The International Spine Study Group works to consistently put forward high quality, meaningful research. The findings are shared via podium presentations, posters, and published manuscripts. Explore all publications from the ISSG here.

    Morse KW, Lafage R, Passias P, et al. A Comparison of Three Different Positioning Techniques on Surgical Corrections and Postoperative Alignment in Cervical Spinal Deformity (CD) Surgery. Spine (Phila Pa 1976) 2021;46:567–70. Read more...

    Passias PG, Horn SR, Soroceanu A, et al. Development of a Novel Cervical Deformity Surgical Invasiveness Index. Spine (Phila Pa 1976) 2020;45:116–23. Read more...

    Neuman BJ, Harris AB, Klineberg EO, et al. Defining a Surgical Invasiveness Threshold for Increased Risk of a Major Complication Following Adult Spinal Deformity Surgery. Spine (Phila Pa 1976) 2021;46:931–8. Read more...

    Passias PG, Brown AE, Bortz C, et al. A Risk-Benefit Analysis of Increasing Surgical Invasiveness Relative to Frailty Status in Adult Spinal Deformity Surgery. Spine (Phila Pa 1976) 2021;46:1087–96. Read more...

    Lafage R, Ang B, Schwab F, et al. Depression Symptoms Are Associated with Poor Functional Status among Operative Spinal Deformity Patients. Spine (Phila Pa 1976) 2021;46:447–56. Read more...

    Klineberg EO, Wick JB, Lafage R, et al. Development and validation of a multidomain surgical complication classification system for adult spinal deformity. Spine (Phila Pa 1976) 2021;46:E267–73. Read more...

    Sciubba D, Jain A, Kebaish KM, et al. Development of a Preoperative Adult Spinal Deformity Comorbidity Score That Correlates With Common Quality and Value Metrics: Length of Stay, Major Complications, and Patient-Reported Outcomes. Glob Spine J 2021;11:146–53. Read more...

    Sheikh Alshabab B, Gupta MC, Lafage R, et al. Does Achieving Global Spinal Alignment Lead to Higher Patient Satisfaction and Lower Disability in Adult Spinal Deformity? Spine (Phila Pa 1976) 2021;46:1105–10. Read more...

    Passias P, Horn S, Lafage V, et al. Effect of age-Adjusted alignment goals and distal inclination angle on the fate of distal junctional kyphosis in cervical deformity surgery. J Craniovertebr Junction Spine 2021;12:65–71. Read more...

    Virk S, Platz U, Bess S, et al. Factors influencing upper-most instrumented vertebrae selection in adult spinal deformity patients: Qualitative case-based survey of deformity surgeons. J Spine Surg 2021;7:37–47. Read more...

    Plais N, Bao H, Lafage R, et al. Fractional Curve in Adult Spinal Deformity: Is it a Driver of or a Compensation for Coronal Malalignment? Clin Spine Surg 2021;34:E276–81. Read more...

    Horn SR, Passias PG, Passfall L, et al. Improvement in some Ames-ISSG cervical deformity classification modifier grades may correlate with clinical improvement. J Clin Neurosci 2021;89:297–304. Read more...

    Passias PG, Bortz C, Pierce KE, et al. Appropriate Risk Stratification and Accounting for Age-Adjusted Reciprocal Changes in the Thoracolumbar Spine Reduces the Incidence and Magnitude of Distal Junctional Kyphosis in Cervical Deformity Surgery. Spine (Phila Pa 1976) 2021;46:1437–47. Read more...

    Gum JL, Shasti M, Yeramaneni S, et al. Improvement in SRS-22R Self-Image Correlate Most with Patient Satisfaction after 3-Column Osteotomy. Spine (Phila Pa 1976) 2021;46:822–7. Read more...

    Daniels AH, Durand WM, Lafage R, et al. Lateral Thoracolumbar Listhesis as an Independent Predictor of Disability in Adult Scoliosis Patients: Multivariable Assessment Before and After Surgical Realignment. Neurosurgery 2021;89:1080–6. Read more...

    Yao Y-C, Kim HJ, Bannwarth M, et al. Lowest Instrumented Vertebra Selection to S1 or Ilium Versus L4 or L5 in Adult Spinal Deformity: Factors for Consideration in 349 Patients With a Mean 46-Month Follow-Up. Glob Spine J. Epub ahead of print 2021. DOI: 10.1177/21925682211009178. Read more...

