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Background: With an aging population, degenerative spinal diseases are contributing significantly to the healthcare's burden. Spinal alignment in the context of adult spinal deformities has become an important domain of research., Methods: We conducted a narrative review of the latest considerations in spinal alignment within the context of degenerative spinal conditions, discussed current strategies for morphological assessment and finally identified potential areas for future research., Results: This review reported that degenerative spinal conditions lead to a complex disruption of spinal alignment. It also highlighted the importance of spino-pelvic alignment with specific attention to compensatory mechanisms that occur in response to spinal deformities. Emerging technologies including Artificial Intelligence and epigenetics are showing promises in terms of patient care., Conclusions: Understanding spinal alignment in degenerative conditions underscores the importance of dynamic and individualized assessments. Future research should integrate emerging technologies along with traditional clinical practices in order to optimize patient outcomes and minimize complications for patients suffering from degenerative spinal diseases., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Author(s).)

Objectives: Distal junctional failure (DJF) is less commonly described than proximal junctional failure following posterior spinal fusion, and particularly adult spinal deformity (ASD) surgery. We describe a case series of patients with DJF, taking into account sagittal spinopelvic alignment, and suggest potential risk factors in light of the current literature. Methods: We performed a single-center, retrospective review of posterior spinal fusion patients with DJF who underwent subsequent revision surgery between June 2009 and January 2019. Demographics and surgical details were collected. Radiographical measurements included the following: preoperative and postoperative sagittal and coronal alignment for each index or revision surgery. The upper-instrumented vertebra (UIV), lower instrumented vertebra (LIV), and fusion length were recorded. Results: Nineteen cases (64.7 ± 13.5 years, 12 women, seven men) were included. The mean follow-up was 4.7 ± 2.4 years. The number of instrumented levels was 6.79 ± 2.97. Among the patients, 84.2% (n = 16) presented at least one known DJF risk factor. LIV was frequently L5 (n = 10) or S1 (n = 2). Six patients had an initial circumferential fusion at the distal end. Initial DJFs were vertebral fracture distal to the fusion (n = 5), screw pull-out (n = 9), spinal stenosis (n = 4), instability (n = 4), and one early DJK. The distal mechanical complications after a first revision included screw pull-out (n = 4), screw fracture (n = 3), non-union (n = 2), and an iatrogenic spondylolisthesis. Conclusions: In this case series, insufficient sagittal balance restoration, female gender, osteoporosis, L5 or S1 LIV in long constructs were associated with DJF. Restoring spinal balance and circumferentially fusing the base of constructs represent key steps to maintain correction and prevent revisions.

Background Context: The social and technological mutation of our contemporary period disrupts the traditional dyad that prevails in the relationship between physicians and patients., Purpose: The solicitation of a second opinion by the patient may potentially alter this dyad and degrade the mutual trust between the stakeholders concerned. The doctor-patient relationship has often been studied from the patient's perspective, but data are scarce from the spine surgeon's point of view., Study Design/setting: This qualitative study used the grounded theory approach, an inductive methodology emphasizing field data and rejecting predetermined assumptions., Patient Sample: We interviewed spine surgeons of different ages, experiences, and practice locations. We initially contacted 30 practitioners, but the final number (24 interviews; 11 orthopedists and 13 neurosurgeons) was determined by data saturation (the point at which no new topics appeared)., Outcome Measures: Themes and subthemes were analyzed using semistructured interviews until saturation was reached., Methods: Data were collected through individual interviews, independently analyzed thematically using specialized software, and triangulated by three researchers (an anthropologist, psychiatrist, and neurosurgeon)., Results: Index surgeons were defined when their patients went for a second opinion and recourse surgeons were defined as surgeons who were asked for a second opinion. Data analysis identified five overarching themes based on recurring elements in the interviews: (1) analysis of the patient's motivations for seeking a second opinion; (2) impaired trust and disloyalty; (3) ego, authority, and surgeon image; (4) management of a consultation recourse (measurement and ethics); and (5) the second opinion as an avoidance strategy. Despite the inherent asymmetry in the doctor-patient relationship, surgeons and patients share two symmetrical continua according to their perspective (professional or consumerist), involving power and control on the one hand and loyalty and autonomy on the other. These shared elements can be found in index consultations (seeking high-level care/respecting trust/closing the loyalty gap/managing disengagement) and referral consultations (objective and independent advice/trusting of the index advice/avoiding negative and anxiety-provoking situations)., Conclusions: The second opinion often has a negative connotation with spine surgeons, who see it as a breach of loyalty and trust, without neglecting ego injury in their relationship with the patient. A paradigm shift would allow the second opinion to be perceived as a valuable resource that broadens the physician-patient relationship and optimizes the shared surgical decision-making process., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Study Design: National cross-sectional study., Objective: Thoracic kyphosis (TK) is related to sagittal parameters as pelvic tilt (PT), lumbar lordosis (LL) and pelvic incidence (PI). The equation TK = 2 (PT+LL-PI) was validated for adolescents. The purpose of this study was to investigate if this equation correctly predicts TK regardless of age., Methods: Sagittal alignment parameters were assessed on full spine radiographs of 2599 individuals without spine pathology (1488 females, 1111 males). Calculated TK (CTK) = 2 (PT+LL-PI) and measured TK (MTK) were compared by calculating the gap and using a linear regression between both parameters. Subgroup analyses were performed for gender, age, TK groups (≤20°, 21°-40°, 41°-60°, >60°), and PI groups (<45°, 45°-60°, >60°)., Results: Average values in the total population were: MTK 45.0°, CTK 36.9°. Average TK gap was 8.1°, 5.2° in females (intercept 11.7, slope .61) and 11.9° in males (intercept 7.1, slope .58). The mean gap was 3.6° for 15-34 years, 5.7° under 15 years and it increased progressively after 35 years with a maximum of 19.9° over 80 years. The gap also increased with the amount of MTK: -3.5° for TK<20° up to 17.3° for TK >60°. Differences in gaps were minor between PI groups. The intercept was smallest and slopes >.6 for PI <45° and TK ≤20°., Conclusion: The formula TK=2 (PT+LL-PI) yielded moderate accuracy for adolescents and young adults, but did not fit for over 35 years and under 15. The amount and variance in TK increased in elderly subjects, which made the formula less accurate.

Background: While prolonged operative time and increased levels fused have been shown to increase the risk of prolonged intensive care unit (ICU) length-of-stay (LOS), studies are limited in guiding decision-making regarding the need for intensive care postoperatively. This is especially the case among the cohort of adolescent idiopathic scoliosis (AIS) patients undergoing posterior spinal fusion (PSF); associations between comorbidities and ICU LOS are not well-delineated., Methods: AIS patients who underwent PSF from January 1st, 2016 to December 1st, 2016 at 101 participating centers were identified using the American College of Surgeons (ACS) National Surgical Quality Im-provement Project (NSQIP) Pediatric database. Patients were subsequently grouped by ICU LOS 0-1 day; 2-3 days; and >3 days. Multivariate regression identified predictors of increased ICU LOS., Results: 2,346 AIS patients were included. The >3 days and 2-3 days groups had higher asthma rates compared to 0-1 day. The >3 days group had higher rates of structural airway abnormalities and he-matologic disorders. Cognitive impairment rates were highest for >3-day ICU LOS. Hematologic dis-orders, structural airway abnormalities, asthma and cognitive impairment were associated with prolonged ICU LOS., Conclusion: These results help inform targets for optimization of acute short-term postoperative care as well as assisting in risk stratification to improve outcomes and reduce costs for ICU-level care of AIS patients at ACS NSQIP Pediatric program-participating hospitals. Level of Evidence: III ., Competing Interests: Disclosures: Marine Coste - Stock or stock Options - Johnson & Johnson, Roche, Sanofi-Aventis, Shire. Vincent Challier - Paid presenter or speaker - AOSPINE, SMAIO SA; Research support - CLARI-ANCE SA; Stock or stock Options - FOLLOW SA. Virginie Lafage - Paid consultant - Alphatec Spine DePuy, Stryker; Paid presenter or speaker - John-son & Johnson Company; Editorial or governing board - European Spine Journal; Paid consultant - Globus Medical; Board or committee member - International Spine Study Group; IP royalties – NuVa-sive; Board or committee member - Scoliosis Research Society. Frank J. Schwab - Research support – DePuy. A Johnson & Johnson Company; IP royalties - K2M, Medtronic Sofamor, Danek, Zimmer; Paid Consultant - Mainstay Medical, Medtronic, Zimmer; Re-search Support – NuVasive, Stryker; Board or committee member - Scoliosis Research Society; VP of International Spine Society Group (ISSG); Stock or stock Options - See Spine LLC, VFT Solutions; Editorial or governing board - spine deformity. Carl B. Paulino - Paid presenter or speaker - DePuy, A Johnson & Johnson Company, Ethicon. The remaining authors have no disclosures to report. The manuscript submitted does not contain information about medical device(s)/drug(s)., (Copyright © The Iowa Orthopaedic Journal 2024.)

