The 5th annual meeting. Themistocles S. Protopsaltis, MD

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1 The 5th annual meeting THE ROLE OF PATIENT SPECIFIC SPINAL ALIGNMENT: SHOULD WE PLAN SURGERY AND ARE ALL PATIENT DEFORMITIES THE SAME? Themistocles S. Protopsaltis, MD Assistant Professor of Orthopaedic Surgery Director of the Bellevue Orthopaedic Spine Service NYU Langone Hospital for Joint Diseases DISCLOSURES Themistocles S. Protopsaltis, MD Consulting: Medicrea, Biomet, AlphaSpine Research Support: Zimmer Spine The International Spine Study Group received grant funding from Depuy Spine in support of this work 1

2 INTRODUCTION Pre-operative planning using sagittal parameters is becoming more prevalent SRS-Schwab Classification includes sagittal modifiers based on disability measures Published alignment targets based on broad age ranges and baseline data Elderly patients have higher rates of PJK and complications Should age be a factor in pre-operative planning? SRS-Schwab Classification 3 Sagittal Modifiers 1 PI minus LL 0 : within 10 +: moderate : marked >20 Global alignment 0 : < 4cm + : 4 to 9.5cm ++ : > 9.5cm Pelvic Tilt 0 : PT<20 + : PT : PT>30 1. Schwab et al., Spine 2013 PREOPERATIVE PLANNING QUESTIONS 1. Should we utilize Preoperative Planning? 2. Are proposed alignment targets valid when we view our postoperative clinical and radiographic results 3. Should we tailor our corrections for specific patients: Age-specific alignment targets 2

3 1 OSTEOTOMIES: WHY SHOULD WE PLAN? DATA ON EFFECTIVENESS AND SAFETY NUMBER OF ASD PROCEDURES INCREASED BY 157% IN 10 YEARS 250,000 Number of discharges with at least one diagnosis of spinal curvature' (ICD-9 code to 737.9) 200, , ,000 Children Adult 50, Healthcare Costs and Utilization Project (HCUP 3

4 UTILIZATION OF WEDGE OSTEOTOMIES # Wedge Osteotomies (77.29 ICD-9-CM) % 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% Wedge Osteotomies by age group > Increases on 275% in less than 10 years ~250 procedures in 2003 ~700 procedures in 2010 Increase proportion of patients >65yo ~20% in 2003 ~40% in 2012 EFFECTIVENESS OF SAGITTAL CORRECTION Outcomes after major realignment surgeries Under-correction () 40% at 3m following index procedure Analysis of risk factors Lack of lordosis versus PI 80% can be predicted Root Cause analysis? Poor planning, execution, intra-op complications, poor intra-op feedback. 4

5 PROPOSED ALIGNMENT TARGETS Based on preoperative alignment and baseline HRQOL Regional Loss of lordosis Versus PI Global Compensatory Pelvic tilt PI-LL < 10 < 4.5cm PT < 20 Adult deformity databases have been used to propose targets for deformity correction (Schwab et al Spine 2013) Alignment targets are based on baseline analysis of HRQOL and alignment TPA is the angle from T1 to femoral heads and a line from femoral heads to the center of S1 endplate TPA combines the information from both and PT 5

6 COMPENSATORY MECHANISM: INCREASE IN PELVIC TILT DOES NOT AFFECT TPA Increasing PT can hide a large sagittal deformity ( decreases) Extreme Pelvic Anteversion PT = 20deg Standing Position PT=31deg Extreme Pelvic Retroversion PT = 48deg TPA remains constant regardless of pelvic retroversion CORRELATIONS WITH HRQOL ODI SF-36 PCS SRS-22 TPA PT PI-LL ODI by TPA Severity less more 30 6

7 COMPENSATORY MECHANISMS: KNEE FLEXION Lower extermity and Pelvic Compensation Mechanisms When Pelvic retroversion insufficient / reaches limit positions head over pelvis TPA 34 TPA 34 is artificially decreased But TPA remains consistent Morvan et al, Eur Spine J 2011 TPA AND SRS-SCHWAB MODIFIERS 7

8 ARE THESE TARGETS VALID? Regional Loss of lordosis Versus PI Global 1, TPA 2 Compensatory Pelvic tilt PI-LL < 10 < 5cm PT < TPA < 15 1 Schwab, Spine Protopsaltis, SRS, NASS QUESTION: ARE THESE TARGETS OF CORRECTION BASED ON BASELINE DATA VALID WHEN ANALYZING POSTOPERATIVE RESULTS 8

