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.

    Smith JS, Shaffrey CI, Kim HJ, et al. Prospective multicenter assessment of all-cause mortality following surgery for adult cervical deformity. Clin Neurosurg 2018;83:1277–85. Read more...

    Miller EK, Ailon T, Neuman BJ, et al. Assessment of a Novel Adult Cervical Deformity Frailty Index as a Component of Preoperative Risk Stratification. World Neurosurg 2018;109:e800–6. Read more...

    Ramchandran S, Protopsaltis TS, Sciubba D, et al. Prospective multi-centric evaluation of upper cervical and infra-cervical sagittal compensatory alignment in patients with adult cervical deformity. Eur Spine J 2018;27:416–25. Read more...

    Ailon T, Hamilton DK, Klineberg E, et al. Radiographic Fusion Grade Does Not Impact HealthRelated Quality of Life in the Absence of Instrumentation Failure for Patients Undergoing Posterior Instrumented Fusion for Adult Spinal Deformity. World Neurosurg 2018;117:e1–7. Read more...

    Passias PG, Jalai CM, Lafage V, et al. Recovery Kinetics of Radiographic and Implant-Related Revision Patients Following Adult Spinal Deformity Surgery. Neurosurgery 2018;83:700–8. Read more...

    Witiw CD, Fessler RG, Nguyen S, et al. Re-operation after Long-Segment Fusions for Adult Spinal Deformity: The Impact of Extending the Construct below the Lumbar Spine. Clin Neurosurg 2018;82:211–8. Read more...

    Daniels AH, DePasse JM, Durand W, et al. Rod Fracture After Apparently Solid Radiographic Fusion in Adult Spinal Deformity Patients. World Neurosurg 2018;117:e530–7. Read more...

    Protopsaltis T, Terran J, Soroceanu A, et al. T1 slope minus cervical lordosis (TS-CL), the cervical answer to PI-LL, defines cervical sagittal deformity in patients undergoing thoracolumbar osteotomy. Int J Spine Surg 2018;12:362–70. Read more...

    Pellisé F, Vila-Casademunt A, Núñez-Pereira S, et al. The Adult Deformity Surgery Complexity Index (ADSCI): a valid tool to quantify the complexity of posterior adult spinal deformity surgery and predict postoperative complications. Spine J 2018;18:216–25. Read more...

    Park P, Fu K-M, Mummaneni PV, et al. The impact of age on surgical goals for spinopelvic alignment in minimally invasive surgery for adult spinal deformity. J Neurosurg Spine 2018;29:560–4. Read more...

    Protopsaltis TS, Lafage R, Smith JS, et al. The Lumbar Pelvic Angle, the Lumbar Component of the T1 Pelvic Angle, Correlates with HRQOL, PI-LL Mismatch, and it Predicts Global Alignment. Spine (Phila Pa 1976) 2018;43:681–7. Read more...

    Raad M, Jain A, Neuman BJ, et al. Association of patient-reported narcotic use with short- and long-term outcomes after adult spinal deformity surgery: Multicenter study of 425 patients with 2-year follow-up. Spine (Phila Pa 1976) 2018;43:1340–6. Read more...

    Iyer S, Kim HJ, Bao H, et al. The Posterior Use of BMP-2 in Cervical Deformity Surgery Does Not Result in Increased Early Complications: A Prospective Multicenter Study. Glob Spine J 2018;8:622–8. Read more...

    Raad M, Neuman BJ, Jain A, et al. The use of patient-reported preoperative activity levels as a stratification tool for short-term and long-term outcomes in patients with adult spinal deformity. J Neurosurg Spine 2018;29:68–74. Read more...

    Chou D, Mummaneni P, Anand N, et al. Treatment of the Fractional Curve of Adult Scoliosis With Circumferential Minimally Invasive Surgery Versus Traditional, Open Surgery: An Analysis of Surgical Outcomes. Glob Spine J 2018;8:827–33. Read more...

    Passias PG, Horn SR, Bortz CA, et al. The relationship between improvements in myelopathy and sagittal realignment in cervical deformity surgery outcomes. Spine (Phila Pa 1976) 2018;43:1117–24. Read more...

