1. 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

2. Why a classification ? Must develop a common language:
exchange of information
comparison of data
Correlation with clinical impact
treatment algorithms
surgical guidelines

3. Scoliosis Prevalence AIS 2-4% of screened pediatric population
Adult >60% of screened elderly population
Demographic :
Life expectancy, birth rates….
Significant growth of aging population segment

4. Adult Scoliosis Classification:
Chicago 2002
Arizona 2003
Chicago 2003
Miami 2004
IMAST
Worldspine
SRS
NASS

5. Adult Scoliosis Classification: Clinical impact
Significant
Spondylolisthesis
Frontal plane subluxation
Lumbar lordosis
Thoracolumbar alignment
Apical level +/-
Global alignment
Not significant
Coronal Cobb
AISA vs DDS
Age

6. 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

7. The Classification Apical Level…curve 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

8. The Classification Lordosis Modifier (T12-S1)
A: marked lordosis >400
B: moderate lordosis 0-400
C: no lordosis present Cobb >00

9. The Classification Subluxation modifier
Maximal intervertebral subluxation
Frontal or sagittal plane
0 : no subluxation
+ : subluxation 1-6mm
++: subluxation >7mm

10. Adult Scoliosis Classification
Intra-, inter-observer variability study
20 cases
full-length films
AP and Lateral
13 one-time readers
6 repeat readers

11. Adult Scoliosis Classification Inter-observer analysis
Disagreements on
thoracic levels (Type II, III)
thoracolumbar vs. lumbar

12. Adult Scoliosis Classification Intra-observer analysis

13. SDSG data set 1/05
Primary curve apex

14. 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%

15. 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%

16. 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%

17. 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%

18. 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%

19. Adult Scoliosis Classification
Lordosis Modifier (T12-S1) A B C

20. Adult Scoliosis Classification
Subluxation Modifier (maximal, in mm)

21. Adult Scoliosis Classification

22. 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

23. 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 ?

24. 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