9 METHOD Retrospective review of prospective database Multicenter (11 sites) Ages > 18yo At least one of the following criteria Cobb angle > 20 deg. > 5 cm TK > 60 deg. PT > 25 deg. HRQOL: ODI SRS-22 SF-36 PCS and MCS XR analysis (Spineview ) Baseline and 2 years FU available METHOD Radiographic parameters: Pelvic parameters Pelvic Tilt (PT) Pelvic Incidence (PI) Sacral Slope (SS) Lumbar Lordosis between S1 and L1 (LL) Pelvic Incidence minus Lumbar Lordosis (PI-LL) Thoracic Kyphosis between T12 and T4 (TK) Sagittal Vertical Axis () T1-Pelvic-Angle (TPA) 9

10 Baseline 2 years 11/13/2015 RESULTS Demographics: 843 patients (405 at 2y) 1/3 had prior spine surgery Mean age 53.7yo 84% female Mean BMI 26.7 RESULTS Correlation between Radiographic parameters and HRQOL ODI PCS (SF-36) SRS-22 Total TPA r p r p r p <0.001* <0.001* <0.001* PT <0.001* <0.001* <0.001* PI-LL <0.001* <0.001* <0.001* <0.001* <0.001* <0.001* TPA <0.001* <0.001* <0.001* PT <0.001* <0.001* * PI-LL <0.001* <0.001* <0.001* <0.001* <0.001* <0.001* 10

11 RESULTS 30 Linear regressions: Preoperative regressions ODI Radiographic parameters PT PI-LL TPA cm cm PT - Baseline 15 PT - 2 Years PI-LL - Baseline PI-LL - 2 Years Postoperative regressions Radiographic parameters PT PI-LL TPA cm ODI cm TPA - Baseline TPA - 2 Years Baseline - 2 Years CONCLUSION Target for ASD correction were similar using preoperative and postoperative alignment and HRQOL TPA 14.7 vs cm vs 2.2 cm Correlation between HRQOL and all alignment parameters were stronger on preoperative analysis 1/3 of these patients had prior spine surgery There is a greater spread of deformities and disabilities Better stats. Suggested targets for ASD correction include: PT less than 20, PI-LL mismatch less than 5, TPA less than 15 and less than 2cm 11

12 3 QUESTIONS: SHOULD OUR DEFORMITY CORRECTIONS BE AGE-SPECIFIC? IS THERE AN OPTIMAL ALIGNMENT RANGE WITH LESS PJK? DOES ONE SIZE FIT ALL? Should the alignment targets for these patients be the same? 12

13 STUDY QUESTIONS Are the previously proposed targets of correction appropriate for patients of all ages? TPA <15 < 4.5 cm PT < 20 PI-LL < 10 Are there postoperative alignments in specific age cohorts associated with PJK? METHODS: INCLUSION/EXCLUSION CRITERIA Multicenter Prospective Data Collection (12 sites) Inclusion Criteria Adult Spinal Deformity > 18 yo At least one of the following: PT 25 TK 60 5 cm Coronal Cobb angle 20 Full length Standing X-rays Patients Stratified by age Elderly vs. Middle-aged Categorized postoperatively by alignment Well-aligned vs. poorly-aligned Classification Elderly Middle-aged Well-aligned Poorly-aligned >65 yo Criteria yo Based on age cohort 13

14 RESULTS: DEMOGRAPHICS Total Operative Middle-Aged Operative Elderly n % Female 86% 86% 75% Age (yrs) BMI (kg/m 2 ) Charlson score % Smokers 11% 13% 3% p-value < < Significant differences in patient demographics at baseline RESULTS: ALIGNMENT Elderly patients more poorly aligned at 2YR post-op than middle-aged patients (all p<0.05) TPA PT PI-LL Middle-Aged Elderly