Study Design: Descriptive radiographic analysis of a prospective multi-center database., Objective: This study aims to provide normative values of spinopelvic parameters and their correlations according to age and pelvic incidence (PI) of subjects without spinal deformity., Methods: After Institutional Review Board (IRB) approval, 1540 full spine radiographs were analyzed. Subjects were divided into 3 groups of PI: low PI < 45°, intermediate PI 45-60°, high PI > 60°, and then stratified by age (20-34, 35-49, 50-64, > 65 Y.O). Pelvic and spinal parameters were measured. Statistical analysis between parameters was performed using Bayesian inference and correlation., Results: Mean age was 53.5 years (845 females, 695 males, range 20-93 years).In low PI group, lumbar lordosis (LL) decrease was mainly observed in the 2 younger age groups.In medium and high PI groups, loss of lordosis was linear during aging and occurred mainly on the distal arch of lordosis. Moderate PI group had a stable lordosis apex and thoracolumbar inflection point. High PI group had a stable thoracolumbar inflection point and a more distal lordosis apex in elderly subjects.For all subjects, kyphosis and pelvic tilt (PT) increased with age.There was a constant chain of correlation between PI and age groups. Proximal lumbar lordosis (PLL) was correlated with kyphosis and sagittal vertical axis (SVA C7), while the distal lumbar lordosis (DLL) was correlated with PI and PT., Conclusion: This study provides a detailed repository of sagittal spinopelvic parameters normative values with detailed analysis of segmental kyphosis and lordosis distribution according to gender, age, and PI.

In the United States, nearly 1.2 million people > 12 years old have human immunodeficiency virus (HIV), which is associated with postoperative complications following orthopedic procedures. Little is known about how asymptomatic HIV (AHIV) patients fare postoperatively. This study compares complications after common spine surgeries between patients with and without AHIV. The Nationwide Inpatient Sample (NIS) was retrospectively reviewed from 2005-2013, identifying patients aged > 18 years who underwent 2-3-level anterior cervical discectomy and fusion (ACDF), ≥4-level thoracolumbar fusion (TLF), or 2-3-level lumbar fusion (LF). Patients with AHIV and without HIV were 1:1 propensity score-matched. Univariate analysis and multivariable binary logistic regression were performed to assess associations between HIV status and outcomes by cohort. 2-3-level ACDF ( n = 594 total patients) and ≥4-level TLF ( n = 86 total patients) cohorts demonstrated comparable length of stay (LOS), rates of wound-related, implant-related, medical, surgical, and overall complications between AHIV and controls. 2-3-level LF ( n = 570 total patients) cohorts had comparable LOS, implant-related, medical, surgical, and overall complications. AHIV patients experienced higher postoperative respiratory complications (4.3% vs. 0.4%,). AHIV was not associated with higher risks of medical, surgical, or overall inpatient postoperative complications following most spine surgical procedures. The results suggest the postoperative course may be improved in patients with baseline control of HIV infection.

Introduction: Osteoporosis affects nearly 200 million individuals worldwide. Given this notable disease burden, there have been increased efforts to investigate complications in patients with osteoporosis undergoing cervical fusion (CF). However, there are limited data regarding long-term outcomes in osteoporotic patients in the setting of ≥4-level cervical fusion., Methods: The New York State Statewide Planning and Research Cooperative System database was used to identify patients who underwent posterior or combined anterior-posterior ≥4-level CF for cervical radiculopathy or myelopathy from 2009 to 2011, with a minimum follow-up surveillance of 2 years. The following were compared between patients with and without osteoporosis: demographics, hospital-related parameters, medical/surgical complications, readmissions, and revisions. Binary multivariate stepwise logistic regression was used to identify independent predictors of outcomes., Results: A total of 2,604 patients were included (osteoporosis: n = 136 (5.2%); nonosteoporosis: n = 2,468). Patients with osteoporosis were older (66.9 ± 11.2 vs. 60.0 ± 11.4 years, P < 0.001), more often female (75.7% vs. 36.2%, P < 0.001), and White (80.0% vs. 65.3%, P = 0.007). Both cohorts had comparable comorbidity burdens (Charlson/Deyo: 1.1 ± 1.2 vs. 1.0 ± 1.3, P = 0.262), total hospital charges ($100,953 ± 94,933 vs. $91,618 ± 78,327, P = 0.181), and length of stay (9.7 ± 10.4 vs. 8.4 ± 9.6 days, P = 0.109). Patients with osteoporosis incurred higher rates of overall medical complication rates (41.9% vs. 29.4%, P = 0.002) and individual surgical complications, such as nonunion (2.9% vs. 0.7%, P = 0.006). Osteoporosis was associated with medical complications (OR = 1.57, P = 0.021), surgical complications (OR = 1.52, P = 0.030), and readmissions (OR = 1.86, P = 0.003) at 2 years., Discussion: Among patients who underwent multilevel cervical fusion, those with osteoporosis had higher risk of adverse postoperative outcomes at two years. These data indicate that preoperative screening and management of osteoporosis may be important for optimizing long-term outcomes in patients who require multilevel CF., Data Availability and Trial Registration Numbers: The data used in this study are available for public use at https://www.health.ny.gov/statistics/sparcs/., Competing Interests: No sources of funding were used for any aspect of this study. No conflicts of interest affected this study in any aspect or manner. The following authors have no conflicts of interest to report: AR, RJV, NVS, GAB, PC, HE, LP, OK, MGD, VC, CBP, and BGD. PGP has received grant funding from CSRS; is a speaker and consultant honoraria from Globus Medical, Medicrea, SpineWave, and Zimmer; and has received other financial support from Allosource. RL has stock in Nemaris. FJS has received grant funding from DePuy, NuVasive, Allosource, K2M, Medtronic, and Si Bone; is a speaker and consultant honoraria from Globus Medical, Mainstay Medical, Medtronic, and ZimmerBiomet; has received royalties from Medicrea, Medtronic, and Zimmer; and serves on boards or committees for SRS, Spine Deformity, and ISSG. VL has received grant funding from DePuy, NuVasive, Allosource, K2M, Medtronic, and Si-Bone; is a speaker and consultant honoraria from Globus Medical, DePuy, and Stryker, has received stock in VFT Solutions; and serves on boards or committees for ISSG and SRS. AHD reports consultant honoraria from EOS, Medicrea, Medtronic Sofamor Danek, Novabone, Orthofix Inc., Spineart, and Stryker; has received royalties from Southern Spine, Spineart, and Springer, and other research support from Orthofix Inc. and Springer., (Copyright © 2022 by the American Academy of Orthopaedic Surgeons.)

