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Scoliosis XRay

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Scoliosis XRay, Cobb Angle, Scoliosis Survey X-Ray

  • See Also
  1. Scoliosis
  2. Scoliosis Examination (Forward Bending Test, Scoliometer)
  3. Scoliosis XRay (Cobb Angle)
  • Indications
  1. See Scoliosis
  2. BMI <85%: Scoliometer measurement 7 degrees or more of trunk rotation (~20 degree Cobb Angle)
  3. BMI >85%: Scoliometer measurement 5 degrees or more of trunk rotation (~10 degree Cobb Angle)
  • Technique
  1. Obtain Posteroanterior (PA) XRays of the full spine
    1. Posteroanterior view minimizes Breast radiation
    2. Patients back is to XRay Source
    3. XRay tube positioned 6 feet from 14"x36" cassette
  2. Correct Leg Length Discrepancy with block under foot
  • Measurement
  • Naming the curve
  1. Choose a Vertebra to be the apex
    1. Apex is furthest deviating Vertebra
    2. Apex forms the peak of the convexity
  2. Define the XRays right side
    1. PA Spine views are reverse of normal Chest XRay
    2. Described as if patient examined from behind
    3. Patient's right side is physician's right side
  3. Define direction of curve (left or right)
    1. Based on the direction of the convexity
    2. Left curve has its apex on the left
  4. Define curve location based on apex Vertebrae level
    1. Cervical
    2. Thoracic
    3. Thoracolumbar (apex at T12 or L1)
    4. Lumbar
    5. Double Major (2 curves in different regions)
  • Measurement
  • Cobb Angle
  1. Diagram
    1. BackScoliosisXRay.gif
  2. Technique
    1. Select most tilted Vertebrae above the apex
      1. Draw a line along the top of the Vertebrae
      2. Extend the line into the margin of the Xray
      3. Drop a line down perpendicular to this line
    2. Select most tilted Vertebrae below the apex
      1. Draw a line along the bottom of the Vertebrae
      2. Extend the line into the margin of the Xray
      3. Raise a line up perpendicular to this line
    3. Measure the Cobb Angle (congruent angle)
      1. Angle where the two perpendicular lines meet
  • Interpretation (See Scoliosis)
  1. Red Flag: Left thoracic curve
    1. May suggest spine pathology
  2. Curve Interpretation
    1. Mild: Curve <10-15 degrees
    2. Moderate: Curve 20-50 degrees
    3. Severe: Curve >45-50 degrees
    4. Respiratory compromise: Curve >90 degrees
  • References
  1. Greene (2001) Musculoskeletal Care, AAOS, p. 696-9
  2. Greiner (2002) Am Fam Physician 65(9):1817-22 [PubMed]
  3. Kuznia (2020) Am Fam Physician 101(1):19-23 [PubMed]