Continuing Education Activity

Pectus carinatum is a structural chest wall deformity characterized by anterior protrusion of the sternum and adjacent costal cartilages, affecting approximately 1 in 1000 adolescents. Although frequently identified during periods of rapid growth, the condition varies in severity and may be associated with cosmetic concerns, psychosocial distress, and, less commonly, cardiopulmonary symptoms. Early recognition expands opportunities for successful nonoperative treatment, particularly with orthotic bracing. This course reviews the etiology, epidemiology, clinical presentation, diagnostic evaluation, classification, and evidence-based management of pectus carinatum. Participants learn to perform a comprehensive assessment, identify associated syndromes and musculoskeletal abnormalities, determine appropriate candidates for bracing or surgical correction, and provide longitudinal follow-up. Collaboration with an interprofessional healthcare team, including pediatric clinicians, orthopedic or thoracic surgeons, orthotists, physical therapists, and mental health professionals, enhances coordinated care, treatment adherence, functional outcomes, and quality of life.

Objectives:

• Identify the etiology of pectus carinatum.
• Evaluate physical examination findings, imaging studies, and cardiopulmonary assessments to guide diagnosis and therapeutic decision-making.
• Implement evidence-based nonoperative and operative interventions to improve chest wall alignment, function, and quality of life.
• Explain interprofessional team strategies to improve care coordination and improve patient outcomes for patients with pectus carinatum.

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Introduction

Pectus carinatum, or “keel chest,” like its sister condition pectus excavatum, is a congenital deformation of the anterior chest wall. The condition presents with an outward protrusion of the sternum or rib cage.[1] When the sternal manubrium is prominent, the deformity is often called “pigeon breast,” while the more common chondrogladiolar prominence, in which the body of the sternum protrudes, is referred to as “chicken breast.”[2] The deformity can be symmetric or unilateral, with a rightward tilt of the sternum the more common unilateral condition.[3] Unlike pectus excavatum, pectus carinatum is typically not identified shortly after birth but during the teen years when growth is accelerated.

This condition can be detected as early as age 10, with peaks at 16 and 18 years in females and males, respectively.[4] The condition is often asymptomatic, with patients seeking treatment for cosmetic reasons. When symptoms occur, they typically manifest only as tenderness at the site of the protrusion.[2] Other symptoms related to decreased chest compliance, seen in more severe cases, include dyspnea, exertional tachypnea, and reduced endurance.[5]

Etiology

The precise etiology of pectus carinatum is unknown, although most believe that both pectus carinatum and pectus excavatum result from defective elongation of the costal cartilage.[3] Additional studies have shown a relationship between sternal growth and pectus carinatum, with a stronger association observed in superior chondromanubrial deformities.[6] A genetic component is suggested by the significant portion of patients with a family history of a chest wall defect or deformity, with estimates as high as 25 to 33%.[2][3]

Epidemiology

Pectus carinatum is estimated to occur in up to 0.06% of all live births, with an incidence of approximately 1 per 1000 among teenagers. With more detailed radiographic evidence available with computed tomography (CT), there are suggestions that milder forms of pectus carinatum may occur in up to 5% of the population.[3] Males are more frequently affected, at a ratio of nearly 4:1.[2]

History and Physical

Patients with pectus carinatum present with protrusion of the sternum and ribs, often asymptomatic but occasionally with tenderness at the site of protrusion, reduced pulmonary endurance, or tachypnea with exertion. Respiratory symptoms such as dyspnea and reduced endurance are more common in the chondromanubrial variety, as chest wall flexibility is decreased compared with the chondrogladiolar deformity.[7] The protrusion can be bilateral or unilateral.  There is a family history of chest wall deformity in up to one-third of patients.[3] The condition correlates with scoliosis, Marfan syndrome, mitral valve prolapse, homocystinuria, Morquio syndrome, Noonan syndrome, and osteogenesis imperfecta, though it frequently occurs in isolation.[2][3] Results from some studies have shown an association with asthma or chronic bronchitis in up to 16.4% of patients.[4]

Evaluation

Diagnosis of pectus carinatum is made clinically by visual inspection, with further details offered by lateral chest radiograph or CT. Evaluation of deformity severity is performed radiographically using the Haller index, the ratio of the transverse chest wall diameter to the greatest anteroposterior diameter. Study results suggest that chest radiographs are as effective as CT for determining the Haller index, with the added benefit of reduced radiation exposure to the patient.[8][9] In addition to grading severity, the Haller index also measures treatment progress.