    Buell TJ, Smith JS, Shaffrey CI, et al. Multicenter assessment of surgical outcomes in adult spinal deformity patients with severe global coronal malalignment: Determination of target coronal realignment threshold. J Neurosurg Spine 2021;34:399–412. Read more...

    Buell TJ, Smith JS, Shaffrey CI, et al. Operative Treatment of Severe Scoliosis in Symptomatic Adults: Multicenter Assessment of Outcomes and Complications With Minimum 2-Year Follow-up. Neurosurgery 2021;89:1012–26. Read more...

    Smith JS, Kelly MP, Yanik EL, et al. Operative versus nonoperative treatment for adult symptomatic lumbar scoliosis at 5-year follow-up: Durability of outcomes and impact of treatment-related serious adverse events. J Neurosurg Spine 2021;35:67–79. Read more...

    Scheer JK, Lenke LG, Smith JS, et al. Outcomes of Surgical Treatment for 138 Patients with Severe Sagittal Deformity at a Minimum 2-Year Follow-up: A Case Series. Oper Neurosurg 2021;21:94–103. Read more...

    Passias PG, Alas H, Bess S, et al. Patient-related and radiographic predictors of inferior health-related quality-of-life measures in adult patients with nonoperative spinal deformity. J Neurosurg Spine 2021;34:907–13. Read more...

    Ogura Y, Gum JL, Soroceanu A, et al. Practical answers to frequently asked questions for shared decision-making in adult spinal deformity surgery. J Neurosurg Spine 2021;34:218–27. Read more...

    Passias P, Horn S, Oh C, et al. Predictive model for achieving good clinical and radiographic outcomes at one-year following surgical correction of adult cervical deformity. J Craniovertebr Junction Spine 2021;12:228–35. Read more...

    Alas H, Passias PG, Brown AE, et al. Predictors of serious, preventable, and costly medical complications in a population of adult spinal deformity patients. Spine J 2021;21:1559–66. Read more...

    Virk S, Lafage R, Bess S, et al. Are the Arbeitsgemeinschaft für Osteosynthesefragen (AO) Principles for Long Bone Fractures Applicable to 3-Column Osteotomy to Reduce Rod Fracture Rates? Clin Spine Surg. Epub ahead of print 2021. DOI: 10.1097/BSD.0000000000001289. Read more...

    Pierce KE, Passias PG, Brown AE, et al. Predictors of Superior Recovery Kinetics in Adult Cervical Deformity Correction: An Analysis Using a Novel Area under the Curve Methodology. Spine (Phila Pa 1976) 2021;46:559–66. Read more...

    Pierce KE, Passias PG, Brown AE, et al. Prioritization of realignment associated with superior clinical outcomes for cervical deformity patients. Neurospine 2021;18:506–14. Read more...

    Pierce K, Passias P, Brown A, et al. Prioritization of realignment associated with superior clinical outcomes for surgical cervical deformity patients. J Craniovertebr Junction Spine 2021;12:311–7. Read more...

    Passias PG, Pierce KE, Brown AE, et al. Redefining cervical spine deformity classification through novel cutoffs: An assessment of the relationship between radiographic parameters and functional neurological outcomes. J Craniovertebr Junction Spine 2021;12:157–64. Read more...

    Chou D, Chan AY, Park P, et al. Revision Surgery Rates After Minimally Invasive Adult Spinal Deformity Surgery: Correlation with Roussouly Spine Type at 2-Year Follow-Up? World Neurosurg 2021;148:e482–7. Read more...

    Passias P, Passfall L, Horn S, et al. Risk-benefit assessment of major versus minor osteotomies for flexible and rigid cervical deformity correction. J Craniovertebr Junction Spine 2021;12:263–8. Read more...

    Joshi RS, Lau D, Scheer JK, et al. State-of-the-art reviews predictive modeling in adult spinal deformity: applications of advanced analytics. Spine Deform 2021;9:1223–39. Read more...

    Protopsaltis TS, Stekas N, Smith JS, et al. Surgical outcomes in rigid versus flexible cervical deformities. J Neurosurg Spine 2021;34:716–24. Read more...

