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Study Design: Prospective Cohort Study., Objective: The present study aims to determine if the racial representation of patients enrolled in a large prospective scoliosis registry is reflective of the general United States population. Further, we studied whether there was an association between race, pre-operative parameters, outcomes and loss to follow-up., Methods: Prospectively collected data for patients who underwent spinal fusion for adolescent idiopathic scoliosis (AIS) was reviewed, including self-reported race/ethnicity. The U.S. pediatric population and U.S. patients enrolled in the prospective registry were compared. The data obtained was analyzed for variations between races, for pre-operative variables and follow-up., Results: Of the 2210 included patients in the registry 66% of patients reported as White, while 52% of the 2018 U.S. pediatric population reported as White. 15% of the registry reported as Hispanic/Latino compared to 22% of the U.S. pediatric population, 13% Black compared to 14% of the U.S. pediatric population, and 4% Asian compared to 5% of the U.S. pediatric population. Asian and White patients had statistically significant higher 2-year follow-up in all but one of six enrollment sites ( P < 0.001). Native American, Other, and Hispanic/Latino patients had the highest BMIs. Native American and Black patients had the highest pre-op thoracic Cobb angles. Pre-op ages of Black, Hispanic, and Native American patients were statistically lower ( P < 0.01)., Conclusion: This study demonstrates the association between race and patient follow-up and pre-operative factors in patients who underwent surgery for AIS. Black, Native American, and Hispanic populations were underrepresented both at pre-op and follow-up when compared to their relative proportion in the U.S. pediatric population., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Julia Todderud, Bharadwaj Jilakara or any member of his or her immediate family, has no funding or commercial associations (e.g. consultancies, stock ownership, equity interest, patent/licensing arrangements, etc.) that might pose a conflict of interest in connection with the submitted article. Setting Scoliosis Straight Foundation receives research grants from DePuy Synthes Spine, Medtronic Spine, ZimVie, NuVasive, Stryker Spine, Atec/EOS Imaging in support of Harms Study Group research. Dr Larson reports consulting activities with OrthoPediatrics, Medtronic, Zimmer Biomet, Depuy Synthes, and Globus Medical outside of the submitted work. Ms. Marks reports she is employed at Setting Scoliosis Straight Foundation. Dr Newton reports grants/research support to his institution from Depuy Synthes, EOS Imaging, Scoliosis Research Society Stryker Spine, Alphatech, Setting Scoliosis Straight Foundation, and royalties from Depuy Synthes, Thieme Publishing, Stryker/K2M, and consulting feeds from Depuy Synthes, Stryker/K2M, MiRus, Globus Medical, Pacira, and Medtronic, and other stock with Accelus and with Spinology. Dr Fletcher reports consulting activities with Medtronic, CRICO, and Orthopediatrics and research funding from Harrison Foundation, Scoliosis Research Society, and 1998 Society outside of the submitted work. Dr Pahys reports consulting with DePuy Synthes, Nuvasive, and ZimVie outside of the submitted work.

Study Design: Retrospective multicenter study., Objective: We reviewed 15-year trends in operative factors, radiographic and quality of life outcomes, and complication rates in children with cerebral palsy (CP)-related scoliosis who underwent spinal fusion., Summary of Background Data: Over the past two decades, significant efforts have been made to decrease complications and improve outcomes of this population., Materials and Methods: We retrospectively reviewed a multicenter registry of pediatric CP patients who underwent spinal fusion from 2008 to 2020. We evaluated baseline and operative, hospitalization, and complication data as well as radiographic and quality of life outcomes at a minimum 2-year follow-up., Results: Mean estimated blood loss and transfusion volume declined from 2.7±2.0 L in 2008 to 0.71±0.34 L in 2020 and 1.0±0.5 L in 2008 to 0.5±0.2 L in 2020, respectively, with a concomitant increase in antifibrinolytic use from 58% to 97% (all, P <0.01). Unit rod and pelvic fusion use declined from 33% in 2008 to 0% in 2020 and 96% in 2008 to 79% in 2020, respectively (both, P <0.05). Mean postoperative intubation time declined from 2.5±2.6 to 0.42±0.63 days ( P< 0.01). No changes were observed in preoperative and postoperative coronal angle and pelvic obliquity, operative time, frequency of anterior/anterior-posterior approach, and durations of hospital and intensive care unit stays. Improvements in the Caregiver Priorities and Child Health Index of Life with Disabilities postoperatively did not change significantly over the study period. Complication rates, including reoperation, superficial and deep surgical site infection, and gastrointestinal and medical complications remained stable over the study period., Conclusions: Over the past 15 years of CP scoliosis surgery, surgical blood loss, transfusion volumes, duration of postoperative intubation, and pelvic fusion rates have decreased. However, the degree of radiographic correction, the rates of surgical and medical complications (including infection), and health-related quality of life measures have broadly remained constant., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Severe adolescent idiopathic scoliosis (AIS) can be treated with instrumented fusion, but the number of anchors needed for optimal correction is controversial., Methods: We conducted a multicenter, randomized study that included patients undergoing spinal fusion for single thoracic curves between 45° and 65°, the most common form of operatively treated AIS. Of the 211 patients randomized, 108 were assigned to a high-density screw pattern and 103, to a low-density screw pattern. Surgeons were instructed to use ≥1.8 implants per spinal level fused for patients in the high-implant-density group or ≤1.4 implants per spinal level fused for patients in the low-implant-density group. The primary outcome measure was the percent correction of the coronal curve at the 2-year follow-up. The power analysis for this trial required 174 patients to show equivalence, defined as a 95% confidence interval (CI) within a ±10% correction margin with a probability of 90%., Results: In the intention-to-treat analysis, the mean percent correction of the coronal curve was equivalent between the high-density and low-density groups at the 2-year follow-up (67.6% versus 65.7%; difference, -1.9% [95% CI: -6.1%, 2.2%]). In the per-protocol cohorts, the mean percent correction of the coronal curve was also equivalent between the 2 groups at the 2-year follow-up (65.0% versus 66.1%; difference, 1.1% [95% CI: -3.0%, 5.2%]). A total of 6 patients in the low-density group and 5 patients in the high-density group required reoperation (p = 1.0)., Conclusions: In the setting of spinal fusion for primary thoracic AIS curves between 45° and 65°, the percent coronal curve correction obtained with use of a low-implant-density construct and that obtained with use of a high-implant-density construct were equivalent., Level of Evidence: Therapeutic Level I . See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/H763 )., (Copyright © 2023 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: Vertebral body tethering and other non-fusion techniques for the treatment of pediatric idiopathic scoliosis are increasing in popularity. There is limited physician consensus on this topic as the result of a paucity of published data regarding which patients most benefit from non-fusion strategies. Thus, much of the decision-making is left to patients and parents, who must select a treatment based on their goals and values and the information available from health-care providers, the internet, and social media. We sought to understand patient and family preferences regarding the attributes of fusion versus non-fusion surgery that drive these choices., Methods: Patients and families were recruited from 7 pediatric spine centers and were asked to complete a survey-based choice experiment that had been jointly developed with the U.S. Food and Drug Administration (FDA) to evaluate patient preferences. Choices between experimentally designed alternatives were analyzed to estimate the relative importance of outcomes and requirements associated with the choice options (attributes). The attributes included appearance, confidence in the planned correction, spinal motion, device failure, reoperation, and recovery period. The inclusion criteria were (1) an age of 10 to 21 years and (2) a diagnosis of adolescent idiopathic scoliosis in patients who were considering, or who had already undergone, treatment with fusion or non-fusion surgery. Preference weights were estimated from the expected changes in choice given changes in the attributes., Results: A total of 344 respondents (124 patients, 92 parents, and 128 parent/patient dyads) completed the survey. One hundred and seventy-three patients were enrolled prior to surgery, and 171 were enrolled after surgery. Appearance and motion were found to be the most important drivers of choice. For the entire cohort, fusion was preferred over non-fusion. For patients who were considering surgery, the most important attributes were preservation of spinal motion and appearance., Conclusions: Patients and families seeking treatment for idiopathic scoliosis value appearance and preservation of spinal motion and, to a lesser extent, reoperation rates when considering fusion versus non-fusion surgery., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article ( http://links.lww.com/JBJS/H751 )., (Copyright © 2023 Written work prepared by employees of the Federal Government as part of their official duties is, under the United States Copyright Act, a ‘work of the United States Government’ for which copyright protection under that Act is not available. As such, copyright protection does not extend to the contributions of employees of the Federal Government prepared as part of their employment.)

Study Design: Retrospective cohort., Objective: The aim of this study was to design a risk-stratified benchmarking tool for adolescent idiopathic scoliosis (AIS) surgeries., Summary of Background Data: Machine learning (ML) is an emerging method for prediction modeling in orthopedic surgery. Benchmarking is an established method of process improvement and is an area of opportunity for ML methods. Current surgical benchmark tools often use ranks and no "gold standards" for comparisons exist., Materials and Methods: Data from 6076 AIS surgeries were collected from a multicenter registry and divided into three datasets: encompassing surgeries performed (1) during the entire registry, (2) the past 10 years, and (3) during the last 5 years of the registry. We trained three ML regression models (baseline linear regression, gradient boosting, and eXtreme gradient boosted) on each data subset to predict each of the five outcome variables, length of stay (LOS), estimated blood loss (EBL), operative time, Scoliosis Research Society (SRS)-Pain and SRS-Self-Image. Performance was categorized as "below expected" if performing worse than one standard deviation of the mean, "as expected" if within 1 SD, and "better than expected" if better than 1 SD of the mean., Results: Ensemble ML methods classified performance better than traditional regression techniques for LOS, EBL, and operative time. The best performing models for predicting LOS and EBL were trained on data collected in the last 5 years, while operative time used the entire 10-year dataset. No models were able to predict SRS-Pain or SRS-Self-Image in any useful manner. Point-precise estimates for continuous variables were subject to high average errors., Conclusions: Classification of benchmark outcomes is improved with ensemble ML techniques and may provide much needed case-adjustment for a surgeon performance program. Precise estimates of health-related quality of life scores and continuous variables were not possible, suggesting that performance classification is a better method of performance evaluation., Competing Interests: The authors report no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Background: Late infection after posterior spinal arthrodesis for adolescent idiopathic scoliosis (AIS) is the leading cause of late revision. While implant removal and antibiotic therapy are usually curative, patients may experience deformity progression. The goal of this study was to compare outcomes after implant exchange (IE) or removal (IR) to treat late-onset (≥1 y postoperative) deep surgical site infection (SSI) after spinal arthrodesis in patients with AIS., Methods: Using a multicenter AIS registry, patients who underwent posterior spinal fusion between 2005 and 2019 and developed late deep SSI treated with IE or IR were identified. Radiographic, surgical, clinical, and patient-reported outcomes at most recent follow-up were compared., Results: Of 3,705 patients, 47 (1.3%) developed late infection 3.8±2.2 years (range 1 to 9.7 y) after index surgery. Mean follow-up after index surgery was 6.1 years, with 2.8 years (range 25 to 120 mo) of follow-up after revision surgery. Twenty-one patients were treated with IE and 26 with IR. At the latest follow-up, average major-curve loss of correction (1° vs 9°, P <0.001) and increase in kyphosis (1° vs. 8°, P =0.04) were smaller in the IE group than in the IR group. Two IR patients but no IE patients had reoperation. Patients who underwent IE had higher Scoliosis Research Society 22-Item Patient Questionnaire (SRS-22) total scores (4.38 vs. 3.81, P =0.02) as well as better subscores for self-image, function, and satisfaction at the latest follow-up than those who underwent IR only. There were no significant between-group differences in operative duration, estimated blood loss, length of hospital stay, or changes in SRS-22 total scores. No patient had a subsequent infection during the follow-up period., Conclusions: When treating late-onset deep SSI after posterior spinal fusion for AIS, single-stage IE is associated with better maintenance of major curve correction, sagittal profile, and patient-reported outcomes and fewer reoperations compared with IR, with no significant differences in blood loss, operative duration, or length of stay. No time interval from index surgery to IR was observed where the corrected deformity remained stable. Both techniques were curative of infection., Level of Evidence: Level III., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Competing Interests: Competing interests: PF reports grants from DePuy, grants from NIAMS, grants from PCORI, outside the submitted work. JF reports personal fees from The Solsidan Group, grants from Zimmer-Biomet, outside the submitted work; and as a minority shareholder of Prognostix AB. PON reports grants and other from Setting Scoliosis Straight Foundation, other from Rady Children’s Specialists of San Diego, grants, personal fees and non-financial support from DePuy Synthes Spine, grants and other from Scoliosis Research Society, grants from EOS imaging, personal fees from Thieme Publishing, grants from NuVasive, other from Electrocore, other from International Pediatric Orthopedic Think Tank, grants, non-financial support and other from Orthopediatrics, grants, personal fees and non-financial support from Stryker K2M, grants and non-financial support from Alphatech, grants from Mazor Robotics, personal fees from Pacira, personal fees from Globus Medical, personal fees from Medtronic, outside the submitted work; In addition, PON has a patent Anchoring systems and methods for correcting spinal deformities (8540754) with royalties paid to DePuy Synthes Spine, a patent Low profile spinal tethering systems (8123749) licensed to DePuy Spine, a patent Posterior spinal fixation licensed to Stryker/K2M, and a patent Posterior cervical fixation with royalties paid to Stryker/K2M. Danica Marinac-Dabic is an Editorial Board Member.

