What are common chest wall deformities?

Common Chest Wall Deformities

The most common chest wall deformities are pectus excavatum (funnel chest) accounting for approximately 88% of cases, followed by pectus carinatum (pigeon chest) at about 5% of cases. 1, 2, 3

Types of Chest Wall Deformities

Congenital Deformities

1. Pectus Excavatum (Funnel Chest)

   • Depression of the anterior chest wall
   • Often associated with other skeletal abnormalities including straight thoracic spine
   • May be a feature in connective tissue disorders like Marfan syndrome and Noonan syndrome 4
   • Can cause both physiological and psychological impacts on patients

2. Pectus Carinatum (Pigeon Chest)

   • Protrusion deformity of the sternum
   • Primarily a cosmetic concern but can cause significant psychological distress 2

3. Flail Chest/Chest Wall Instability

   • Characterized by paradoxical movement of a chest wall segment during respiration
   • Can be congenital or acquired (more commonly from trauma)
   • Rare in congenital form 5

4. Rib Abnormalities

   • Rib crowding
   • Horizontal positioning of ribs (often resulting from collapsed thoracic vertebrae)
   • Associated with conditions like osteogenesis imperfecta 5

Acquired Deformities

1. Post-surgical deformities

   • Following thoracotomy or sternotomy
   • Can include sternal nonunion and dehiscence 5

2. Post-traumatic deformities

   • Following rib fractures or flail chest injuries
   • Can lead to long-term respiratory impairment 5

3. Radiation-induced changes

   • Following radiation therapy for lung or chest wall tumors
   • Can lead to chest wall edema, cortical thinning, and eventual rib fractures 5

Clinical Significance

Physiological Impact

• Respiratory effects:

  • Restrictive lung disease pattern
  • Decreased vital capacity
  • Paradoxical breathing in severe cases 5
  • Breathing impairments often due to altered thoracic kinematics 5

• Cardiovascular effects:

  • Cardiac compression in severe pectus excavatum
  • Potential association with aortic root dilation in Marfan syndrome 4
  • Hemodynamic effects requiring surgical correction in some cases

Psychological Impact

• Body image concerns
• Social development issues
• Psychological distress that may warrant intervention even in the absence of physiological compromise 4, 6

Diagnostic Approach

Imaging Modalities

1. Chest Radiography

   • Initial screening tool
   • Can identify structural abnormalities of sternum, ribs, and thoracic spine
   • Limited in precise localization and characterization 5

2. CT Scan

   • Gold standard for evaluation of chest wall deformities
   • Allows precise characterization of anatomy and degree of deformity
   • Useful for surgical planning
   • 3D reconstructions provide valuable information for patient education and surgical planning 7
   • Can assess degree of healing and residual deformities post-treatment 5

3. MRI

   • Superior soft tissue contrast
   • Useful for evaluating associated soft tissue abnormalities
   • Particularly valuable for post-treatment evaluation and recurrence detection 5

4. Ultrasound

   • Limited role in primary evaluation
   • May help evaluate associated pleural or diaphragmatic complications 5

Management Considerations

Indications for Intervention

• Cardiopulmonary compromise
• Significant respiratory limitations affecting quality of life
• Significant psychological impact affecting quality of life 4
• Progressive deformity

Treatment Options

1. Non-surgical approaches

   • Bracing for mild to moderate pectus carinatum
   • Physical therapy for associated musculoskeletal issues

2. Surgical approaches

   • Minimally Invasive Repair of Pectus Excavatum (MIRPE/Nuss procedure)

     • Thoracoscopic placement of temporary metal bar behind sternum
     • Shorter procedure length and excellent cosmetic results 6

   • Modified Ravitch procedure

     • Open surgical approach
     • Involves resection of abnormal costal cartilages and sternal osteotomy

Special Considerations

• In patients with associated connective tissue disorders like Marfan syndrome:
  • Cardiovascular management takes precedence over pectus repair
  • Delay surgical repair if aortic root dilation is approaching surgical thresholds (≥4.5 cm) 4
  • Regular cardiovascular monitoring is essential

Pitfalls and Caveats

• Chest wall deformities can be mistaken for chest masses on imaging
• Proper patient selection is critical for optimal surgical outcomes
• Timing of intervention is important - treating patients before adulthood increases success rates 3
• Respiratory impairment in conditions like osteogenesis imperfecta may be independent of the degree of scoliosis or chest wall deformity 5
• Post-radiation chest wall complications may develop months to years after treatment 5