The Reliability of the AO Spine Upper Cervical Classification System in Children: Results of a Multi-Center Study.

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.

Abbreviated Outpatient Upper Extremity Fracture Care to Avoid Clinic and Hospital Environmental Encounters During the COVID-19 Pandemic: A New Approach to Fracture Care?

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.

Low Preoperative Lung Functions in Children With Early Onset Scoliosis Predict Postoperative Length of Stay.

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.

Repeat Pediatric Trisomy 21 Radiographic Exam: Does Atlantoaxial Instability Develop Over Time?

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.

Persistence and Progression of Airway Obstruction in Children With Early Onset Scoliosis.

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.

The Reliability of the AOSpine Thoracolumbar Classification System in Children: Results of a Multicenter Study.

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 (kF) 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 (αk) 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 (αk) 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 (kF=0.82; CI, 0.77-0.87) across all raters. Subclassification reliability was substantial (αK=0.79; CI, 0.62-0.90). Adjusted intraobserver reproducibility was almost perfect (kF=0.81; CI, 0.71-0.90) for both primary classifications and for subclassifications (αk=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.

Anaphylactic reaction to tranexamic acid in an adolescent undergoing posterior spinal fusion.

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.

BrAIST-Calc: Prediction of Individualized Benefit From Bracing for Adolescent Idiopathic Scoliosis.

STUDY DESIGN: Prospective multicenter study data were used for model derivation and 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 the superiority of bracing over observation to prevent curve progression to the surgical threshold; 42% of untreated subjects had a good outcome, and 28% progressed to the 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. MATERIALS AND METHODS: Logistic regression was used to predict curve progression to <45° at skeletal maturity (good prognosis) in 269 BrAIST subjects who were observed or braced. Predictors included age, sex, body mass index, 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 data set and an independent cohort (n=299) through estimates of discrimination and calibration. RESULTS: The final model included age, sex, body mass index, Risser stage, Cobb angle, and hours of brace wear per day. The model demonstrated strong discrimination ( c -statistics 0.83-0.87) and calibration in all data sets. 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 a 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 overbracing of AIS, improve adherence, and, most importantly, decrease the likelihood of spinal fusion in this population.

Baumann angle and radial-ulnar overlap: a radiographic study to control for the angle of the x-ray beam.

BACKGROUND: Baumann's angle (BA) is the most common radiographic measurement used to assess coronal plane alignment of the distal humerus. However, it can vary greatly based on the x-ray beam angle, which can lead to multiple radiographs causing excessive radiation exposure, cost, and discomfort for the acutely injured child. The lateral capitellohumeral angle is a measure of sagittal plane alignment, and its variability has been reported. In this study, we sought to determine whether there were surrogate measures that could act as internal controls for the angle of the x-ray beam to give an accurate BA. METHODS: Elbow radiographs from uninjured children stratified by age into 6 groups were reviewed. BA and lateral capitellohumeral angle as well as several predetermined measurements that could be potential surrogate measures for the angle of the x-ray beam were performed. Statistical significance was found between BA and radial-ulnar overlap (RUO), which was analyzed further and plotted in linear graph fashion. RESULTS: The Pearson correlation coefficient (0.58) between BA and RUO was significant at P=0.001. The average BA was 71±7.2 degrees (1 SD) and the average RUO was 0.34±0.26. The following linear graph equation was obtained to define the relationship between RUO and BA: BA=12.36 (RUO)+67. Further derivation gives us an equation to "correct" BA for a given RUO: corrected BA=measured BA-12.36 (RUO-0.34). Application of this formula lessened the SD of BA from 7.2 to 5.9 degrees and decreased the percentage of BA measurements outside of 1 SD from 30% to 14%. CONCLUSIONS: RUO is a reliable surrogate measure to control for the angle of the x-ray beam and improve the reliability when measuring BA that can be easily applied in the clinical setting. CLINICAL RELEVANCE: The ability to accurately correct the BA based on a given RUO gives the physician the confidence to adequately interpret imperfect radiographs in the emergency room setting and minimize repeat radiographs.

Does using the medial or lateral humeral line improve reliability of Baumann angle measurement on plain x-ray? The effect of humeral length visualized on the x-ray.