Study Design: Retrospective cross-sectional study., Objective: The aim was to describe spinopelvic alignment types by pelvic incidence (PI) and age to compare the Roussouly classification between pediatric and adult populations., Summary of Background Data: The Roussouly classification was validated for adults. Alignment types may vary during growth., Materials and Methods: Radiographs of 1706 non pathologic individuals (5-49 yr) were analyzed. Individuals ≤19 years were stratified by chronological age and skeletal maturity (triradiate cartilage, Risser), and compared with adults. Global and spinopelvic alignment parameters were assessed. Roussouly Types 1, 2, 3, 3A (anteverted pelvis), and 4 were determined. The distribution of parameters was analyzed by Bayesian inference. The relationship between PI and age by Roussouly type was modeled by linear regression., Results: The Sagittal Vertical Axis C7 decreased during growth and was significantly smaller in adults (20-34 yr) (Pr>0.99). Thoracic kyphosis and lumbar lordosis increased during growth and were larger in adults (Pr<0.025). Lordosis increased mainly in the cranial arch (Pr<0.025). PI and pelvic tilt increased during growth and were larger in adults (Pr<0.025). In children and adolescents, PI<45° represented the largest proportion, significantly larger compared with adults (Pr>0.99). Proportions of Roussouly Types 1 and 2 were similar throughout ages. Types 3 and 4 were rarer during the prepubertal period (Pr<0.025). The proportion of Type 3A was significantly higher in children and adolescents (Pr>0.99). Linear regression showed that Type 4 had the largest PI increase with age, with significantly higher curve slope compared with other types (Pr>0.9999). Types 3, 3A and 2 had similar slopes and lowest PI increase with age., Conclusion: Global and spinopelvic alignment changed during childhood and adolescence, leading to different kyphosis and lordosis distribution compared with adults. Growth-related PI increase influenced Roussouly types with typical predominance of Type 3A in the pediatric population and larger PI increase in Type 4., Level of Evidence: Level III., Competing Interests: Y.P.C. is consultant for Stryker, Clariance, SpineVision, Philips and Ceraver; he received royalties and grants unrelated to this study from Stryker and Clariance. B.I. is consultant for Zimmer Biomet, Medtronic and Implanet. B.B. is associate editor for OTSR Elsevier-Masson and consultant for Medicrea, Medtronic, Implanet, Vexim Stryker, and 3M. F.L. is consultant for Spineart and SMAIO. Guillaume Riouallon is consultant for Medtronic, Stryker and NewClip; he received royalties from Euros. V.C. is shareholder of Follow Health SA and consultant for Clariance. I.O. is consultant for Medtronic and Depuy Synthes; he received grants from DePuy Synthes unrelated to this study and royalties from Clariance, Alphatec and Spineart. L.B.is consultant for Neo and Euros; he received grants from DePuy Synthes unrelated to this study. F.S. received funding to attend meetings from Medicrea, Medtronic and Euros. J.-C.L.H. is consultant for Medtronic and BD Bard; he received royalties and grants unrelated to this study from Medtronic. V.F. is consultant for Clariance; he received royalties Medicrea and Clariance. A.F. is consultant for OSD. The remaining authors report no conflicts of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: Retrospective cross-sectional study., Objective: The aim was to describe existing global sagittal alignment parameters across ages and to analyze differences according to gender and pelvic incidence (PI)., Summary of Background Data: Variability with age has been reported. It remains unclear how gender and spinopelvic morphology could additionally influence global alignment parameters., Materials and Methods: Radiographs of 2599 individuals (5-93 y) were analyzed. Translation parameters were: Sagittal Vertical Axis (SVA)-C7, SVA-C2, SVA-Center Acoustic Meatus (CAM), C7/Sacrofemoral Distance (SFD) ratio. Inclination parameters were: C7-Vertical Tilt (VT), T1-VT and T9-VT, Odontoid-Hip Axis (OD-HA), OD-CAM. Pelvic compensation parameters were: T1-Pelvic Angle (TPA), Global Tilt (GT), Spino-Sacral Angle (SSA). Global sagittal alignment (GSA) was considered among formulae. The distribution of parameters was analyzed using a Bayesian inference. Correlations with spinopelvic parameters were investigated., Results: SVA-C7, SVA-C2, SVA-CAM were larger in males and high PI, and increased significantly after 50 years (Pr>0.9999). C7/SFD decreased during growth and was larger in low PI (Pr=0.951). There was no correlation with spinopelvic parameters. Age-related variations of inclination parameters were nonsignificant. T1-VT and T9-VT increased with PI and were significantly larger in high PI (Pr>0.95). C7-VT was significantly larger in low PI (Pr>0.9999). OD-HA and OD-CAM were constant and increased after 80 years. TPA and GT increased with PI (Pr>0.9999) and age after 35 years (Pr>0.9999). SSA decreased nonsignificantly after 50 years. TPA correlated with PI (ρ=0.6130) and pelvic tilt (PT) (ρ=0.8375). GT correlated with PI (ρ=0.5961) and PT (ρ=0.8996). SSA correlated with sacral slope (ρ=0.9026). GSA was larger in high PI (Pr>0.9999) and increased after 35 years (Pr>0.9999). GSA correlated with PT (ρ=0.7732)., Conclusion: Translation parameters increase with age, more prominently in males and high PI. Variations of inclination parameters are smaller. Pelvic compensation parameters and GSA increase with age and are closely related to PT and spinopelvic morphology., Level of Evidence: Level III., Competing Interests: Y.P.C. is consultant for Stryker, Clariance, Philips and Ceraver; he received royalties and grants unrelated to this study from Stryker and Clariance. B.I. is consultant for Zimmer Biomet, Medtronic and Implanet. F.L. is consultant for Spineart and SMAIO. G.R. is consultant for Medtronic, Stryker and NewClip; he received royalties from Euros. V.C. is shareholder of Follow Health SA and consultant for Clariance. I.O. is consultant for Medtronic and Depuy Synthes; he received grants from DePuy Synthes unrelated to this study and royalties from Clariance, Alphatec and Spineart. L.B. is consultant for Neo and Euros; he received grants from DePuy Synthes unrelated to this study. F.S. received funding to attend meetings from Medicrea, Medtronic, and Euros. J.-C.L.H. is consultant for Medtronic and BD Bard; he received royalties and grants unrelated to this study from Medtronic. V.F. is consultant for Clariance; he received royalties Medicrea and Clariance. A.F. is consultant for OSD. B.B. is associate editor for OTSR Elsevier-Masson and consultant for Medicrea, Medtronic, Implanet, Vexim Stryker, and 3M. The remaining authors declare no conflict of interest., (Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Background: There is limited literature evaluating the impact of isolated cannabis use on outcomes for patients following spinal surgery. This study sought to compare 90-day complication, 90-day readmission, as well as 2-year revision rates between baseline cannabis users and non-users following thoracolumbar spinal fusion (TLF) for adult spinal deformity (ASD)., Methods: The New York Statewide Planning and Research Cooperative System (SPARCS) database was queried between January 2009 and September 2013 to identify all patients who underwent TLF for ASD. Inclusion criteria were age ≥18 years and either minimum 90-day (for complications and readmissions) or 2-year (for revisions) follow-up surveillance. Cohorts were created and propensity score-matched based on presence or absence of isolated baseline cannabis use. Baseline demographics, hospital-related parameters, 90-day complications and readmissions, and two-year revisions were retrieved. Multivariate binary stepwise logistic regression identified independent outcome predictors., Results: 704 patients were identified (n=352 each), with comparable age, sex, race, primary insurance, Charlson/Deyo scores, surgical approach, and levels fused between cohorts (all, p>0.05). Cannabis users (versus non-users) incurred lower 90-day overall and medical complication rates (2.4% vs. 4.8%, p=0.013; 2.0% vs. 4.1%, p=0.018). Cohorts had otherwise comparable complication, revision, and readmission rates (p>0.05). Baseline cannabis use was associated with a lower risk of 90-day medical complications (OR=0.47, p=0.005). Isolated baseline cannabis use was not associated with 90-day surgical complications and readmissions, or two-year revisions., Conclusion: Isolated baseline cannabis use, in the absence of any other diagnosed substance abuse disorders, was not associated with increased odds of 90-day surgical complications or readmissions or two-year revisions, though its use was associated with reduced odds of 90-day medical complications when compared to non-users undergoing TLF for ASD. Further investigations are warranted to identify the physiologic mechanisms underlying these findings. Level of Evidence: III ., (Copyright © The Iowa Orthopaedic Journal 2022.)

Purpose: The aim was to describe radiographic cervical sagittal alignment variations according to age, gender and pelvic incidence (PI) and to investigate relationships with thoracic alignment., Methods: A total of 2599 individuals (5-93 years) without spinal deformity were studied. Cranial cervical parameters were: McGregor slope, occipita-C2 angle, McGregor-C2 lordosis and C1-C2 lordosis. Caudal cervical parameters were: C2-C7, cranial arch and caudal arch lordosis and C7- and T1-slope. A Bayesian inference compared parameter distributions. Correlations with spinopelvic and global alignment parameters were investigated., Results: Among cranial cervical parameters, variations of McGregor slope were non-significant. McGregor-C2 lordosis and C1-C2 lordosis were smaller in males and increased significantly during growth, whereas the occipito-C2 angle decreased (Pr > 0.95). The occipito-C2 angle was larger and McGregor-C2 lordosis was smaller in low PI (Pr > 0.95). Among caudal cervical parameters, C2-C7 lordosis and C7- and T1-slope were larger in males and increased after 50 years (Pr > 0.95). Lordosis changes were non-significant in the cranial arch, whereas values increased in the caudal arch after 35 years (Pr > 0.95). Caudal parameter differences were non-significant between PI groups. Strong correlations existed between C2-C7, caudal arch lordosis, C7-slope, T1-slope and thoracic kyphosis. The sagittal vertical axis C2 correlated with caudal arch lordosis and T1-slope (ρ > 0.5; Pr > 0.95)., Conclusion: Cervical alignment parameters vary according to age, gender and PI. In the cranial cervical spine, changes occur mainly during growth. In the caudal cervical spine, lordosis increases in the caudal arch, which is related to thoracic kyphosis increase with age. The caudal cervical arch acts as a compensatory segment by progressive extension, allowing horizontal gaze., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Introduction: Outcomes after anterior cervical diskectomy and fusion (ACDF) and cervical total disk arthroplasty (TDA) are satisfactory, but related morbidity and revision surgery rates are notable. This study sought to determine complication variations among ACDF, TDA, and combined ACDF-TDA as well as predictors of postoperative complications., Methods: Patients undergoing 1- to 2-level ACDF and/or TDA with at least a 2-year follow-up from 2009 to 2011 were identified from the Statewide Planning and Research Cooperative System database. Patient demographics, hospital-related parameters, mortality, and postoperative outcomes were compared, and their predictors were identified using multivariate logistic regression., Results: A total of 16,510 and 449 individuals underwent ACDF and cervical TDA, respectively, and 201 underwent ACDF-TDA. ACDF-TDA patients had the highest rates of cardiac complications and pulmonary embolism (PE) (P ≤ 0.006), whereas TDA patients had higher individual surgical and device/implant/internal fixation complications (P ≤ 0.025). ACDF-TDA patients experienced the lowest rate of revisions. Cervical TDA increased the odds of any surgical complications (OR = 2.5, P = 0.002), overall complications (OR = 1.57, P = 0.034), and revisions (OR = 2.29, P < 0.001). Deyo index predicted any medical/surgical complications (OR = 1.43 and 1.19, respectively). Female sex was associated with increased odds of readmission (OR 1.30, P < 0.001) but was protective against medical complications (OR = 0.81, P = 0.013)., Discussion: Combined ACDF-TDA procedures were not associated with increases in 2-year individual or overall complications, readmissions, or revisions., Level of Evidence: Level 3-Therapeutic study.

Background: Currently, the functional status of patients undergoing spine surgery is assessed with quality-of-life questionnaires, and a more objective and quantifiable assessment method is lacking. Dr. Jean Dubousset conceptually proposed a four-component functional test, but to our knowledge, reference values derived from asymptomatic individuals have not yet been reported, and these are needed to assess the test's clinical utility in patients with spinal deformities., Questions/purposes: (1) What are the reference values for the Dubousset Functional Test (DFT) in asymptomatic people? (2) Is there a correlation between demographic variables such as age and BMI and performance of the DFT among asymptomatic people?, Methods: This single-institution prospective study was performed from January 1, 2018 to May 31, 2018. Asymptomatic volunteers were recruited from our college of medicine and hospital staff to participate in the DFT. Included participants did not report any musculoskeletal problems or trauma within 5 years. Additionally, they did not report any history of lower limb fracture, THA, TKA, or patellofemoral arthroplasty. Patients were also excluded if they reported any active medical comorbidities. Demographic data collected included age, sex, BMI, and self-reported race. Sixty-five asymptomatic volunteers were included in this study. Their mean age was 42 ± 15 years; 27 of the 65 participants (42%) were women. Their mean BMI was 26 ± 5 kg/m. The racial distribution of the participants was 34% white (22 of 65 participants), 25% black (16 of 65 participants), 15% Asian (10 of 65 participants), 9% subcontinental Indian (six of 65 participants), 6% Latino (four of 65 participants), and 10% other (seven of 65 participants). In a controlled setting, participants completed the DFT after verbal instruction and demonstration of each test, and all participants were video recorded. The four test components included the Up and Walking Test (unassisted sit-to-stand from a chair, walk forward/backward 5 meters [no turn], then unassisted stand-to-sit), Steps Test (ascend three steps, turn, descend three steps), Down and Sitting Test (stand-to-ground, followed by ground-to-stand, with assistance as needed), and Dual-Tasking Test (walk 5 meters forwards and back while counting down from 50 by 2). Tests were timed, and data were collected from video recordings to ensure consistency. Reference values for the DFT were determined via a descriptive analysis, and we calculated the mean, SD, 95% CI, median, and range of time taken to complete each test component, with univariate comparisons between men and women for each component. Linear correlations between age and BMI and test components were studied, and the frequency of verbal and physical pausing and adverse events was noted., Results: The Up and Walking Test was completed in a mean of 15 seconds (95% CI, 14-16), the Steps Test was completed in 6.3 seconds (95% CI, 6.0-6.6), the Down and Sitting Test was completed in 6.0 seconds (95% CI, 5.4-6.6), and the Dual-Tasking Test was performed in 13 seconds (95% CI, 12-14). The length of time it took to complete the Down and Sitting (r = 0.529; p = 0.001), Up and Walking (r = 0.429; p = 0.001), and Steps (r = 0.356; p = 0.014) components increased with as the volunteer's age increased. No correlation was found between age and the time taken to complete the Dual-Tasking Test (r = 0.134; p = 0.289). Similarly, the length of time it took to complete the Down and Sitting (r = 0.372; p = 0.005), Up and Walking (r = 0.289; p = 0.032), and Steps (r = 0.366; p = 0.013) components increased with increasing BMI; no correlation was found between the Dual-Tasking Test's time and BMI (r = 0.078; p = 0.539)., Conclusions: We found that the DFT could be completed by asymptomatic volunteers in approximately 1 minute, although it took longer for older patients and patients with higher BMI., Clinical Relevance: We believe, but did not show, that the DFT might be useful in assessing patients with spinal deformities. The normal values we calculated should be compared in future studies with those of patients before and after undergoing spine surgery to determine whether this test has practical clinical utility. The DFT provides objective metrics to assess function and balance that are easy to obtain, and the test requires no special equipment.

Background: Hangman's fractures account for 15% to 20% of all cervical spine fractures. The grading system developed by Effendi and modified by Levine and Edwards is generally used as the basis for management decisions. Nonetheless, the optimal management remains controversial. The objective of this study was to describe the treatments used in France in patients with hangman's fractures. The complications and healing rates were analysed according to the fracture type and treatment used., Hypothesis: Among patients with hangman's fracture, those with disc damage must be treated surgically., Material and Methods: A prospective, multi-centre, observational study was conducted under the aegis of the French Society for Spine Surgery (SociétéFrançaisedeChirurgieRachidienne, SFCR). Patients were included if they had computed tomography (CT) evidence of hangman's fracture. Follow-up data were collected prospectively. Fracture healing was assessed on CT scans obtained 3 and 12 months after the injury. The type of treatment and complications were recorded routinely., Results: We included 34 patients. The fracture type according to Effendi modified by Levine and Edwards was I in 68% of patients, II in 29% of patients, and III in a single patient (3%). The treatment was non-operative in 21 (62%) patients and surgical in 11 (32%). All 28 patients re-evaluated after 1 year had evidence of fracture healing. The remaining 6 patients were lost to follow-up., Conclusion: Hangman's fracture is associated with low rates of mortality and neurological complications. Non-operative treatment is appropriate in Type I hangman's fracture, with a 100% healing rate in our study. Types II and III are characterised by damage to the ligaments and discs requiring either anterior C2-C3 fusion or posterior C1-C3 screw fixation., Level of Evidence: III., (Copyright © 2019 Elsevier Masson SAS. All rights reserved.)

Purpose: The French Society of Spine Surgery (SFCR) conducted a prospective epidemiologic multicenter study. The purpose was to investigate mortality, complication, and fusion rates in patients with odontoid fracture, depending on age, comorbidities, fracture type, and treatment., Methods: Out of 204 patients, 60 were ≤ 70 years and 144 were > 70 years. Demographic data, comorbidities, treatment types and complications (general medical, infectious, neurologic, and mechanical), and death were registered within the first year. Fractures were classified according to Anderson-D'Alonzo and Roy-Camille on the initial CT. A 1-year follow-up CT was available in 144 patients to evaluate fracture consolidation., Results: Type II and oblique-posterior fractures were the most frequent patterns. The treatment was conservative in 52.5% and surgical in 47.5%. The mortality rate in patients ≤ 70 was 3.3% and 16.7% in patients > 70 years (p = 0.0002). Fracture pattern and treatment type did not influence mortality. General medical complications were significantly more frequent > 70 years (p = 0.021) and after surgical treatment (p = 0.028). Neurologic complications occurred in 0.5%, postoperative infections in 2.0%, and implant-related mechanical complications in 10.3% (associated with pseudarthrosis). Fracture fusion was observed in 93.5% of patients ≤ 70 years and in 62.5% >70 years (p < 0.0001). Pseudarthrosis was present in 31.5% of oblique-posterior fractures and in 24.3% after conservative treatment., Conclusions: Age and comorbidities influenced mortality and medical complication rates most regardless of fracture type and treatment choice. Pseudarthrosis represented the main complication, which increased with age. Pseudarthrosis was most frequent in type II and oblique-posterior fractures after conservative treatment.

Background: Three-column osteotomies (3CO) provide substantial correction for adult spinal deformity (ASD), but carry risks of complications and revisions. The risk-benefit balance of 3CO in the elderly remains unclear., Objective: To evaluate sagittal alignment and complications after 3CO in a population over 70-yr old., Methods: Radiographic retrospective review of consecutive patients over 70 yr ("Elderly") undergoing 3CO for ASD. Demographic, operative, and outcomes data were collected. Full-spine radiographs were analyzed at baseline and 2-yr postoperatively. Results were compared to a group of young controls ("Young") matched by global sagittal alignment., Results: Elderly (n = 55) and Young (n = 52) were similar in operating room time, blood loss, levels fused, and revision surgeries. Elderly and Young groups had similar baseline radiographic malalignment for pelvic tilt, pelvic incidence-lumbar lordosis (PI-LL), and sagittal vertical axis (P > .5 for all). At 2-yr postoperatively, both groups underwent significant improvement in the setting of sagittal alignment parameters (Elderly: sagittal vertical axis 150 mm to 59 mm, P < .001; pelvic tilt 33° to 25°, P < .001; PI-LL 35° to PI-LL 6°, P < .001). However, the Elderly group underwent significantly greater correction in PI-LL than the Young group (-29° vs -20°, P = .024). There were no differences in total, intraoperative or postoperative complications or revisions between groups, though the Elderly group had more intraoperative complications when major blood loss was included. The Elderly group had more severe proximal junctional kyphosis (22.1° vs 9.6° in Young; P < .001)., Conclusion: Compared to young patients, elderly patients may achieve the same, or even better, correction in radiographic spinopelvic parameters. In addition, not only the total intraoperative and postoperative complication rates but also revision rates were comparable between both groups.

