Study Design. Prospective multicenter study data used for model derivation; externally-validated using retrospective cohort data. Objective. Derive and validate a prognostic model of benefit from bracing for adolescent idiopathic scoliosis (AIS). Summary of Background Data. The Bracing in Adolescent Idiopathic Scoliosis Trial (BrAIST) demonstrated superiority of bracing over observation to prevent curve progression to surgical threshold; 42% of untreated subjects had a good outcome and 28% progressed to surgical threshold despite bracing, likely due to poor adherence. To avoid over-treatment and to promote patient goal setting and adherence, bracing decisions (who and how much) should be based on physician and patient discussions informed by individual-level data from high-quality predictive models. Methods. Logistic regression was used to predict curve progression to <45 degrees at skeletal maturity (good prognosis) in 269 BrAIST subjects who were observed or braced. Predictors included age, sex, body mass index (BMI), Risser stage, Cobb angle, curve pattern and treatment characteristics (hours of brace wear and in-brace correction). Internal and external validity were evaluated using jackknifed samples of the BrAIST dataset and an independent cohort (n=299) via estimates of discrimination and calibration. Results. The final model included age, sex, BMI, Risser stage, Cobb angle and hours of brace wear/day. The model demonstrated strong discrimination (c-statistics 0.83 - 0.87) and calibration in all datasets. Classifying patients as low risk (high probability of a good prognosis) at the probability cut point of 70% resulted in a specificity of 92% and positive predictive value of 89%. Conclusion. This externally-validated model can be used by clinicians and families to make informed, individualized decisions about when, and how much, to brace to avoid progression to surgery. If widely adopted, this model could decrease over-bracing of AIS, improve adherence and most importantly, decrease the likelihood of spinal fusion in this population.

Background: There is no uniform classification system for traumatic upper cervical spine injuries in children. This study assesses the reliability and reproducibility of the AO Upper Cervical Spine Classification System (UCCS), which was developed and validated in adults, to children. Methods: Twenty-six patients under 18 years old with operative and nonoperative upper cervical injuries, defined as from the occipital condyle to the C2–C3 joint, were identified from 2000 to 2018. Inclusion criteria included the availability of computed tomography and magnetic resonance imaging at the time of injury. Patients with significant comorbidities were excluded. Each case was reviewed by a single senior surgeon to determine eligibility. Educational videos, schematics describing the UCCS, and imaging from 26 cases were sent to 9 pediatric orthopaedic surgeons. The surgeons classified each case into 3 categories: A, B, and C. Inter-rater reliability was assessed for the initial reading across all 9 raters by Fleiss’s kappa coefficient (kF) along with 95% confidence intervals. One month later, the surgeons repeated the classification, and intra-rater reliability was calculated. All images were de-identified and randomized for each read independently. Intra-rater reproducibility across both reads was assessed using Fleiss’s kappa. Interpretations for reliability estimates were based on Landis and Koch (1977): 0 to 0.2, slight; 0.2 to 0.4, fair; 0.4 to 0.6, moderate; 0.6 to 0.8, substantial; and >0.8, almost perfect agreement. Results: Twenty-six cases were read by 9 raters twice. Sub-classification agreement was moderate to substantial with α κ estimates from 0.55 for the first read and 0.70 for the second read. Inter-rater agreement was moderate (kF 0.56 to 0.58) with respect to fracture location and fair (kF 0.24 to 0.3) with respect to primary classification (A, B, and C). Krippendorff’s alpha for intra-rater reliability overall sub-classifications ranged from 0.41 to 0.88, with 0.75 overall raters. Conclusion: Traumatic upper cervical injuries are rare in the pediatric population. A uniform classification system can be vital to guide diagnosis and treatment. This study is the first to evaluate the use of the UCCS in the pediatric population. While moderate to substantial agreement was found, limitations to applying the UCCS to the pediatric population exist, and thus the UCCS can be considered a starting point for developing a pediatric classification. Level of Evidence: Level III.