    Kim HJ, Virk S, Elysee J, et al. Surgical strategy for the management of cervical deformity is based on type of cervical deformity. J Clin Med;10. Epub ahead of print 2021. DOI: 10.3390/jcm10214826. Read more...

    Passias P, Brown A, Alas H, et al. The impact of postoperative neurologic complications on recovery kinetics in cervical deformity surgery. J Craniovertebr Junction Spine 2021;12:393–400. Read more...

    Durand WM, Lafage R, Hamilton DK, et al. Artificial intelligence clustering of adult spinal deformity sagittal plane morphology predicts surgical characteristics, alignment, and outcomes. Eur Spine J 2021;30:2157–66. Read more...

    Passias PG, Alas H, Naessig S, et al. Timing of conversion to cervical malalignment and proximal junctional kyphosis following surgical correction of adult spinal deformity: A 3-year radiographic analysis. J Neurosurg Spine 2021;34:830–8. Read more...

    Mummaneni PV, Hussain I, Shaffrey CI, et al. The minimally invasive interbody selection algorithm for spinal deformity. J Neurosurg Spine 2021;34:741–8. Read more...

    Bannwarth M, Smith JS, Bess S, et al. Use of rhBMP-2 for adult spinal deformity surgery: patterns of usage and changes over the past decade. Neurosurg Focus 2021;50:1–9. Read more...

    Passias PG, Pierce KE, Naessig S, et al. At What Point Should the Thoracolumbar Region Be Addressed in Patients Undergoing Corrective Cervical Deformity Surgery? Spine (Phila Pa 1976) 2021;46:E1113–8. Read more...

    Pierce KE, Passias PG, Daniels AH, et al. Baseline Frailty Status Influences Recovery Patterns and Outcomes following Alignment Correction of Cervical Deformity. Neurosurgery 2021;88:1121–7. Read more...

    Alas H, Passias P, Diebo B, et al. Cervical deformity patients with baseline hyperlordosis or hyperkyphosis differ in surgical treatment and radiographic outcomes. J Craniovertebr Junction Spine 2021;12:279–86. Read more...

    Kim HJ, Yao Y-C, Bannwarth M, et al. Cervicothoracic Versus Proximal Thoracic Lower Instrumented Vertebra Have Comparable Radiographic and Clinical Outcomes in Adult Cervical Deformity. Glob Spine J. Epub ahead of print 2021. DOI: 10.1177/21925682211017478. Read more...

    Yagi M, Ames CP, Hosogane N, et al. Comparable satisfaction and clinical outcomes after surgery for adolescent idiopathic scoliosis in the adult (AISA) between the US and Japan. J Orthop Sci. Epub ahead of print 2021. DOI: 10.1016/j.jos.2021.08.014. Read more...

    Alluri RK, Sheikh B, Elysee JC, et al. Shoulder Balance in Adult Spinal Deformity Patients Undergoing Selective Lumbar Fusion. Spine (Phila Pa 1976) 2022;47:E385–9. Read more...

    Katsuura Y, Lafage R, Kim HJ, et al. Alignment Targets, Curve Proportion and Mechanical Loading: Preliminary Analysis of an Ideal Shape Toward Reducing Proximal Junctional Kyphosis. Glob Spine J 2022;12:1165–74. Read more...

    Alshabab BS, Lafage R, Smith JS, et al. Evolution of Proximal Junctional Kyphosis and Proximal Junctional Failure Rates over 10 Years of Enrollment in a Prospective Multicenter Adult Spinal Deformity Database. Spine (Phila Pa 1976) 2022;47:922–30. Read more...

    Kim HJ, Alluri RK, Lafage R, et al. Upper versus Lower Lumbar Lordosis Corrections in Relation to Pelvic Tilt - An Essential Element in Surgical Planning for Sagittal Plane Deformity. Spine (Phila Pa 1976) 2022;47:1145–50. Read more...

    Kim HJ, Yao Y-C, Shaffrey CI, et al. Neurological Complications and Recovery Rates of Patients With Adult Cervical Deformity Surgeries. Glob Spine J 2022;12:1091–7. Read more...

    Lafage R, Fong AM, Klineberg E, et al. Complication rate evolution across a 10-year enrollment period of a prospective multicenter database. J Neurosurg Spine 2022;36:1012–22. Read more...