Purpose: To identify the prevalence and predictors of nonspecific back pain in primary thoracic adolescent idiopathic scoliosis (AIS) patients at 10 years after surgery., Methods: This was a case-control multi-center study. A query of patients who underwent surgical correction of major thoracic AIS between 1997 and 2007 with 10-year follow-up was reviewed. SRS-22 pain scores at 10 years were classified as below normal (≤ 2 standard deviations below average for controls of similar age/sex from published literature) or within/above the control range., Results: One hundred and seventy-one patients with an average of 10.5 ± 0.8-years follow-up were included. Average age at surgery was 14 ± 2 years. The rate of pain was 23% for males and 11% for females (p = 0.08). Differences in age, 10-year SRS mental health score, and radiographic measures were noted. Of 12 patients who underwent revision surgery, 42% reported below normal pain scores versus 11% in cases without revision (p = 0.012). Classification and regression tree (CART) analysis identified 10-year thoracic curve magnitude and 10-year mental health scores as significant predictors. Thoracic Cobb of ≤ 26° at 10 years was associated with a 7% rate of below normal pain scores compared to 27.5% when the curve was > 26° (OR = 4.8, p < 0.05). Of those with a curve ≤ 26°, no patients had abnormal pain if the SRS mental health score was > 4.2 and 15% had more pain than normal if mental health score was ≤ 4.2 (OR 23, p < 0.05)., Conclusion: Increased primary thoracic curve magnitude (> 26°) at 10 years was the primary predictor of increased pain. For patients with less coronal deformity (< 26°), a poor mental health score was associated with an increased rate of pain. Male gender and revision surgery may also play a role in increased pain, however, the overall frequency of these variables were low., Level of Evidence: Level 3., (© 2021. Scoliosis Research Society.)

Design: Prospective cerebral palsy (CP) registry review., Objectives: (1) Evaluate the incidence/risk factors of gastrointestinal (GI) complications in CP patients after spinal fusion (SF); and (2) investigate the validity of the modified Clavien-Dindo-Sink classification., Background: Perioperative GI complications result in increased length of stay (LOS) and patient morbidity/mortality. However, none have analyzed the outcomes of GI complications using an objective classification system., Methods: A prospective/multicenter CP database identified 425 children (mean, 14.4 ± 2.9 years; range, 7.9-21 years) who underwent SF. GI complications were categorized using the modified Clavien-Dindo-Sink classification. Grades I-II were minor complications and grades III-V major. Patients with and without GI complications were compared., Results: 87 GI complications developed in 69 patients (16.2%): 39 minor (57%) and 30 major (43%). Most common were pancreatitis (n = 45) and ileus (n = 22). Patients with preoperative G-tubes had 2.2 × odds of developing a GI complication compared to oral-only feeders (OR 2.2; 95% CI 0.98-4.78; p = 0.006). Similarly, combined G-tube/oral feeders had 6.7 × odds compared to oral-only (OR 6.7; 95% CI 3.10-14.66; p < 0.001). The likelihood of developing a GI complication was 3.4 × with normalized estimated blood loss (nEBL) ≥ 3 ml/kg/level fused (OR 3.41; 95% CI 1.95-5.95; p < 0.001). Patients with GI complications had more fundoplications (29% vs. 17%; p = 0.03) and longer G-tube fasting periods (3 days vs. 2 days; p < 0.001), oral fasting periods (5 days vs. 2 days; p < 0.001), ICU admissions (6 days vs. 3 days; p = 0.002), and LOS (15 days vs. 8 days; p < 0.001). LOS correlated with the Clavien-Dino-Sink classification., Conclusion: Gastrointestinal complications such as pancreatitis and ileus are not uncommon after SF in children with CP. This is the first study to investigate the validity of the modified Clavien-Dindo-Sink classification in GI complications after SF. Our results suggest a correlation between complication severity grade and LOS. The complexity of perioperative enteral nutritional supplementation requires prospective studies dedicated to enteral feeding protocols., Level of Evidence: Therapeutic-level III.

Study Design: A multicenter, prospectively collected database of 20 years of operatively treated adolescent idiopathic scoliosis (AIS) was utilized to retrospectively examine pre- and postoperative thoracic kyphosis at 2-year follow-up., Objective: To determine if the adoption of advanced three-dimensional correction techniques has led to improved thoracic kyphosis correction in AIS., Summary of Background Data: Over the past 20 years, there has been an evolution of operative treatment for AIS, with more emphasis on sagittal and axial planes. Thoracic hypokyphosis was well treated with an anterior approach, but this was not addressed sufficiently in early posterior approaches. We hypothesized that patients with preoperative thoracic hypokyphosis prior to 2000 would have superior thoracic kyphosis restoration, but the learning curve with pedicle screws would reflect initially inferior restoration and eventual improvement., Methods: From 1995 to 2015, 1063 patients with preoperative thoracic hypokyphosis (<10°) were identified. A validated formula for assessing three-dimensional sagittal alignment using two-dimensional kyphosis and thoracic Cobb angle was applied. Patients were divided into 1995-2000 (Period 1, primarily anterior), 2001-2009 (Period 2, early thoracic pedicle screws), and 2010-2015 (Period 3, modern posterior) cohorts. Two-way repeated measures analysis of variance and post-hoc Bonferroni corrections were utilized with P < 0.05 considered significant., Results: Significant differences were demonstrated. Period 1 had excellent restoration of thoracic kyphosis, which worsened in Period 2 and improved to near Period 1 levels during Period 3. Period 3 had superior thoracic kyphosis restoration compared with Period 2., Conclusion: Although the shift from anterior to posterior approaches in AIS was initially associated with worse thoracic kyphosis restoration, this improved with time. The proportion of patients restored to >20° kyphosis with a contemporary posterior approach has steadily improved to that of the era when anterior approaches were more common., Level of Evidence: 3.

Study Design: Prospective cohort review., Objective: To compare two AIS databases to determine if a performance improvement-based surgeon group has different outcomes compared to a national database. The American College of Surgeon's National Quality Improvement Program (ACS-NSQIP) and a surgeon study group (SG) collect prospective data on AIS surgery outcomes. NSQIP offers open enrollment to all institutions, and SG membership is limited to 15 high-volume institutions, with a major initiative to improve surgeon performance. While both provide important outcome benchmarks, they may reflect outcomes that are not relatable nationwide., Methods: The ASC-NSQIP Pediatric Spine Fusion and SG database were queried for AIS 30- and 90-day complication data for 2014 and 2015. Prospective enrollment and a dedicated site coordinator with rigorous data quality assurance protocols existed for both registries. Outcomes were compared between groups with respect to superficial and deep surgical site infections (SSI), neurologic injury, readmission, and reoperation., Results: There were a total of 2927 AIS patients included in the ASC-NSQIP data and 721 in the SG database. Total complication rate was 9.4% NSQIP and 3.6% SG. At 90 days, there were fewer surgical site infections reported by SG than ASC-NSQIP (0.6% vs. 1.6%, p = 0.03). Similarly, there were less spinal cord injuries (0.8% vs 1.5%, p = 0.006), 30-day readmissions (0.8% vs. 2.6%, p = 0.002), and 30-day reoperations (0.6% vs. 1.7%, p = 0.02) in the SG cohort., Conclusions: Comparison of these two data sets suggests a range of complications and readmission rates, with the SG demonstrating lower values. These results are likely multi-factorial with the performance improvement initiative of the SG playing a role. Understanding the rate and ultimate risk factors for readmission and complications from big data sources has the potential to further drive quality improvement., Level of Evidence: III.

Study Design: Retrospective review., Objective: The aim of this study was to determine whether major postoperative complications ("complications") are associated with 2-year improvements in Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) scores after scoliosis surgery, and whether complications and preoperative characteristics predict 2-year improvements in CPCHILD Total score., Summary of Background Data: Spinal arthrodesis can halt the progression of spinal deformity in patients with cerebral palsy (CP)-related scoliosis. However, these patients are prone to postoperative complications., Methods: Using a multicenter CP registry, we identified 222 patients aged ≤21 years who underwent spinal fusion from 2008 to 2015 and had ≥2-year follow-up. We compared CPCHILD score improvement between 71 patients who had 1 or more complications ("complications group") versus 151 who did not ("no-complications group"). Complications were deep infections, thromboembolic events, and cardiopulmonary, gastrointestinal, and neurologic complications. Multiple linear regression was used to identify predictors of 2-year postoperative CPCHILD score improvement (alpha = 0.05)., Results: At 2-year follow-up, the complications group had similar mean improvement in CPCHILD score across all domains compared with the no-complications group (P > 0.05). When stratifying by complication type, deep infection was associated with less improvement in CPCHILD Comfort and Emotions (P = 0.02), Quality of Life (P < 0.01), and Total (P = 0.04) scores. When controlling for Gross Motor Function Classification System subcategory, age, and body mass index, only preoperative CPCHILD Total score and postoperative deep infection (F[4, 176] = 14; P < 0.0001; R = 0.24) predicted 2-year improvement in CPCHILD Total score. Higher preoperative Total score and postoperative deep infection independently predicted less improvement in Total score., Conclusion: Postoperative deep infection and higher preoperative CPCHILD Total score independently predicted less improvement in CPCHILD Total score. Other major postoperative complications were not associated with differences in 2-year postoperative improvements in CPCHILD scores across all domains., Level of Evidence: 3.