Background: To minimize in-person visits during the COVID-19 pandemic, a new fracture care protocol for children with complete and stable, nondisplaced or minimally displaced upper extremity (UE) fractures has been implemented. This protocol involves immobilization with a bivalved cast, which allows for home cast removal during a telemedicine visit, and no follow-up radiographs, thus eliminating the requirement for a return to clinic. The purpose of this study is to evaluate the outcomes and parent satisfaction of this new abbreviated fracture care protocol. Methods: Between May 2020 and April 2021, during the COVID-19 pandemic, children with complete and stable, nondisplaced or minimally displaced UE fractures were treated with a bivalved cast and 1 follow-up telemedicine visit for home cast removal. A prospective longitudinal study of these patients was performed. The PROMIS Upper Extremity questionnaire was administered at enrollment and 3 months follow-up. Parents completed a satisfaction survey after home cast removal. Demographic data and information regarding complications were collected. A historical cohort of controls treated with standard cast in 2019 was used for comparison. Results: A total of 56 patients with a mean age of 8±3 years (range 2 to 15) were prospectively enrolled in this study. Parent-reported PROMIS Upper Extremity scores showed a significant increase from 24.9 (95% confidence interval=20.8-29.1) at enrollment to 51.6 (95% confidence interval=50.8-52.5) at 3 months follow-up ( P <0.001). Results of the satisfaction survey (n=39) showed all parents were either very satisfied (85%) or satisfied (15%). In addition, 10% of parents would have initially preferred to come into clinic for cast removal and 90% of parents would prefer this new treatment plan in the future. Patients in the abbreviated care cohort returned to clinic for a median 1 in-person visits, compared with 2 for historical controls (n=183, P <0.001). Abbreviated care patients received fewer (1.0) radiographs than controls (2.0, P <0.001). Complication rate did not differ between the groups ( P= 0.77). Conclusions: Complete and stable, nonminimally or minimally displaced UE fractures can be cared for safely and effectively in a single in-person visit, with a telemedicine cast removal visit. Parents are satisfied with this abbreviated protocol and prefer it to additional in-person visits. Level of Evidence: Level III.

BACKGROUND:Atlantoaxial instability (AAI) is common in pediatric patients with Trisomy 21 and can lead to spinal cord injury during sports, trauma, or anesthetized neck manipulation. Children with Trisomy 21 therefore commonly undergo radiographic cervical spine screening, but recommendations on age and timing vary. The purpose of this study was to determine if instability develops over time.METHODS:We performed a retrospective review for all pediatric Trisomy 21 patients receiving at least 2 cervical spine radiographic series between 2008 and 2020 at our institution. Atlantodens interval (ADI) and space available for the cord at C1 (SAC) were measured; bony abnormalities such as os odontoidium, and age and time between radiographs were noted. AAI was determined by ADI ≥6 mm or SAC ≤14 mm based on our groups' prior study. Those who developed instability were compared with those who did not.RESULTS:A total of 437 cervical spine radiographic series from 192 patients were evaluated, with 160 included. Mean age at first radiograph was 7.4±4.4 years, average ADI was 3.1 mm (±1.2), and SAC was 18.1 mm (±2.6). The average time between first and last radiographs was 4.3 years (±1.8), with average final ADI 3.2 mm (±1.4) and SAC 18.9 mm (±2.9). Seven patients (4%) had instability: 4 were unstable on their initial studies and 3 (1.6%) on subsequent imaging. Os odontoideum was found in 5 (71%) unstable spines and 3 (2%) stable spines (P<0.0001); only 1 patient that became unstable on subsequent radiograph did not have an os. There was no specific age cut-off or surveillance time period after which one could be determined no longer at risk.CONCLUSIONS:Trisomy 21 patients have a 4.4% overall rate of AAI in our series with a 1.6% rate of progression to instability over ∼4 years. Given this nearly 1 in 23 risk of instability, we recommend initial surveillance radiograph for all children over 3 years with Trisomy 21; repeat asymptomatic surveillance should continue in those with os odontoideum given their high instability risk.LEVEL OF EVIDENCE:Level II-diagnostic study.

