Pre-operative carbohydrate drink in pediatric spine fusion: randomized control trial.

PURPOSE: As rapid discharge protocols for pediatric spine fusion shorten stays, gastrointestinal (GI) complications are uncovered and cause delays in discharge. A pre-operative carbohydrate (CHO) drink has been shown to improve perioperative GI symptoms and functional return but has not been examined in pediatric spine patients. We aimed to determine if a preoperative CHO drink is safe in pediatric spine fusion patients, and if it improves their comfort scores and return of bowel function. METHODS: We prospectively randomized ASA-1 and -2 pediatric spine fusion patients to either a pre-anesthesia carbohydrate drink 2 h prior to surgery or to a control group (standard 8 h NPO), blinded to surgical team. We documented time to return to flatus, bowel movement, GI symptoms, and comfort scores for 72 h post-operatively or until discharge. RESULTS: 62 patients were randomized. There was no significant differences between the groups' pre-operative characteristics, surgical details, nor post-operative morphine dose equivalents, except for EBL (405 cc control, 340 cc CHO drink, p = 0.044). There were no perioperative complications related to ingestion of the CHO drink. CHO group had a positive trend for earlier return of flatus (21% vs. 3% return at 12 h), and comfort scores for anxiety and abdominal pain, but no statistically significant differences. There was no difference in length of stay or time to first bowel movement. CONCLUSION: There were no complications related to ingestion of a CHO drink 2 h prior to pediatric spinal fusion surgery. Further studies are needed to develop a study blinded to the participants with larger sample size. Level of evidence I.

Intraoperative Neuromonitoring for Spines at Risk During Nonspine Surgery: A 9-Year Review.

BACKGROUND: Patients with certain spinal anomalies are at risk for rare but devastating spinal cord injuries under anesthesia. We created a Spine at Risk (SAR) program to evaluate and recommend precautions for such patients, including intraoperative neuromonitoring (IONM) use for the highest-risk patients. We aimed to review all monitored nonspine procedures to determine rate of potential spinal cord injuries avoided in those who would otherwise have been unmonitored. METHODS: We performed a retrospective review of our institutional SAR program from 2011 to 2019 to analyze the number of nonspine anesthetized procedures that were done under IONM, the characteristics of those that had an IONM alert; and the clinical outcomes. RESULTS: Of the 3,453 patients flagged for SAR review, 1121 (33%) received a precaution recommendation, and 359 (10% of all flagged) were given IONM recommendations. Of those, 57 patients (16% of recommendations, 2% of all flagged) had a total of 102 nonspine anesthetized procedures done under IONM. Seven patients had a total of 10 cases with IONM alerts. Two cases were aborted when improved signals could not be obtained after working through a checklist; one of these patients woke with transient neurological deficits. Signals improved to baseline in 7 cases by working through a signal loss checklist. One case was aborted preoperatively when monitorable baseline signals could not be obtained. CONCLUSIONS: In the highest-risk spinal anomaly patients, we monitored an average of 11.7 nonspine cases per year, with a 10% rate of IONM alerts, and no permanent neurological deficits. Although the majority of patients remain safe during procedures, in the most critical patients IONM allowed the team to identify and react to alerts that may have otherwise led to permanent neurological injury. This is the largest series of spinal cord-monitored nonspine pediatric cases. It is important for pediatric orthopedic surgeons to evaluate at-risk patients and recommend IONM where appropriate, to protect both patients and our procedural colleagues. LEVEL OF EVIDENCE: Case series, level IV.

Can we automate spine fusion surgical site infection data capture?

PURPOSE: Spine fusion surgical site infection (SSI) rate is reported to national quality databases and used as a benchmark for orthopedic departments and hospital systems. However, accurate data require resource-heavy administrative review and even this has shown to vary. We aimed to create a passive electronic medical record (EMR) algorithm to automatically capture spine fusion SSI and compared its accuracy against the administrative chart review and self-reported morbidity and mortality (M&M) rates. METHODS: We retrospectively reviewed a single institution's spine fusion records for 7 years for all 90-day post-operative SSIs. We used Centers for Disease Control and Prevention (CDC) SSI definition coupled with intention to treat as an infection by orthopedics/infectious disease service as the gold standard. We compared our gold standard to administrative hand-checked SSI data, anonymously reported departmental M&M, and a passive EMR algorithm (ICD-9 or -10 post-operative SSI diagnosis code entered, or all four of: positive culture, antibiotic prescription between 3-90 days post-op, re-operation/re-admission, and a qualifying diagnosis). RESULTS: Nine hundred and fourteen spine fusions were included, with a 2.8% SSI rate (0.9% superficial and 2.0% deep). Passive EMR algorithm was the most sensitive at 89% (vs 76% administrative review, 73% M&M); all were highly specific at 99-100%. M&M was 100% positively predictive, administrative review 95%, and EMR 79%. CONCLUSION: Our passive EMR algorithm was more sensitive to pediatric spine fusion 90-day SSI than self-reported M&M and hand-checked administrative chart review. Although EMR may over-report, it can be used by others to narrow the initial sample for review, reduce resource burden involved with administrative spine SSI review, and provide a quality check for M&M self-reporting. LEVEL OF EVIDENCE: III.