    Scheer JK, Lafage R, Schwab FJ, et al. Under Correction of Sagittal Deformities Based on Ageadjusted Alignment Thresholds Leads to Worse Health-related Quality of Life whereas over Correction Provides No Additional Benefit. Spine (Phila Pa 1976) 2018;43:388–93. Read more...

    Khalsa AS, Mundis GM, Yagi M, et al. Variability in Assessing Spinopelvic Parameters with Lumbosacral Transitional Vertebrae. Spine (Phila Pa 1976) 2018;43:813–6. Read more...

    Langella F, Villafañe JH, Lafage V, et al. Xipho-pubic angle (XPA) correlates with patient’s reported outcomes in a population of adult spinal deformity: results from a multi-center cohort study. Eur Spine J 2018;27:670–7. Read more...

    Yeramaneni S, Ames CP, Bess S, et al. Center variation in episode-of-care costs for adult spinal deformity surgery: results from a prospective, multicenter database. Spine J 2018;18:1829–36. Read more...

    Passias PG, Horn SR, Jalai CM, et al. Cervical alignment changes in patients developing proximal junctional kyphosis following surgical correction of adult spinal deformity. Clin Neurosurg 2018;83:675–82. Read more...

    Passias PG, Poorman GW, Lafage V, et al. Cervical Versus Thoracolumbar Spinal Deformities A Comparison of Baseline Quality-of-Life Burden. Clin Spine Surg 2018;31:413–9. Read more...

    Passias PG, Jalai CM, Smith JS, et al. Characterizing Adult Cervical Deformity and Disability Based on Existing Cervical and Adult Deformity Classification Schemes at Presentation and Following Correction. Clin Neurosurg 2018;82:192–201. Read more...

    Buell TJ, Buchholz AL, Quinn JC, et al. A pilot study on posterior polyethylene tethers to prevent proximal junctional kyphosis after multilevel spinal instrumentation for adult spinal deformity. Oper Neurosurg 2019;16:256–66. Read more...

    Buell TJ, Chen C-J, Quinn JC, et al. Alignment Risk Factors for Proximal Junctional Kyphosis and the Effect of Lower Thoracic Junctional Tethers for Adult Spinal Deformity. World Neurosurg 2019;121:e96–103. Read more...

    Ames CP, Smith JS, Pellisé F, et al. Development of Deployable Predictive Models for Minimal Clinically Important Difference Achievement Across the Commonly Used Health-related Quality of Life Instruments in Adult Spinal Deformity Surgery. Spine (Phila Pa 1976) 2019;44:1144–53. Read more...

    Ames CP, Smith JS, Pellisé F, et al. Development of predictive models for all individual questions of SRS-22R after adult spinal deformity surgery: a step toward individualized medicine. Eur Spine J 2019;28:1998–2011. Read more...

    Eastlack RK, Srinivas R, Mundis GM, et al. Early and Late Reoperation Rates With Various MIS Techniques for Adult Spinal Deformity Correction. Glob Spine J 2019;9:41–7. Read more...

    Passias PG, Poorman GW, Horn SR, et al. Effect of Obesity on Radiographic Alignment and ShortTerm Complications After Surgical Treatment of Adult Cervical Deformity. World Neurosurg 2019;125:e1082–8. Read more...

    Daniels AH, Reid DBC, Tran SN, et al. Evolution in Surgical Approach, Complications, and Outcomes in an Adult Spinal Deformity Surgery Multicenter Study Group Patient Population. Spine Deform 2019;7:481–8. Read more...

    Kelly MP, Kallen MA, Shaffrey CI, et al. Examining the Patient-Reported Outcomes Measurement Information System versus the Scoliosis Research Society–22r in adult spinal deformity. J Neurosurg Spine 2019;30:801–6. Read more...

    Passias PG, Alas H, Lafage R, et al. Global spinal deformity from the upper cervical perspective. What is “Abnormal” in the upper cervical spine? J Craniovertebr Junction Spine 2019;10:152–9. Read more...

    Bortz CA, Passias PG, Segreto FA, et al. Grading of complications after cervical deformitycorrective surgery: Are existing classification systems applicable? Clin Spine Surg 2019;32:263–8. Read more...