    Lafage R, Passias P, Sheikh Alshabab B, et al. Patterns of Lumbar Spine Malalignment Leading to Revision Surgery for Proximal Junctional Kyphosis: A Cluster Analysis of Over- Versus Under-Correction. Glob Spine J. Epub ahead of print 2022. DOI: 10.1177/21925682211047461. Read more...

    Lafage R, Schwab F, Elysee J, et al. Surgical Planning for Adult Spinal Deformity: Anticipated Sagittal Alignment Corrections According to the Surgical Level. Glob Spine J 2022;12:1761–9. Read more...

    Lafage R, Smith JS, Alshabab BS, et al. When can we expect global sagittal alignment to reach a stable value following cervical deformity surgery? J Neurosurg Spine 2022;36:616–23. Read more...

    Lafage R, Smith JS, Elysee J, et al. Sagittal age-adjusted score (SAAS) for adult spinal deformity (ASD) more effectively predicts surgical outcomes and proximal junctional kyphosis than previous classifications. Spine Deform 2022;10:121–31. Read more...

    Lafage R, Smith JS, Fong AM, et al. Proximal and distal reciprocal changes following cervical deformity malalignment correction. J Neurosurg Spine 2022;37:599–606. Read more...

    Lafage R, Smith JS, Soroceanu A, et al. Predicting Mechanical Failure Following Cervical Deformity Surgery: A Composite Score Integrating Age-Adjusted Cervical Alignment Targets. Glob Spine J. Epub ahead of print 2022. DOI: 10.1177/21925682221086535. Read more...

    Chan AK, Eastlack RK, Fessler RG, et al. Two- and three-year outcomes of minimally invasive and hybrid correction of adult spinal deformity. J Neurosurg Spine 2022;36:595–608. Read more...

    Lafage R, Virk S, Elysee J, et al. Radiographic Characteristics of Cervical Deformity (CD) Using a Discriminant Analysis: The Value of Extension Radiographs. Clin Spine Surg 2022;35:E504–9. Read more...

    Le HV, Wick JB, Lafage R, et al. Surgical Factors and Treatment Severity for Perioperative Complications Predict Hospital Length of Stay in Adult Spinal Deformity Surgery. Spine (Phila Pa 1976) 2022;47:136–43. Read more...

    Line B, Bess S, Gum JL, et al. Opioid use prior to surgery is associated with worse preoperative and postoperative patient reported quality of life and decreased surgical cost effectiveness for symptomatic adult spine deformity; A matched cohort analysis. North Am Spine Soc J;9. Epub ahead of print 2022. DOI: 10.1016/j.xnsj.2021.100096. Read more...

    Le HV, Wick JB, Lafage R, et al. Association of findings on preoperative extension lateral cervical radiography with osteotomy type, approach, and postoperative cervical alignment after cervical deformity surgery. J Neurosurg Spine 2022;36:93–8. Read more...

    Louie PK, Iyer S, Khanna K, et al. Revision Strategies for Harrington Rod Instrumentation: Radiographic Outcomes and Complications. Glob Spine J 2022;12:654–62. Read more...

    McCarthy MH, Lafage R, Smith JS, et al. How Much Lumbar Lordosis does a Patient Need to Reach their Age-Adjusted Alignment Target? A Formulated Approach Predicting Successful Surgical Outcomes. Glob Spine J. Epub ahead of print 2022. DOI: 10.1177/21925682221092003. Read more...

    Mundis GM, Godzik J, Park P, et al. Prospective multicenter study of minimally invasive surgery for the treatment of adult spinal deformity. J Neurosurg Spine 2022;36:767–74. Read more...

    Mundis GM, Walker CT, Smith JS, et al. Kickstand rods and correction of coronal malalignment in patients with adult spinal deformity. Eur Spine J 2022;31:1197–205. Read more...

    Passias PG, Ahmad W, Kummer N, et al. Examination of the Economic Burden of Frailty in Patients With Adult Spinal Deformity Undergoing Surgical Intervention. Neurosurgery 2022;90:148–53. Read more...

