Transcript Force-Plate MSD Meeting September 28, 2005

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
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
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
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
Health assessment
questionnaires
Radiographic analysis
• full length, standing films
• Cobb angle,
• apical level of deformity,
• sagittal plane lumbar alignment
•ODI / SRS-29
Classification System
•Apical level
•Lumbar lordosis score
•Intervertebral subluxation score
Adult Scoliosis Classification
1. Type
Type I
Type II
Type III
Type IV
Type V
Thoracic
only
Upper Thoracic
major
Lower Thoracic
major
Thoraco-lumbar
major
Lumbar
major
no other
curves
Apex
T9-T10
Apex
T9-T10
Apex
T11-L1
Apex
L2-L4
2. Modifiers
Lumbar Lordosis
A : marked >400
B : moderate 0-400
C : no lordosis, Cobb >00
Intervertebral
Subluxation
0 : none at any level
+ : max = 1-6mm
++ : max >7mm
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 ?
Results 1/2
Mean Age (±SD) and Mean Cobb Angle (±SD)
amongst Curve type for 947 Patients
80
T12-S1 lordosis
Mean 46° (SD 25)
70
60
Not obtainable in 85 cases
50
40
30
20
10
Type I
17
No lordosis
Cobb >0
Moderate lordosis
Cobb 0-40
Marked lordosis
Cobb>40
n=44
n=261
Type II
Type III
Type IV
Type V
Total
48
260
343
279
947
Mean Max Intervertebral Subluxation
Frontal plane : 4.2mm (SD 6.2)
Sagittal plane : 1.2mm (SD 3.1)
Division into categories
n=557
No subluxation (n=526,
Moderate subluxation/1-6mm (n=109)
Marked subluxation/>7mm (n=299)
Not obtainable in 13 cases
0
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)
lower thoracic (T8-T10)
thoracolumbar (T11-L1)
lumbar (L2-L4)
37%
39%
48%
37%
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 2004-2005].
Previous study + updated findings of the
SDSG database => Attempt at
classification of scoliosis
References
[Schwab & al 2004]
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