    Verma R, Lafage R, Scheer J, et al. Improvement in Back and Leg Pain and Disability following Adult Spinal Deformity Surgery: Study of 324 Patients with 2-year Follow-up and the Impact of Surgery on Patient-reported Outcomes. Spine (Phila Pa 1976) 2019;44:263–9. Read more...

    Bortz CA, Passias PG, Segreto F, et al. Indicators for nonroutine discharge following cervical deformity-corrective surgery: Radiographic, surgical, and patient-related factors. Clin Neurosurg 2019;85:E509–19. Read more...

    Than KD, Park P, Tran S, et al. Analysis of Complications with Staged Surgery for Less Invasive Treatment of Adult Spinal Deformity. World Neurosurg 2019;126:e1337–42. Read more...

    Park P, Fu K-M, Eastlack RK, et al. Is achieving optimal spinopelvic parameters necessary to obtain substantial clinical benefit? An analysis of patients who underwent circumferential minimally invasive surgery or hybrid surgery with open posterior instrumentation. J Neurosurg Spine 2019;30:833–8. Read more...

    Lafage R, Obeid I, Liabaud B, et al. Location of correction within the lumbar spine impacts acute adjacent-segment kyphosis. J Neurosurg Spine 2019;30:69–77. Read more...

    Chou D, Mundis G, Wang M, et al. Minimally Invasive Surgery for Mild-to-Moderate Adult Spinal Deformities: Impact on Intensive Care Unit and Hospital Stay. World Neurosurg 2019;127:e649–55. Read more...

    Iyer S, Kim HJ, Theologis A, et al. Outcomes of Fusions From the Cervical Spine to the Pelvis. Glob Spine J 2019;9:6–13. Read more...

    Horn SR, Passias PG, Bortz CA, et al. Predicting extended operative time and length of inpatient stay in cervical deformity corrective surgery. J Clin Neurosci 2019;69:206–13. Read more...

    Passias PG, Oh C, Horn SR, et al. Predicting the occurrence of complications following corrective cervical deformity surgery: Analysis of a prospective multicenter database using predictive analytics. J Clin Neurosci 2019;59:155–61. Read more...

    Neuman BJ, Harris A, Jain A, et al. Reciprocal Changes in Cervical Alignment after Thoracolumbar Arthrodesis for Adult Spinal Deformity. Spine (Phila Pa 1976) 2019;44:E1311–6. Read more...

    Segreto FA, Lafage V, Lafage R, et al. Recovery Kinetics: Comparison of Patients Undergoing Primary or Revision Procedures for Adult Cervical Deformity Using a Novel Area under the Curve Methodology. Clin Neurosurg 2019;85:E40–51. Read more...

    Passias PG, Segreto FA, Lafage R, et al. Recovery kinetics following spinal deformity correction: a comparison of isolated cervical, thoracolumbar, and combined deformity morphometries. Spine J 2019;19:1422–33. Read more...

    Agarwal N, Angriman F, Goldschmidt E, et al. Relationship between body mass index and sagittal vertical axis change as well as health-related quality of life in 564 patients after deformity surgery. J Neurosurg Spine 2019;31:697–702. Read more...

    Passias PG, Horn SR, Raman T, et al. The impact of osteotomy grade and location on regional and global alignment following cervical deformity surgery. J Craniovertebr Junction Spine 2019;10:160–6. Read more...

    Ames CP, Smith JS, Pellisé F, et al. Artificial Intelligence Based Hierarchical Clustering of Patient Types and Intervention Categories in Adult Spinal Deformity Surgery: Towards a New Classification Scheme that Predicts Quality and Value. Spine (Phila Pa 1976) 2019;44:915–26. Read more...

    Burton DC, Sethi RK, Wright AK, et al. The Role of Potentially Modifiable Factors in a Standard Work Protocol to Decrease Complications in Adult Spinal Deformity Surgery: A Systematic Review, Part 1. Spine Deform 2019;7:669–83. Read more...

    Sethi RK, Burton DC, Wright AK, et al. The Role of Potentially Modifiable Factors in a Standard Work Protocol to Decrease Complications in Adult Spinal Deformity Surgery: A Systematic Review, Part 2. Spine Deform 2019;7:684–95. Read more...