15 Pre-to-Post baseline 2 year 11/13/2015 RESULTS: HRQOL All groups were highly disabled at baseline Elderly had worse SF-36 PCS HRQOL All Patients Middle-Age Patients Elderly Patients p-value ODI SF-36 PCS ODI SF-36 PCS 44.1 ± ± ± ± ± ±8 <0.001* 28.6 ± ± ± ± ± ± * RESULTS: HRQOL All groups improved significantly pre to postop HRQOL All patients Middle-Age Patients Elderly Patients Mean ±SD p-value Mean ±SD p-value Mean ±SD p-value ODI ±17.8 <0.001* ±18.8 <0.001* ±16 <0.001* SF-36 PCS 8.1 ±10.6 <0.001* 7.2 ±10.8 <0.001* 9.3 ±10.1 <0.001* 15

16 RESULTS: ALIGNMENT TARGETS Linear regression analysis performed to identify thresholds for TPA and in each population Mild disability: ODI=20 Severe disability: ODI=40 RESULTS: ALIGNMENT TARGETS Linear regression analysis performed to identify thresholds for TPA and in elderly and middle-aged Mild disability: ODI=20 Severe disability: ODI=40 16

17 RESULTS: PJK Posotperatively we classified the patients as WA/PA by age Using linear regression model Middle-Aged Patients Poorly Aligned Well Aligned Elderly Patients Poorly Aligned Well Aligned TPA > 15 TPA < 15 TPA > 20 TPA < 20 Higher 2YR PJK rate in elderly cohort Elderly: 56% Middle-Aged: 42% 60% 50% 40% 30% 20% 10% 0% Middle-Aged Patients Elderly Patients Poorly Aligned Well Aligned RESULTS: PJK Does the WA group include overcorrected patients who will also tend to develop PJK? Stratify patients into 3 groups: OC / WA / PA OC group defined by PI-LL < -10 for MA => TPA 8 PI-LL TPA Middle-Age Patients mm mm for ED, OC group defined by proportion OC/WA for MA Middle Aged OC WA PA < >15 OC ED /WA ED = OC MA / WA MA OC ED = 8 / 15*25 Elderly < >25 17

18 RESULTS: PJK PJK rate by group: overcorrected / well aligned / poorly aligned OC WA PA Overall MA 57.7%* 20.8%* 44.0% 42.0% ED 59.3% 50.0% 55.0% 55.2% * Significant difference between this 2 groups (p=0.008) CONCLUSIONS Based on this data, targets for deformity correction should differ by age Elderly patients: 15 < TPA < 25 ; 2cm < < 5.5cm Middle-aged patients: 8 < TPA < 15 ; -1cm < < 2cm Elderly ASD patients have larger global deformities and higher PJK rates Elderly ASD patients benefit just as much as younger patients from deformity correction (HRQOL) PJK is a multifactorial phenomenon, one piece of which is achieving optimal alignment 18

19 5 EXAMPLE CASES: CASE: YOUNGER PATIENT 45 year old M with post-traumatic lumbar kyphosis TPA 36 9 cm PT 34 PI-LL 31 19

20 CASE: YOUNGER PATIENT 45 year old M with post-traumatic lumbar kyphosis TK = -8 Recruiting thoracic hypokyphosis and pelvic retroversion TPA 36 9 cm PT 34 PI-LL 31 CASE: YOUNGER PATIENT 45 year old M with post-traumatic lumbar kyphosis TK = -8 etk = 38 etk = (PI ) for PI <40) Recruiting thoracic hypokyphosis and pelvic retroversion TPA 36 9 cm PT 34 PI-LL 31 20

21 CASE: YOUNGER PATIENT 45 year old M with post-traumatic lumbar kyphosis Undergoes PSO L3 and T10- Plevis TPA 36 9 cm PT 34 PI-LL 31 TPA cm PT 25 PI-LL 9 CASE: YOUNGER PATIENT 45 year old M with post-traumatic lumbar kyphosis Undergoes PSO L3 and T10- Plevis TPA 36 9 cm PT 34 PI-LL 31 TPA cm PT 25 PI-LL 9 21

22 CASE: YOUNGER PATIENT 45 year old M with posttraumatic lumbar kyphosis Undergoes PSO L3 and T10-Plevis 2 years F/U: broken rods and loss of sagittal alignment TPA 36 9 cm PT 34 PI-LL 31 TPA cm PT 25 PI-LL 9 TPA cm PT 29 PI-LL 38 CASE: YOUNGER PATIENT 45 year old M with posttraumatic lumbar kyphosis Undergoes PSO L3 and T10-Plevis 2 years F/U: broken rods and loss of sagittal alignment TPA 36 9 cm PT 34 PI-LL 31 TPA cm PT 25 PI-LL 9 TPA cm PT 29 PI-LL 38 22