Interfacet distance at L4 is increased in spines with high-pelvic incidence.

Pelvic incidence (PI) is an angular measurement linked to spinal pathologies. There is an increasing distance between facet joints moving caudally down the sagittal plane of the spine. We defined pedicle divergence (PD) as the ratio of interfacet distance (IFD) between adjacent levels. This study aimed to evaluate the relationship between PI and PD. Two hundred and thirty specimens were obtained from the Hamann-Todd Osteological Collection. Specimens were catalogued for age, sex, race, PI, PD, and lumbar facet angle. Multivariate linear regression analysis was performed to determine the relationship between variables. IRB approval was not required. Average age at death was 57.0 years ±6.2 years. There were 211 (92%) male specimens and 176 (77%) were white. Average PI was 47.1 ± 10.5°. For PD between L3/L4, there was a relationship with PI (ß = -0.18, p = 0.008). For PD between L4/L5, there was an opposite relationship with PI (ß = 0.21, p = 0.003). Regression analyses of the interfacet to body ratio at each level found an association with PI only at L4 (p = 0.008). This study demonstrated that PI has a significant association with IFD in the lower lumbar spine. Increasing PI was associated with increased PD between L3/L4 and decreased PD between L4/L5. These results further support the close relationship between pelvic morphology and the lower lumbar spine, and suggest that L4 may have an important role in compensating for aberrant PI.

A delayed diagnosis of high-grade spondylolisthesis.

ABSTRACT: Spondylolysis, or pars defect, occurs in nearly half of children with back pain. Despite the marked prevalence, diagnosis of spondylolysis with spondylolisthesis often is delayed or missed secondary to referred pain and uncharacteristic presentation. This article describes an 8-year-old patient with 15 months of right heel pain who was initially treated by her primary care provider for presumed Sever disease before being referred to orthopedics. After orthopedic consultation, she was diagnosed with a high-grade spondylolisthesis with L5 nerve root compression. Although spondylolysis is an infrequent diagnosis, particularly in a patient this young, missing the diagnosis can significantly reduce a patient's quality of life.

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.

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.

The body image disturbance questionnaire-scoliosis better correlates to quality of life measurements than the spinal assessment questionnaire in pediatric idiopathic scoliosis.

PURPOSE: Idiopathic scoliosis (IS) patients can have body dissatisfaction which can affect their perception of health. Two body image measures, the Spinal Appearance Questionnaire (SAQ) and the Body Image Disturbance Questionnaire-Scoliosis (BIDQ-S), have been used in pediatric IS with variable correlation to the SRS-22r and radiographs, but have not been compared to each other. As patient reported outcomes (PROs) continue to be highlighted in large database studies and national hospital ranking system scoring, we should narrow use to the best and most efficient. We aim to determine which of two better correlates to pediatric IS patients' radiographs and quality of life (QoL) scores. METHODS: Consecutive IS patients aged 10-19 years old without surgery prospectively completed BIDQ-S, SAQ, SRS-22r, and PedsQL self-reported outcome measures. BIDQ-S and SAQ were compared in correlation to the two QoL surveys, as well as to radiographic major curve, shoulder asymmetry, lateral upright ribcage offset at apex, and coronal/sagittal balance. Spearman's r was used for correlations. RESULTS: 104 surveys with mean age 14.4 years and mean major curve 42° (14°-74°) were included. BIDQ-S and SAQ scores strongly correlated to each other (r = 0.76), but BIDQ-S had a stronger correlation to total SRS-22r (- 0.75 vs - 0.61 SAQ), PedsQL total (- 0.76 vs - 0.55) and better or no difference in each SRS-22r and PedsQL domain. Both poorly correlated to radiographs (main curve: r = 0.32 BIDQ-S, 0.31 SAQ). CONCLUSION: The BIDQ-S correlates better to SRS-22r and PedsQL for pediatric IS patients than the SAQ. Neither correlate well to radiographs. LEVEL OF EVIDENCE: III.

Classifying vertebral artery anatomy abnormality in children with skeletal dysplasia.

PURPOSE: Skeletal dysplasia (SKD) have predictably abnormal occipitocervical skeletal anatomy, but a similar understanding of their vertebral artery anatomy is not known. