A comprehensive clinical impact classification of Adult Scoliosis F. Schwab K. Bridwell S. Berven J-P Farcy S. Glassman J. Harrast W. Horton M. Ferguson Spine Deformity Study Group, San Diego 2005

Why a classification ? Must develop a common language: exchange of information comparison of data Correlation with clinical impact treatment algorithms surgical guidelines

Scoliosis Prevalence AIS 2-4% of screened pediatric population Adult >60% of screened elderly population Demographic : Life expectancy, birth rates…. Significant growth of aging population segment

Adult Scoliosis Classification: Chicago 2002 Arizona 2003 Chicago 2003 Miami 2004 IMAST Worldspine SRS NASS

Adult Scoliosis Classification: Clinical impact Significant Spondylolisthesis Frontal plane subluxation Lumbar lordosis Thoracolumbar alignment Apical level +/- Global alignment Not significant Coronal Cobb AISA vs DDS Age

The Classification Simple Basic structure 3 parameters Lumbar lordosis T12-S1 Maximal intervertebral subluxation (frontal/sagittal) Apical level of deformity (lumbar dominant) Selected for high clinical impact: SRS-22, ODI

The Classification Apical Level…curve Type Type I : thoracic-only scoliosis Type II: upper thoracic major curve, apex T4-8 (with a thoracolumbar or lumbar curve) Type III: lower thoracic major curve, apex T9-T10 (with thoracolumbar or lumbar curve) Type IV: thoracolumbar major curve, apex T11-L1 (with any other minor curve) Type V: lumbar major curve, apex L2-L4

The Classification Lordosis Modifier (T12-S1) A: marked lordosis >400 B: moderate lordosis 0-400 C: no lordosis present Cobb >00

The Classification Subluxation modifier Maximal intervertebral subluxation Frontal or sagittal plane 0 : no subluxation + : subluxation 1-6mm ++: subluxation >7mm

Adult Scoliosis Classification Intra-, inter-observer variability study 20 cases full-length films AP and Lateral 13 one-time readers 6 repeat readers

Adult Scoliosis Classification Inter-observer analysis Disagreements on thoracic levels (Type II, III) thoracolumbar vs. lumbar

Adult Scoliosis Classification Intra-observer analysis

SDSG data set 1/05 Primary curve apex

Adult Scoliosis Classification Type I curves (thoracic only) 17 subjects (12F, 5 M) Coronal Cobb mean 43 (SD17) Mean SRS pain 67 (SD 19) Mean SRS function 66 (SD 23) Mean ODI 27 (SD 20) Surgical rate 41%

Adult Scoliosis Classification Type II curves (upper thoracic major, apex T4-7) 48 subjects (43F, 5 M) Coronal Cobb mean 47 (SD 22) Mean SRS pain 65 (SD 20) Mean SRS function 69 (SD 18) Mean ODI 28 (SD 22) Surgical rate 35%

Adult Scoliosis Classification Type III curves (lower thoracic major, apex T8-10) 260 subjects (215 F, 44 M) Coronal Cobb mean 50 (SD 20) Mean SRS pain 65 (SD 21) Mean SRS function 72 (SD 17) Mean ODI 24 (SD 20) Surgical rate 39%

Adult Scoliosis Classification Type IV curves (thoracolumbar major apex T11-L1) 343 subjects (302 F, 40 M) Coronal Cobb mean 47 (SD 19) Mean SRS pain 60 (SD 19) Mean SRS function 65 (SD 17) Mean ODI 31 (SD 19) Surgical rate 48%

Adult Scoliosis Classification Type V curves (lumbar major, apex L2-L4) 279 subjects (242 F, 37 M) Coronal Cobb mean 42 (SD 19) Mean SRS pain 61 (SD 19) Mean SRS function 63 (SD 17) Mean ODI 34 (SD 19) Surgical rate 37%

Adult Scoliosis Classification Lordosis Modifier (T12-S1) A B C

Adult Scoliosis Classification Subluxation Modifier (maximal, in mm)

Adult Scoliosis Classification

Adult Scoliosis A valid Classification Simple approach possible High clinical impact Frontal and sagittal plane considerations Validated through largest database available Reliable system Intra- and inter-observer

Adult Scoliosis Classification The Classification – clinical impact Apex Lumbar Lordosis Intervertebral subluxation Do we need descriptive parameters ? exact number/patterns of curves Cobb angles Levels of instability, DJD Other parameters ?

Adult Scoliosis Classification Next Steps: Refine group definitions Combine with Surgical Classification T-L junction L-S junction Longitudinal analysis Ongoing review as database grows