INTRODUCTION:Children with early onset scoliosis (EOS) undergoing spine surgery often have significant respiratory disease. Preoperative risk assessments that predict an increased length of hospital stay (LOS) for this group have not been previously evaluated.METHODS:A voluntary protocol using preoperative lung function studies began among participants of a multicenter registry in 2016. Preoperative assessments were standardized to include spirometry, blood hemoglobin levels, serum bicarbonate, albumin and prealbumin; radiographic parameters of the spine, C-EOS classification and need for preoperative pulmonary assistance before initial growth friendly device insertion or "definitive" spine fusion. Primary outcome was LOS postoperatively. Data, including age, diagnosis, and type of surgery, was collected prospectively. Secondary outcomes measured included intensive care unit LOS, requirement for new pulmonary assistance on discharge, and pulmonary complications. Groups were compared using the Fisher exact tests.RESULTS:Of 525 children enrolled, 101 (20%) had preoperative spirometry. Median age was 8.9 years [interquartile range (IQR): 4.27]. Etiologies for EOS included 29 neuromuscular (28%), 33 idiopathic (32%), 19 syndromic (19%), and 22 congenital (21%) scoliosis. Eighty (78%) had growing rod (GR) insertions; 23 (22%) had spine fusion SF. Eighteen subjects (17%) were hospitalized ≥7 days (median=9 d); 83 had a LOS <7 days (median=3 d). Percentage of forced vital capacity (FVC%) predicted was inversely associated with LOS ≥7 days with a median of 75.3% (IQR: 41.7) for LOS <7 days and 51.7% (IQR: 41.6) (P=0.02). There were no detectable differences in LOS for other preoperative values.CONCLUSION:FVC predicted ≤50% preoperatively in children undergoing initial growth friendly rod insertion or definitive fusion after growth friendly treatment is associated with an increased risk of postoperative hospital stays ≥7 days. As demonstrated in previous studies, severe restrictive lung disease (FVC% predicted at or below 50%) is associated with increased risk of poorer outcomes for EOS patients.

Purpose We implemented an EMR-based “Spine at Risk” (SAR) alert program in 2011 to identify pediatric patients at risk for intraoperative spinal cord injury (SCI) and prompt an evaluation for peri-operative recommendations prior to anesthetic. SAR alerts were activated upon documentation of a qualifying ICD-9/10 diagnosis or manually entered by providers. We aimed to determine the frequency of recommended precautions for those auto-flagged by diagnosis versus by provider, the frequency of precautions, and whether the program prevented SCIs during non-spinal surgery. Methods We performed a retrospective chart review of patients from 2011 to 19 with an SAR alert. We recorded how the chart was flagged, recommended precautions, and reviewed data for SCIs at our institution during non-spinal operations. Results Of the 3453 patients with an SAR alert over the 9-year study period, 1963 were auto-flagged by diagnosis and 1490 by manual entry. Only 38.7% and 24.3% of the patients in these respective groups were assigned precaution recommendations, making the auto-flag 62.8% better than providers at identifying patients needing precautions. Cervical spine positioning precautions were needed most frequently (86.7% of diagnosis-flagged; 30.0% of provider-flagged), followed by intraoperative neuromonitoring (IONM) (25.2%; 6.1%), thoracolumbar positioning restrictions (16.1%; 7.9%), and fiberoptic intubation (13.9%; 5.7%). There were no SCIs in non-spinal procedures during the study. Conclusion EMR-based alerts requiring evaluation by a Neurosurgeon or Orthopaedic surgeon prior to anesthesia can prevent SCIs during non-spinal procedures. The majority of identified patients are not found to be at risk, and will not require special precautions. Level of evidence III.

OBJECTIVE: The outcomes of conservative and operative treatment of os odontoideum in children remain unclear. Our objective was to study the outcomes of conservative and surgical treatment of idiopathic os odontoideum in children and compare these outcomes in age- and treatment-matched nonidiopathic children with os odontoideum. METHODS: A retrospective multicenter review identified 102 children with os odontoideum, of whom 44 were idiopathic with minimum 2-year follow-up. Ten patients were treated conservatively, and 34 underwent spinal arthrodesis. Both groups were matched with nonidiopathic patients by age and type of treatment. Cervical arthrodesis was recommended for patients with increased atlantoaxial distance or reduced space available for the cord in flexion-extension radiographs. RESULTS: All 20 children undergoing conservative treatment remained asymptomatic during follow-up, but 1 nonidiopathic patient developed cervical instability. The idiopathic group had significantly less severe radiographic cervical instability and less neurologic complications than the nonidiopathic group (P < 0.05 for all comparisons). Thirty-three (97%) patients in the idiopathic group and 32 (94%) patients in the nonidiopathic group (94%) had spinal fusion at final follow-up (P = 0.55). The risk of complications (15% vs. 41%; odds ratio 0.234, 95% confidence interval 0.072-0.757, P = 0.015) and nonunion (6% vs. 24%; odds ratio 0.203, 95% confidence interval 0.040-0.99, P = 0.040) were significantly lower in the idiopathic than in the nonidiopathic group. Idiopathic children undergoing rigid fixation achieved spinal fusion. CONCLUSIONS: Idiopathic patients with stable atlantoaxial joint at presentation remained asymptomatic and intact during conservative treatment. Idiopathic children with os odontoideum undergoing spinal arthrodesis had significantly fewer complications and nonunion than nonidiopathic children.