    Passias PG, Bortz C, Pierce KE, et al. Comparing and Contrasting the Clinical Utility of Sagittal Spine Alignment Classification Frameworks: Roussouly Versus SRS-Schwab. Spine (Phila Pa 1976) 2022;47:455–62. Read more...

    Chou D, Lafage V, Chan AY, et al. Patient outcomes after circumferential minimally invasive surgery compared with those of open correction for adult spinal deformity: initial analysis of prospectively collected data. J Neurosurg Spine 2022;36:203–14. Read more...

    Passias PG, Ahmad W, Oh C, et al. Development of Risk Stratification Predictive Models for Cervical Deformity Surgery. Neurosurgery 2022;91:928–35. Read more...

    Passias PG, Alas H, Kummer N, et al. Cervical deformity patients with baseline hyperlordosis or hyperkyphosis differ in surgical treatment and radiographic outcomes. J Craniovertebr Junction Spine 2022;13:271–7. Read more...

    Passias PG, Brown AE, Bortz C, et al. Increasing Cost Efficiency in Adult Spinal Deformity Surgery: Identifying Predictors of Lower Total Costs. Spine (Phila Pa 1976) 2022;47:21–6. Read more...

    Passias PG, Frangella NJ, Williamson TK, et al. Changes in health-related quality of life measures associated with degree of proximal junctional kyphosis. Spine Deform. Epub ahead of print 2022. DOI: 10.1007/s43390-022-00607-4. Read more...

    Passias PG, Krol O, Moattari K, et al. Evolution of Adult Cervical Deformity Surgery Clinical and Radiographic Outcomes Based on a Multicenter Prospective Study: Are Behaviors and Outcomes Changing with Experience? Spine (Phila Pa 1976) 2022;47:1574–82. Read more...

    Passias PG, Krol O, Passfall L, et al. Three-Column Osteotomy in Adult Spinal Deformity: An Analysis of Temporal Trends in Usage and Outcomes. J Bone Jt Surg 2022;104:1895–904. Read more...

    Passias PG, Kummer N, Williamson TK, et al. Highest Achievable Outcomes for Patients Undergoing Cervical Deformity Corrective Surgery by Frailty. Neurosurgery 2022;91:693–700. Read more...

    Daniels AH, Durand WM, Steinbaum AJ, et al. Examination of Adult Spinal Deformity Patients Undergoing Surgery with Implanted Spinal Cord Stimulators and Intrathecal Pumps. Spine (Phila Pa 1976) 2022;47:227–33. Read more...

    PASSIAS PG, POORMAN GW, Vasquez-Montes D, et al. Predictive Analytics for Determining Extended Operative Time in Corrective Adult Spinal Deformity Surgery. Int J Spine Surg 2022;16:291–9. Read more...

    Passias PG, Naessig S, Kummer N, et al. Predicting development of severe clinically relevant distal junctional kyphosis following adult cervical deformity surgery, with further distinction from mild asymptomatic episodes. J Neurosurg Spine 2022;36:960–7. Read more...

    Passias PG, Kummer NA, Williamson TK, et al. The Additional Economic Burden of Frailty in Adult Cervical Deformity Patients Undergoing Surgical Intervention. Spine (Phila Pa 1976) 2022;47:1418–25. Read more...

    Passias PG, Segreto FA, Moattari KA, et al. Is frailty responsive to surgical correction of adult spinal deformity? An investigation of sagittal re-alignment and frailty component drivers of postoperative frailty status. Spine Deform 2022;10:901–11. Read more...

    Pellisé F, Serra-Burriel M, Vila-Casademunt A, et al. Quality metrics in adult spinal deformity surgery over the last decade: a combined analysis of the largest prospective multicenter data sets. J Neurosurg Spine 2022;36:226–34. Read more...

    Pellisé F, Vila-Casademunt A, Núñez-Pereira S, et al. Surgeons’ risk perception in ASD surgery: The value of objective risk assessment on decision making and patient counselling. Eur Spine J 2022;31:1174–83. Read more...

    Uribe JS, Koffie RM, Wang MY, et al. Are Minimally Invasive Spine Surgeons or Classical Open Spine Surgeons More Consistent with Their Treatment of Adult Spinal Deformity? World Neurosurg. Epub ahead of print 2022. DOI: 10.1016/j.wneu.2022.05.078. Read more...

