When to operate on Adult Scoliosis patients and when to say ‘No’ Frank Schwab, MD Jean-Pierre Farcy, MD NYU-Hospital for Joint Diseases New York University School of Medicine Department of Orthopaedic Surgery What is Adult Scoliosis? What is Adult Scoliosis? • Coronal plane deformity • Sagittal plane deformity Adolescent deformity in an adult • Imbalance/malalignment AISA – Focal – Regional De-novo deformity…of aging – Global DDS Scoliosis Prevalence – AIS 2-4% of screened pediatric population – Adult >60% of screened elderly population# Demographics : Life expectancy, birth rates…. Significant growth of aging population segment # Schwab et al. SPINE 2005 May 1;30(9):1082-5 Adolescent Idiopathic Scoliosis: surgical treatment Curve severity Skeletal maturity • Cobb angle • Risser sign • progression Curve pattern Classification • apex • Lenke • distribution Surgical • King • sagittal strategy • overhang Adult Scoliosis Scoliosis: treatment approach Curve severity • Cobb angle • progression Skeletal maturity Classification • Risser sign ? Cosmesis PT Pain Pain Mgmt Bracing Disability Surgery The aging spine Spine 30’s 50’s skeletal disc degen. facet DJD Stable spine maturity MRI changes disc collapse ankylosis Unfavorable degeneration stenosis spondylo deformity Adult Scoliosis Progressive collapse Stable ankylosis Adult Scoliosis / Deformity What are the disability / pain generators ? 98 patients (Schwab,Farcy. SPINE 2004) • adult scoliosis, all levels • SF-36 • radiographic-clinical analysis 325 patients (Schwab, Farcy. SDSG. SRS 2004) • thoracolumbar/lumbar scoliosis • SRS instrument, ODI • radiographic-clinical correlation Adult Scoliosis : Clinical impact • Significant • Not significant – Spondylolisthesis – Lateral Subluxation – Coronal Cobb – Lumbar lordosis – Age – Thoracolumbar – Adolescent vs. de-novo alignment degenerative scoliosis – Apical level – Sagittal Balance (SVA) Statistically significant: SRS-22, ODI, SF-12/36 Adult Scoliosis: the disability / pain generators plain radiographs • Apical level of deformity (lumbar dominant) • Lumbar lordosis T12-S1 • Maximal intervertebral subluxation (frontal/sagittal) • Sagittal balance (PlC7-S1 offset) Selected for high clinical impact: SRS, ODI, SF-36 (excluding fractures or other pathologies…) Classification of Adult Deformity Schwab et al. SPINE 2006 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 (<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 level Modifier + 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 Adult Scoliosis 947 patients: (86% female, 14% male) Average age 48 years (SD 18) Coronal Cobb mean 460 (SD 19) ODI SRS Oswestry SRS Function SRS Pain Mean SD Mean SD Mean SD p = 0.002 p < 0.001 p = 0.007 Lordosis Lordosis modifier A (< -40) 27 19 69 17 65 20 Lordosis modifier C ( >= 0) 37 16 57 15 56 17 Oswestry SRS Function SRS Pain Mean SD Mean SD Mean SD p < 0.001 p < 0.001 p < 0.001 Subluxation Subluxation Modifier 0 27 20 68 18 64 20 Subluxation Modifier ++ 34 18 63 16 58 19 Global Balance Adult Scoliosis / Deformity Thus….deformity = disability ? Yes, certain aspects … Coronal/Sagittal Focal: subluxation Regional: loss of lordosis Global: sagittal imbalance Sagittal plane … Not coronal Cobb angle Adult Scoliosis / Deformity: Why surgery ? Young adult: AISA Curve progression likely – Disability later (potential) – More difficult to treat later >500 thoracic • Depending upon age >300 lumbar (progressive) – Surgical risks greater later Progression with disability Cosmetic concerns Weinstein S,. Spine 24(24), 1999 Adult Scoliosis / Deformity: Why surgery ? Older Adult: Pain unacceptable AISA = DDS Disability unacceptable Pain/disability failed conservative care Risk/Benefit ratio - favorable Adult Scoliosis / Deformity If the justification for surgery is acceptable…. …..when is it really reasonable to operate ? Don’t do it Sure success Adult Scoliosis / Deformity Not a candidate for surgery: – young AISA…no disability, mild/mod curve, happy – patient who does not want surgery – patient is unlikely to survive surgery – patient does not understand risk/benefit • unrealistic expectations – planned operation is not reasonable • experience, team, environment Adult Scoliosis / Deformity Possibly Excellent candidate for surgery: – young AISA…progressive, severe curve (>700) DDS or AISA older adult: Perfectly isolated pain generator, failed extensive non-operative care • Well informed, wishes to pursue operative care • Excellent health • Realistic expectations, highly motivated – team has abundant experience only excellent results with planned intervention Adult Scoliosis / Deformity The common cases: • Patient might consider surgery with certain assurances • Health is acceptable (not ideal), • Pain generators present (there are several), • Non-operative care tried (variable participation and response), • Expectations are overall rather realistic. • The surgeon comfortable with intervention ? When to operate on Adult Scoliosis patients and when to say No How can we select the best patients for surgery ? (and how to optimize the chances of a successful outcome) • non-operative care vs. surgery • If surgery…which strategy/approach – Specific treatment algorithms lacking – few studies to guide us….where is the data ? Adult Scoliosis: Thoracolumbar / Lumbar Deformity Who gets surgery…and what type ? (n=809) Operative rates – Lordosis • Lost lordosis vs. good lordosis (B vs. A) 51% vs 37%, p<0.05 – Subluxation modifier • Marked subluxation vs. none (++ vs. 0) 52% vs. 36 %, p<0.05 – Sagittal Balance • Well balanced versus marked imbalance (N vs. VP) 39% vs.59%, p<0.05 Adult Scoliosis: Thoracolumbar / Lumbar Deformity Who gets surgery…and what type ? Use of osteotomies Lordosis >400 lordo vs. no lordo : 25% vs. 50% p=0.01 Sagittal balance no imbalance vs. >9.5cm : 25% vs. 53% p=0.01 Surgical Approach Anterior only: no lost lordosis, no subluxation Circumferential: some lost lordosis, marked subluxation Posterior only: marked loss of lordosis, marked sagittal imbalance Fusion to sacrum Lordosis Loss of lordosis more likely fusion to sacrum (p = .041) Sagittal Balance increasing positive balance: more fixation to sacrum. (<4cm: 59%, 4-9.5cm: 80%, >9.5cm: 88%) (all p<0.05) Adult Scoliosis: Thoracolumbar / Lumbar Deformity How about surgical outcomes ? • 111patients 1-year follow up • 45 patients 2-year follow up • Adult Thoracolumbar / Lumbar major curves • Surgical treatment, complete data – Full-length standing x-rays (0,12,24 months) – SRS, ODI, SF-12 2-year Surgical outcome: Lordosis modifier Lumbar Lordosis A marked lordosis >400 Modifier B moderate lordosis 0-400 C no lordosis present Cobb >00 Mean SRS Total Score at Baseline and Two Years by Lordosis Modifier 80 70 60 50 Mean Score Marked Lordosis 40 Moderate Lordosis No Lordosis 30 20 10 0 Baseline Two Year Measurement Period Lordosis modifier ‘C’…most improved 2-year Surgical outcome: sagittal balance (surgical approach) Sagittal Balance N normal, <4cm positive SVA Modifier P positive, 4-9.5cm VP very positive, >9.5cm Mean Oswestry Disability Index at Baseline and Two Years by Sagittal Balance Modifier and Surgical Approach 60 50 40 <40 Anterior <40 Circum Mean Score <40 Posterior 30 40 to 95 Circum 40 to 95 Circum 96+ Circum posterior 96+ Circum 20 10 0 Baseline Two Year Measurement Period N with anterior approach did worst (VP posterior-only also not so good) P, VP did best with circumferential fusion 2-year Surgical outcome: sagittal balance (fixation to sacrum) Mean SRS Total Score at Baseline and Two Years by Sagittal Balance Modifier and Fixation to the Sacrum 90 80 70 60 <40 Without Mean Score 50 <40 With 40 to 95 Without 40 to 95 With 40 96+ Without 96+ With 30 20 10 0 Baseline Two Year Measurement Period VP without fixation to sacrum got worse P and VP did best with fixation to sacrum (no difference for N) 2-year Surgical outcome: osteotomy or not ? Mean SF-12v2 PCS at Baseline and Two Years by Osteotomy 50 45 40 35 30 Mean Score No Osteotomy 25 Osteotomy 20 15 10 5 0 Baseline Two Year Measurement Period Patients who had osteotomy did better ! Baseline to Two-Year Changes: Significant Interaction ODI / SRS Total Score by lordosis • patients with no lordosis (C) greatest improvement, • Patients with marked