Background: The purpose of this study was to determine whether the new AOSpine thoracolumbar spine injury classification system is reliable and reproducible when applied to the pediatric population. Methods: Nine POSNA (Pediatric Orthopaedic Society of North America) member surgeons were sent educational videos and schematic papers describing the AOSpine thoracolumbar spine injury classification system. The material also contained magnetic resonance imaging and computed tomography imaging of 25 pediatric patients with thoracolumbar spine injuries organized into cases to review and classify. The evaluators classified injuries into 3 primary categories: A, B, and C. Interobserver reliability was assessed for the initial reading by Fleiss kappa coefficient (k F ) along with 95% confidence interval (CI). For A and B type injuries, subclassification was conducted including A0 to A4 and B1 to B2 subtypes. Interobserver reliability across subclasses was assessed using Krippendorff alpha (α k ) along with bootstrapped 95% CI. Imaging was reviewed a second time by all evaluators ~1 month later. All imaging was blinded and randomized. Intraobserver reproducibility was assessed for the primary classifications using Fleiss kappa and subclassification reproducibility was assessed by Krippendorff alpha (α k ) along with 95% CI. Interpretations for reliability estimates were based on Landis and Koch (1977): 0 to 0.2, slight; 0.2 to 0.4, fair; 0.4 to 0.6, moderate; 0.6 to 0.8, substantial; and >0.8, almost perfect agreement. Results: Twenty-five cases were read for a total of 225 initial and 225 repeated evaluations. Adjusted interobserver reliability was almost perfect (k F =0.82; CI, 0.77-0.87) across all raters. Subclassification reliability was substantial (α K =0.79; CI, 0.62-0.90). Adjusted intraobserver reproducibility was almost perfect (k F =0.81; CI, 0.71-0.90) for both primary classifications and for subclassifications (α k =0.81; CI, 0.73-0.86). Conclusions: The reliability for the AOSpine thoracolumbar spine injury slassification System was high amongst POSNA surgeons when applied to pediatric patients. Given a lack of a uniform classification in the pediatric population, the AOSpine thoracolumbar spine injury classification system has the potential to be used as the first universal spine fracture classification in children. Level of Evidence: Level III.