Background: Multiple studies have reported on the risks and preventative measures associated with acute surgical site infection (SSI) in patients with adolescent idiopathic scoliosis (AIS). Few studies have evaluated treatment and results. The purpose of this study was to evaluate the need for development of best practice guidelines based on the management of an acute SSI across 9 different centers., Methods: A prospectively collected, multicenter database of patients undergoing surgical correction of AIS was reviewed for all acute SSI. Infection characteristics, treatment methods, and outcomes were summarized., Results: Twenty-three (0.6%) from a total of 3926 AIS patients were treated for an acute SSI, all of which resolved. Twenty patients had documentation of the infection treatment (10 deep infections, 10 superficial). All ten patients with deep infections underwent operative incision and drainage. Six patients ultimately found to have a superficial infection underwent I&D and another 3 had dressing changes in the office. In the deep group, one patient had instrumentation exchanged and seven patients had bone graft removed. All 16 patients who underwent operative I&D had cultures obtained with 11 positive cultures. All deep infection patients were started on IV antibiotics for 2 days to 6 weeks prior to conversion to oral antibiotics. Five of six operative superficial infections were begun on IV antibiotics with conversion to oral antibiotics. Total antibiotic administration ranged from 5 days to 7 months in the deep infection group and 1 to 6 weeks in the superficial group., Conclusions: While deep infections are consistently treated with I&D, there is significant variability in the surgical and medical management of acute SSI. Considering the universal resolution of the infection, there is opportunity for the development of BPG to minimize treatment morbidity and cost, while optimizing outcomes for this major complication., Level of Evidence: Therapeutic-IV.

Study Design: A prospective multicenter study., Objective: To evaluate the effects of sparing lumbar motion segments on spinal mobility and Scoliosis Research Society-22 scores at 10 years after spinal fusion for major thoracic adolescent idiopathic scoliosis (AIS)., Summary of Background Data: In surgical correction for major thoracic AIS, the long-term benefits of sparing lumbar motion segments remain unclear., Methods: A prospective multicenter registry was reviewed and patients with major thoracic AIS (Lenke types 1-4) and availability of both preoperative and 10-year postoperative mobility data were included. Spinal fusions ending at L1 or above were defined as thoracic fusions (T), and at L2 or below as thoracic and lumber fusions (T + L). Spinal mobility was evaluated with a measuring tape. The excursions between the starting and ending positions were measured using the distance from the spinous processes of C7 to S1 for forward flexion (FF), and the distance from the tip of the middle finger to the floor for lateral flexion (LF). Substantial reduction of mobility was defined as a reduction rate (a ratio of postoperative change divided by preoperative mobility) of 40% or more. Motion data were correlated with lowest instrumented vertebra levels and group comparisons were performed., Results: We identified 151 patients (average age, 25.1 years). The spinal mobility decreased with more distal lowest instrumented vertebrae (FF, rho = 0.208; right LF, 0.257; left LF, 0.371; P ≤ 0.01). Consequently, the incidence of substantial reduction of mobility was lower in the T group (n = 109) than in the T + L group (n = 42) (FF: 17.4% vs. 50%, LF: 14.8% vs. 51.2%; P < 0.001). Patients with substantial reduction in LF had lower Scoliosis Research Society-22 scores for pain, function, satisfaction, and total scores than those without substantial reduction at 10-year follow-up (P < 0.05)., Conclusion: The sparing of lumbar motion segments demonstrated clinically significant benefits at 10-year postoperatively., Level of Evidence: 2.

Study Design: Prospective registry. The evolution of spinal instrumentation has provided better outcomes in adolescent idiopathic scoliosis (AIS); however, there is a paucity of reliable prospective information on 10-year post-operative outcomes of modern surgical techniques., Methods: A prospective multicenter registry of patients who had surgical correction of AIS was reviewed. Patients with major thoracic scoliosis (Lenke types 1-4) operated on between 1997 and 2007, with 10-year post-operative follow-up data were included. Radiographic and clinical outcomes including Scoliosis Research Society (SRS)-22 scores and revision surgeries were evaluated., Results: One hundred and seventy-four patients (mean 25.0 years of age at most recent evaluation) were included. Pedicle screw constructs were used in 102 patients (58%), hook or hybrid constructs in 22 (13%), and anterior screw-rod constructs in 50 (29%). The mean pre-operative thoracic Cobb angle was corrected from 53° to 18° initially. At 10-year follow-up, the mean thoracic curve was 22° (mean 57% correction), with 29 patients (16.7%) having loss of correction (LOC) ≥ 10°. There were a total of 14 revision surgeries performed in 13 patients (7.5%). SRS-22 pain (p = 0.035), self-image (p < 0.001), and total scores (p < 0.001) significantly improved at 2-year follow-up. The mean pain score at 10-year follow-up was similar to pre-operative scores and lower (more pain) than previously published mean scores of normal adults aged 20-40 years (p < 0.05)., Conclusions: Spinal fusion patients report SRS-22 quality of life 10 years after scoliosis surgery that is minimally reduced compared to healthy peers and substantially better than an un-operated cohort of comparably aged scoliosis patients. Adolescents with thoracic idiopathic scoliosis should expect little if any change in their health-related quality of life compared to before surgery, high satisfaction, and a 7.5% chance of revision surgery 10 years after their index spinal fusion., Level of Evidence: Therapeutic II.

Study Design: Retrospective review of a multicenter, prospective database., Objective: Our aim was to compare complication rates and maintenance of radiographic correction at 2 years after posterior spinal fusion (PSF) with or without cross-links in patients with cerebral palsy (CP)-related scoliosis., Summary of Background Data: Cross-links are frequently used in PSF to correct scoliosis in patients with CP because they are thought to increase the stiffness and torsional rigidity of the construct., Methods: We reviewed the records of patients with CP who underwent primary PSF with or without cross-links between August 2008 and April 2015. Inclusion criteria were minimum follow-up of 2 years, availability of complications data (implant failure, surgical site infection, revision), and pre- and postoperative measurements of the major curve (measured using the Cobb method). The 256 patients included in this analysis had a mean age of 14.1 ± 2.7 years. Ninety-four patients had cross-links (57% using one cross-link; 43% using two cross-links) and 162 patients did not have cross-links. P < 0.05 was considered statistically significant., Results: The two groups did not differ significantly with regard to sex, age at surgery, preoperative menarche status, Gross Motor Function Classification System level, major curve magnitude, pelvic obliquity, kyphosis, and lordosis angles. There were no significant differences between groups in the correction achieved or the maintenance of correction at 2 years for the major curve, pelvic obliquity, kyphosis, or lordosis (all P > 0.05). Complication rates were similar between the cross-link group (16%, N = 15) and the non-cross-link group (14%, N = 22)., Conclusion: At 2 years after PSF to treat CP-related scoliosis, patients had no significant differences in the degree of correction achieved, the maintenance of correction, or the rate of complications between those whose fusion constructs used cross-links and those whose constructs did not., Level of Evidence: 3.

Purpose: To investigate the effectiveness of surgical reduction in high-grade spondylolisthesis in maintaining or restoring a normal pelvic balance, as related to the QoL., Methods: It is a retrospective analysis of prospectively collected data of 60 patients (17 males, 43 females) aged 15 ± 3.1 years who underwent surgery for high-grade spondylolisthesis and were followed for a minimum of 2 years after surgery. Patients with a residual high-grade slip following surgery were referred to the postoperative high-grade (PHG) group, while patients with a residual low-grade slip were referred to the postoperative low-grade (PLG) group. Pelvic balance was assessed from pelvic tilt and sacral slope, in order to identify patients with a balanced pelvis or unbalanced pelvis. The SRS-22 questionnaire was completed before surgery and at last follow-up., Results: Postoperatively, there were 36 patients with a balanced pelvis and 24 patients with an unbalanced pelvis. The improvement in QoL was better in patients with a postoperative balanced pelvis. There were 14 patients in the PHG group and 46 patients in the PLG group. Four of seven patients (57%) in the PHG group and 21 of 26 patients (81%) in the PLG group with a preoperative balanced pelvis maintained a balanced pelvis postoperatively (P = 0.1). None of the patients in the PHG group and 11 of 20 patients (55%) in the PLG group improved from an unbalanced to a balanced pelvis postoperatively (P < 0.05)., Conclusions: Surgical reduction in high- to low-grade slip is more effective in maintaining and restoring a normal pelvic balance postoperatively. These slides can be retrieved under Electronic Supplementary Material.

Introduction: Accurate prediction of spontaneous lumbar curve correction (SLCC) after selective thoracic fusion (STF) remains difficult. This study sought to improve prediction accuracy of SLCC. The hypothesis was preoperative and intraoperative variables could predict SLCC < 20°., Methods: A multicenter observational prospective analysis was conducted to determine predictors of SLCC in AIS patients that had posterior STF. Curve types included major thoracic curves (Lenke 1, 3-4).The primary outcome variable was to establish prediction models, and a postoperative lumbar curve (LC) ≤ 20° was defined as the target variable. Multivariate logistic regression models were established to study the relationship between selected variables and a LC ≤ 20° versus a LC > 20° at ≥ 2-year follow-up. Single and dual thresholds models in perspective of clinical rationales were applied to find models with the highest positive/negative predictive values (PPV/NPV). The secondary outcome measure was SRS scores at ≥ 2-year follow-up., Results: 410 patients were included. At ≥ 2-year follow-up 282 patients had LC ≤ 20°. These patients had better SRS-22 scores than those with LC > 20° (P = 0.02). The postoperative LC and LC ≤ 20° were predicted by preoperative LC and LC-bending Cobb angle (P < 0.01, r = 0.4-0.6). Logistic regression models could be established to identify patients at risk for failing the target LC ≤ 20°.For preoperative LC and LC-bending, the prediction model achieved a NPV/PPV of 80%/72%. If the postoperative main thoracic curve is combined with the preoperative LC and a gray area for difficult decisions was allowed, model accuracy could even be improved (NPV/PPV = 96%/81%)., Conclusion: An accurate prediction model for postoperative SLCC was established based on a large analysis of prospective STF cases. These models can support prediction and understanding of postoperative SLCC aiding in surgical decision making when contemplating a selective thoracic fusion. These slides can be retrieved under Electronic Supplementary Material.

Background: Intraoperative blood loss during posterior spinal fusion for adolescent idiopathic scoliosis (AIS) has been reportedly associated with multiple factors. This study aims to investigate the effect of thoracic kyphosis on blood loss in AIS spinal fusion., Methods: Patients with AIS who underwent posterior-only procedures for Lenke I and II type curves were identified. All included patients had intraoperative tranexamic acid. Difference in estimated blood loss per blood volume (EBL/BV) was identified between hypokyphotic curves (-), normal curves (N), and hyperkyphotic curves (+) classified based on Lenke sagittal modifier. Regression analysis was then performed with EBL/BV as dependent variable. Independent variables included radiographically measured T5-T12 kyphosis and calculated 3D T5-T12 kyphosis in addition to sex, body mass index (BMI), operative time, number of fused vertebrae, number of Ponte osteotomy levels, and main thoracic coronal curve., Results: In total, 837 patients were included. For female patients: EBL/BV was significantly higher for (-) (18%) compared with (N) (16%) and (+) (14%). A total of 29 female patients had T5-T12≤0 (-15 to 0 degree). EBL/BV was not significantly higher than patients with T5-T12>0 degree (18%±9% vs. 16%±11%; P=0.212). For male patients: EBL/BV was significantly higher in (-) (23%) compared with (+) (16%). In total, 14 male patients had T5-T12≤0 (-13 to 0) degree. EBL/BV was significantly higher than patients with T5-T12>0 degree (32%±18% vs. 18%±13%; P=0.015). Significant factors in predicting EBL/BV were sex, BMI, number of fused levels, and both 2D and 3D T5-T12 kyphosis. Male sex as well as every fused-level predicted an increase in EBL/BV~2%. Every 10-unit decrease in BMI predicted an increase in EBL/BV of 7%. Every 10-degree decrease in 2D or 3D T5-T12 kyphosis predicted an increase in EBL/BV~1%. The impact of the number of Ponte osteotomy levels was not significant., Conclusions: This study supports the role of sagittal thoracic alignment in affecting EBL/BV in AIS surgery. Male patients with severe thoracic lordosis (T5-T12≤0 degree) are the highest risk group for intraoperative bleeding. These findings are helpful in predicting the intraoperative blood loss for patients with AIS undergoing posterior spinal fusion. In addition to sex and number of fused levels, decreased thoracic kyphosis is associated with increased blood loss., Level of Evidence: Level III-prognostic study.