Introduction: Three types of C1 fracture have been described, according to location: type 1 (anterior or posterior arc), type 2 (Jefferson: anterior and posterior arc), and type 3 (lateral mass). Stability depends on transverse ligament integrity. The main aim of the present study was to analyze complications and consolidation rates according to fracture type, age and treatment., Material and Methods: The French Society of Spinal Surgery (SFCR) performed a multicenter prospective study on C1-C2 trauma. All patients with recent fracture diagnosed on CT were included. Consolidation on CT was studied at 3 months and 1 year. Medical, neurologic, infectious and mechanical complications were inventoried using the KEOPS data-base., Results: Sixty-three of the 417 patients (15.1%) had C1 fracture: type 1 (33.3%), type 2 (38.1%), or type 3 (28.6%). The transverse ligament was intact in 53.9% of cases. Treatment was non-operative in 63.5% of cases, surgical in 27.0%, and surgical after failure of non-operative treatment in 9.5%. There were 8 medical complications, more frequently in patients aged >70 years, following surgery (p<0.0001). The consolidation rate was 84.2% with non-operative treatment, 100% for primary surgery, and 33.3% for secondary surgery (p=0.002). There were 10 cases of non-union, in 4.8% of type 1, 13.6% of type 2 and 33.3% of type 3 fractures (p=0.001)., Conclusion: Medical complications showed association with age and with type of treatment. Non-operative treatment was suited to types 1, 2 and 3 with minimal displacement and intact transverse ligament. C1-C2 fusion was suited to displaced unstable type 2 fracture. Displaced type 3 fracture incurred risk of non-union. Early surgery may be recommended., Level of Evidence: III., (Copyright © 2018. Published by Elsevier Masson SAS.)

Study Design: Inter- and intraobserver reliability study., Object: To assess the reliability of a new radiographic classification of degenerative spondylolisthesis of the lumbar spine (DSLS)., Summary of Background Data: DSLS is a common cause of chronic low back and leg pain in adults. To this date, there is no consensus for a comprehensive analysis of DSLS. The reliability of a new DSLS classification system based on sagittal alignment was assessed., Methods: Ninety-nine patients admitted to our spinal surgery department for surgical treatment of DSLS between January 2012 and December 2015 were included. Three observers measured sagittal alignment parameters with validated software: segmental lordosis (SL), lumbar lordosis (LL), pelvic incidence (PI), pelvic tilt (PT), and sagittal vertical axis (SVA). Full body low-dose lateral view radiographs were analyzed and classified according to three main types: Type 1A: preserved LL and SL; Type 1B: preserved LL and reduced SL (≤5°); Type 2A: PI-LL ≥10° without pelvic compensation (PT <25°); Type 2B: PI-LL ≥10° with pelvic compensation (PT ≥25°); Type 3: global sagittal malalignment (SVA ≥40 mm). The three observers classified radiographs twice with a 3-week interval for intraobserver reproducibility. Interobserver reproducibility was calculated using Fleiss κ and intra-class coefficient. Intraobserver reproducibility was calculated using Cohen κ., Results: Mean age was 68.8 ± 9.8 years. Mean sagittal alignment parameters values were the following: PI: 60.1° ± 12.7°; PI-LL was 12.2° ± 13.9°, PT: 24.7° ± 8.5°; SVA: 44.9 mm ± 44.6 mm; SL: 16.6° ± 8.4°. Intraobserver repeatability showed an almost perfect agreement (ICC > 0.92 and Cohen κ > 0.89 for each observer). Fleiss κ value for interobserver reproducibility was 0.82, with percentage agreement among observers between 88% and 89%., Conclusion: This new classification showed an excellent inter- and intraobserver reliability. This simple method could be an additional sagittal balance tool helping surgeons improve their preoperative DSLS analysis., (Copyright © 2017 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Cervical spine deformity represents a broad spectrum of pathologies that are both complex in etiology and debilitating towards quality of life for patients. Despite advances in the understanding of drivers and outcomes of cervical spine deformity, only one classification system and one system of nomenclature for osteotomy techniques currently exist. Moreover, there is a lack of standardization regarding the indications for each technique. This article reviews the adult cervical deformity (ACD) and current classification and nomenclature for osteotomy techniques, highlighting the need for further work to develop a unified approach for each case and improve communication amongst the spine community with respect to ACD.

Background: Thoracic hyperkyphosis can display pathological deterioration, resulting in either hyperlordotic cervical compensation or sagittal malalignment. Various techniques have been described to treat fixed malalignment. Pedicle subtraction osteotomy (PSO) is commonly used in the lumbar spine and frequently limited to the distal thoracic spine. This series focuses on the surgical specificities of proximal thoracic PSO, with clinical and radiological outcomes., Objective: To report the surgical specificities and assess the clinical and radiological outcomes of proximal thoracic osteotomies for correction of rigid kyphotic deformities., Methods: This is a retrospective review of 10 consecutive patients who underwent single level proximal thoracic PSO (T2-T5). Preoperative and postoperative full-body EOSTM radiographs, perioperative data, and complications were recorded. The surgical technique and its nuances were described in detail., Results: Patients had mean age of 41.8 yr and 50% were female. The technique provided correction of segmental and global kyphosis, 26.6° and 29.5°, respectively. Patients reported reciprocal reduction in C2-C7 cervical lordosis (37.6°-18.6°, P < .001), significantly correlating with the reduction of thoracic hyperkyphosis (R = 0.840, P = .002). Mean operative time was 291 min, blood loss 1650 mL, and mean hospital stay was 13.8 d. Three patients reported complications that were resolved, including 1 patient who was revised because of a painful cross link. There were no neurological complications, pseudarthroses, instrumentation breakage, or wound infections at a minimum of 2-yr follow-up., Conclusion: Proximal thoracic PSO can be a safe and effective technique to treat fixed proximal thoracic hyperkyphosis leading to kyphosis reduction and craniocervical relaxation.

Purpose: There is no consensus for a comprehensive analysis of degenerative spondylolisthesis of the lumbar spine (DSLS). A new classification system for DSLS based on sagittal alignment was proposed. Its clinical relevance was explored., Methods: Health-related quality-of-life scales (HRQOLs) and clinical parameters were collected: SF-12, ODI, and low back and leg pain visual analog scales (BP-VAS, LP-VAS). Radiographic analysis included Meyerding grading and sagittal parameters: segmental lordosis (SL), L1-S1 lumbar lordosis (LL), T1-T12 thoracic kyphosis (TK), pelvic incidence (PI), pelvic tilt (PT), and sagittal vertical axis (SVA). Patients were classified according to three main types-1A: preserved LL and SL; 1B: preserved LL and reduced SL (≤5°); 2A: PI-LL ≥10° without pelvic compensation (PT < 25°); 2B: PI-LL ≥10° with pelvic compensation (PT ≥ 25°); type 3: global sagittal malalignment (SVA ≥40 mm)., Results: 166 patients (119 F: 47 M) suffering from DSLS were included. Mean age was 67.1 ± 11 years. DSLS demographics were, respectively: type 1A: 73 patients, type 1B: 3, type 2A: 8, type 2B: 22, and type 3: 60. Meyerding grading was: grade 1 (n = 124); grade 2 (n = 24). Affected levels were: L4-L5 (n = 121), L3-L4 (n = 34), L2-L3 (n = 6), and L5-S1 (n = 5). Mean sagittal parameter values were: PI: 59.3° ± 11.9°; PT: 24.3° ± 7.6°; SVA: 29.1 ± 42.2 mm; SL: 18.2° ± 8.1°. DSLS types were correlated with age, ODI and SF-12 PCS (ρ = 0.34, p < 0.05; ρ = 0.33, p < 0.05; ρ = -0.20, and p = 0.01, respectively)., Conclusion: This classification was consistent with age and HRQOLs and could be a preoperative assessment tool. Its therapeutic impact has yet to be validated., Level of Evidence: 4.

OBJECTIVE It is becoming increasingly necessary for surgeons to provide evidence supporting cost-effectiveness of surgical treatment for cervical spine pathology. Anticipating surgical risk is critical in accurately evaluating the risk/benefit balance of such treatment. Determining the risk and cost-effectiveness of surgery, complications, revision procedures, and mortality rates are the most significant limitations. The purpose of this study was to determine independent risk factors for medical complications (MCs), surgical complications (SCs), revisions, and mortality rates following surgery for patients with cervical spine pathology. The most relevant risk factors were used to structure an index that will help quantify risk and anticipate failure for such procedures. METHODS The authors of this study performed a retrospective review of the National Inpatient Sample (NIS) database for patients treated surgically for cervical spine pathology between 2001 and 2010. Multivariate models were performed to calculate the odds ratio (OR) of the independent risk factors that led to MCs and repeated for SCs, revisions, and mortality. The models controlled for age (< and > 65 years old), sex, race, revision status (except for revision analysis), surgical approach, number of levels fused/re-fused (2-3, 4-8, ≥ 9), and osteotomy utilization. ORs were weighted based on their predictive category: 2 times for revision surgery predictors and 4 times for mortality predictors. Fifty points were distributed among the predictors based on their cumulative OR to establish a risk index. RESULTS Discharges for 362,989 patients with cervical spine pathology were identified. The mean age was 52.65 years, and 49.47% of patients were women. Independent risk factors included medical comorbidities, surgical parameters, and demographic factors. Medical comorbidities included the following: pulmonary circulation disorder, coagulopathy, metastatic cancer, renal failure, congestive heart failure, alcohol abuse, neurological disorder, nonmetastatic cancer, liver disease, rheumatoid arthritis/collagen vascular diseases, and chronic blood loss/anemia. Surgical parameters included posterior approach to fusion/re-fusion, ≥ 9 levels fused/re-fused, corpectomy, 4-8 levels fused/re-fused, and osteotomy; demographic variables included age ≥ 65 years. These factors increased the risk of at least 1 of MC, SC, revision, or mortality (risk of death). A total of 50 points were distributed among the factors based on the cumulative risk ratio of every factor in proportion to the total risk ratios. CONCLUSIONS This study proposed an index to quantify the potential risk of morbidity and mortality prior to surgical intervention for patients with cervical spine pathology. This index may be useful for surgeons in patient counseling efforts as well as for health insurance companies and future socioeconomics studies in assessing surgical risks and benefits for patients undergoing surgical treatment of the cervical spine.