Background: Treatment outcomes and risk factors for neurological deficits in pediatric patients with an os odontoideum are unclear. Methods: We reviewed the data for 102 children with os odontoideum who were managed at 11 centers between 2000 and 2016 and had a minimum duration of follow-up of 2 years. Thirty-one children had nonoperative treatment, and 71 underwent instrumented posterior cervical spinal arthrodesis for the treatment of C1-C2 instability. Nonoperative treatment consisted of observation (n = 29) or immobilization with a cervical collar (n = 1) or halo body jacket (n = 1). Surgical treatment consisted of atlantoaxial (n = 50) or occipitocervical (n = 21) arthrodesis. One patient also underwent transoral odontoidectomy. Results: Thirty children (29%) presented with neurological deficits, 28 of whom had radiographic atlantoaxial instability (atlantoaxial distance >5 mm) or limited space (≤13 mm) available for the spinal cord (risk ratio, 7.8 [95% confidence interval, 2.0 to 31] compared with children with no radiographic risk factors). The 27 children without neurological deficits or atlantoaxial instability at presentation underwent nonoperative treatment and remained asymptomatic. Of the initial nonoperative cohort, one child developed atlantoaxial instability, and another had a persistent neurological deficit; both children underwent spinal arthrodesis during the study period. One child with cervical instability declined surgery and remained asymptomatic. Spinal fusion occurred in 68 patients in the surgical group by the end of the study period (mean, 3.7 years; range, 2.0 to 11.8 years). Surgical complications occurred in 21 children, including nonunion in 12, new neurological deficits in 4, cerebrospinal fluid leak in 2, symptomatic instrumentation requiring removal 2, and vertebral artery injury in 1. Nine children underwent revision surgery. In the surgical group, Japanese Orthopaedic Association neurological function scores improved significantly from preoperatively to the latest follow-up for the upper extremities (p = 0.026) and lower extremities (p = 0.007). Conclusions: The risk of developing a neurological deficit was strongly associated with atlantoaxial instability and limited space available for the spinal cord in children with os odontoideum. Nonoperative treatment was safe for asymptomatic patients without atlantoaxial instability. Spinal arthrodesis resolved the neurological deficits of children with symptomatic os odontoideum. Level of Evidence: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Prognostic study and validation using prospective clinical trial data. To derive and validate a model predicting curve progression to ≥45° before skeletal maturity in untreated patients with adolescent idiopathic scoliosis (AIS). Studies have linked the natural history of AIS with characteristics such as sex, skeletal maturity, curve magnitude, and pattern. The Simplified Skeletal Maturity Scoring System may be of particular prognostic utility for the study of curve progression. The reliability of the system has been addressed; however, its value as a prognostic marker for the outcomes of AIS has not. The BrAIST trial followed a sample of untreated AIS patients from enrollment to skeletal maturity, providing a rare source of prospective data for prognostic modeling. The development sample included 115 untreated BrAIST participants. Logistic regression was used to predict curve progression to ≥45° (or surgery) before skeletal maturity. Predictors included the Cobb angle, age, sex, curve type, triradiate cartilage, and skeletal maturity stage (SMS). Internal and external validity was evaluated using jackknifed samples of the BrAIST data set and an independent cohort (n = 152). Indices of discrimination and calibration were estimated. A risk classification was created and the accuracy evaluated via the positive (PPV) and negative predictive values (NPV). The final model included the SMS, Cobb angle, and curve type. The model demonstrated strong discrimination (c-statistics 0.89–0.91) and calibration in all data sets. The classification system resulted in PPVs of 0.71–0.72 and NPVs of 0.85–0.93. This study provides the first rigorously validated model predicting a short-term outcome of untreated AIS. The resultant estimates can serve two important functions: 1) setting benchmarks for comparative effectiveness studies and 2) most importantly, providing clinicians and families with individual risk estimates to guide treatment decisions. Level 1, prognostic.

In the current study, Diebo and colleagues [2] present a set of functional tests that seem relatively simple and quick to perform. They state that the purpose for examining these tests is to establish “a more objective and quantifiable assessment method” [2] than current quality-of-life questionnaires for patients undergoing spine surgery for spinal deformities. In light of the increasing cost of these procedures and the frequency at which adults undergo spinal deformity surgery, this goal seems laudable. There are many different “objective” functional tests available and validated like the 6-minute walk, timed up and go, stair up and down, and the 10-meter walk test. The Dubousset Functional Test, which measures mainly activities and functions that are most likely to be improved by adult spinal deformity surgery (upright standing, walking, and sitting, for example) is similar to many of these tests, but can be performed more quickly. However, multilevel spinal fusion reduces ROM, which affects other activities that depend on flexion and rotation. Studies have shown substantial negative impact on activities of daily living using the Lumbar Stiffness Disability Index (LSDI) and amodified version of the LSDI [3, 4]. For those undergoing a four-level lumbar fusion, for example, 30% to 70% of patients report “considerable effect on” or “no ability to” put on shoes, put on pants, cut toenails, wipe after toileting, squat down, or take a bath [4]. This may be one reason that some patient-reported outcome measures (PROMs) do not demonstrate substantial improvement for many patients who undergo adult spinal deformity surgery, despite what appears to be a successful correction of other objective measurements such as coronal and sagittal alignment, balance parameters, and pain [1]. Patients who show a substantial clinical benefit from adult spinal deformity surgery may be those who already have profound stiffness. Are physical function tests that asses actual daily function more objective than PROM/health-related quality of life (HRQOL) questionnaires? The results are mixed. For example, patients who don’t return to sport after ACL reconstruction report lower PROM scores but demonstrate physical performance tests comparable to thosewho do [11], and accelerometer data in patients with spine fusions show no differences in daily activity levels despite measured improvements in balance, gait speed, and the distances the patients are able to walk [10]. Another study in patientswho underwent lumbar decompression with or without oneor two-level fusions found increased gait cycles per hour and higher-intensity gait-cycle frequency, but found that PROMs improved much more so than did measured activity [9].

