Surgical treatment analysis of 809 thoracolumbar and lumbar major adult deformity cases by a new adult scoliosis 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 PT Pain Mgmt Bracing Surgery Curve severity Cobb angle progression Cosmesis Pain Disability Background Adult deformity: Treatment approach

Multi-center prospective study Classification System Apical level Lumbar lordosis modifier Intervertebral subluxation modifier Global Balance modifier 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 Background

1. Type 2. Modifiers Lumbar Lordosis A : marked >40 0 B : moderate C : no lordosis, Cobb >0 0 Intervertebral Subluxation 0 : none at any level + : max = 1-6mm ++ : max >7mm 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 Background Adult Scoliosis Classification N Neutrally balanced <4cm P Positively balanced 4-9.5cm VP Very Positive >9.5cm Global Balance

Reliable classification with significant correlation to clinical symptoms Prediction of treatment patterns and surgical rates ??? Purpose Adult Scoliosis Classification

Materials & Methods 1. 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 questionnaires ODIOswestry Disability Index (ODI) SRS-22Scoliosis Research Society instrument (SRS-22) SF-12Short From 12 (SF-12)

Materials & Methods 3. 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 Subluxation 0 : none at any level + : max = 1-6mm ++ : max >7mm Sagittal Balance N Neutrally balanced<4cm P Positively balanced4-9.5cm VP Very Positive>9.5cm

4. Treatment approach Surgical vs. non-surgical If Surgical: Anterior, Posterior, circumferential Use of osteotomies Extension of fusion to sacrum Materials & Methods 5. Data Analysis Treatment Analysis regarding HRQOL measures SRS-22, ODI, SF-12 Correlation analysis Classification types vs. treatment given

806 thoracolumbar/lumbar major deformities –Type IV n=311 –Type V n=495 –Mean age 53.1 y.o. (+/- 15.3) –700 Females (87%) –106 Males (13%) Results Patients Distribution

Rates of operative treatment –Lordosis modifier  B vs. A (51% vs. 37%, p<0.05), trend for A vs. C (46%) –Subluxation modifier  ++ vs. 0 (52% vs. 36 %, p<0.05), trend vs. + (42 %) –Sagittal Balance  N vs. VP: 39% vs. 59%, p<0.05 Results Surgical 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 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 p<0.05) Results Treatment Analysis: Type IV, V curves

Surgical Approach Anterior only Anterior only –mostly lordosis modifier A –Subluxation modifier 0 –Sagittal balance modifier N Circumferential: Circumferential: –trend most common modifier B –Most commonly subluxation modifier ++ Posterior only: Posterior only: –mostly lordosis modifier C –Sagittal balance modifier VP Use of osteotomies Lordosis modifier A vs. C Lordosis modifier A vs. C –25% vs. 50% p=0.01 Sagittal balance N vs. VP Sagittal balance N vs. VP – 25% vs. 53% p=0.01 Results Treatment Analysis: Type IV, V curves

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 Results Main findings

Clinical Impact established: Clinical Impact established: –HRQOL –Treatment….non-op vs. surgical –Surgical strategy…we’re getting there results of treatment How about results of treatment ? Work toward surgical guidelines 2 yr f/u Discussion - Conclusion Adult scoliosis classification

Can we broaden to a: Comprehensive Adult Deformity Classification Reliable Clinical impact disability surgical rate Surgical strategy ? Discussion - Conclusion Adult scoliosis classification

Type Ithoracic-only curve (no other curves) IIupper thoracic major, apex T4-8 IIIlower thoracic major, apex T9-T10 IVthoracolumbar major curve, apex T11-L1 Vlumbar major curve, apex L2-L4 Type Kno scoli (<10 0 ), principal sagittal plane deformity Lumbar LordosisAmarked lordosis >40 0 ModifierBmoderate lordosis Cno lordosis present Cobb >0 0 Subluxation0no intervertebral subluxation any level Modifier+maximal measured subluxation 1-6mm ++maximal subluxation >7mm Sagittal Balance Nnormal, <4cm positive SVA ModifierPpositive, 4-9.5cm VPvery positive, >9.5cm Classification of Adult Deformity

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 Next Steps Adult scoliosis classification