Treatment / Management

Treatment of pectus carinatum typically falls into one of three categories: nonsurgical bracing, surgical correction, or cosmetic concealment. Orthotic braces are the first-line treatment option, as acceptable results are often achievable, and the use of an external brace does not preclude surgical intervention if it is unsuccessful.[10] The braces are worn either under or over the patient’s clothing for between 14 and 24 hours per day, depending on the manufacturer and the severity of the chest wall protrusion. A nonsurgical correction is most effective when applied before the patient’s growth spurt and less effective after age 19, due to changes in chest wall flexibility.[11] However, due to the lengthy treatment period (often months to years) and slow progression of the correction, many patients do not view this as an acceptable option.

Surgical repair has been classically performed using the technique developed by Ravitch in 1949.[12] This invasive procedure involves an incision of the anterior chest wall and elevation of the pectoralis major muscle followed by resection of the deformed costal cartilage. Transverse sternotomy is followed by fixation of the corrected chest wall.[13] 

This method is now infrequently utilized as less invasive techniques have been developed. A minimally invasive method developed by Abramson utilizes a modified Nuss bar used to correct pectus excavatum and has been in extensive use since 2006.[14] A metal bar is inserted into the presternal space through an incision on the lateral chest wall and secured to the bilateral ribs with metal plates. The bar is left in place for approximately 2 years and then removed. Although now the favored surgical option, this modified Nuss procedure is used primarily for the chondrogladiolar type of pectus carinatum, given the decreased flexibility of the chest wall in the chondromanubrial variation.[7]

Some patients not seeking medical treatment for correction have turned to bodybuilding to sculpt the musculature around the chest wall deformity, thereby minimizing the appearance of the protrusion. While this does not correct the abnormality, it can improve self-esteem and confidence. For female patients, breast augmentation has also been used to alter the physical appearance of the chest to make the pectus carinatum less apparent.

Differential Diagnosis

The diagnosis of pectus carinatum is made by visual inspection with or without radiographic support. Most cases occur in isolation, though there is a strong association with several conditions that may require evaluation. Marfan syndrome, a connective tissue disorder affecting up to 0.3% of the general population,[15] frequently presents with a pectus deformity. Two-thirds of patients with Marfan syndrome have a pectus deformity, with 12% of those being pectus carinatum. It is appropriate to refer patients with a pectus deformity for evaluation, as more than 5% of those presenting with pectus carinatum or pectus excavatum will also have Marfan syndrome.[15]

Another syndrome strongly associated with pectus carinatum is Morquio syndrome, or mucopolysaccharidosis type IVA.[16] This rare genetic disease of dysfunctional glycosaminoglycan catabolism occurs in approximately 1 in 200000 births and presents with scoliosis, short stature, hypermobile joints, a bell-shaped chest, and cardiac abnormalities. The severe form of this disease becomes apparent at an early age with knock-knees and breastbone prominence, whereas the more slowly progressing variety may not become apparent until adolescence.

Prognosis

The prognosis for patients diagnosed with pectus carinatum is excellent. Even without treatment, patients may have no symptoms and no long-term adverse health effects. Treatment is typically for cosmetic reasons, and both external bracing and minimally invasive surgical techniques have demonstrated the ability to improve the appearance of the chest wall.

Complications

An often overlooked aspect of pectus carinatum is the psychological impact the deformity has on the patient. Presentation of the condition occurs during the teenage years when body image formation is occurring. Coping strategies may develop, such as wearing clothes that minimize the appearance of pectus or withdrawing from group activities and team sports to avoid the unwanted attention of their peers. Those who pursue cosmesis with body-building should be made aware that the American Academy of Pediatrics does not support that level of strenuous activity in children whose skeletons are still maturing.[17]

Deterrence and Patient Education

Written materials regarding pectus carinatum should be provided to the patient by their healthcare provider, and the patient should be encouraged to ask any questions or express any concerns they have about their condition and the available treatment options. When appropriate, patients should be referred to a specialist who will be better able to provide support, treatment, or further evaluation. 

Enhancing Healthcare Team Outcomes

Pectus carinatum can be diagnosed on visual inspection by health care professionals at all levels. Pediatricians, primary care clinicians, and nurse practitioners are often the first to evaluate these patients and determine if further assessment or treatment is needed. Coordination with team members in radiology, surgery, nursing, and psychiatry can provide patients a means to treat, monitor, and cope with the condition. Management of pectus carinatum is best managed by an interprofessional team comprising physicians, surgeons, specialty-trained nurses, and therapists who work and communicate collaboratively to achieve the best patient outcomes. 

