Table 4.
SRS Classification of Adult Spinal Deformity21).
| Primary curve types |
| Single thoracic (ST) |
| Double thoracic (DT) |
| Double major (DM) |
| Triple major (TM) |
| Thoracolumbar (TL) |
| Lumbar “denovo”/idiopathic (L) |
| Primary sagittal plane deformity (SP) |
| Adult spinal deformity modifiers |
| Regional sagittal modifier (include only if outside normal range as listed) |
| • (PT) Proximal thoracic (T2-T5): ≥+20° |
| • (MT) Main thoracic (T5-T12): ≥+50° |
| • (TL) Thoracolumbar (T10-L2): ≥+20° |
| • (L) Lumbar (T12-S1): ≥ −40° |
| Lumbar degenerative modifier (include only if present) |
| • (DDD) 2 disc height and facet arthropathy based on X-ray includelowest involved level between L1 and S1 |
| • (LIS) Listhesis (rotational, lateral antero, retro) ≥3 mm includelowest level between L1 and L5 |
| • (JCT) Junctional L5-S1 curve ≥10° (intersection angle superiorendplates L5 and S1) |
| Global balance modifier (include only if imbalance present) |
| • (SB) Sagittal C7 plumb ≥5 cm anterior or posterior to sacral promontory |
| • (CB) Coronal C7 plumb ≥3 cm right or left of CSVL |
| SRS definition of regions |
| • Thoracic: apex T2-T11-T12 disc |
| • Thoracolumbar: apex T12-L1 |
| • Lumbar: apex L1-L2 disc-L4 |
| Criteria for specific major curve types |
| 1. Thoracic curves |
| • Curve ≥40° |
| • Apical vertebral body lateral to C7 plumbline |
| • T1 rib or clavicle angle ≥10° upper thoracic curves |
| 2. Thoracolumbar and lumbar curves |
| • Curve ≥30° |
| • Apical vertebral body lateral to CSVL |
| 3. Primary sagittal plane deformity |
| • No major coronal curve |
| • One or more regional sagittal measurements (PT, MT, TL, L) outside |