Polysomnograms (PSGs) are not used in most spine centers for children with EOS. There are no standards for PSG referrals, and the yield from PSGs is unknown. We describe referrals for PSGs in 96 children > 5 years old with EOS, their lung functions, types of EOS, and frequency of abnormal PSGs.

Etiology of early onset scoliosis as described by C-EOS does not predict pulmonary function. Further study is required to provide granularity with regard to specific C-EOS classifications.

Study Design. Descriptive cross-sectional study. Objective. To measure respiratory muscle function in children with early onset scoliosis (EOS), determine the frequency of respiratory muscle weakness, and correlate these measures with vital capacity, body mass index, and Cobb angle. Summary of Background Data. Progressive restrictive respiratory disease is common among children with moderate to severe EOS. Reduced respiratory muscle strength is associated with the loss of lung function in adolescents and adults with scoliosis. We hypothesized that reduced inspiratory and expiratory respiratory muscle strength also occur in children with EOS and correlate with reduced vital capacity, poor nutritional status, and severity of the spine deformity. Methods. We measured maximum inspiratory pressure (MIP) and maximum expiratory pressure (MEP), forced vital capacity (FVC), body mass index IBMI), and Cobb angle in 49 children with EOS but with no diagnosis of underlying muscle weakness. We measured these indices in 12 children serially over 18 months to see if abnormal respiratory muscle function was sustained. Results. FVC averaged 51% (SD 21) of predicted norms with 26 subjects having an FVC <50% predicted. The mean MIP was 57% (SD 25) and the mean MEP was 53% (SD 23) of predicted norms. Thirteen (27%) of the group had MIP values >2SD below the age and sex-based norms. BMI ranged between 1% and 99% of age-based norms. Cobb angle averaged 59° (SD27). MIP% and MEP% significantly correlated with FVC% (r =0.37, P = 0.01 and r = 0.52, P < 0.001 respectively)) but not with BMI or Cobb angle. Reduced MIP% and MEP% were sustained over 7 to 41 months. Conclusion. Respiratory muscle weakness is common and persistent in children with EOS and correlates with reductions in vital capacity. Mechanisms for abnormal respiratory function are unclear but must be determined to develop surgical treatment strategies that preserve respiratory muscle function in children with EOS throughout childhood. Level of Evidence: 2

Tranexamic acid is an anti-fibrinolytic agent frequently used in pediatric surgery. Common side effects include nausea, flushing, and headache, but in rare instances, it may produce anaphylaxis; with only one previously reported case in a 72-year-old man. We report a case of a delayed anaphylactic reaction in a pediatric patient undergoing posterior spine fusion; and discuss the intraoperative management of the acute event, immunologic confirmation, and subsequent anesthetic approach.

STUDY DESIGN:Retrospective dose-simulation comparison.OBJECTIVE:To determine if sufficient detail for preoperative analysis of bony anatomy can be acquired at substantially lower doses than those typically used.SUMMARY OF BACKGROUND DATA:Computed tomography (CT) is a preoperative planning tool for spinal surgery. The pediatric population is at risk to express the harmful effects of ionizing radiation. Preoperative CT scans are presently performed at standard pediatric radiation doses not tailored for surgical planning.METHODS:We used the validated GE Noise Injection software to retrospectively modify existing spine and chest CT scans from 10 patients to create CT images that simulated a standard dose (100%), 50% dose, and 25% dose scans. 4 orthopedic surgeons and a pediatric radiologist, blinded to dose, measured minimum medial-lateral pedicle width and maximum anterior-posterior bony length along the axis of presumed pedicle screw placement. A total of 90 axial images were generated to create our sample set. Measurements were evaluated for accuracy, precision, and consistency.RESULTS:For any given rater, there was no clinically relevant difference between measurements at the different dose levels and no apparent degradation in precision at the different dose levels. Consistent variation was observed between raters, the likely result of individual differences in measurement approach.CONCLUSION:Spinal CT scans done for preoperative planning can be performed at 25% of current radiation doses without a loss in surgical planning measurement accuracy or precision. These 25% dose-reduced scans would have average Computed Tomography Dose Index volume dose levels of roughly 1.0 to 2.5 mGy (depending on patient size) and size-specific dose estimates of roughly 2.5 mGy representing a substantial dose savings compared to current practice for many sites. Standardization of consistent landmarks may be useful to further improve inter-rater concordance.

