1. F Schwab 1,2, JP Farcy 1,2, K Bridwell 2, S Berven 2, S Glassman 2,
A clinical impact classification of scoliosis in the adult. A multi-center clinical and radiographic analysis
F Schwab 1,2, JP Farcy 1,2, K Bridwell 2, S Berven 2, S Glassman 2,
J Harrast 2, W Horton 2
1 Maimonides Medical Center, Orthopaedic Surgery, Division of Spinal Surgery 2 Spinal Deformity Study Group
SRS 2005

2. Background
Unlike pediatric and adolescent scoliosis, no accepted classification system exists for adult scoliosis
Scoliosis in the adult population
prevalence as high as 60%
significant pain and disability
Quality of life issues
Classification systems provide
Common language for communication
Correlation with clinical impact
treatment algorithms
surgical guidelines

3. Purpose
Develop a reliable classification system for adult scoliosis validated through a large database
Use radiographic criteria with significant correlation to clinical symptoms to develop a classification system for adult scoliosis

4. Materials and Methods Multi-center prospective study
Inclusion Criteria
scoliosis with apex T4 to L4
thoracic
thoracolumbar,
lumbar spine
degenerative or idiopathic
947 consecutive patients
Spinal Deformity Study Group
Radiographic analysis
full length, standing films
Cobb angle,
apical level of deformity,
sagittal plane lumbar alignment
Health assessment
questionnaires
ODI / SRS-29
Classification System
Apical level
Lumbar lordosis score
Intervertebral subluxation score

5. 1. Type 2. Modifiers Adult Scoliosis Classification Type I Type II
Thoracic
only
Type II
Upper Thoracic
major
Type III
Lower Thoracic
Type IV
Thoraco-lumbar
Type V
Lumbar
no other curves
Apex
T9-T10
T11-L1
L2-L4
2. Modifiers
Intervertebral
Subluxation
0 : none at any level
+ : max = 1-6mm
++ : max >7mm
Lumbar Lordosis
A : marked >400
B : moderate 0-400
C : no lordosis, Cobb >00

6. Classification Reliability ?
Data Processing
Classification Reliability ?
Inter- and intra-observer analysis
Excellent reliability :
Type : k > 0.6 / 0.8
Lordosis & subluxation : k > 0.9 / 0.9
Xray parameters vs health scores ?
Grouped by apical level, lumbar lordosis, subluxation
t-test amongst subgroups in terms of ODI and SRS
Xray parameters vs treatment ?
Same radiological groups
Surgical vs conservative rate ?

7. Results 1/2 T12-S1 lordosis Mean 46° (SD 25)
Mean Age (±SD) and Mean Cobb Angle (±SD) amongst Curve type for 947 Patients
T12-S1 lordosis
Mean 46° (SD 25)
Not obtainable in 85 cases 17 48
260
343
279
947
No lordosis
Cobb >0
Moderate lordosis
Cobb 0-40
Marked lordosis
Cobb>40
n=44
n=261
n=557
Mean Max Intervertebral Subluxation
Frontal plane : 4.2mm (SD 6.2)
Sagittal plane : 1.2mm (SD 3.1)
Division into categories
No subluxation (n=526,
Moderate subluxation/1-6mm (n=109)
Marked subluxation/>7mm (n=299)
Not obtainable in 13 cases

8. Results 2/2
Correlation between function / Curve Type / XRay parameter / Treatment
Thoracic curves (Type I, II, III)
Lower apical level & loss of lumbar lordosis (modifier A vs. C)
Higher subluxation score (modifier ++ vs. O)
=> lead to significantly higher SRS pain scores
Thoracolumbar (type IV) and lumbar major (type V) curves
Loss of lumbar lordosis (modifier A vs. C)
Higher subluxation score (modifier ++ vs. O)
=> significantly greater disability by ODI/SRS instruments ( p<0.01)
Surgical rate vs Major curve Apical level
upper thoracic (T4-T7) 37%
lower thoracic (T8-T10) 39%
thoracolumbar (T11-L1) 48%
lumbar (L2-L4) 37%

9. Unique multi-center analysis of adult scoliosis
Discussion Conclusion
Unique multi-center analysis of adult scoliosis
Xray parameters (lower curve apex and loss of thoracolumbar lordosis, loss of lumbar lordosis, frontal and sagittal intervertebral subluxation) correlated with health measures (ODI, SRS), Cobb angle did not [Schwab & al ].
Previous study + updated findings of the SDSG database => Attempt at classification of scoliosis

10. References [Schwab & al 2004] [Schwab & al 2005]
Deformity apex, thoracolumbar alignment, but not Cobb angle, determine disability in adult major thoracic scoliosis. IMAST2004
[Schwab & al 2005]
Deformity apex, lordosis and olisthesis in Adult Scoliosis: correlation with disability. A multi-center radiographic and health status analysis. ISSLS 2005
[Spinal Deformity Study Group]
Annual meetings : Chicago 2002, Arizona 2003, Chicago 2003, Miami 2004, San Diego 2005
[Book]
O’Brien, M.F.; Kuklo, T.R.; Blanke, K.M.; Lenke, L.G.: Spinal Deformity Study Group – Radiographic Measurement Manual. Medtronic Sofamor Danek USA, Inc