Force-Plate MSD Meeting September 28, 2005

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Surgical treatment analysis of 809 thoracolumbar
and lumbar major adult deformity cases by a new
adult scoliosis classification system
F Schwab, JP Farcy, K Bridwell, S Berven, S
Glassman, W Horton, M Shainline Spinal
Deformity Study Group
Zorab Symposium 2006
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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

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Background

• Curve severity
• Cobb angle
• progression

• Skeletal maturity
• Risser sign

Cosmesis
PT Pain Mgmt Bracing Surgery
Pain
Disability
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Background
Multi-center prospective study
Clinical Group Scoliosis with apex T4 to
L4 Degenerative or idiopathic 809 consecutive
patients
Radiographic analysis full length, standing
films Cobb angle, apical level of
deformity, sagittal plane lumbar alignment
Health assessment questionnaires ODI / SRS-29 /
SF-12
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Background
1. Type
Type I Thoracic only
Type II Upper Thoracic major
Type III Lower Thoracic major
Type IV Thoraco-lumbar major
Type V Lumbar major
no other curves
Apex T9-T10
Apex T9-T10
Apex T11-L1
Apex L2-L4
2. Modifiers
Global Balance
Lumbar Lordosis
Intervertebral Subluxation
A marked gt400 B moderate 0-400 C no
lordosis, Cobb gt00
0 none at any level max 1-6mm
max gt7mm
N Neutrally balanced lt4cm P Positively
balanced 4-9.5cm VP Very Positive gt9.5cm
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Purpose

• Reliable classification with significant
  correlation to clinical symptoms

Prediction of treatment patterns and surgical
rates ???
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Materials Methods

• 1. Clinical group
• Spinal Deformity Study Group database
• Prospective, consecutive 809 patients review
• Ages gt 18 y.o.
• Thoracolumbar or lumbar major scoliosis
• Type IV and Type V deformities only.

• 2. Health questionnaires
• Oswestry Disability Index (ODI)
• Scoliosis Research Society instrument (SRS-22)
• Short From 12 (SF-12)

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Materials Methods

• 3. Radiographic parameters
• Full-length standing films
• Frontal Cobb angle,
• Apical level,
• Sagittal lumbar alignment (T12-S1),

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Materials Methods

• 4. Treatment approach
• Surgical vs. non-surgical
• If Surgical
• Anterior, Posterior, circumferential
• Use of osteotomies
• Extension of fusion to sacrum

• 5. Data Analysis
• Treatment Analysis regarding
• HRQOL measures
• SRS-22, ODI, SF-12
• Correlation analysis
• Classification types vs. treatment given

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Results

• 806 thoracolumbar/lumbar major deformities
• Type IV n311
• Type V n495
• Mean age 53.1 y.o. (/- 15.3)
• 700 Females (87)
• 106 Males (13)

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Results

• Rates of operative treatment
• Lordosis modifier
• B vs. A (51 vs. 37, plt0.05), trend for A vs. C
  (46)

• Subluxation modifier
• vs. 0 (52 vs. 36 , plt0.05), trend vs. (42
  )

• Sagittal Balance
• N vs. VP 39 vs. 59, plt0.05

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Results
92 highest level of fixation above apex of
major curve. 97 lowest level of fixation below
apex of major curve. 10 to level of sublux, 87
at least one level beyond
Fusion to sacrum Apical Level Trend for type V
patients more likely to have fixation to sacrum
(p.074) Lordosis Modifier mod B patients more
likely fusion to sacrum than mod A patients
(p.041) Sagittal Balance Modifier increasing
positive balance more likely fixation extended
to the sacrum. (mod N 59, mod P 80, mod VP
88) (all plt0.05)
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Results

• Surgical Approach
• Anterior only
• mostly lordosis modifier A
• Subluxation modifier 0
• Sagittal balance modifier N
• Circumferential
• trend most common modifier B
• Most commonly subluxation modifier
• Posterior only
• mostly lordosis modifier C
• Sagittal balance modifier VP

• Use of osteotomies
• Lordosis modifier A vs. C
• 25 vs. 50 p0.01
• Sagittal balance N vs. VP
• 25 vs. 53 p0.01

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Results

• Treatment
• Good lordosis (modifier A) less likely to have
  surgery
• Most likely to require surgery
• loss of lordosis (C),
• marked subluxation ()
• sagittal plane imbalance (VP)
• If surgery
• Cross level of subluxation
• Osteotomies to realign sagittal plane
• lordosis modifier C gets most likely to require
  osteotomy
• fusion to sacrum with increasing sagittal
  imbalance, lost lordosis

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Discussion - Conclusion

• Clinical Impact established
• HRQOL
• Treatment.non-op vs. surgical
• Surgical strategywere getting there

2 yr f/u
How about results of treatment ? Work toward
surgical guidelines
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Discussion - Conclusion
Adult scoliosis classification

• Reliable
• Clinical impact
• disability
• surgical rate
• Surgical strategy ?

Can we broaden to a Comprehensive Adult
Deformity Classification
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Classification of Adult Deformity
Type I thoracic-only curve (no other
curves) II upper thoracic major, apex T4-8
III lower thoracic major, apex
T9-T10 IV thoracolumbar major curve, apex
T11-L1 V lumbar major curve, apex L2-L4 Type
K no scoli (lt100), principal sagittal plane
deformity Lumbar Lordosis A marked lordosis
gt400 Modifier B moderate lordosis 0-400 C no
lordosis present Cobb gt00 Subluxation 0 no
intervertebral subluxation any level Modifier
maximal measured subluxation 1-6mm
maximal subluxation gt7mm Sagittal Balance
N normal, lt4cm positive SVA Modifier P positi
ve, 4-9.5cm VP very positive, gt9.5cm
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Next Steps

• Refine Classification
• Pelvic modifier
• Co-morbidity index
• Patient expectation scale

• Longitudinal follow up
• who responds well to conservative care
• who benefits (how much) from surgery
• Complications ?

• Surgical analysis (2yr f/u)
• what strategies are most effective