BACKGROUND: Baumann angle (BA) is a common measure of coronal plane alignment of the distal humerus. We hypothesize that the reliability of measuring BA would be improved by using the medial and lateral cortical margins of the humerus seen on plain x-ray, rather than the estimated central humeral line, which is the "standard" technique. Further, we analyze whether the amount of humerus visible on the film improves the reliability of the method. METHODS: A total of 71 anteroposterior elbow digital radiographs from patients aged 0 to 12 were measured 3 times by 5 qualified observers. Each digital measurement included (1) BA using the estimated central humeral line; (2) BA using the medial humeral line (BA-MHL); and (3) BA using the lateral humeral line (BA-LHL). Inadequate radiographs or those showing any indication of current or previous fracture were excluded. Intraobserver reliability was estimated for each rater using a 1-way analysis of variance model and interobserver reliability of each set of measurements was estimated using a 2-way analysis of variance. RESULTS: The mean and SD for the BA, BA-MHL, and BA-LHL in females were 70.0 (6.73), 68.0 (6.84), and 72.3 (7.93), respectively, and for males 73.0 (5.22), 70.0 (5.56), and 76.0 (6.18), respectively. Intraobserver reliability (intraclass correlation coefficient) for BA, BA-MHL, and BA-LHL averaged 0.85, 0.92, and 0.90, respectively. Average interobserver reliability (intraclass correlation coefficient) for BA, BA-MHL, and BA-LHL were 0.79, 0.71, and 0.76, respectively. Intraobserver and interobserver reliability of BA and BA-LHL were significantly improved when at least 7 cm of humerus was visible on the x-ray, as compared with <7 cm visible. CONCLUSIONS: Intrarater reliability is better for both BA-LHL and BA-MHL than for standard BA (using the estimated central humeral axis). Interrater reliability was best using standard BA. Reliability of all methods is improved when >7 cm of the distal humerus is visible on the radiograph. In addition, at least 7 cm of the distal humerus on anteroposterior radiographs improves reliability of measuring BA. LEVEL OF EVIDENCE: Diagnostic study-Level II.

The pediatric "Spine at Risk" program: 9-year review of a novel safety screening tool.

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.

The lateral capitellohumeral angle in normal children: mean, variation, and reliability in comparison to Baumann's angle.

BACKGROUND: Angular deformity is the most common complication of supracondylar humerus fracture. Baumann's angle (BA) is an established radiographic measure of coronal plane deformity after this injury. Numerous radiographic methods have been used to assess sagittal plane deformity, however, the mean, variability, and reliability of these measures has not been established. The purpose of this study was to determine the mean, SD, and intraobserver/interobserver reliability of the lateral capitellohumeral angle (LCHA) in children without evidence of fracture and compare them with those of BA. METHODS: Seventy-one sets of anteroposterior and lateral elbow radiographs were selected and stratified into 6-year age categories with equal number of males and females in each category. Five physicians performed 3 separate measurements of LCHA and BA on each film set. Statistical calculations were performed to determine mean, SD, measurement reliability, and differences between patients groups. RESULTS: The mean LCHA ±1 SD and BA ± 1 SD measurements were 50.8 ± 6 degrees and 71.5 ± 6.2 degrees, respectively, and did not vary significantly by age, side, or sex (P>0.05). The LCHA showed good intraobserver (correlation coefficient 0.67) and fair interobserver (0.37) reliability, whereas BA showed excellent intraobserver (0.86) and interobserver (0.80) reliability. The expected SD for repeated measurement of a radiograph by a single observer was 2.6 degrees for BA and 5.2 degrees for LCHA. CONCLUSIONS: The LCHA is a simple measurement to perform using digital tools. In normal elbows, the mean angle is 51 ± 6 degrees and does not vary by age, side, or sex. LCHA variability in normal elbow radiographs is similar to BA. Its reliability is inferior to BA, but improves with age. Sagittal angulation abnormality of at least 12 degrees (<39 or >63 degrees) is necessary to be confident that the change is not because of measurement error alone. Further research is needed to better define the relationship of sagittal plane angular deformity to clinical outcome. LEVEL OF EVIDENCE: Diagnostic study with poor reference standard, Level IV.

Results of Conservative and Surgical Management in Children with Idiopathic and Nonidiopathic Os Odontoideum.

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. LEVEL OF EVIDENCE: III.

An Updated Algorithm for Radiographic Screening of Upper Cervical Instability in Patients With Down Syndrome.