Background: Although cervical spondylotic myelopathy (CSM) can be devastating, its relative impact on general health remains unclear. Patient responses to the Short Form Survey 36-Health Survey (SF-36) Physical Component Summary (PCS)/Mental Component Summary (MCS) were compared between CSM and other diseases to evaluate their respective impacts on quality of life. The objective of this study was to compare SF-36 PCS/MCS scores in CSM with population and disease-specific norms., Methods: Retrospective analysis of a prospective, multicenter AOSpine North American CSM Study database. Inclusion criteria were symptomatic disease, age older than 18 years, cord compression on magnetic resonance imaging or computed tomography myelography, and baseline SF-36 values. SF-36 PCS/MCS scores in CSM were compared with national normative values and disease-specific norms using Student t test. Analysis of variance was used to assess differences across age groups and offsets from age-matched controls. Threshold for significance was P < 0.05., Results: There were 285 patients who met the inclusion criteria. The mean age was 56.6 ± 12.0 years, with male predominance (60%). SF-36 scores revealed significant baseline disability (PCS: 34.5 ± 9.8; MCS: 41.5 ± 14.4). Although there were no differences across age groups, when compared with age-matched normative data, younger patients had a larger PCS offset than older patients. CSM caused worse physical disability than most diseases except heart failure. Only back pain/sciatica induced worse mental disability., Conclusions: CSM affects quality of life to an extent greater than diabetes or cancer. Although mean impact of CSM does not vary with age, younger patients suffer from greater differences in baseline function. This study highlights the impact of myelopathy on patient function, particularly among younger age groups, and suggests that CSM merits a similar caliber of healthy policy attention as more well-studied diseases., (Published by Elsevier Inc.)

Study Design: Retrospective review of the Nationwide Inpatient Sample from 2001 to 2010, a prospectively collected national database., Objective: Structure an index to quantify adult spinal deformity (ASD) surgical risk based on risk factors for medical complications, surgical complications, revisions (R), mortality (M) rates, and length of hospital stay., Summary of Background Data: Evidence supporting ASD surgery cost-effectiveness and anticipating surgical risk is critical to evaluate the risk/benefit balance of such treatment for patients., Materials and Methods: Discharges ages 25+, 4+ levels fused, diagnoses specific for scoliosis, and refusions. Five multivariate models determined independent risk factors that increased the risk of ≥1 for medical complications, surgical complications, R, M, and length of hospital stay. Models controlled for age, sex, race, revision status, surgical approach, levels fused, and osteotomy utilization. Odds ratios (ORs) were weighted using Nationwide Inpatient Sample weight files and based on their predictive category: 2 times for revision predictors and 4 times for mortality predictors. Predictors with OR≥1.5 were considered clinically relevant. Fifty points were distributed among the predictors based on their accumulative OR to establish a risk index., Results: A total of 10,912 ASD discharges were identified (mean age: 62 y; 73% females; 14% revision cases). The structured risk index incorporated the following factors based on accumulative ORs: pulmonary circulation disorder (42.05), drug abuse (21.86), congestive heart failure (15.25), neurological disorder (17.31), alcohol abuse (13.24), renal failure (11.64), age>65 (12.28), coagulopathy (11.65), level +9 (6.7), revision (3.35), and osteotomy (3). These risk factors were scored: 14, 7, 5, 5, 4, 4, 4, 4, 2, 1, 1, respectively. Three risk thresholds were proposed: mild (0-10), moderate (10-20), severe >20/50 points., Conclusions: This study proposes an index to quantify the possible risk of morbidity before ASD surgery that will help patients, health insurance companies, and socioeconomic studies in assessing surgical risk/benefits., Level of Evidence: Level III.

Study Design: Retrospective single-center., Objective: To investigate rotatory subluxation (RS) in adult spinal deformity (ASD) with three-dimensional (3D) stereoradiographic images and analyze relationships between RS, transverse plane parameters, spinopelvic parameters, and clinical outcomes., Background: Recent research has demonstrated that sagittal plane malalignment and listhesis correlate with ASD patient-reported outcomes. However, there is still a lack of knowledge regarding the clinical impact of 3D evaluation and rotatory subluxation. Recent developments in stereoradiography allow clinicians to obtain full-body standing radiographs with low-dose radiation and 3D reconstruction., Methods: One hundred thirty lumbar ASD patients underwent full-spine biplanar radiographs (EOS Imaging, Paris, France). Clinical outcomes were recorded. Using sterEOS software, spinopelvic parameters and lateral listhesis were measured. 3D transverse plane parameters included apical axial vertebral rotation, axial intervertebral rotation (AIR), and torsion index (sum of AIR in the curve). ASD patients were divided in three groups: AIR <5°, 5°< AIR <10°, AIR >10°. Groups were compared with respect to radiographic and clinical data. Correlations were performed between the transverse and sagittal plane parameters and clinical outcomes., Results: Patients with AIR >10° were significantly older, with larger Cobb angle (39.5°) and greater sagittal plane deformity (pelvic incidence-lumbar lordosis mismatch 11.7° and pelvic tilt 22.6°). The AIR >10° group had significantly greater apical vertebra axial rotation apex (24.8°), torsion index (45°), and upper-level AIR (21.5°) than the two other groups. Overall, 27% of AIR patients did not have two-dimensional (2D) lateral listhesis. Patients with AIR >10° had significantly worse Oswestry Disability Index and more low back pain., Conclusion: For patients in which lateral listhesis was unreadable in 2D imaging, rotatory subluxation was revealed using stereoradiography and at an earlier disease stage. Moreover, different 3D transverse plane parameters are related to different patient-reported outcomes. Therefore, axial rotation can be considered in evaluation of lumbar degenerative scoliosis severity and prognosis., Level of Evidence: Level III., (Copyright © 2017 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Study Design: A monocentric open-label randomized controlled trial (MRCT)., Objective: Comparison of clinical and radiological outcomes between isolated instrumented posterior fusion (PLF) and associated instrumented posterior fusion and interbody fusion by transforaminal approach (PLF + TLIF) for patients suffering from one-level lumbar degenerative spondylolisthesis (DS) undergoing surgery., Summary of Background Data: DS is a common cause of symptomatic lumbar stenosis. PLF has shown better clinical outcome than decompression with noninstrumented posterolateral fusion. TLIF with interbody cage showed better fusion rate than PLF. There is a need for randomized controlled trials to compare PLF with and without TLIF as to clinical and radiological outcomes., Methods: This is a MRCT comparing PLF and TLIF techniques in surgical treatment of DS. Sixty patients were included in a secured database from 2009 to 2011 and randomized into two groups: 30 PLF with posterior pedicle screws and intertransverse autologuous graft, and 30 TLIF in which an interbody fusion by transforaminal approach was added. Data included clinical (pain and disability), surgical (blood loss and operating time), and radiological (alignment and fusion) parameters at baseline and 2-year follow-up. Comparison was made by Student t test and Chi-square test., Results: There was a significant improvement in each group for pain and disability but no difference between the groups. Radiographic assessment showed better posterolateral fusion rate for TLIF without superiority in segmental lordosis improvement. A case of deformity cascade with spino-pelvic mismatch at baseline was noted in PLF., Conclusion: Posterior decompression and instrumented fusion is an efficient technique that proved its significant clinical benefit in the surgical treatment of DS. TLIF did not show its superiority neither in clinical nor alignment parameters despite a better fusion rate. These results suggest that TLIF is not mandatory in this specific indication. Sagittal alignment analysis by standing full-body images should be considered in DS care., Level of Evidence: 2.