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References

1.

Park CH, Kim TH, Haam SJ, Lee S. Does overgrowth of costal cartilage cause pectus carinatum? A three-dimensional computed tomography evaluation of rib length and costal cartilage length in patients with asymmetric pectus carinatum. Interact Cardiovasc Thorac Surg. 2013 Nov;17(5):757-63. [PMC free article: PMC3805208] [PubMed: 23868604]

2.

Goretsky MJ, Kelly RE, Croitoru D, Nuss D. Chest wall anomalies: pectus excavatum and pectus carinatum. Adolesc Med Clin. 2004 Oct;15(3):455-71. [PubMed: 15625987]

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Coelho Mde S, Guimarães Pde S. Pectus carinatum. J Bras Pneumol. 2007 Jul-Aug;33(4):463-74. [PubMed: 17982540]

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Fonkalsrud EW. Surgical correction of pectus carinatum: lessons learned from 260 patients. J Pediatr Surg. 2008 Jul;43(7):1235-43. [PubMed: 18639675]

6.

Haje SA, Harcke HT, Bowen JR. Growth disturbance of the sternum and pectus deformities: imaging studies and clinical correlation. Pediatr Radiol. 1999 May;29(5):334-41. [PubMed: 10382210]

7.

Katrancioglu O, Akkas Y, Karadayi S, Sahin E, Kaptanoğlu M. Is the Abramson technique effective in pectus carinatum repair? Asian J Surg. 2018 Jan;41(1):73-76. [PubMed: 27825548]

8.

Poston PM, McHugh MA, Rossi NO, Patel SS, Rajput M, Turek JW. The case for using the correction index obtained from chest radiography for evaluation of pectus excavatum. J Pediatr Surg. 2015 Nov;50(11):1940-4. [PubMed: 26235532]

9.

Khanna G, Jaju A, Don S, Keys T, Hildebolt CF. Comparison of Haller index values calculated with chest radiographs versus CT for pectus excavatum evaluation. Pediatr Radiol. 2010 Nov;40(11):1763-7. [PubMed: 20473605]

10.

Cohee AS, Lin JR, Frantz FW, Kelly RE. Staged management of pectus carinatum. J Pediatr Surg. 2013 Feb;48(2):315-20. [PubMed: 23414858]

11.

Jung J, Chung SH, Cho JK, Park SJ, Choi H, Lee S. Brace compression for treatment of pectus carinatum. Korean J Thorac Cardiovasc Surg. 2012 Dec;45(6):396-400. [PMC free article: PMC3530724] [PubMed: 23275922]

12.

RAVITCH MM. Unusual sternal deformity with cardiac symptoms operative correction. J Thorac Surg. 1952 Feb;23(2):138-44. [PubMed: 14909306]

13.

Kálmán A. Initial results with minimally invasive repair of pectus carinatum. J Thorac Cardiovasc Surg. 2009 Aug;138(2):434-8. [PubMed: 19619792]

14.

Abramson H. [A minimally invasive technique to repair pectus carinatum. Preliminary report]. Arch Bronconeumol. 2005 Jun;41(6):349-51. [PubMed: 15989893]

15.

Behr CA, Denning NL, Kallis MP, Maloney C, Soffer SZ, Romano-Adesman A, Hong AR. The incidence of Marfan syndrome and cardiac anomalies in patients presenting with pectus deformities. J Pediatr Surg. 2019 Sep;54(9):1926-1928. [PubMed: 30686517]

16.

Tomatsu S, Mackenzie WG, Theroux MC, Mason RW, Thacker MM, Shaffer TH, Montaño AM, Rowan D, Sly W, Alméciga-Díaz CJ, Barrera LA, Chinen Y, Yasuda E, Ruhnke K, Suzuki Y, Orii T. Current and emerging treatments and surgical interventions for Morquio A syndrome: a review. Res Rep Endocr Disord. 2012 Dec;2012(2):65-77. [PMC free article: PMC4020877] [PubMed: 24839594]

17.

American Academy of Pediatrics Council on Sports Medicine and Fitness. McCambridge TM, Stricker PR. Strength training by children and adolescents. Pediatrics. 2008 Apr;121(4):835-40. [PubMed: 18381549]

Disclosure: Bruce McHam declares no relevant financial relationships with ineligible companies.

Disclosure: Lana Winkler declares no relevant financial relationships with ineligible companies.