    Yang J, Khalifé M, Lafage R, et al. What Factors Predict the Risk of Proximal Junctional Failure in the Long Term, Demographic, Surgical, or Radiographic?: Results from a Time-dependent ROC Curve. Spine (Phila Pa 1976) 2019;44:777–84. Read more...

    Durand WM, Daniels AH, Hamilton DK, et al. Younger Patients Are Differentially Affected by Stiffness-Related Disability Following Adult Spinal Deformity Surgery. World Neurosurg 2019;132:e297–304. Read more...

    Iyer S, Kim HJ, Bao H, et al. Cervical Deformity Patients Have Baseline Swallowing Dysfunction but Surgery Does Not Increase Dysphagia at 3 Months: Results From a Prospective Cohort Study. Glob Spine J 2019;9:532–9. Read more...

    Staub BN, Lafage R, Kim HJ, et al. Cervical mismatch: The normative value of T1 slope minus cervical lordosis and its ability to predict ideal cervical lordosis. J Neurosurg Spine 2019;30:31–7. Read more...

    Smith JS, Shaffrey CI, Kim HJ, et al. Comparison of Best Versus Worst Clinical Outcomes for Adult Cervical Deformity Surgery. Glob Spine J 2019;9:303–14. Read more...

    Yang J, Lafage V, Lafage R, et al. Determinants of Patient Satisfaction 2 Years after Spinal Deformity Surgery. Spine (Phila Pa 1976) 2019;44:E45–52. Read more...

    Pellisé F, Serra-Burriel M, Smith JS, et al. Development and validation of risk stratification models  for adult spinal deformity surgery. J Neurosurg Spine 2019;31:587–99 Read more...

    Passias PG, Bortz CA, Segreto FA, et al. Development of a Modified Cervical Deformity Frailty  Index: A Streamlined Clinical Tool for Preoperative Risk Stratification. Spine (Phila Pa 1976) 2019;44:169–76. Read more...

    Goldschmidt E, Angriman F, Agarwal N, et al. A New Piece of the Puzzle to Understand Cervical  Sagittal Alignment: Utilizing a Novel Angle δto Describe the Relationship among T1 Vertebral  Body Slope, Cervical Lordosis, and Cervical Sagittal Alignment. Clin Neurosurg 2020;86:446–51. Read more...

    Durand WM, Daniels AH, Hamilton DK, et al. Artificial Intelligence Models Predict Operative Versus Nonoperative Management of Patients with Adult Spinal Deformity with 86% Accuracy. World Neurosurg 2020;141:e239–53. Read more...

    Pierce KE, Passias PG, Alas H, et al. Does Patient Frailty Status Influence Recovery following Spinal Fusion for Adult Spinal Deformity?: An Analysis of Patients with 3-Year Follow-up. Spine (Phila Pa 1976) 2020;45:E397–405. Read more...

    Passias PG, Bortz CA, Lafage V, et al. Durability of satisfactory functional outcomes following surgical adult spinal deformity correction: A 3-year survivorship analysis. Oper Neurosurg 2020;18:118–25. Read more...

    Yanik EL, Kelly MP, Lurie JD, et al. Effect modifiers for patient-reported outcomes in operatively and nonoperatively treated patients with adult symptomatic lumbar scoliosis: a combined analysis of randomized and observational cohorts. J Neurosurg Spine 2020;33:17–26. Read more...

    Line BG, Bess S, Lafage R, et al. Effective Prevention of Proximal Junctional Failure in Adult Spinal Deformity Surgery Requires a Combination of Surgical Implant Prophylaxis and Avoidance of Sagittal Alignment Overcorrection. Spine (Phila Pa 1976) 2020;45:258–67. Read more...

    Soroceanu A, Smith JS, Lau D, et al. Establishing the minimum clinically important difference in neck disability index and modified japanese orthopaedic association scores for adult cervical deformity. J Neurosurg Spine 2020;33:441–5. Read more...

    Yang J, Lafage R, Gum JL, et al. Group-based trajectory modeling: A novel approach to classifying discriminative functional status following adult spinal deformity surgery: Study of a 3-year follow-up group. Spine (Phila Pa 1976) 2020;45:903–10. Read more...

    Passias PG, Segreto FA, Horn SR, et al. Fatty infiltration of the cervical extensor musculature, cervical sagittal balance, and clinical outcomes: An analysis of operative adult cervical deformity patients. J Clin Neurosci 2020;72:134–41. Read more...

