
The type of PC that is present at birth (congenital PC) may be recognized earlier, but the more common form is acquired, becoming clinically significant during puberty. Since the condition is caused by a structural overgrowth of cartilage, it will not spontaneously correct itself. While PC is not a significant health threat, the visible nature of the protrusion can lead to psychological distress and self-image issues.
Factors Influencing Development and Severity
The exact cause of Pectus Carinatum remains unknown, but it is understood to be a complex issue involving the growth of the chest wall. A strong genetic component is suspected because about 25% of patients have a family member with some form of chest wall abnormality. The core problem is the abnormal growth of the costal cartilage, which acts like a spring, pushing the sternum forward.
The severity of the protrusion is influenced by the rapid growth spurts that occur during adolescence. As the long bones grow quickly, the abnormal costal cartilage also experiences accelerated growth, increasing the outward pressure on the sternum. This explains why the deformity often worsens dramatically during the teenage years.
PC is categorized by the specific location of the protrusion. The most common type is chondrogladiolar prominence, which affects the middle and lower part of the sternum. A rarer form is chondromanubrial prominence, where the upper part of the breastbone protrudes. The condition also has associations with various connective tissue disorders, such as Marfan syndrome and Ehlers-Danlos syndrome.
Treatment Options for Pectus Carinatum
Since Pectus Carinatum does not correct itself, treatment is usually recommended for moderate to severe cases, or when the deformity causes psychological impact. The primary goal of treatment is to apply pressure to the protruding sternum to reshape the chest wall. The approach chosen depends mainly on the patient’s age and chest flexibility.
Non-surgical treatment using an external dynamic compression brace is the preferred first-line method for most growing adolescents. This custom-fitted brace applies consistent, gentle pressure to the apex of the protrusion, gradually remodeling the flexible cartilage. Bracing is most effective when the chest wall is still malleable, typically in patients under 18 years old.
For bracing to be successful, high patient compliance is required; the brace is usually worn for 8 to 12 hours or more daily, typically for six to eighteen months. A specialist regularly adjusts the brace’s pressure to ensure effective correction. Surgical options are reserved for severe or rigid deformity, cases where bracing has failed, or patients who have completed skeletal growth.
The traditional surgical procedure is the Ravitch technique, which involves removing the deformed costal cartilage and repositioning the sternum. Less invasive surgical options, such as the modified Ravitch procedure, are also used. Surgery is generally avoided until the patient is older to prevent potential recurrence during a subsequent growth spurt. Bracing is favored because it is non-invasive and has a high success rate.