Study Design: Cost-utility analysis OBJECTIVE.: To compare the cost utility of operative versus nonoperative treatment of adolescent idiopathic scoliosis (AIS) and identity factors that influence cost-utility estimates., Summary of Background Data: AIS affects 1% to 3% of children aged 10 to 16 years. When the major coronal curve reaches 50°, operative treatment may be considered. The cost utility of operative treatment of AIS is unknown., Methods: A decision-analysis model comparing operative versus nonoperative treatment was developed for a hypothetical 15-year-old skeletally mature girl with a 55° right thoracic (Lenke 1) curve. The AIS literature was reviewed to estimate the probability, health utility, and quality-adjusted life years (QALYs) for each event. For the conservative model, we assumed that operative treatment did not result directly in any QALYs gained, and the health utility in AIS patients was the same as the age-matched US population mean. Costs were inflation-adjusted at 3.22% per year to 2015 US dollars. Costs and benefits were discounted at 3%. Probabilistic sensitivity analysis was performed using mixed first-order and second-order Monte Carlo simulations. Incremental cost utility ratio (ICUR) and incremental net monetary benefit were calculated. One-way sensitivity analyses were performed by varying cost, probability, and QALY estimates., Results: Operative treatment was favored in 98.5% of simulations, with a median ICUR of $20,600/QALY (95% confidence interval, $20,500-$21,900) below the societal willingness-to-pay threshold (WTPT) of $50,000/QALY. The median incremental net monetary benefit associated with operative treatment was $15,100 (95% confidence interval, $14,800-$15,700). Operative treatment produced net monetary benefit across various WTPTs. Factors that most affected the ICUR were net costs associated with uncomplicated operative treatment, undergoing surgery during adulthood, and development of pulmonary complications., Conclusion: Cost-utility analysis suggests that operative treatment of AIS is favored over nonoperative treatment and falls below the $50,000/QALY WTPT for patients with Lenke 1 curves., Level of Evidence: 2.

Study Design: A retrospective analysis of a prospective registry., Objective: Our objective was to prospectively assess caregivers' perceptions regarding changes in the health-related quality of life (HRQL) of patients with cerebral palsy (CP) after spinal arthrodesis. We assessed caregiver perceptions from three perspectives: 1) qualitative assessment of changes in global quality of life, comfort, and health; 2) relative valuation of spine surgery versus other common interventions in CP patients; and 3) quantitative changes in HRQL scores., Summary of Background Data: Studies of children with CP who undergo surgical treatment of spinal deformity have focused largely on radiographic changes., Methods: We queried a multicenter prospective registry of CP patients with level IV or V motor function according to the Gross Motor Function Classification System who were treated with spinal arthrodesis, and whose caregivers completed preoperative and 2-year postoperative qualitative and quantitative HRQL surveys. A total of 212 caregivers and their patients were included in the study., Results: At 2-year follow-up, most caregivers reported that patients' global quality of life, comfort, and health were "a lot better" after spinal arthrodesis. Spinal arthrodesis was ranked as the most beneficial intervention in the patients' lives by 74% of caregivers, ahead of hip, knee, and foot surgeries and baclofen pump insertion. Gastrostomy tube insertion was the only intervention ranked superior to spinal arthrodesis in terms of impact. Quantitative HRQL scores improved significantly during 2-year follow-up across various domains., Conclusion: In qualitative and quantitative HRQL assessments, caregivers reported overall improvement in patients' lives after spinal arthrodesis. Caregivers ranked spine surgery as the most beneficial intervention in the patients' lives, secondary only to gastrostomy tube insertion., Level of Evidence: 2.

Study Design: Delphi process with multiple iterative rounds using a nominal group technique., Objective: The aim of this study was to use expert opinion to achieve consensus on various methods for minimizing blood loss in patients undergoing posterior spinal fusion (PSF) for adolescent idiopathic scoliosis (AIS)., Background Data: Perioperative blood loss management represents a critical component of safely performing PSF in children with AIS. Little consensus exists on ways to mitigate excessive blood loss after PSF., Methods: An expert panel composed of 21 pediatric spine surgeons was selected. Using the Delphi process and iterative rounds using a nominal group technique, participants in this panel were presented with a detailed literature review and asked to voice opinion collectively during three rounds of voting. Agreement >80% was considered consensus. Interventions without consensus were discussed and revised, if feasible., Results: Consensus was reached to support 21 best practice guideline measures for perioperative management of blood loss in patients undergoing PSF for AIS. Areas included preoperative assessment and preparation, intraoperative strategies to decrease blood loss, and postoperative transfusion indications., Conclusion: We present a consensus-based best practice guideline consisting of 21 recommendations for strategies to minimize and manage blood loss during PSF. This can serve to reduce variability in practice in this area, help develop hospital specific protocols, and guide future research., (Copyright © 2018 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Background: Spinal fusion surgery is associated with greater blood loss in patients with cerebral palsy (CP) than in patients with adolescent idiopathic scoliosis. Risk factors for loss of 1 blood volume (LOBV) in patients with CP have not been well studied. We investigated the incidence of and risk factors for LOBV during spinal fusion surgery in young patients with CP., Methods: We queried a multicenter registry of CP patients for all patients 21 years or younger who had undergone spinal fusion from 2008 through 2013; 272 patients met these criteria. We analyzed data on patient characteristics, preoperative laboratory values, radiographic measures, and surgical characteristics. For univariate analysis, we used χ tests and logistic regression models. Factors that were significant in the univariate analysis were used to construct a multivariate logistic regression model. Significance was set at P<0.01., Results: Incidence of LOBV was 39.7%. On multivariate analysis, unit rod construct and coronal curve magnitude were significantly associated with LOBV (P<0.01). The multivariate model accounted for 32.2% of variance in LOBV. Compared with patients with pedicle screw-rod constructs, patients with unit rod constructs had 12.6-fold higher odds of LOBV (P<0.01). For each 1-degree increase in coronal curve magnitude, odds of LOBV increased 1.03-fold (P<0.01)., Conclusions: In patients with CP, there is a substantial risk of LOBV during spinal fusion surgery. Use of unit rod constructs and greater preoperative coronal curves were significant risk factors for LOBV during surgery., Level of Evidence: Level II.

Purpose: The minimal clinically important difference (MCID) of the Appearance domain of the SRS-22 questionnaire is an increase ≥1.0 in surgically treated patients with adolescent idiopathic scoliosis (AIS). However, no study has sought to identify the factors associated with an SRS-22 Appearance score increase greater than the MCID at 2 years., Methods: A retrospective analysis was performed on a prospectively collected multicenter database of 1020 surgically treated AIS patients with a minimum 2-year follow-up. Patients were divided into two cohorts: "I" = Improved after surgery (Δ Appearance ≥1.0) and "NI" = Not improved after surgery (Δ Appearance <1.0). Univariate regression was used to find a significant difference between the cohorts for individual measures. Multivariate logistic regression was used to find continuous predictors., Results: 663 (65%) patients were improved greater than the MCID, and 357 were not improved (35%). The improved cohort trended toward a greater percentage of underweight patients (p = 0.074) with lower preoperative SRS Appearance scores (p < 0.001) and larger preoperative trunk shifts (p = 0.033). Postoperatively, those patients with greater percent correction of thoracic (p = 0.021) and lumbar (p = 0.003) Cobb angles, smaller apical lumbar translation (p = 0.006), and a greater correction in trunk shift (p = 0.003) were most likely to attain the MCID., Conclusion: Several factors influence which patients are most likely to attain the MCID following surgery for AIS. Factors such as preoperative appearance scores and body weight are patient specific; other factors such as percent correction of the thoracic and lumbar Cobb angles, trunk shift, and lumbar apical translation may be influenced by the surgeon., Level of Evidence: II.