lordosis (A) little or no improvement ODI / SRS Total Score by sagittal balance by surgical approach • well balanced least disabled, fused short of sacrum did best • very imbalance (VP) most disabled and worse off if not fused to sacrum SF-12v2 / SRS Total Score by Subluxation • significant subluxation (++,+) more improvement than no subluxation SF-12v2 PCS / SRS Total score by Osteotomy Status • patients with osteotomy had lower baseline scores •At 2 years f/u, patients with an osteotomy had higher scores Adult Scoliosis: Thoracolumbar / Lumbar Deformity Follow-up data • When is improvement clinically significant ? – Set a bar of 10-point increase in SRS score • From 100pt. Scale – Assumption of patient perceived improvement • Minimal Clinically Important Difference – Berven et al. Minimum 10 point SRS instrument improvement Met Ten-Point SRS Improvement Criterion by Year and Gender 100% 100% 100% 90% 80% 69% 70% Percent Meeting Criterion 62% 60% One Year 50% Two Year 40% 30% 20% 10% 0% Female Male Gender Minimum 10 point SRS instrument improvement Met Ten-Point SRS Improvement Criterion by Year and Lordosis Modifier 100% 100% 100% 90% 80% 78% Percent Meeting Criterion 70% 67% 61% 60% 57% One Year 50% Two Year 40% 30% 20% 10% 0% A - marked lordosis B - moderate lordosis C - No lordosis present Lordosis Modifier Loss of lumbar lordosis…greater likelihood of clinical success Minimum 10 point SRS instrument improvement Met Ten-Point SRS Improvement Criterion by Year and Sagittal Balance Modifier 100% 90% 88% 80% 73% 73% Percent Meeting Criterion 70% 64% 63% 60% 60% One Year 50% Two Year 40% 30% 20% 10% 0% Under 40 40 to 95 96 and Greater Sagittal Balance Modifier At 2-yr follow up: greater imbalance patients more likely to have successful outcome Minimum 10 point SRS instrument improvement Met Ten-Point SRS Improvement Criterion by Year and Osteotomy 100% 90% 80% 80% 73% 70% Percent Meeting Criterion 66% 59% 60% One Year 50% Two Year 40% 30% 20% 10% 0% No Osteotomy Performed Osteotomy Performed Osteotomy Patients having osteotomies more likely to have successful outcome Minimum 10 point SRS instrument improvement Met Ten-Point SRS Improvement Criterion by Year and Baseline SF-12 PCS 100% 92% 90% 83% 80% 78% Percent Meeting Criterion 70% 67% 60% 58% 58% One Year 50% 44% 44% Two Year 40% 30% 20% 10% 0% Under 25 25 to Under 35 35 to Under 45 45 and Higher Baseline SF-12 PCS Patients with lower baseline scores more likely to achieve significant improvement When to operate on Adult Scoliosis patients and when to say No How can we select the best patients for surgery ? (and how to optimize the chances of a successful outcome) Can we predict who will have successful surgery ? Predictive Models – Gender – Surgical Approach – Osteotomy – Age – Fixation to Sacrum – Apical Modifier – SF-12v2 Physical Component Summary – Lordosis Modifier – SF-12v2 Mental Component Summary – Subluxation Modifier – SRS Total Score – Sagittal Balance – Oswestry Disability Index Outcome ? Models to predict Clinical Improvement with Surgery Strength of Predictive Models Outcome Score % Correct Area Under ROC % of Surgical Cases (meeting the Classification by Curve (.80 and above Failing to Meet MCID threshold) Model is considered good Criterion discrimination) SRS Pain 81.1% .864 39.5% SRS Appearance 75.4% .838 33.3% SRS 78.1% .845 53.5% Pain and Appearance SF-12v2 PCS 77.9% .862 47.6% Follow-up data: Conclusions The winners – Greater disability at start (SRS, ODI, SF-12) – Male – Subluxation >6mm – Lost lumbar lordosis <400 – Osteotomy Who benefits least • minimal baseline disability (SRS, ODI, SF-12) • No subluxation, no marked sagittal imbalance • Good lordosis, >400 • Lack of osteotomy When to operate on Adult Scoliosis patients and when to say No How can we select the best patients for surgery ? (and how to optimize the chances of a successful outcome) apex Regional deformity SRS, ODI, SF-12 Global sagittal balance Surgical approach gender osteotomy Focal deformity Adult Scoliosis / Deformity: next steps Refine Classification + Predictive outcomes model SRS ODI SF-12/36 Treatment Algorithm Thank you….