Study Design: Prospective multicenter study of adult spinal deformity (ASD) surgery., Objective: To clarify the effect of ASD surgery on each health-related quality of life (HRQOL) subclass/domain., Summary of Background Data: For patients with ASD, surgery offers superior radiological and HRQOL outcomes compared with nonoperative care. HRQOL may, however, be affected by surgical advantages related to corrective effects, yielding adequate spinopelvic alignment and stability or disadvantages because of long segment fusion., Methods: The study included 170 consecutive patients with ASD from a multicenter database with more than 2-year follow-up period. We analyzed each HRQOL domain/subclass (short form-36 items, Oswestry Disability Index, Scoliosis Research Society-22 [SRS-22] questionnaire), and radiographic parameters preoperatively and at 1 and 2 years postoperatively. We divided the patients into two groups each based on lowest instrumented vertebra (LIV; above L5 or S1 to ilium) or surgeon-determined preoperative pathology (idiopathic or degenerative). Improvement rate (%) was calculated as follows: 100 × |pre.-post.|/preoperative points (%) (+, advantages; -, disadvantages)., Results: The scores of all short form-36 items and SRS-22 subclasses improved at 1 and 2 years after surgery, regardless of LIV location and preoperative pathology. Personal care and lifting in Oswestry Disability Index were, however, not improved after 1 year. These disadvantages were correlated to sagittal modifiers of SRS-Schwab classification similar to other HRQOL. The degree of personal care disadvantage mainly depended on LIV location and preoperative pathology. Although personal care improved after 2 years postoperatively, no noticeable improvements in lifting were recorded., Conclusion: HRQOL subclass analysis indicated two disadvantages of ASD surgery, which were correlated to sagittal radiographic measures. Fusion to the sacrum or ilium greatly restricted the ability to stretch or bend, leading to limited daily activities for at least 1 year postoperatively, although this effect may subside after another year. Consequently, spinal surgeons should note the effect of surgical treatment on each HRQOL domain and counsel patients about the implications of surgery., Level of Evidence: 4.

Study Design: A retrospective cohort., Objective: The aim of this study was to investigate the cervical alignment necessary for the maintenance of horizontal gaze that depends on underlying thoracolumbar alignment., Summary of Background Data: Cervical Sagittal Curve (CC) is affected by thoracic and global alignment. Recent studies suggest large variability in normative CC ranging from lordotic to kyphotic alignment. No previous studies have assessed the effect of global spinal alignment on CC in maintenance of horizontal gaze., Methods: Patients without previous history of spinal surgery and able to maintain their horizontal gaze while undergoing full body imaging were included. Patients were stratified on the basis of thoracic kyphosis (TK) into (<30, 30-40, 40-50, and >50) and then by SRS-Schwab sagittal vertical axis (SVA) modifier into (posterior alignment SVA <0, aligned 0-50, and malaligned >50 mm). Cervical alignment was assessed among SVA grade in TK groups. Stepwise linear regression analysis was applied on random selection of 60% of the population. A simplified formula was developed and validated on the remaining 40%., Results: In each TK group (n = 118, 137, 125, 197), lower CC (C2-C7) was significantly more lordotic by increased Schwab SVA grade. T1 slope and cervical SVA significantly increased with increased thoracolumbar (C7-S1) SVA. Upper CC (C0-C2) and mismatch between T1 slope and CC (T1-CL) were similar. Regression analysis revealed LL minus TK (LL-TK) as an independent predictor (r = 0.640, r = 0.410) with formula: CC = 10- (LL-TK)/2. Validation revealed that the absolute difference between the predicted CC and the actual CC was 8.5°. Moreover, 64.2% of patients had their predicted C2-C7 values within 10° of the actual CC., Conclusion: Cervical kyphosis may represent normal alignment in a significant number of patients. However, in patients with SVA >50 and greater thoracic kyphosis, cervical lordosis is needed to maintain the gaze. Cervical alignment can be predicted from underlying TK and lumbar lordosis, which may be clinically relevant when considering correction for thoracolumbar or cervical deformityLevel of Evidence: 3.

Purpose: In adult spinal deformity (ASD), patients increase pelvic tilt (PT) to maintain standing alignment. Previously, ASD patients with low PT and high disability were described. This study investigates this unusual population in terms of demographic, radiographic, and clinical features after three-column osteotomy (3CO)., Methods: In this multicenter retrospective study, ASD patients underwent single lumbar 3CO. Since PT is proportional to pelvic incidence (PI), the low PT group (LowPT) was defined as having a baseline (BL) PT/PI <25th percentile. HRQOL and full spine x-rays were analyzed at BL and 1 year. LowPT patients were compared to those with high PT/PI (HighPT) in a matched range of T1 pelvic angle., Results: LowPT group had PT/PI <0.4 (n = 31). High disability was reported at baseline for both groups with significant improvement postoperatively, but without difference between groups. LowPT had significantly smaller lack lumbar lordosis but larger SVA, T1 spinopelvic inclination. Postoperatively, there were improvements in all sagittal modifiers except PT in LowPT. 33 % of LowPT had an increase in PT (>5°) postoperatively. This subset had more deformity at baseline, achieving good T1SPi postoperative correction but without achieving the SRS-Schwab target SVA at 1 year., Conclusion: LowPT group had high levels of disability. After 3CO surgery, low PT patients experience only partial improvements in sagittal vertical axis (SVA) and 33 % of the group increased their PT. Further work is necessary to determine optimal realignment approaches for this unusual set of patients. It is unclear if neuromuscular pathology plays a role in the setting of high SVA without pelvic retroversion.

OBJECTIVE Sagittal malalignment requires higher energy expenditure to maintain an erect posture. Because the clinical impact of sagittal alignment is affected by both the severity of the deformity and recruitment of compensatory mechanisms, it is important to investigate new parameters that reflect both disability level and compensatory mechanisms for all patients. This study investigated the clinical relevance of the global sagittal axis (GSA), a novel measure to evaluate the standing axis of the human body. METHODS This is a retrospective review of patients who underwent full-body radiographs and completed health-related quality of life (HRQOL) questionnaires: Oswestry Disability Index (ODI), Scoliosis Research Society-22, EuroQol-5D (EQ-5D), and the visual analog scale for back and leg pain. The GSA was defined as the angle formed by a line from the midpoint of the femoral condyles to the center of C-7, and a line from the midpoint between the femoral condyles to the posterior superior corner of the S-1 sacral endplate. After evaluating the correlation of GSA/HRQOL with sagittal parameters, linear regression models were generated to investigate how ODI and GSA related to radiographic parameters (T-1 pelvic angle, pelvic retroversion, knee flexion, and pelvic posterior translation). RESULTS One hundred forty-three patients (mean age 44 years) were included. The GSA correlated significantly with all HRQOL (up to r = 0.6 with EQ-5D) and radiographic parameters (up to r = 0.962 with sagittal vertical axis). Regression between ODI and sagittal radiographic parameters identified the GSA as an independent predictor (r = 0.517, r 2 = 0.267; p < 0.001). Analysis of standardized coefficients revealed that when controlling for deformity, the GSA increased with a concurrent decrease in pelvic retroversion (-0.837) and increases in knee flexion (+0.287) and pelvic posterior translation (+0.193). CONCLUSIONS The GSA is a simple, novel measure to assess the standing axis of the human body in the sagittal plane. The GSA correlated highly with spinopelvic and lower-extremities sagittal parameters and exhibited remarkable correlations with HRQOL, which exceeded other commonly used parameters.

Background: The maintenance of horizontal gaze is an essential function of upright posture and global sagittal spinal alignment. Horizontal gaze is classically measured by the chin-brow vertical angle (CBVA), which is not readily measured on most lateral spine radiographs., Objective: To evaluate relations between CBVA and the slope of the line of sight, the slope of McGregor's line (McGS), and Oswestry Disability Index., Methods: Patients were identified from a single center database of 531 spine patients who underwent full-body EOS x-rays. Correlations between CBVA, the slope of the line of sight, and McGS were assessed. Using a quadratic regression with Oswestry Disability Index and CBVA, windows of low disability were identified. Comparison of sagittal spinopelvic parameters was carried out between patients with "ascending gaze" and "neutral position.", Results: Three hundred three patients were included (74% female, mean age 54.8 years, body mass index 26.6 ± 6.0 kg/m). CBVA strongly correlated with the slope of the line of sight (r = 0.996) and McGS (r = 0.862). Regression studies between Oswestry Disability Index and CBVA yielded a range of values corresponding to low disability (-4.7 degrees to 17.7 degrees). Similarly, a low disability range for the slope of the line of sight (-5.1 degrees to 18.5 degrees) and McGS (-5.7 degrees to 14.3 degrees) was computed. Patients with "ascending gaze" had a worse spinopelvic alignment than "neutral position" patients., Conclusion: The slope of the line of sight and McGS correlated strongly with CBVA and can be used as surrogate measures. The range of values for these measures corresponding to low disability was identified. These values can be used as a general guideline to assess alignment for diagnostic purposes. Cervical compensatory mechanism may modify the natural head position in sagittally misaligned patients., Abbreviations: CBVA, chin-brow vertical angleHRQoL, health-related quality of lifeMcGS, slope of McGregor's lineODI, Oswestry Disability IndexSLs, slope of the line of sight.