Study Design: Retrospective review of prospective registry., Objectives: To assess the following in children with cerebral palsy (CP) who develop deep surgical site infection (DSSI) after spinal fusion: (1) rate of infection recurrence after treatment; (2) treatments used; (3) radiographic outcomes; and (4) differences in Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) scores versus those of children with no infection (NI)., Summary of Background Data: Studies show high rates of surgical site infection in patients with CP but do not address late recurrence or quality-of-life effects., Methods: One hundred fifty-one children with CP underwent spinal fusion surgery from 2008 through 2011 and had ≥2-year follow-up. Patients who developed DSSI were compared with patients with NI. Student t tests were used to analyze deformity; analysis of variance was used to analyze CPCHILD scores in both groups preoperatively and at final follow-up., Results: Eleven patients developed DSSI. Causative organisms were polymicrobial infection (5 cases), Escherichia coli (2 cases), and Proteus mirabilis, Staphylococcus aureus, Enterococcus faecalis, and Peptostreptococcus (1 case each). All patients underwent irrigation and debridement and received at least 6 weeks of antibiotics. Six had negative-pressure-dressing-assisted wound closure; 5 had primary closure. At mean 4-year follow-up (range, 3-5 years) no patient had recurrent infection. From immediate postoperative to final follow-up, no patient had significant loss of coronal curve (p = .77) or pelvic obliquity (p = .71) correction. However, at final follow-up, comfort and emotions, overall quality-of-life, and total CPCHILD scores in the DSSI group were significantly lower compared with the NI group (p = .005, .022, and .026, respectively)., Conclusions: In children with CP who developed DSSI after spinal fusion, there was no recurrence of infection or deformity after infection treatment. CPCHILD scores in patients with DSSI were lower compared with the NI group., (Copyright © 2016 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Background: The Gross Motor Function Classification System (GMFCS) of cerebral palsy categorizes patients by mobility. Patients at GMFCS level 5 are considered the most disabled and at high risk of hip and spine problems, yet they represent a wide spectrum of function. Our aim was to subclassify patients at GMFCS level 5 who underwent spinal arthrodesis on the basis of central neuromotor impairments and to assess whether subclassification predicted postoperative complications and changes in health-related quality of life., Methods: Using a prospective cerebral palsy registry, we identified 199 patients at GMFCS level 5 who underwent spinal arthrodesis from 2008 to 2013. Patients were assigned to subgroups according to preoperative central neuromotor impairments: the presence of a gastrostomy tube, a tracheostomy, history of seizures, and nonverbal status. Nine percent of patients had 0 impairments (GMFCS level 5.0), 14% had 1 impairment (level 5.1), 26% had 2 impairments (level 5.2), and 51% had 3 or 4 impairments (level 5.3). The Caregiver Priorities and Child Health Index of Life with Disabilities (CPCHILD) questionnaire was used for preoperative and postoperative health-related quality-of-life outcome assessments, and major complications were recorded., Results: The rate of major complications increased significantly with higher GMFCS level-5 subtype (p = 0.002), with 12% at level 5.0, 21% at level 5.1, 31% at level 5.2, and 49% at level 5.3. Five of the 7 patients who died within the follow-up period were at level 5.3. No significant differences were found among subgroups with respect to the magnitude of correction of the major coronal curve or pelvic obliquity. Preoperative and final follow-up CPCHILD total scores decreased significantly from GMFCS level 5.0 to level 5.3. However, no significant differences were found by subgroup with respect to the magnitude of improvement in CPCHILD total scores from the preoperative to the final follow-up evaluation (p = 0.597)., Conclusions: Stratification based on central neuromotor impairments can help to identify patients with cerebral palsy at GMFCS level 5 who are at higher risk for developing complications after spinal arthrodesis., Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence., (Copyright © 2016 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: Anterior-posterior spinal fusion (APSF) is the traditional treatment for patients with idiopathic scoliosis and open triradiate cartilage (OTRC). Our goals were to assess whether posterior-only spinal fusion (PSF) with pedicle screws can halt deformity progression as effectively as APSF in patients with OTRC, and whether selection of the distal fusion level influences curve progression., Methods: We studied a prospective multicenter database to identify all children with 2-year radiographic and clinical follow-up who were 11 years or younger with Risser grade 0 and OTRC who were treated with (1) PSF (OTRC-PSF group, N=20); or (2) APSF (OTRC-APSF group, N=9). A reference group was constructed of 20 children who were 18 years or younger with Risser grade 4 or 5 and closed triradiate cartilage (CTRC) and who were treated with PSF (CTRC-PSF group) and matched in preoperative curve magnitude and type to the OTRC-PSF group. The 3 groups were compared with respect to operative time, blood loss, length of hospital stay, and radiographic and functional outcomes (significance, P<0.05)., Results: OTRC-APSF patients had significantly longer operative time (P<0.01), greater blood loss (P=0.02), and longer hospital stays (P<0.01) than OTRC-PSF patients. At 2 years, 7 (35%) OTRC-PSF patients had >10 degrees of curve progression compared with no patients in the OTRC-APSF group (P=0.042) and 1 patient in the CTRC-PSF group (P=0.018). The OTRC-PSF group had the highest number of patients fused to the stable vertebra. Of the 11 OTRC-PSF patients fused to 1 vertebra short of stable, 6 (55%) had >10 degrees of curve progression. Of the 9 OTRC-PSF patients fused to at least the stable vertebra or lower, only 1 (11%) had curve progression. There were no significant differences in Scoliosis Research Society outcome scores between OTRC-PSF patients who did and those who did not have >10 degrees of curve progression., Conclusions: PSF with pedicle screws was associated with curve progression in a significantly greater proportion of patients with OTRC compared with APSF. Not fusing to stable was also associated with curve progression in patients treated with PSF but not APSF., Level of Evidence: Level III-therapeutic.

Study Design: Review of a prospective database registry., Objective: To compare the Scoliosis Research Society (SRS)-22 and SRS-24 outcomes instruments in terms of scores, rate of ceiling effects, and discriminant ability in patients with pre- and postoperative adolescent idiopathic scoliosis., Summary of Background Data: Despite improvements noted with the SRS-22, the SRS-24 is still occasionally used prospectively and for comparisons with previous studies reporting SRS-24 scores. Previous work has demonstrated that postoperative scores from the 2 versions are not interchangeable., Methods: A multicenter prospective registry of patients who underwent surgical correction of adolescent idiopathic scoliosis was queried for preoperative and 2-year postoperative SRS-22 and SRS-24 scores. Scores were compared between versions and ceiling effects were identified. Groups of deformity severity were created to evaluate discriminant ability., Results: 829 patients were identified. The SRS-22 scores for pain and general function were significantly greater than SRS-24 scores (P < 0.001), whereas the SRS-22 scores were significantly lower than the SRS-24 for self-image (P < 0.001). Preoperative ceiling effect was only noted in 1 domain each. Both versions were able to discriminate between large (80°+) and small (<45°) preoperative curves in all domains and total scores (P < 0.05). Postoperatively, the SRS-22 scores for all shared domains and total score were significantly greater than SRS-24 scores (P < 0.001). Ceiling effects in 5 of 5 domain scores were noted postoperatively for SRS-22 and in 4 of 7 for SRS-24. With a smaller range of deformity postoperatively, only the SRS-22 self-image domain was able to discriminate between large (29°+) and small (≤11°) residual curves (P < 0.05)., Conclusion: Scores obtained by the SRS-22 and the SRS-24 are not translatable despite shared domains. Whereas both versions demonstrated preoperative discriminant ability, postoperative discrimination of residual deformity is lacking in both. Patient-reported outcomes of treatment are crucial in advancing treatment, and improvement in the ability to assess subjective outcomes is essential., Level of Evidence: 3.

Objective: The purpose of this study was to assess L4-S1 inter-vertebral coronal motion of the unfused distal segments of the spine in patients with adolescent idiopathic scoliosis (AIS) after instrumented fusion with regards to postoperative time and fusion length, independently., Methods: Coronal motion was assessed by standardized radiographs acquired in maximum right and left bending positions. The intervertebral angles were measured via digital radiographic measuring software and the motion from the levels of L4-S1 was summed. The entire cohort was included to evaluate the effect of follow-up time on residual motion. Patients were grouped into early (<5 years), midterm (5-10 years), and long-term (>10 years) follow-up groups. A subset of patients (n = 35) with a primary thoracic curve and a nonstructural modifier type "C" lumbar curve were grouped as either selective fusion (lowest instrumented vertebra [LIV] of L1 and above) or longer fusion (LIV of L2 and below) and effect on motion was evaluated., Results: The data for 259 patients are included. The distal residual unfused motion (from L4 to S1) remained unchanged across early, midterm, to long-term follow-up. In the selective fusion subset of patients, a significant increase in motion from L4 to S1 was seen in the patients who were fused long versus the selectively fused patients, irrespective of length of follow-up time., Conclusion: Motion in the unfused distal lumbar segments did not vary within the >10-year follow-up period. However, in patients with a primary thoracic curve and a nonstructural lumbar curve, the choice to fuse longer versus shorter may have significant consequences. The summed motion from L4 to S1 is 50% greater in patients fused longer compared with those patients with a selective fusion, in which postoperative motion is shared by more unfused segments. The implications of this focal increased motion are unknown, and further research is warranted but can be surmised., (Copyright © 2015 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Study Design: Retrospective review of a prospectively collected multicenter database of patients with adolescent idiopathic scoliosis (AIS)., Objective: To determine if Ponte osteotomies improve correction in Lenke 1A and 1B AIS curves treated with pedicle screws., Summary of Background Data: There is little data studying the risks and benefits of Ponte osteotomies in AIS., Methods: We identified patients with Lenke 1A and 1B curve types treated with pedicle screw constructs and a 2-year follow-up. They were grouped based on whether they did (PO) or did not (NoPO) have Ponte osteotomies. Demographic, surgical, and radiographic data collected preoperatively and at 2 years were statistically analyzed using unpaired Student t test and Fisher exact test., Results: One hundred ninety-one patients met the inclusion criteria (mean age of 14.7 ± 2.2 years), and among those, 125 patients (65.4%) had Ponte osteotomies (average of 4.3 ± 1.5 Pontes per patient). The patients treated with Ponte osteotomies had similar clinical and radiographic parameters (major Cobb: PO = 51.5°, NoPO = 50.8°, p = .6) to the patients who did not have Ponte osteotomies except that they had stiffer and more lordotic curves (Flexibility Index: PO = 47.3%, NoPO = 54.5%, p = .04; T5-T12 kyphosis: PO = 18.7°, NoPO = 23.2°, p = .02). At 2 years, the patients treated with Ponte osteotomies had significantly better thoracic Cobb angle correction (Correction Index: PO = 67.1%, NoPO = 61.8%, p = .01) and an increase in T5-T12 kyphosis (PO = +3.0°, NoPO = -0.4°, p = .045). The Ponte group demonstrated greater rib prominence correction (PO = 53.2%, NoPO = 38.4%, p = .02). There were no neurologic events in this cohort., Conclusions: Although the use of Ponte osteotomies was not randomized, these data suggest that greater deformity correction in all 3 planes may be possible when Ponte osteotomies are performed for the stiffer and more lordotic Lenke 1A and 1B curves. The clinical significance of these overall small statistical differences remains to be determined., Level of Evidence: III., (Copyright © 2015 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Purpose: Pedicle screw constructs combined with direct vertebral body derotation (DVBD) provide a powerful corrective force of the rib prominence associated with adolescent idiopathic scoliosis (AIS). We wished to evaluate the incidence and correlative factors associated with recurrence of rib prominence (RRP) developing postoperatively despite adequate initial correction., Methods: 103 patients with AIS underwent pedicle screw fixation with DVBD without thoracoplasty and had postoperative scoliometer readings at 6, 12, and 24 months. Patients with RRP, defined as a postoperative scoliometer increase ≥5°, were compared to those without recurrence., Results: The mean rib prominence measured 14.0 ± 4.3° preoperatively, with a correction of 50.3 ± 26.7 % at 6 months, 49.0 ± 39.0 % at 1 year, and 49.1 ± 26.7 % at 2 years. RRP was identified in 15.5 % of the patients with a correction of 57.5 ± 25.5 % at 6 months, 47.2 ± 42.5 % at 1 year, and 40.4 ± 21.6 % at 2 years. At 2 years, the RRP group demonstrated a significantly larger major coronal Cobb (p < 0.05) and a trend towards less curve correction (p = 0.09). Patients with open triradiates had a significantly higher rate of RRP compared to those with closed (p = 0.01). Worsening apical vertebral rotation at 2 years post-operation occurred in 43.8 % (7/16) of the patients with RRP., Conclusion: RRP after posterior fusion for AIS with all pedicle screw constructs and DVBD occurred in 15.5 % of patients in our study. Patients with open triradiate cartilage had a significantly higher rate of RRP, although most with RRP were skeletally mature. There was a trend towards loss of coronal correction and increased apical vertebral rotation at 2 years in patients with RRP. The potential for RRP after adequate initial correction should be discussed with patients., Level of Evidence: 2.

Study Design: Comparison of the Scoliosis Research Society-22 (SRS-22) questionnaire with a 7-item Rasch-derived questionnaire (SRS-7)., Objective: To compare the construct and discriminant validity, internal consistency, responsiveness, and dimensionality of SRS-7 against SRS-22 in operatively treated children with adolescent idiopathic scoliosis., Summary of Background Data: SRS-22 has not been shown to possess linearity or unidimensionality (internal validity)., Methods: A multicenter database was queried for children with adolescent idiopathic scoliosis who underwent spinal fusion and answered all preoperative and 1-year postoperative SRS-22 questions. SRS-7 scores for the 685 patients were calculated from SRS-22 item responses. Traditional psychometric properties were assessed for both instruments (significance, P < 0.01)., Results: SRS-7 and SRS-22 scores correlated preoperatively and postoperatively (r = 0.78, P < 0.001, and r = 0.78, P < 0.001, respectively). Both instruments showed good discriminant validity in segregating 4 groups of patients with adolescent idiopathic scoliosis by curve magnitudes (F = 8.36, P < 0.001, and F = 8.38, P < 0.001, respectively). Pre- and postoperative SRS-7 and SRS-22 had internal consistency Cronbach α values of 0.64 and 0.67, and 0.85 and 0.85, respectively. With SRS-7, mean postsurgical improvement was 18.7 points (46.6-65.3, P < 0.001), with effect size measures of Cohen d = 1.57, Hedge g = 1.57, and r = 0.62. With SRS-22, mean improvement was 11.6 points (84.5-96.1, P < 0.01), with effect size measures of Cohen d = 1.25, Hedge g = 1.25, and r = 0.53. Iterative principal factor analysis of pre- and postoperative SRS-7 and SRS-22 showed the presence of 1 dominant latent factor (unidimensionality) and 4 latent factors (multidimensionality), respectively., Conclusion: SRS-7 shows good concurrent and discriminative validity, reasonable internal consistency, and excellent responsiveness. It has the advantages over SRS-22 of being short, unidimensional, and an interval scale., Level of Evidence: 4.