    Wick JB, Le HV, Lafage R, et al. Assessment of Adult Spinal Deformity Complication Timing and Impact on 2-Year Outcomes Using a Comprehensive Adult Spinal Deformity Classification System. Spine (Phila Pa 1976) 2022;47:445–54. Read more...

    Durand WM, Babu JM, Hamilton DK, et al. Adult Spinal Deformity Surgery Is Associated with Increased Productivity and Decreased Absenteeism From Work and School. Spine (Phila Pa 1976) 2022;47:287–94. Read more...

    Durand WM, Disilvestro KJ, Kim HJ, et al. Low-Density Pedicle Screw Constructs Are Associated with Lower Incidence of Proximal Junctional Failure in Adult Spinal Deformity Surgery. Spine (Phila Pa 1976) 2022;47:463–9. Read more...

    Elias E, Bess S, Line B, et al. Outcomes of operative treatment for adult spinal deformity: a prospective multicenter assessment with mean 4-year follow-up. J Neurosurg Spine 2022;37:607–16. Read more...

    Elias E, Bess S, Line BG, et al. Operative treatment outcomes for adult cervical deformity: a prospective multicenter assessment with mean 3-year follow-up. J Neurosurg Spine 2022;37:855–64. Read more...

    Gum JL, Line B, Carreon LY, et al. Reaching the medicare allowable threshold in adult spinal deformity surgery: multicenter cost analysis comparing actual direct hospital costs versus what the government will pay. Spine Deform 2022;10:425–31. Read more...

    Yeramaneni S, Wang K, Gum J, et al. Diagnosis-Related Group–Based Payments for Adult Spine Deformity Surgery Significantly Vary across Centers: Results from a Multicenter Prospective Cohort Study. World Neurosurg 2023;171:e153–61. Read more...

    Ye J, Rider SM, Lafage R, et al. Distal junctional kyphosis in adult cervical deformity patients: where does it occur? Eur Spine J. Epub ahead of print 2023. DOI: 10.1007/s00586-023-07631-6. Read more...

    Duvvuri P, Lafage R, Bannwarth M, et al. The Shape of the Fused Spine is Associated With Acute Proximal Junctional Kyphosis in Adult Spinal Deformity: An Assessment Based on Vertebral Pelvic Angles. Glob Spine J. Epub ahead of print 2023. DOI: 10.1177/21925682221150770. Read more...

    Passias PG, Naessig S, Sagoo N, et al. Establishment of an Individualized Distal Junctional Kyphosis Risk Index following the Surgical Treatment of Adult Cervical Deformities. Spine (Phila Pa 1976) 2023;48:49–55. Read more...

    Smith JS, Elias E, Sursal T, et al. How Good Are Surgeons at Achieving Their Preoperative Goal Sagittal Alignment Following Adult Deformity Surgery? Glob Spine J. Epub ahead of print 2023. DOI: 10.1177/21925682231161304. Read more...

    Passias PG, Kummer N, Imbo B, et al. Improvements in Outcomes and Cost After Adult Spinal Deformity Corrective Surgery Between 2008 and 2019. Spine (Phila Pa 1976) 2023;48:189–95. Read more...

    Lovecchio F, Lafage R, Line B, et al. Optimizing the Definition of Proximal Junctional Kyphosis: A Sensitivity Analysis. Spine (Phila Pa 1976) 2023;48:414–20. Read more...

    Durand WM, Daniels AH, DiSilvestro K, et al. Patient satisfaction after multiple revision surgeries for adult spinal deformity. J Neurosurg Spine 2023;38:75–83. Read more...

    Ayres EW, Protopsaltis TS, Ani F, et al. Predicting the Magnitude of Distal Junctional Kyphosis Following Cervical Deformity Correction. Spine (Phila Pa 1976) 2023;48:232–9. Read more...

    Neuman BJ, Wang KY, Harris AB, et al. Return to work after adult spinal deformity surgery. Spine Deform 2023;11:197–204. Read more...

    Anand N, Mummaneni PV, Uribe JS, et al. Spinal Deformity Complexity Checklist for Minimally Invasive Surgery: Expert Consensus from the Minimally Invasive International Spine Study Group. World Neurosurg. Epub ahead of print 2023. DOI: 10.1016/j.wneu.2023.02.082. Read more...