Sports Medicine: Just the Facts

RADIOGRAPHIC LINES AND ANGLES

IN SPORTS MEDICINE

Peter H Seidenberg, MD

CERVICAL SPINE—LATERAL

RETROPHARYNGEALSPACE

• Distance from the posterior pharyngeal wall to the
  anteroinferior aspect of C-2.


• Normal is <7 mm.

RETROTRACHEALSPACE

• Distance from the posterior wall of the trachea to the
  anteroinferior aspect of C-6.


• Normal in adults is <22 mm.


• Normal in children is <14 mm.

ANTERIORVERTEBRALLINE

• Drawn along the anterior margins of the vertebral
  bodies.


• Should run smoothly without angulation or disrup-
  tion.

POSTERIORVERTEBRALLINE

• Drawn along the posterior margins of the vertebral
  bodies.


• Outlines anterior margin of spinal canal.


• Should run smoothly without angulation or disrup-
  tion.

SPINOLAMINARLINE

• Drawn along the anterior margins of the bases of the
  spinous processes at the junction with the lamina.


• Outlines posterior margin of the spinal canal.


• Should run smoothly without angulation or disrup-
  tion.

POSTERIORSPINOUSLINE

• Drawn along the tips of the spinous processes from
  C-2 to C-7.


• Should run smoothly without angulation or disrup-
  tion.

CLIVUS–ODONTOIDLINE

• Drawn from the dorsum sellae along the clivus to the
  anterior margin of the foramen magnum.


• Should point to the junction of the anterior and middle
  thirds of the tip of the odontoid process.

TORGRAT I O

• Used to check for presence of developmental cervical
  stenosis.


• Spinal canal to vertebral body ratio.


• Distance spinolaminar line to posterior aspect of ver-
  tebral body/diameter of vertebral body
  
  
  • Normal >1.0
  
  
  • Abnormal <0.8
  
  
  
  

MCRAE’SLINE

• Diameter of line drawn through foramen magnum
  opening.
  •Normal: Tip of odontoid process of axis should be at
  or below McRae’s line.

CHAMBERLAIN’SLINE

• Posterior edge of foramen magnum to the most poste-
  rior aspect of the hard palate.


• Normally odontoid tip 3 mm above Chamberlain’s
  line.


• More than 6.6 mm above this line signifies cranial set-
  tling.

MCGREGOR’SLINE

• Most posterior aspect of hard palate to the lowest
  border of the posterior skull.
  •Normal: Tip of odontoid process <4.5 mm above line

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APPENDIX

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