Background: Our goal was to analyze the relationship between patient size and the proportion of blood volume lost during spinal arthrodesis in patients with a diagnosis of adolescent idiopathic scoliosis, Scheuermann kyphosis, or cerebral palsy. We hypothesized that smaller patients (those with less blood volume) lose a greater proportion of circulating total blood volume during surgery., Methods: We reviewed a large, multicenter database, identifying patients with adolescent idiopathic scoliosis (1832), Scheuermann kyphosis (106), or cerebral palsy (196) who had undergone posterior spinal arthrodesis for spinal deformity. Blood volume (estimated from body weight) was used as a measure of patient size. Our primary outcome was the proportion of total circulating blood volume lost (intraoperative blood loss/blood volume, expressed as a percentage)., Results: On multivariate analysis, there was a negative relationship between intraoperative blood loss/blood volume and blood volume in patients with adolescent idiopathic scoliosis (coefficient, -5.8; p < 0.001), Scheuermann kyphosis (coefficient, -2.5; p < 0.001), or cerebral palsy (coefficient, -20.3; p < 0.001), indicating that, despite adjustment for all other factors, smaller patients lost a greater proportion of their blood volume. In patients with adolescent idiopathic scoliosis or Scheuermann kyphosis, multivariate analysis showed that intraoperative blood loss/blood volume also increased significantly when the patient was male and with a greater number of levels fused., Conclusions: There is an inverse relationship between the proportion of blood volume lost during deformity correction surgery and size in patients with adolescent idiopathic scoliosis, cerebral palsy, or Scheuermann kyphosis., (Copyright © 2015 by The Journal of Bone and Joint Surgery, Incorporated.)

Study Design: A retrospective analysis of a prospectively collected multicenter database., Objective: To identify the radiographical and clinical outcomes in Lenke 3 curves fused selectively (S) versus nonselectively (NS)., Summary of Background Data: Surgical treatment options for Lenke 3 curves include fusion of both curves (NS) or selective thoracic curve fusion (S). Selective fusion of the thoracic curve spares lumbar motion segments; however, it may result in marked residual deformity., Methods: A prospectively collected multicenter database was retrospectively reviewed for adolescent idiopathic scoliosis Lenke 3 curves treated with posterior spinal fusion with a minimum of 2 years of follow-up. Patients were divided into 2 groups: NS (nonselective fusion) and S (selective thoracic fusion). Radiographical and clinical data were compared between the groups using the unpaired Student t test and analysis of variance., Results: A total of 74 patients met our inclusion criteria, with 49 (66.2%) in the NS group and 25 (33.8%) in the S group. Overall, both groups were similar preoperatively except for lumbar Cobb (NS = 56.3°, S = 47.2°, P < 0.001), lumbar lordosis (NS = 56.9°, S = 67.2°, P = 0.001), lumbar rotational prominence (NS = 11.2°, S = 8.2°, P < 0.05), and lumbar apical translation (NS = 3.2 cm, S = 1.9 cm, P < 0.05). Postoperatively, NS fusion demonstrated significantly less coronal imbalance of 2 cm or less (NS = 10.2%, S = 56.0%, P < 0.001), better lumbar curve correction (NS = 68.2%, S = 51.9%, P < 0.001), better lumbar apical translation correction (NS = 1.2 cm, S = 2.1 cm, P < 0.01), and better percent correction of the lumbar prominence (NS = 66.5%, S = 40.4%, P < 0.05). Scoliosis Research Society Questionnaire 22 scores at 2 years were similar between the groups., Conclusion: Despite preoperatively smaller lumbar curves with less apical translation and lumbar prominence, most patients with selective fusions were out of balance postoperatively and had inferior radiographical outcomes as compared with their nonselective comparison cohort with similar patient-reported outcomes. Long-term follow-up is required to determine whether the trade-off of sparing motion segments at the expense of somewhat lessened radiographical outcomes is worthwhile.

Background: Single-surgeon series investigating the learning curve involved in surgery for spinal deformity may be confounded by changes in technology and techniques. Our objective with this multicenter, prospective study was to present a cross-sectional analysis of the impact of surgeon experience on surgery for adolescent idiopathic scoliosis., Methods: All posterior-only surgical procedures for adolescent idiopathic scoliosis performed in the 2007 to 2008 academic year, with a minimum of two years of patient follow-up, were included. Two groups were created on the basis of surgeon experience: a young surgeons' group, which included patients of surgeons with less than five years of experience, and an experienced surgeons' group, which included patients of surgeons with five or more years of experience., Results: Nine surgeons (four young and five experienced) operated on a total of one hundred and sixty-five patients with adolescent idiopathic scoliosis. The surgeons' experience ranged from less than one year to thirty-six years in practice. The two groups had similar preoperative curve-magnitude measurements, SRS-22 (Scoliosis Research Society-22) scores, and distribution by Lenke curve type. There were significant operative and postoperative differences. The young surgeons fused an average of 1.2 levels more than the experienced surgeons (p = 0.045). The mean intraoperative estimated blood loss (EBL) of the young surgeons' group was more than twice that of the experienced surgeons' group (2042 mL compared with 1013 mL; p < 0.001). The duration of surgery was 458 minutes for the young surgeons compared with 265 minutes for the experienced surgeons (p < 0.001). The overall SRS-22 scores were significantly worse in the young surgeons' group (a mean of 4.1 compared with 4.5; p = 0.001). The difference between groups was also significant for the domains of pain (p = 0.016), self-image (p = 0.008), and function (p < 0.001). Complication rates did not differ significantly between the groups., Conclusions: Operative results and health-related quality of life following surgery for adolescent idiopathic scoliosis were significantly and positively correlated with surgeon experience., Level of Evidence: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence., (Copyright © 2014 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: Nonstructural curves are defined in the Lenke classification system for adolescent idiopathic scoliosis as bending out to <25 degrees. A caveat in the original paper states, however, that if the difference in Cobb magnitude between the major and minor curves is <5 degrees, then the minor curve should be considered structural, regardless of its Cobb magnitude. It is unclear whether following this rule affects patient outcomes., Methods: A multicenter retrospective study using a prospectively collected database was performed on surgical adolescent idiopathic scoliosis patients, with 2 years of minimum follow-up. All the lumbar curves measured <25 degrees on bending x-ray. Curves (major and minor) that were within <5 degrees of each other were analyzed in 2 treatment subsets: nonselective fusion (NS) and selective thoracic fusion (STF1), and compared with similar selective fusion cases with false double major curves with a lumbar curve between 5 and 10 degrees less in magnitude than the thoracic curve magnitude (STF2). Preoperative and 2-year postoperative radiographic and SRS-22 parameters were compared., Results: Of 58 patients, there were 14 NS, 11 STF1, and 33 STF2. NS had larger preoperative curves than STF1, but achieved better lumbar correction (58%) than STF1 (32%) or STF2 (41%) (P=0.004). STF1 tended to have more preoperative coronal imbalance than STF2 (-2.26 vs. -1.12 cm) (P=0.066) but were similar at 2 years. Preoperative thoracic rib prominence measures were similar for all groups, but NS had significantly worse rib prominence than STF1 (NS: 8.4 vs. STF1: 4.4, P=0.046) at 2 years. There were no differences among the 3 groups in SRS-22 scores preoperatively and at 2 years., Conclusions: Almost half of the cases with curves within <5 degrees of each other did not follow the 5-degree rule, suggesting that there is variability among surgeons in their definition of what is truly structural. Selective thoracic fusion cases behaved similarly regardless of whether or not the curves were within 5 degrees of each other. The results of our analysis of the 5-degree caveat challenge its utility as a criterion for defining structural curves., Level of Evidence: Level II.

Study Design: Prospective cohort., Objective: To (1) calculate the rate of deep wound infection in children with cerebral palsy (CP) after spinal fusion surgery; (2) identify factors (patient, laboratory, and surgical) associated with deep wound infection development; and (3) report causative organisms., Summary of Background Data: Wound infection after spine fusion for CP is more common than after spine fusion for most other diagnoses., Methods: We prospectively gathered data on 204 consecutive pediatric patients with CP who underwent surgery at 7 institutions. Univariate and multivariate regression analysis was performed to analyze patient, laboratory, and surgical characteristics to identify factors that were significantly associated with infection development. Statistical significance was set at a value of P less than 0.05., Results: Deep wound infection developed in 13 (6.4%) children. The mean time to infection development was 34.2 ± 60.2 days. On univariate analysis, older age, larger curve size, presence of gastrostomy/gastrojejunostomy tube, higher preoperative serum white blood cell count, and longer operative time were significantly associated with deep wound infection. On multivariate analysis, only the presence of a gastrostomy/gastrojejunostomy tube remained significant (1.9-fold risk of deep wound infection compared with patients without tubes). Escherichia coli was the most common organism cultured from the wound sites (5 patients). Other infective agents were: Pseudomonas aeruginosa (2), methicillin-susceptible Staphylococcus aureus (1), Proteus mirabilis (1), and polymicrobial organisms (4)., Conclusion: Deep wound infection occurred in 6.4% of children with CP after spinal fusion. The presence of a gastrostomy/gastrojejunostomy tube was a significant predictor of infection. Gram-negative organisms were the most common causative agents. Surgeons should be cognizant of these factors when treating children with CP and may consider Gram-negative antibiotic prophylaxis.

Study Design: Review of a prospective database registry of surgical patients with adolescent idiopathic scoliosis (AIS)., Objective: The purpose of this study was to examine the prevalence of postoperative pain and its impact on patient-reported postoperative outcomes using the Scoliosis Research Society (SRS)-22 outcomes questionnaire., Summary of Background Data: Although reportedly rare, postoperative pain can be a devastating situation for the patient with AIS. Most recent studies examining outcomes in AIS surgical treatment use the SRS Pain domain score to assess pain in this population., Methods: A prospectively enrolled multicenter database was queried. Patients with minimum 2-year follow-up and 2-year SRS scores were included. Postoperative pain after the acute phase of recovery when reported by the patient to the treating surgeon/clinical team in follow-up is recorded as a complication in the database. Patients included in this series were grouped as either reporting pain or not to the surgeon/clinical team postoperatively. Pre- and postoperative SRS scores were then compared between these 2 groups using analysis of variance (P < 0.05)., Results: Five hundred and eighty-four patients meeting the inclusion criteria were identified. Sixty-one (11%) reported pain at sometime between 2 weeks and 2 years postoperatively. Thirteen were within the 6-month postoperative period. Of the remaining 48 reporting pain between 6 and 24 months postoperatively, 41 (7% of the total cohort) had no obvious cause for their pain. More than half of these patients (26/41) were referred for further treatment (physical therapy, referral to pain specialist, further imaging). These 41 patients had significantly decreased 2-year SRS scores in the domains of Pain, Self-image, Mental health, and Total score (P < 0.05). The patients with postoperative pain were found to have significantly lower preoperative Pain domain scores (P < 0.001), indicative of greater pain preoperatively, yet there were no other domains effected preoperatively. For this group the pre- to postoperative SRS pain scores did not show significant change (P > 0.05)., Conclusion: Unexplained pain after the 6-month postoperative period occurred in 7% of the cohort. The results indicate that patients reporting pain to their surgeons/clinical team postoperatively have lower pain scores on a subjective outcome instrument thus further validating the SRS-22 outcome tool. This reported pain seems to be associated with decreases in other SRS-22 domains. Interestingly, these patients also have lower preoperative pain scores than those without postoperative pain. Study into causes of pain in AIS and whether preoperative education and expectations targeted at this population would positively impact outcomes is warranted, especially because on average patients after AIS surgery have less pain., Level of Evidence: 3.