Purpose: Regarding the close interaction between the spinal balance and the pelvis orientation no parameter is routinely used to describe and to evaluate the global spinopelvic balance, taking into account simultaneously the spinal part and the pelvic part of the global alignment. The global tilt was described to analyze malalignment, considering spinal and pelvic imbalance together. From a geometrical point of view, the global tilt is the sum of the C7 vertical tilt and the pelvic tilt. The aim of this study is to evaluate the global tilt by analyzing its correlation with spinal malalignment., Methods: A cohort of patients who underwent a lumbar pedicle subtraction osteotomy (PSO) for major sagittal malalignment was realized. All patients had preoperative and postoperative full spine EOS radiographies to measure spinopelvic parameters. The lack of lordosis was calculated after prediction of theoretical lumbar lordosis. Correlation analysis between different spinopelvic parameters, including the global tilt, was performed for preoperative and postoperative values., Results: Thirty-one consecutive patients were included. All parameters were correlated with spinal malalignment but the global tilt was the most correlated parameter in preoperative (r = 0.71) and in postoperative (r = 0.78). When spinal and pelvic parameters were analyzed separately, 19% of patients presented mismatches between spine and pelvis., Conclusion: This study highlights the interest of a global parameter evaluating the spinal balance and the pelvic balance together. The global tilt appeared to be the most correlated parameter in this study with spinal malalignment and could be used for the interpretation of clinical series in spine surgery.

Object: Previous forceplate studies analyzing the impact of sagittal-plane spinal deformity on pelvic parameters have demonstrated the compensatory mechanisms of pelvis translation in addition to rotation. However, the mechanisms recruited for this pelvic rotation were not assessed. This study aims to analyze the relationship between spinopelvic and lower-extremity parameters and clarify the role of pelvic translation., Methods: This is a retrospective study of patients with spinal deformity and full-body EOS images. Patients with only stenosis or low-back pain were excluded. Patients were grouped according to T-1 spinopelvic inclination (T1SPi): sagittal forward (forward, > 0.5°), neutral (-6.3° to 0.5°), or backward (< -6.3°). Pelvic translation was quantified by pelvic shift (sagittal offset between the posterosuperior corner of the sacrum and anterior cortex of the distal tibia), hip extension was measured using the sacrofemoral angle (SFA; the angle formed by the middle of the sacral endplate and the bicoxofemoral axis and the line between the bicoxofemoral axis and the femoral axis), and chin-brow vertical angle (CBVA). Univariate and multivariate analyses were used to compare the parameters and correlation with the Oswestry Disability Index (ODI)., Results: In total, 336 patients (71% female; mean age 57 years; mean body mass index 27 kg/m(2)) had mean T1SPi values of -8.8°, -3.5°, and 5.9° in the backward, neutral, and forward groups, respectively. There were significant differences in the lower-extremity and spinopelvic parameters between T1SPi groups. The backward group had a normal lumbar lordosis (LL), negative SVA and pelvic shift, and the largest hip extension. Forward patients had a small LL and an increased SVA, with a large pelvic shift creating compensatory knee flexion. Significant correlations existed between lower-limb parameter and pelvic shift, pelvic tilt, T-1 pelvic angle, T1SPi, and sagittal vertical axis (0.3 < r < 0.8; p < 0.001). ODI was significantly correlated with knee flexion and pelvic shift., Conclusions: This is the first study to describe full-body alignment in a large population of patients with spinal pathologies. Furthermore, patients categorized based on T1SPi were found to have significant differences in the pelvic shift and lower-limb compensatory mechanisms. Correlations between lower-limb angles, pelvic shift, and ODI were identified. These differences in compensatory mechanisms should be considered when evaluating and planning surgical intervention for adult patients with spinal deformity.

Study Design: Retrospective multicenter database review., Objective: The aim of this study was to evaluate national postoperative outcomes and hospital characteristics trends from 2001 to 2010 for advanced age CSM patients., Summary of Background Data: Recent studies show increases in US cervical spine surgeries and CSM diagnoses. However, few have compared national outcomes for elderly and younger CSM patients., Methods: A Nationwide Inpatient Sample (NIS) analysis from 2001 to 2010, including CSM patients 25+ who underwent anterior and/or posterior cervical fusion or laminoplasty. Fractures, 9+ levels fused, or any cancers were excluded. Measures included demographics, outcomes, and hospital-related data for 25 to 64 versus 65+ and 65 to 75 versus 76+ age groups. Univariate and logistic regression modeling evaluated procedure-related complications risk in 65+ and 76+ age groups (OR[95% CI])., Results: Discharges for 35,319 patients in the age range of 25 to 64 years and 19,097 at the age 65+ years were identified. Average comorbidity indices for patients at 65+ years were higher compared to the 25 to 64 years age group (0.79 vs. 0.0.44, P < 0.0001), as was the total complications rate (11.39% vs. 5.93%, P < 0.0001) and charges ($57,449.94 vs. $49,951.11, P < 0.0001). Hospital course for aged 65+ patients was longer (4.76 vs. 3.26 days, P < 0.0001). Mortality risk was higher in the 65+ cohort (3.38[2.93-3.91]), adjusted for covariates. 65+ patients had increased risk of all complications except device-related, for which they had decreased risk (0.61[0.56-0.67]). Patients 76+ years displayed increased hospital charges ($59,197.60 vs. $56,601.44, P < 0.001) and courses (5.77 vs. 4.28 days, P < 0.001) compared to those in the age group 65 to 75 years. These same patients presented with increased Deyo scores (0.83 vs. 0.77, P < 0.001), had increased total complications rate (13.87% vs. 10.20%, P < 0.001), and displayed increased risk for postoperative shock (6.34 [11.16-3.60], P < 0.001), digestive system (1.92 [2.40-1.54], P < 0.001), and wound dehiscence (1.71 [2.56-1.15], P < 0.001)., Conclusion: Patients aged 65+ years undergoing CSM surgical management have a higher mortality risk, more procedure-related complications, higher comorbidity burden, longer hospital course, and higher charges. This study provides clinically useful data for surgeons to educate patients and to improve outcomes.

Study Design: Retrospective review of prospective, multicenter database., Objective: The aim of the study was to determine age-specific spino-pelvic parameters, to extrapolate age-specific Oswestry Disability Index (ODI) values from published Short Form (SF)-36 Physical Component Score (PCS) data, and to propose age-specific realignment thresholds for adult spinal deformity (ASD)., Summary of Background Data: The Scoliosis Research Society-Schwab classification offers a framework for defining alignment in patients with ASD. Although age-specific changes in spinal alignment and patient-reported outcomes have been established in the literature, their relationship in the setting of ASD operative realignment has not been reported., Methods: ASD patients who received operative or nonoperative treatment were consecutively enrolled. Patients were stratified by age, consistent with published US-normative values (Norms) of the SF-36 PCS (<35, 35-44, 45-54, 55-64, 65-74, >75  y old). At baseline, relationships between between radiographic spino-pelvic parameters (lumbar-pelvic mismatch [PI-LL], pelvic tilt [PT], sagittal vertical axis [SVA], and T1 pelvic angle [TPA]), age, and PCS were established using linear regression analysis; normative PCS values were then used to establish age-specific targets. Correlation analysis with ODI and PCS was used to determine age-specific ideal alignment., Results: Baseline analysis included 773 patients (53.7 y old, 54% operative, 83% female). There was a strong correlation between ODI and PCS (r = 0.814, P < 0.001), allowing for the extrapolation of US-normative ODI by age group. Linear regression analysis (all with r > 0.510, P < 0.001) combined with US-normative PCS values demonstrated that ideal spino-pelvic values increased with age, ranging from PT = 10.9 degrees, PI-LL = -10.5 degrees, and SVA = 4.1 mm for patients under 35 years to PT = 28.5 degrees, PI-LL = 16.7 degrees, and SVA = 78.1 mm for patients over 75 years. Clinically, older patients had greater compensation, more degenerative loss of lordosis, and were more pitched forward., Conclusion: This study demonstrated that sagittal spino-pelvic alignment varies with age. Thus, operative realignment targets should account for age, with younger patients requiring more rigorous alignment objectives.

Study Design: Retrospective review of a prospective database., Objective: To describe a novel method that uses baseline normalization and area under the curve (AUC) to compare surgical outcomes between patients surgically treated anteriorly versus posteriorly for cervical spondylotic myelopathy (CSM)., Summary and Background Data: It is important to control for baseline characteristics, especially disease severity, when evaluating differences in outcomes between 2 treatment groups. However, current methods of reporting outcomes are limited perhaps diminish the health impact of the entire postoperative recovery experience., Methods: In the prospective, multicenter AO Spine North America CSM database, 147 patients had complete modified Japanese Orthopaedic Association (mJOA) data at baseline and at 6-, 12-, and 24-months postoperatively and were either treated anteriorly (n = 94) or posteriorly (n = 53). Each patient's follow-up mJOA scores were normalized by dividing them by the patient's baseline value. A graph was then plotted with the time point on the x-axis and the normalized score or "recovery index" on the y-axis. The AUC was calculated and then compared between the anterior and posterior surgical approach groups., Results: The non-normalized recovery profile of the anterior group was better than that of the posterior group, as the patients treated anteriorly had less functional impairment at baseline. After normalization, patients in the anterior and posterior group had similar recovery indices and AUCs at 6-months following surgery. At 24-months, patients treated posteriorly had a significantly higher recovery index (1.32) and a larger AUC (16.3) than those treated anteriorly (1.11, 14.5, P = 0.004 and P = 0.006, respectively)., Conclusion: This is the first study to apply AUC analysis to patients with CSM. In surgical patients with CSM, those treated anteriorly achieved a higher mJOA score at all time points than those treated posteriorly. The recovery indices, however, were not significantly different between approach groups at 6 months., Level of Evidence: 3.