Surgical treatment analysis of 809 Surgical treatment analysis of 809 thoracolumbar and lumbar major adult thoracolumbar and lumbar major adult

deformity cases by a new adult deformity cases by a new adult scoliosis classification systemscoliosis classification system

Zorab Symposium 2006

F Schwab, JP Farcy, K Bridwell, S Berven, S Glassman, W Horton, M Shainline

Spinal Deformity Study Group

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

Skeletal maturity• Risser sign

PTPain MgmtBracingSurgery

Curve severity• Cobb angle• progression

Cosmesis

Pain

Disability

BackgroundAdult deformity: Treatment approach

Multi-center prospective studyMulti-center prospective study

Classification SystemClassification SystemApical level

Lumbar lordosis modifierIntervertebral subluxation modifier

Global Balance modifier

Clinical GroupClinical GroupScoliosis with apex T4 to L4Degenerative or idiopathic809 consecutive patients

Radiographic analysisRadiographic analysis full length, standing films

Cobb angle,apical level of deformity,

sagittal plane lumbar alignment

Health assessment Health assessment questionnairesquestionnaires

ODI / SRS-29 / SF-12

Background

1. Type

2. Modifiers

Lumbar LordosisLumbar Lordosis

A : marked >400

B : moderate 0-400

C : no lordosis, Cobb >00

Intervertebral SubluxationIntervertebral Subluxation

0 : none at any level+ : max = 1-6mm++ : max >7mm

Type IThoracic

only

Type IIUpper Thoracic

major

Type IIILower Thoracic

major

Type IVThoraco-lumbar

major

Type VLumbarmajor

no other curves

ApexT9-T10

ApexT9-T10

ApexT11-L1

ApexL2-L4

BackgroundAdult Scoliosis Classification

N Neutrally balanced <4cm

P Positively balanced 4-9.5cm

VP Very Positive >9.5cm

Global BalanceGlobal Balance

Reliable classificationReliable classification withwith significant significant

correlation to clinical correlation to clinical symptomssymptoms

Prediction of treatment Prediction of treatment patterns and surgical patterns and surgical

rates ???rates ???

PurposeAdult Scoliosis Classification

Materials & Methods

1. Clinical group1. Clinical group• Spinal Deformity Study Group database• Prospective, consecutive 809 patients review• Ages > 18 y.o.• Thoracolumbar or lumbar major scoliosis

•Type IV and Type V deformities only.

2. Health questionnaires2. Health questionnaires• Oswestry Disability Index (ODIODI) • Scoliosis Research Society instrument (SRS-22SRS-22)• Short From 12 (SF-12SF-12)

Materials & Methods

3. Radiographic parameters3. Radiographic parameters• Full-length standing films • Frontal Cobb angle, • Apical level, • Sagittal lumbar alignment (T12-S1),

Lumbar Lordosis

A : marked >40°B : moderate 0-40 °C : no lordosis, Cobb >0°

Intervertebral Subluxation0 : none at any level+ : max = 1-6mm++ : max >7mm

Sagittal Balance

N Neutrally balanced <4cmP Positively balanced 4-9.5cmVP Very Positive >9.5cm

4. Treatment approach4. Treatment approach • Surgical vs. non-surgical • If Surgical:

• Anterior, Posterior, circumferential• Use of osteotomies • Extension of fusion to sacrum

Materials & Methods

5. Data Analysis5. Data Analysis• Treatment Analysis regarding

• HRQOL measures• SRS-22, ODI, SF-12

• Correlation analysis• Classification types vs. treatment given

806 806 thoracolumbar/lumbar thoracolumbar/lumbar major deformitiesmajor deformities

– Type IV Type IV n=311 n=311 – Type V Type V n=495 n=495

– Mean age 53.1 y.o. (+/- 15.3)Mean age 53.1 y.o. (+/- 15.3)– 700 Females (87%) 700 Females (87%) – 106 Males (13%)106 Males (13%)

ResultsPatients Distribution

Rates of operative treatment

– Lordosis modifierLordosis modifier BB vs. vs. AA (51% vs. 37%, p<0.05), trend for A vs. C (46%) (51% vs. 37%, p<0.05), trend for A vs. C (46%)

– Subluxation modifierSubluxation modifier ++++ vs. vs. 00 (52% vs. 36 %, p<0.05), trend vs. + (42 %) (52% vs. 36 %, p<0.05), trend vs. + (42 %)

– Sagittal BalanceSagittal Balance NN vs. vs. VPVP: 39% vs. 59%, p<0.05: 39% vs. 59%, p<0.05

ResultsSurgical rates

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 LevelTrend for type V patients more likely to have fixation to sacrum (p=.074)

Lordosis Modifiermod B patients more likely fusion to sacrum than mod A patients (p=.041)

Sagittal Balance Modifierincreasing positive balance: more likely fixation extended to the sacrum. (mod N: 59%, mod P: 80%, mod VP: 88%) (all p<0.05)

ResultsTreatment Analysis: Type IV, V curves

Surgical ApproachSurgical Approach

Anterior only Anterior only – mostly lordosis modifier Amostly lordosis modifier A– Subluxation modifier 0Subluxation modifier 0– Sagittal balance modifier NSagittal balance modifier N

Circumferential:Circumferential:– trend most common trend most common

modifier Bmodifier B– Most commonly subluxation Most commonly subluxation

modifier ++modifier ++

Posterior only:Posterior only: – mostly lordosis modifier Cmostly lordosis modifier C– Sagittal balance modifier VPSagittal balance modifier VP

Use of osteotomiesUse of osteotomies

Lordosis modifierLordosis modifier A vs. C A vs. C – 25% vs. 50% p=0.0125% vs. 50% p=0.01

Sagittal balanceSagittal balance N vs. VP N vs. VP– 25% vs. 53% p=0.0125% vs. 53% p=0.01

ResultsTreatment Analysis: Type IV, V curves

TreatmentTreatment

• 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 surgeryIf 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

ResultsMain findings

Clinical ImpactClinical Impact established: established:– HRQOLHRQOL– Treatment….non-op vs. surgicalTreatment….non-op vs. surgical– Surgical strategy…we’re getting thereSurgical strategy…we’re getting there

How about results of treatment results of treatment ?Work toward surgical guidelines

2 yr

f/u

Discussion - ConclusionAdult scoliosis classification

Can we broaden to a:

Comprehensive Adult Deformity Comprehensive Adult Deformity ClassificationClassification

ReliableReliableClinical impactClinical impact

• disability• surgical rate

Surgical strategy ?Surgical strategy ?

Discussion - Conclusion

Adult scoliosis classification

Type I thoracic-only curve (no other curves)II upper thoracic major, apex T4-8 III lower thoracic major, apex T9-T10IV thoracolumbar major curve, apex T11-L1V lumbar major curve, apex L2-L4Type K no scoli (<100), principal sagittal plane deformity

Lumbar Lordosis A marked lordosis >400

Modifier B moderate lordosis 0-400

C no lordosis present Cobb >00

Subluxation 0 no intervertebral subluxation any levelModifier + maximal measured subluxation 1-6mm

++ maximal subluxation >7mm

Sagittal Balance N normal, <4cm positive SVA Modifier P positive, 4-9.5cm

VP very positive, >9.5cm

Classification of Adult Deformity

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

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

•Complications ?

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

Next StepsAdult scoliosis classification