Study Design: Prospective, longitudinal cohort., Objective: To evaluate the incidence, timing, and risk factors for reoperation in patients with adolescent idiopathic scoliosis (AIS) treated with pedicle screws (PSs) compared with hybrid (Hb) constructs., Summary of Background Data: Rates of return to the operating room (OR) after definitive fusion for AIS vary, with a paucity of data on PS constructs., Methods: A prospective multicenter database was retrospectively queried to identify consecutive patients with AIS who underwent posterior spinal fusion with either PS or Hb constructs with a minimum 2-year follow-up. All reoperations were stratified into an early group (<60 d) or a late group (>60 d). Univariate and multivariate logistical analyses were performed to identify potential risk factors related to reoperation., Results: A total of 627 patients met the inclusion criteria (PS = 540, Hb = 87). There was a statistically significant difference in the rate of reoperations between the PS (3.5%) and Hb groups (12.6%), P < 0.001. Early return to the OR occurred in 2.0% of the patients with PS compared with 3.4% in the Hb group, P = 0.43. Late returns to the OR occurred in 1.5% of PS group versus 9.2% of the Hb group, P < 0.001. Multivariate analysis revealed longer operating time as an independent risk factor for an unplanned return to the OR in patients treated with PSs (P < 0.05)., Conclusion: Our results suggest that patients with AIS treated with PS have decreased rates of unplanned return to the OR when compared with patients with Hb constructs. The majority of returns to the OR were early (<60 d) for the PS group compared with late (>60 d) for the Hb group. Longer operative times increased the risk of unplanned reoperation for the PS group., Level of Evidence: 3.

Objective: To define the current rate of postoperative surgical site infections (SSIs) in a large prospective series of surgical adolescent idiopathic scoliosis (AIS) cases., Methods: A multicenter, prospective database of patients who underwent surgical correction of AIS was reviewed. Early SSIs were defined as occurring within 90 days after the index operation, as per the Center for Disease Control's definitions. Treatment and outcome information on all confirmed SSIs was compiled. Variables associated with the occurrence of an SSI were evaluated., Results: Of the 1,757 patients analyzed, 28 developed an SSI within the first 90 days postoperatively (1.6%). Patient weight was associated with SSI (p < .001). There was a trend in correlation with the number of levels fused (p = .07) and blood loss as a percentage of blood volume (p = .07) and the incidence of SSI. There was no correlation with any other variables. There was variation in the rate of SSI among the 9 centers, ranging from 0.6% to 4.4% (p = .27). Of the 28 infections, 26 resolved with surgery and/or antibiotics and did not need implant removal. Only 2 patients had late pain. In addition to the 28 confirmed SSIs, there were an additional 68 other wound issues (4.2%) that did not meet the Center for Disease Control criteria for an SSI., Conclusions: Early SSIs after AIS surgery occurred at a rate of 1.6%. The federal mandate to eliminate SSI and the proposed lack of reimbursement for its treatment may change clinical practice, and these data provide average SSI rates across multiple centers for future comparison. Investigations into variations in practice between centers might yield areas for potential improvement in SSI for AIS patients. Fortunately, 92% of patients were able to retain their implants and were free of pain at final follow-up., (Copyright © 2013 Scoliosis Research Society. Published by Elsevier Inc. All rights reserved.)

Study Design: Retrospective analysis., Objective: To determine if statistically significant differences exist between operative idiopathic early-onset scoliosis (IEOS) and adolescent idiopathic scoliosis (AIS) in primary curve characteristics, stable vertebra, kyphosis, or lumbar deformity and, if so, to identify the clinical significance of these differences., Summary of Background Data: To our knowledge, no study has statistically compared radiographical measures of operative IEOS and AIS., Methods: We identified operative patients (60, IEOS; 1537, AIS) in 2 multicenter databases and measured preoperative radiographical parameters of interest. The measurements were compared using the Student t test and other appropriate statistical methods (significance, P = 0.05)., Results: The IEOS and AIS groups were significantly different in primary curve magnitude (70° ± 20° vs. 54° ± 13°, respectively; P < 0.001), stable vertebra location (L3.0 ± 1.4 vs. L2.1 ± 2.2, respectively; P = 0.001), and T2 to T12 kyphosis (40° ± 15° vs. 31° ± 13°, respectively; P < 0.001). Distribution of major curve apex was unimodal centered close to the thoracolumbar junction in IEOS versus bimodal in AIS. Primary curve type was thoracic in 83% and 79% and thoracolumbar/lumbar in 17% and 21% of patients with IEOS and AIS, respectively. When the overall cohorts were separated into curve types and these subsets were compared, statistically significant differences were found between IEOS and AIS in thoracic primary curves (apex, magnitude, direction, proximal and distal Cobb vertebrae, and lumbar deformity) and thoracolumbar/lumbar primary curves (magnitude)., Conclusion: Significant radiographical differences exist between operative IEOS and AIS curves. IEOS curves are greater in magnitude, more kyphotic, less well compensated, and have a more caudal apex and stable vertebra. These findings suggest that younger patients may require more distal instrumentation and that proximal fixation techniques should consider the additional pullout forces created by the greater kyphosis.

Background: Loss of coronal correction has been reported in the presence of a solid posterior fusion mass in patients who are skeletally immature. Significant increases in postoperative coronal curvature are typically attributed to the presence of pseudarthrosis, loss of instrumentation fixation, or adding-on. We evaluated the clinical and radiographic factors associated with a loss of correction that was not attributed to these etiologies as well as the impact of pedicle screw fixation on loss of correction., Methods: A prospective, longitudinal study database was retrospectively queried for patients with at least 2 years of follow-up who underwent surgery for adolescent idiopathic scoliosis. Loss of correction was defined (1) clinically, as a >5 degree increase in the inclinometer reading at any time interval after surgery, excluding preoperative values; or (2) radiographically, as an increase of ≥ 10 degrees in the coronal Cobb angle of an instrumented curve. Patients with pseudarthrosis, adding-on, or loss of fixation were excluded., Results: Ninety-three of 800 patients (11.6%) had loss of deformity correction. Twenty-one patients (2.5%) had >5 degrees of inclinometer change and 76 patients (9.5%) had ≥10 degrees of Cobb change, with a mean loss of 10.85±4.2 degrees. When comparing pedicle screw constructs only, 10% of patients developed loss of correction as opposed to 20% of the patients with hybrid constructs (P=0.036). Factors associated with loss of correction were: age, hybrid construct, magnitude of thoracic curve, thoracic apical translation, and T1 tilt angle., Conclusion: This study reports a high percentage of loss of coronal correction (12%) after 2 years of follow-up that was not associated with infection, adding-on, or apparent pseudarthrosis. Larger magnitude thoracic curves with apical deviation and hybrid constructs were associated with an increased likelihood of loss of curve correction where use of pedicle screw fixation seems to decrease its incidence., Level of Evidence: III.

Object: In the surgical management of adolescent idiopathic scoliosis (AIS), patients are often preoperatively informed that they will gain height as a result of their surgery. However, current estimations conflict significantly and do not have any clinical correlation. The authors developed a formula that would predict postoperative gains in height after deformity correction in AIS., Methods: A large, multicenter, prospective database was retrospectively queried for AIS patients with Lenke Type 1, 2, or 3 curves having undergone posterior spinal fusion alone. A univariate and multivariate analysis was performed to identify which factors contributed significantly to changes in height., Results: Four hundred forty-seven patients were included in the series. Factors correlating with changes in postoperative height included: upper thoracic curve magnitude, main thoracic curve magnitude, lumbar curve magnitude, T2-12 kyphosis, T5-12 kyphosis, curve flexibility, number of levels fused, presence of Ponte osteotomies, total preoperative coronal Cobb angle, change in coronal curve magnitude, total preoperative sagittal curvature, change in sagittal curvature, and thoracic curve correction. When combined in a multivariate regression analysis the following variables remained significant: thoracic curve magnitude (p < 0.01), number of levels fused (p < 0.01), change in total sagittal curvature (p < 0.01), and the presence of osteotomies (p = 0.03). The contribution from the thoracic curve magnitude was significantly greater than any of the other parameters identified (R2 = 0.140). Change in height (in cm) = ([thoracic curve magnitude × 0.039] + [number of levels fused × 0.193] - [change in sagittal curvature × 0.033] + [x × 0.375]) - 1.858, where x = 1 if 1 or more osteotomies were performed and x = 0 if no osteotomy was performed., Conclusions: The authors' results suggest that changes in the coronal plane contribute more significantly to height changes than those in the sagittal plane and approximately 0.39 cm of height gain can be expected for each 10° of coronal curve preoperatively. Unfortunately, a significant fraction of the postoperative height changes cannot be predicted by currently measured parameters.

Study Design: Prospective, consecutive, nonrandomized, multicenter study., Objective: The purpose of this study was to compare the outcomes of idiopathic scoliosis treatment for Lenke 1 curves with 3 treatment approaches., Summary of Background Data: Surgical treatment options for Lenke 1 or primary main thoracic curve pattern in adolescent idiopathic scoliosis include thoracoscopic anterior spinal fusion, open anterior spinal fusion, and posterior spinal fusion (PSF) and instrumentation procedures., Methods: This was a prospective, consecutive, nonrandomized, multicenter study of surgical correction in adolescent idiopathic scoliosis. Patients with Lenke type 1 curve patterns from 7 sites were enrolled in this minimum 2-year follow-up study. Changes in pre- to postoperative radiographs, pulmonary function tests, Scoliosis Research Society questionnaire scores, and trunk rotation measures were compared., Results: A total of 149 patients (age: 14.5 ± 2 yr) were included (91% follow-up at 2 yr). The 3 groups were similar preoperatively in thoracic and lumbar curve size. There were 55 patients with thoracoscopic anterior spinal fusion, 17 patients with open anterior spinal fusion, and 64 patients with PSF. The fusion included on average 3 to 4 more levels in PSF than the 2 anterior approaches (P ≤ 0.001). Surgical time tended to be greater in the anterior groups by approximately 2 to 3 hours; however, blood loss was greatest with PSF. At 2 years, all 3 approaches showed similar improvements in the thoracic Cobb angle, coronal balance, the lumbar Cobb angle, Scoliosis Research Society questionnaire scores, and trunk rotation measures. The PSF approach resulted in overall reduction in kyphosis compared with the anterior approaches. Postoperative hyperkyphosis was an issue only in the 2 anterior groups. Major complication rates were similar., Conclusion: All 3 approaches resulted in similarly satisfactory outcomes for the majority of patients with specific advantages to each technique. The patients with PSF had more levels fused, yet with the shortest operative time. The thoracoscopic anterior spinal fusion group had the smallest incisions and the lowest requirement for transfusion. The open anterior spinal fusion group had a modest loss of pulmonary function without any clear advantages compared with the other 2 groups., Level of Evidence: 2.