Background: Obstructive lung disease occurs in 30% of children with early onset scoliosis (EOS); changes in degree of airway obstruction over time have not been reported. Methods: Longitudinal patterns of incidental, persistent, and progressive airway obstruction were retrospectively analyzed in a cohort of children with EOS with at least 1 forced expiratory volume in 1 second (FEV1)/forced vital capacity (FVC) value <85% on serial spirometric assessments over a ≥3-year observation period. The prevalence of clinical features and the severity of coronal and sagittal spine deformities for each group at the beginning and end of the study period were compared. Results: Airway obstruction was incidental in 12 (24%) and persistent in 37 (76%) of 49 children with EOS. Twenty of 37 (54%) of those with persistent obstruction developed progressive airway obstruction. The decline in FEV1/FVC over 6±2 years was insignificant in the incidental group (4%±2%) and the persistent nonprogressive group (7%±4%) but significant in the progressive group (13%±4%, t test; P =0.002). In total, 29% of the 49 children at the onset and 57% at the end of the study had airway obstruction. The incidental, persistent nonprogressive, and progressive groups did not differ with regard to age, diagnosis distribution, or sex. The initial coronal curve size, apex, direction of the curve, and degree of kyphosis were statistically similar among the 3 groups. Coronal curve magnitude inversely correlated with FEV1/FVC at the end but not the beginning of the study ( r =−0.19, P =0.002). Six of 19 responded to bronchodilator treatment, suggesting concurrent asthma. Airway obstruction did not relate to restrictive pulmonary abnormalities measured by FVC at first or last timepoints [slope=−0.076 (95% confidence interval, −0.99 to 0.038; P =0.19)]. Changes in degrees of airway obstruction and restrictive lung disease over time did not correlate [slope=−0.125 (95% confidence interval, −0.294 to 0.044; P =0.14)]. Conclusions: Children with EOS and progressive airway obstruction represent an important subgroup which may require new surgical and nonsurgical treatment strategies to prevent loss of lung function over time.

Study Design. Retrospective cohort.Objective. The objective of this study was to define the intraoperative radiation exposure during freehand surgical technique with fluoroscopic assistance for placement and confirmation of posterior instrumentation in patients with adolescent idiopathic scoliosis and compare data with published values using intraoperative cone-beam computed tomography (CBCT) for similar cases.Summary of Background Data. The treatment of idiopathic-like scoliosis used freehand placement of posterior instrumentation with fluoroscopic confirmation. Computer-assisted navigation systems coupled with intraoperative CBCT have been introduced to aid in accurate placement of instrumentation. Multiple studies report the improved accuracy of instrumentation using CBCT; however, there is a paucity of information regarding the radiation exposure when using CBCT in comparison with fluoroscopically assisted freehand technique.Methods. Forty-three idiopathic-like scoliosis operations performed by 4 spine surgeons at an academic institution were retrospectively reviewed. Radiation exposure was recorded intraoperatively for each case. Effective dose was determined using published effective dose to dose-length product conversion factors. Values were compared with previous studies reporting radiation exposure for similar cases using CBCT for intraoperative navigation and confirmation of instrumentation placement.Results. Calculated average effective dose using fluoroscopically assisted pedicle screw placement was 0.189 mSv (range, 0.00029-0.953 mSv; SD = 0.16711) per case. Average radiation exposure time was 26 seconds (SD = 18 s) per case, with an average of 11 vertebral levels fused. The literature reports effective dose for CBCT ranging from 7.29 to 9.72 mSv per case for intraoperative navigation and 14.58 to 19.44 mSv per case for both intraoperative navigation and confirmation of screw placement with CBCT.Conclusion. We have demonstrated that the use of standard fluoroscopy results in markedly lower radiation exposure during a standard posterior instrumented fusion for idiopathic-like scoliosis than by the use of CBCT; this conclusion is limited by the retrospective nature of the study and lack of a control group.