Thoracic Spine Anatomy

Topic updated on 01/04/16 11:29am
  • Vertebral prominens
    • the long prominent spinous process found at T1
  • Costal facets
    • articulation between ribs and vertebral segments
    • present on all vertebral bodies and transverse processes from T1 to T9
    • articulation with ribs leads to increased rigidity of thoracic spine (most rigid in axial skeleton)
  • Vertebral body size  
    • increases progressively from T1 to T12
  • Spinal canal dimensions  
    • varies from T1 to T12
  • The orientation of the facets (zygapophyseal) joints determines the degree and plane of motion at that level
    •  varies throughout the spine to meet physiologic function
    • cervical spine (C3-7)
      • planes
        • 0° coronal
        • 45° sagittal (angled superio-medially) 
      • function
        • allows flexion-extension, lateral flexion, rotation
    • thoracic spine
      • planes
        • 20° coronal
        • 55° sagittal (facets in coronal plane) 
        • 6 degrees of freedom  
      • function
        • allows some rotation, minimal flexion-extension (also limited by ribs)  
        • prevents downward flexion on heart and lungs  
    • lumbar spine
      • plane
        • 50° coronal
        • 90° sagittal (facets in sagittal plane)  
      • function
        • allows flexion-extension, minimal rotation
        • helps increase abdominal pressure 
Thoracic Pedicle Anatomy
  • Pedicle diameter
    • the pedicle wall is twice as thick medially as laterally
    • T4 has the narrowest pedicle diameter (on average)  
    • T7 can be irregular and have a narrow diameter on the concave side in AIS
    • T12 usually has larger pedicle diameter than L1
  • Pedicle length
    • pedicle length decreases from T1 to T4 and then increases again as you move distal in the thoracic spine
      • T1: 20mm
      • T4: 14mm (shortest pedicle)
      • T10: 20 mm
  • Pedicle angle
    • transverse pedicle angle  
      • varies from 10deg (mid thoracic spine) to 30deg (L5)
    • sagittal pedicle angle  
      • 15-17deg cephalad for majority of thoracic spine
      • neutral (0deg) for lumbar spine except L5 (caudal) 
Erector Spinae Muscles
  • Characteristics  
    • functions to extend the trunk
    • located dorsal to vertebral column
    • innervated by dorsal rami of spinal nerves
  • Erector spinae muscles include
    • spinalis
      • most medial
      • origin and insertion: spinous process to spinous process
    • longissimus
      • intermediate 
      • origin and insertion: transverse process to transverse process
    • iliocostalis
      • most lateral
      • origin: ilium and ribs 
      • insertion: ribs and transverse process
Surgical Approaches
  • Surgical approaches for thoracic disc herniation  
    • laminectomy/hemilaminectomy
    • transpedicular
    • costotransversectomy
    • lateral extracavitary
    • anterior intracavitary
      • thoracotomy
      • VATS (video assisted thoracoscopic surgery)


Please Rate Educational Value!
Average 2.0 of 26 Ratings

Qbank (1 Questions)

(OBQ08.190) In the adult spine, which of the following pedicles have the smallest average transverse diameter. Topic Review Topic

1. T1
2. T6
3. T12
4. L3
5. L5



Thorasic Spine: As a general rule the starting point for insertion of Pedicle sc...
See More Videos



Topic Comments