Study Design: Retrospective case control study., Objective: To compare patients with Marfan syndrome and matched patients with adolescent idiopathic scoliosis (AIS) to illustrate the differences and identify areas for potential surgical improvement., Summary of Background Data: Patients with Marfan syndrome commonly require spinal deformity surgery, but practice guidelines and results are not as established as those for patients with AIS., Methods: We matched 34 adolescents with Marfan syndrome with patients with AIS (ratio, 1:2) for age, sex, and degree of major deformity. Overall mean age was 14 ± 2 years and mean curves were 51° thoracic and 46° lumbar. Mean follow-up was 5.3 and 3.6 years, respectively., Results: The Marfan syndrome group had significantly more thoracolumbar kyphosis correction (9.5° vs. 0.1°, P = 0.05), significantly more levels fused (12 ± 2 vs. 9 ± 3, P ≤ 0.01), significantly more fusions to the pelvis (7 vs. 0, P = 0.01), and significantly more correction of sagittal imbalance (2.4 vs. -0.6 cm, P = 0.035). The Marfan syndrome group also had more intraoperative cerebrospinal fluid leaks (3 vs. 0, P = 0.01), significantly more instrumentation complications (3 vs. 1, P = 0.007), more reoperations for indications [such as fixation failure, distal degeneration, and spine fracture (9 vs. 0, P = 0.01)], and lower SRS-22 total (3.9 vs. 4.5, P = 0.01) and partial (P < 0.015) subscores. There were no significant differences between the groups in progression of unfused proximal thoracic curves, blood loss, neurological deficit, hospital stay, percent correction, or infection rate., Conclusion: Patients with Marfan syndrome differ in several ways from those with AIS: they require more levels of surgical correction, more distal fusion, greater correction of sagittal balance, and more reoperations, and they have more intraoperative cerebrospinal fluid leaks and instrumentation-related complications. Knowledge of these differences is important for planning surgery.

Study Design: Prospective, longitudinal cohort (nonrandomized)., Objective: To compare thoracoplasty (Th), direct vertebral body derotation (DVBD), and Th and DVBD with respect to correction of the rib prominence and Scoliosis Research Society (SRS) self-image scores in patients undergoing surgery for adolescent idiopathic scoliosis (AIS)., Summary of Background Data: Rib prominence correction is one of the main goals of AIS surgery. Th and DVBD are powerful tools for correction of the rib prominence; however, a paucity of literature exists comparing Th, DVBD, and Th and DVBD., Methods: A prospective longitudinal database was queried to identify patients with AIS who underwent a posterior spinal fusion with pedicle screws and 2 years of follow-up. A total of 326 patients were identified and divided into 3 groups: (1) Th alone (N = 47), (2) DVBD alone (N = 196), and (3) both Th and DVBD (N = 83). Patients were subdivided into categories on the basis of their preoperative inclinometer reading: (1) ≤9° (mild), (2) 10 to 15° (moderate), and (3) ≥ 16° (severe). Pre- and postoperative inclinometer readings and SRS self-image scores were compared using analysis of variance., Results: Overall, the groups were similar preoperatively except for the DVBD group having higher percentage of thoracic flexibility. The preoperative rib prominence values were Th = 13.2, DVBD = 14.0, and Th and DVBD = 12.9 (P = 0.27). Taken collectively, the postoperative 2-year inclinometer readings were similar for all 3 groups (Th = 5.2, DVBD = 7.0, Th and DVBD = 5.6; P = 0.66). However, the SRS-22 self-image scores were significantly better for patients having both Th and DVBD (Th = 3.37, DVBD = 3.44, Th and DVBD = 3.76; P < 0.01). When patients were stratified by severity of preoperative rib prominence, all patients with mild prominences achieved similar corrections, although SRS self-image scores were highest in the Th and DVBD group. In patients with larger rib prominences, the addition of Th was necessary for optimal rib prominence correction, but there was no difference in SRS-22 self-image scores., Conclusion: Our results suggest that Th alone, DVBD alone, or both Th and DVBD provide equivalent inclinometer results in patients with mild preoperative rib prominences (≤ 9°), but higher SRS-22 self-image scores are achieved using both Th and DVBD. For larger rib prominences, better inclinometer readings are achieved with Th, although SRS-22 self-image scores are comparable.

Study Design: Retrospective review., Objective: To determine the association of patient characteristics and spinal curve parameters with Lenke curve types., Summary of Background Data: The Lenke curve classification may be used for surgical planning and clinical research., Methods: We retrospectively reviewed the records of 1912 patients with adolescent idiopathic scoliosis who underwent initial surgery at 21 years of age or younger; collected data on patient's age, patient's sex, primary curve magnitude (<50°, 50°-75°, and .75°), and Scoliosis Research Society (SRS) outcomes questionnaire (SRS-22) score; and compared that data by Lenke curve type. Analysis of variance and χ tests were used as appropriate (significance level, P ≤ 0.005). RESULTS.: Lenke types vary by sex: male patients had more major thoracic (types 1-4) than major thoracolumbar/lumbar (types 5 and 6) curves, fewer lumbar C-modifiers (32% vs. 44%), and less apical lumbar translation (1.1 vs. 1.7 cm). Lenke types vary by frequency: the most common type was 1 (50%); the least common, 4 (4%). Lenke types vary by magnitude: type 4 had the greatest percentage of large curves (52% of curves .75°), most smaller curves were types 1 and 5, and type 4 had the largest mean magnitude (78° ± 17°). Lenke types vary by patient age: type 5 curves occurred in the oldest patients (average age at surgery: 15.4 ± 2.2 vs. 14.3 ± 14.6 years for all others) despite having the lowest mean magnitude (P = 0.001); curve size was negatively correlated with age at surgery (r = -0.16, P = 0.001). Lenke types vary by patient self-image: patients with type 4 curves had lower preoperative SRS outcome scores for self-image than did patients with type 1 curves (P = 0.005)., Conclusion: Lenke types vary by sex, frequency magnitude, patient age, and patient self-image, which should be considered in designing studies.

Study Design: Multicenter retrospective review of prospectively collected data., Objective: To determine the extent of rib deformity correction that can be expected with direct vertebral body derotation (DVBD) and investigate factors that may correlate with improved rib deformity correction., Summary of Background Data: DVBD is a powerful tool in the surgical correction of axial rotation in adolescent idiopathic scoliosis. The application of DVBD has decreased the use of thoracoplasty for cosmetic rib deformity correction, but the outcomes of DVBD without adjuvant thoracoplasty have not been well defined., Methods: A multicenter database was retrospectively queried to identify patients with adolescent idiopathic scoliosis who underwent posterior spinal fusion with at least 2 years of follow-up and Lenke type 1 to 3 curves. All patients had undergone DVBD maneuvers during their surgery, and patients having undergone concurrent thoracoplasty were excluded from the study. The absolute change and percentage change from preoperative inclinometer readings were correlated with preoperative clinical and radiographic data., Results: A total of 148 patients fulfilled the inclusion criteria. The mean age was 14.7 ± 2.1 years with a mean primary thoracic curve of 55.3° ± 9.3°. The mean preoperative inclinometer reading was 14.8° ± 4.5°, which reduced to 7.5° ± 4.0° postoperatively. Patients had a mean improvement of 54% ± 29% in rib prominence using DVBD. We attempted to correlate 23 of the most commonly used preoperative clinical, radiographic, and operative measures with postoperative inclinometer improvement. Interestingly, none correlated with rib deformity correction, including preoperative rib deformity (P = 0.16), thoracic curve flexibility (P = 0.71), presence of osteotomies (P = 0.60), and thoracic curve magnitude (P = 0.78)., Conclusion: Utilizing DVBD, the surgeon can expect approximately 50% reduction in the rib deformity as assessed by inclinometer. This is irrespective of preoperative inclinometer measures, thoracic curve flexibility, and vertebral body rotation on standing and bending radiographs.

Purpose: We sought to clarify the effect of applying derotation maneuvers in the correction of adolescent idiopathic scoliosis (AIS) on the sagittal plane., Methods: We retrospectively queried a large, multicenter, prospectively collected database for patients who underwent surgical correction of AIS. All patients had at least 2 years of follow-up and documentation as to whether or not a derotation maneuver was performed during surgery. All patients underwent posterior spinal fusion with pedicle screw constructs. Patients who underwent concurrent anterior procedures were excluded., Results: A total of 323 patients were identified, of whom 66 did not have direct vertebral body derotation (DVBD) maneuvers applied during the deformity correction. The remaining 257 had a vertebral body derotation maneuver performed during their surgical correction. Although no significant differences were identified between the two groups when comparing pre-op and post-op thoracic kyphosis using T2-12 and T5-12 endplates, the absolute change in angulation measured from T2-12 was significantly different between the two groups. Postoperatively, the derotation group had a mean decrease in thoracic kyphosis of 5.1±15.3° as compared to 10.8±18.9° in the control group, P = 0.03., Conclusion: Although patients in both groups had decreased mean thoracic kyphosis postoperatively, application of DVBD in the correction of scoliosis did not additionally worsen the sagittal profile.

Study Design: Retrospective review., Objective: To compare the incidence of and risk factors for proximal junctional kyphosis (PJK) in adolescent idiopathic scoliosis (AIS) following posterior spinal fusion using hook, pedicle screw, or hybrid constructs., Summary of Background Data: Proximal junctional kyphosis is a recently recognized phenomenon in adults and adolescents after AIS surgery. The postoperative effect on PJK with the use of hooks, hybrid constructs, or screws has not been compared in a multicenter study to date., Methods: From a multicenter database, the preoperative and 2-year follow-up radiographic measurements from 283 patients with AIS treated with posterior spinal fusion using hooks (group 1, n = 51), hybrid constructs (group 2, n = 177), pedicle screws (group 3, n = 37), and pedicle screws with hooks only at the top level (group 4, n = 18) were compared., Results: The average proximal level kyphosis at 2 years after surgery was 8.2 degrees (range -1 to 18) in the all screw constructs, representing a significant increase when compared with hybrid and all hook constructs, 5.7 degrees (P = 0.02) and 5.0 degrees (P = 0.014), respectively. Conversely, average postoperative T5-T12 kyphosis was significantly less (P = 0.016) in the screw group compared with the all hook group. Of potential interest, but currently not statistically significant, was the trend towards a decrease in proximal kyphosis in constructs with all pedicle screws except hooks at the most cephalad segment, 6.4 degrees . The incidence of PJK (assuming PJK is a kyphotic deformity greater than 15 degrees ) was 0% in group 1, 2.3% in group 2, 8.1% in group 3, and 5.6% in group 4 (P = 0.18). Patients with PJK had an increased body mass index compared with those who did not meet criteria for PJK (P = 0.013)., Conclusion: Adjacent level proximal kyphosis was significantly increased with pedicle screws, but the clinical significance of this is unclear. A potential solution is the substitution of hooks at the upper-instrumented vertebrae, but further investigation is required.