    Park P, Than KD, Mummaneni PV, et al. Factors affecting approach selection for minimally invasive versus open surgery in the treatment of adult spinal deformity: Analysis of a prospective, nonrandomized multicenter study. J Neurosurg Spine 2020;33:601–6. Read more...

    Segreto FA, Passias PG, Lafage R, et al. Incidence of acute, progressive, and delayed proximal junctional kyphosis over an 8-year period in adult spinal deformity patients. Oper Neurosurg 2020;18:75–82. Read more...

    Wang MY, Park P, Tran S, et al. Intermediate-term clinical and radiographic outcomes with less invasive adult spinal deformity surgery: patients with a minimum follow-up of 4 years. Acta Neurochir (Wien) 2020;162:1393–400. Read more...

    Daniels AH, Reid DBC, Durand WM, et al. Assessment of Patient Outcomes and Proximal Junctional Failure Rate of Patients with Adult Spinal Deformity Undergoing Caudal Extension of Previous Spinal Fusion. World Neurosurg 2020;139:e449–54. Read more...

    Virk S, Passias P, Lafage R, et al. Intraoperative alignment goals for distinctive sagittal morphotypes of severe cervical deformity to achieve optimal improvements in health-related quality of life measures. Spine J 2020;20:1267–75. Read more...

    Decker S, Lafage R, Krettek C, et al. Is sacral extension a risk factor for early proximal junctional kyphosis in adult spinal deformity surgery? Asian Spine J;14. Epub ahead of print 2020. DOI: 10.31616/ASJ.2018.0314. Read more...

    Yagi M, Ames CP, Hosogane N, et al. Lower Satisfaction After Adult Spinal Deformity Surgery in Japan Than in the United States Despite Similar SRS-22 Pain and Function Scores: A Propensity-Score Matched Analysis. Spine (Phila Pa 1976) 2020;45:E1097–104. Read more...

    Wang MY, Uribe J, Mummaneni PV, et al. Minimally Invasive Spinal Deformity Surgery: Analysis of Patients Who Fail to Reach Minimal Clinically Important Difference. World Neurosurg 2020;137:e499–505. Read more...

    Beyer G, Khalifé M, Lafage R, et al. Pelvic Compensation in Sagittal Malalignment: How Much Retroversion Can the Pelvis Accommodate? Spine (Phila Pa 1976) 2020;45:E203–9. Read more...

    Horn SR, Passias PG, Oh C, et al. Predicting the combined occurrence of poor clinical and radiographic outcomes following cervical deformity corrective surgery. J Neurosurg Spine 2020;32:182–90. Read more...

    Passias PG, Horn SR, Oh C, et al. Predicting the Occurrence of Postoperative Distal Junctional Kyphosis in Cervical Deformity Patients. Neurosurgery 2020;86:E38–46. Read more...

    Passias PG, Segreto FA, Bortz CA, et al. Probability of severe frailty development among operative and nonoperative adult spinal deformity patients: an actuarial survivorship analysis over a 3-year period. Spine J 2020;20:1276–85. Read more...

    Smith JS, Buell TJ, Shaffrey CI, et al. Prospective multicenter assessment of complication rates associated with adult cervical deformity surgery in 133 patients with minimum 1-year follow-up. J Neurosurg Spine 2020;33:588–600. Read more...

    Bortz C, Passias PG, Pierce KE, et al. Radiographic benefit of incorporating the inflection between the cervical and thoracic curves in fusion constructs for surgical cervical deformity patients. J Craniovertebr Junction Spine 2020;11:131–8. Read more...

    Kim HJ, York PJ, Elysee JC, et al. Cervical, Thoracic, and Spinopelvic Compensation After Proximal Junctional Kyphosis (PJK): Does Location of PJK Matter? Glob Spine J 2020;10:6–12. Read more...

    Kim HJ, Wang S-J, Lafage R, et al. Recurrent Proximal Junctional Kyphosis: Incidence, Risk Factors, Revision Rates, and Outcomes at 2-Year Minimum Follow-up. Spine (Phila Pa 1976) 2020;45:E18–24. Read more...