STUDY DESIGN: Retrospective evaluation of cervical spine images from 2006-2012 for the purposes of "screening" children with Down syndrome for instability. OBJECTIVE: To determine whether a full series of cervical spine images including flexion/extension lateral (FEL) radiographs was needed to avoid missing upper cervical instability. SUMMARY OF BACKGROUND DATA: The best algorithm, measurements, and criteria for screening children with Down syndrome for upper cervical instability are controversial. Many authors have recommended obtaining flexion and extension views. We noted that patients who require surgical stabilization due to myelopathy or cord compression typically have grossly abnormal radiographic measurements on the neutral upright lateral (NUL) cervical spine radiograph. METHODS: The atlanto-dental interval, space available for cord, and basion axial interval were measured on all films. The Weisel-Rothman measurement was made in the FEL series. Clinical outcome of those with abnormal measurements were reviewed. Sensitivity, specificity, and positive and negative predictive values of NUL and FEL radiographs for identifying clinically significant cervical spine instability were calculated. RESULTS: A total of 240 cervical spine series in 213 patients with Down syndrome between the ages of 4 months and 25 years were reviewed. One hundred seventy-two children had an NUL view, and 88 of these patients also had FEL views. Only one of 88 patients was found to have an abnormal atlanto-dental interval (≥6 mm), space available for cord at C1 (≤14 mm), or basion axial interval (>12 mm) on an FEL series that did not have an abnormal measurement on the NUL radiograph. This patient had no evidence of cord compression or myelopathy. CONCLUSIONS: Obtaining a single NUL radiograph is an efficient method for radiographic screening of cervical spine instability. Further evaluation may be required if abnormal measurements are identified on the NUL radiograph. We also propose new "normal" values for the common radiographic measurements used in assessing risk of cervical spine instability in patients with Down syndrome. LEVEL OF EVIDENCE: Level IV.

Bracing in Adolescent Idiopathic Scoliosis Trial (BrAIST): Development and Validation of a Prognostic Model in Untreated Adolescent Idiopathic Scoliosis Using the Simplified Skeletal Maturity System.

STUDY DESIGN: Prognostic study and validation using prospective clinical trial data. OBJECTIVE: To derive and validate a model predicting curve progression to ≥45° before skeletal maturity in untreated patients with adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: 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. METHODS: 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). RESULTS: 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. CONCLUSIONS: 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 OF EVIDENCE: Level 1, prognostic.

Os Odontoideum in Children: Treatment Outcomes and Neurological Risk Factors.

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.

Early-Onset Spinal Deformity in Skeletal Dysplasias: A Multicenter Study of Growth-Friendly Systems.

PURPOSE: Severe, early-onset spinal deformity is common in patients with skeletal dysplasia. These deformities often present at young ages and are associated with significant pulmonary dysfunction. The objective of this study is to verify the effectiveness of growth-friendly spinal instrumentation systems in promoting growth in patients with skeletal dysplasia and early-onset kyphoscoliosis. METHODS: A retrospective, multicenter comparative cohort study was performed. Twenty-three patients identified to have a skeletal dysplasia (SKD) were evaluated for diagnosis, age at treatment, gender, and type of growing rod construct (spine vs. rib constructs). Patients were matched by age and construct type with similarly treated patients with early-onset scoliosis (CON) without skeletal dysplasia. Radiographic parameters including maximum coronal and sagittal Cobb angle with levels, T1-S1 height, and T1-T12 height were measured. RESULTS: T1-T12 (12.8 vs. 15.2 cm, p = .01) and T1-S1 (21.2 vs. 24.5 cm, p = .05) heights were significantly shorter for the SKD group at implantation, and kyphosis tended to be more severe in children with SKD (p = .80 and .07, respectively). Kyphosis did not improve with treatment. Scoliosis improved (p < .01), and ΔT1-T12 and ΔT1-S1 significantly increased in both groups (p < .01). Complication rates were similar between the two groups; however, patients with SKD had more intraoperative monitoring changes and hardware failures (p < .005). CONCLUSION: Although patients with SKD start with shorter spine lengths, gains in spine length appear to be comparable to other forms of EOS. Neuromonitoring changes and implant failures are more common in the SKD group. SIGNIFICANCE: The effectiveness of growth-friendly techniques in promoting growth in early-onset spinal deformities in patients with skeletal dysplasia has not been previously studied. We report the first comprehensive review of this topic. Growth-friendly techniques are an appropriate treatment option in this patient population.

Paper #4: Referral Patterns and Prevalence of Sleep Abnormalities in Children with EOS.

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.

Paper #2: Classification of Early Onset Scoliosis (C-EOS) and Pulmonary Function Outcomes.

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.