23 CASE: YOUNGER PATIENT 45 year old M with posttraumatic lumbar kyphosis Undergoes PSO L3 and T10-Plevis 2 years F/U: broken rods and loss of sagittal alignment TPA 36 9 cm PT 34 PI-LL 31 TPA cm PT 25 PI-LL 9 TPA cm PT 29 PI-LL 38 CASE: YOUNGER PATIENT 45 year old M with posttraumatic lumbar kyphosis Undergoes PSO L3 and T10-Plevis 2 years F/U: broken rods and loss of sagittal alignment Revised with L4 PSO TPA 36 9 cm PT 34 PI-LL 31 TPA cm PT 25 PI-LL 9 TPA cm PT 29 PI-LL 38 23

24 CASE: YOUNGER PATIENT 45 year old M with posttraumatic lumbar kyphosis Undergoes PSO L3 and T10-Plevis 2 years F/U: broken rods and loss of sagittal alignment Revised with L4 PSO TPA 36 9 cm TPA cm TPA cm Lower extremity compensation resolved PT 34 PT 25 PT 29 PI-LL 31 PI-LL 9 PI-LL 38 CASE: YOUNGER PATIENT 45 year old M with posttraumatic lumbar kyphosis Undergoes PSO L3 and T10-Plevis 2 years F/U: broken rods and loss of sagittal alignment Revised with L4 PSO TPA 36 TPA 21 TPA 37 TPA 14 9 cm 5.2 cm 6.8 cm 2.3 cm PT 34 PT 25 PT 29 PT 16 PI-LL 31 PI-LL 9 PI-LL 38 PI-LL -2 24

25 CASE: YOUNGER PATIENT 45 year old M with posttraumatic lumbar kyphosis Undergoes PSO L3 and T10-Plevis 2 years F/U: broken rods and loss of sagittal alignment Revised with L4 PSO TPA 36 TPA 21 TPA 37 TPA 14 9 cm PT cm PT cm PT cm PT 16 Pelvic compensation resolved PI-LL 31 PI-LL 9 PI-LL 38 PI-LL -2 CASE: OLDER PATIENT 65 year old F with prior T4-pelvis fusion Broken rods, loss of sagittal alignment TPA cm PT 36 PI-LL 30 25

26 CASE: OLDER PATIENT 65 year old F with prior T4-pelvis fusion Broken rods, loss of sagittal alignment TPA cm PT 36 PI-LL 30 CASE: OLDER PATIENT 65 year old F with prior T4-pelvis fusion Broken rods, loss of sagittal alignment PT maximized, recruiting lower extremity compensation TPA cm PT 36 PI-LL 30 26

27 CASE: OLDER PATIENT 65 year old F with prior T4-pelvis fusion Broken rods, loss of sagittal alignment PT maximized, recruiting lower extremity compensation Preop Planning: Grade IV osteotomy = 30 TPA cm PT 36 PI-LL 30 TPA cm PT 22 CASE: OLDER PATIENT 65 year old F with prior T4-pelvis fusion Broken rods, loss of sagittal alignment PT maximized, recruiting lower extremity compensation Preop Planning: Grade IV osteotomy = 30 TPA cm PT 36 PI-LL 30 TPA cm PT 22 27

28 CASE: OLDER PATIENT Revised w/ L4 PSO TPA cm PT 36 PI-LL 30 TPA cm PT 22 TPA PT -- CASE: OLDER PATIENT Revised w/ L4 PSO TPA cm PT 36 PI-LL 30 TPA cm PT 22 TPA PT -- 28

29 CASE: OLDER PATIENT TPA 44 TPA 18 TPA 17 TPA cm 3.2 cm cm PT 36 PT 22 PT -- PT 23 PI-LL 30 CASE: OLDER PATIENT TPA 44 TPA 18 TPA 17 TPA cm 3.2 cm cm PT 36 PT 22 PT -- PT 23 PI-LL 30 29

30 CASE: OLDER PATIENT TPA 44 TPA 44 TPA 17 TPA cm 16 cm cm PT 36 PT 36 PT -- PT 23 PI-LL 30 CASE: OLDER PATIENT TPA 44 TPA 44 TPA 17 TPA cm 16 cm cm PT 36 PT 36 PT -- PT 23 PI-LL 30 PI-LL 30 30

31 THANK YOU 31