A comprehensive clinical impact classification of Adult Scoliosis

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A comprehensive clinical impact classification of
Adult Scoliosis

• F. Schwab
• K. Bridwell
• S. Berven
• J-P Farcy
• S. Glassman
• J. Harrast
• W. Horton
• M. Ferguson

Spine Deformity Study Group, San Diego 2005
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Why a classification ?

• Must develop a common language
• exchange of information
• comparison of data
• Correlation with clinical impact
• treatment algorithms
• surgical guidelines

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Scoliosis

• Prevalence
• AIS 2-4 of screened pediatric population
• Adult gt60 of screened elderly population

Demographic Life expectancy, birth
rates. Significant growth of aging population
segment
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Adult Scoliosis Classification

• Chicago 2002
• Arizona 2003
• Chicago 2003
• Miami 2004

IMAST Worldspine SRS NASS
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Adult Scoliosis ClassificationClinical impact

• Significant
• Spondylolisthesis
• Frontal plane subluxation
• Lumbar lordosis
• Thoracolumbar alignment
• Apical level /-
• Global alignment

• Not significant
• Coronal Cobb
• AISA vs DDS
• Age

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The Classification

• Simple
• Basic structure 3 parameters
• Lumbar lordosis T12-S1
• Maximal intervertebral subluxation
  (frontal/sagittal)
• Apical level of deformity (lumbar dominant)

Selected for high clinical impact SRS-22, ODI
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The Classification

• Apical Levelcurve Type
• Type I thoracic-only scoliosis
• Type II upper thoracic major curve, apex T4-8
• (with a thoracolumbar or lumbar curve)
• Type III lower thoracic major curve, apex T9-T10
• (with thoracolumbar or lumbar curve)
• Type IV thoracolumbar major curve, apex T11-L1
• (with any other minor curve)
• Type V lumbar major curve, apex L2-L4
• (with any other minor curve)

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The Classification

• Lordosis Modifier (T12-S1)
• A marked lordosis gt400
• B moderate lordosis 0-400
• C no lordosis present Cobb gt00

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The Classification

• Subluxation modifier
• Maximal intervertebral subluxation
• Frontal or sagittal plane
• 0 no subluxation
• subluxation 1-6mm
• subluxation gt7mm

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Adult Scoliosis Classification

• Intra-, inter-observer variability study
• 20 cases
• full-length films
• AP and Lateral
• 13 one-time readers
• 6 repeat readers

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Adult Scoliosis ClassificationInter-observer
analysis

• Disagreements on
• thoracic levels (Type II, III)
• thoracolumbar vs. lumbar

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Adult Scoliosis ClassificationIntra-observer
analysis
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SDSG data set 1/05
Primary curve apex
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Adult Scoliosis Classification

• Type I curves (thoracic only)
• 17 subjects (12F, 5 M)
• Coronal Cobb mean 43 (SD17)
• Mean SRS pain 67 (SD 19)
• Mean SRS function 66 (SD 23)
• Mean ODI 27 (SD 20)
• Surgical rate 41

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Adult Scoliosis Classification

• Type II curves (upper thoracic major, apex T4-7)
• 48 subjects (43F, 5 M)
• Coronal Cobb mean 47 (SD 22)
• Mean SRS pain 65 (SD 20)
• Mean SRS function 69 (SD 18)
• Mean ODI 28 (SD 22)
• Surgical rate 35

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Adult Scoliosis Classification

• Type III curves (lower thoracic major, apex
  T8-10)
• 260 subjects (215 F, 44 M)
• Coronal Cobb mean 50 (SD 20)
• Mean SRS pain 65 (SD 21)
• Mean SRS function 72 (SD 17)
• Mean ODI 24 (SD 20)
• Surgical rate 39

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Adult Scoliosis Classification

• Type IV curves (thoracolumbar major apex T11-L1)
• 343 subjects (302 F, 40 M)
• Coronal Cobb mean 47 (SD 19)
• Mean SRS pain 60 (SD 19)
• Mean SRS function 65 (SD 17)
• Mean ODI 31 (SD 19)
• Surgical rate 48

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Adult Scoliosis Classification

• Type V curves (lumbar major, apex L2-L4)
• 279 subjects (242 F, 37 M)
• Coronal Cobb mean 42 (SD 19)
• Mean SRS pain 61 (SD 19)
• Mean SRS function 63 (SD 17)
• Mean ODI 34 (SD 19)
• Surgical rate 37

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Adult Scoliosis Classification

• Lordosis Modifier (T12-S1)

A
B
C
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Adult Scoliosis Classification

• Subluxation Modifier (maximal, in mm)

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Adult Scoliosis Classification
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Adult Scoliosis

• A valid Classification
• Simple approach possible
• High clinical impact
• Frontal and sagittal plane considerations
• Validated through largest database available
• Reliable system
• Intra- and inter-observer

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Adult Scoliosis Classification
The Classification clinical impact Apex Lumbar
Lordosis Intervertebral subluxation
Do we need descriptive parameters ? exact
number/patterns of curves Cobb angles Levels of
instability, DJD
Other parameters ?
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Adult Scoliosis Classification

• Next Steps
• Refine group definitions
• Combine with Surgical Classification
• T-L junction
• L-S junction
• Longitudinal analysis
• Ongoing review as database grows