    Lafage R, Beyer G, Schwab F, et al. Risk Factor Analysis for Proximal Junctional Kyphosis After Adult Spinal Deformity Surgery: A New Simple Scoring System to Identify High-Risk Patients. Glob Spine J 2020;10:863–70. Read more...

    Daniels AH, Reid D, Durand W, et al. Sexual Dysfunction Secondary to Lumbar Stiffness in Adult Spinal Deformity Patients Before and After Long-Segment Spinal Fusion. World Neurosurg 2020;139:e474–9. Read more...

    Protopsaltis TS, Soroceanu A, Tishelman JC, et al. Should Sagittal Spinal Alignment Targets for Adult Spinal Deformity Correction Depend on Pelvic Incidence and Age? Spine (Phila Pa 1976) 2020;45:250–7. Read more...

    Plais N, Bao H, Lafage R, et al. The clinical impact of global coronal malalignment is underestimated in adult patients with thoracolumbar scoliosis. Spine Deform 2020;8:105–13. Read more...

    Protopsaltis TS, Ramchandran S, Tishelman JC, et al. The Importance of C2 Slope, a Singular Marker of Cervical Deformity, Correlates with Patient-reported Outcomes. Spine (Phila Pa 1976) 2020;45:184–92. Read more...

    Segreto FA, Passias PG, Brown AE, et al. The Influence of Surgical Intervention and Sagittal Alignment on Frailty in Adult Cervical Deformity. Oper Neurosurg 2020;18:583–9. Read more...

    Mummaneni PV, Park P, Shaffrey CI, et al. The MISDEF2 algorithm: An updated algorithm for patient selection in minimally invasive deformity surgery. J Neurosurg Spine 2020;32:221–8. Read more...

    Kim HJ, Virk S, Elysee J, et al. The morphology of cervical deformities: A two-step cluster analysis to identify cervical deformity patterns. J Neurosurg Spine 2020;32:353–9. Read more...

    Durand WM, Daniels AH, Hamilton DK, et al. The spino-pelvic ratio: a novel global sagittal parameter associated with clinical outcomes in adult spinal deformity patients. Eur Spine J 2020;29:2354–61. Read more...

    Klineberg EO, Passias PG, Poorman GW, et al. Classifying Complications: Assessing Adult Spinal Deformity 2-Year Surgical Outcomes. Glob Spine J 2020;10:896–907. Read more...

    Daniels AH, Reid DB, Durand WM, et al. Upper-thoracic versus lower-thoracic upper instrumented vertebra in adult spinal deformity patients undergoing fusion to the pelvis: Surgical decision-making and patient outcomes. J Neurosurg Spine 2020;32:600–6. Read more...

    Ames CP, Smith JS, Gum JL, et al. Utilization of Predictive Modeling to Determine Episode of Care Costs and to Accurately Identify Catastrophic Cost Nonwarranty Outlier Patients in Adult Spinal Deformity Surgery: A Step Toward Bundled Payments and Risk Sharing. Spine (Phila Pa 1976) 2020;45:E252–65. Read more...

    Cruz DL, Ayres EW, Spiegel MA, et al. Validation of the recently developed Total Disability Index: A single measure of disability in neck and back pain patients. J Neurosurg Spine 2020;32:533–41. Read more...

    Ogura Y, Gum JL, Hostin RA, et al. Cost-effectiveness of surgical treatment of adult spinal deformity: comparison of posterior-only versus anteroposterior approach. Spine J 2020;20:1464–70. Read more...

    Jain A, Yeramaneni S, Kebaish KM, et al. Cost-Utility Analysis of rhBMP-2 Use in Adult Spinal Deformity Surgery. Spine (Phila Pa 1976) 2020;45:1009–15. Read more...

    Line B, Bess S, Lafage V, et al. Counseling Guidelines for Anticipated Postsurgical Improvements in Pain, Function, Mental Health, and Self-image for Different Types of Adult Spinal Deformity. Spine (Phila Pa 1976) 2020;45:1118–27. Read more...

    Virk S, Elysee J, Gupta M, et al. Defining an Algorithm of Treatment for Severe Cervical Deformity Using Surgeon Survey and Treatment Patterns. World Neurosurg 2020;139:e541–7. Read more...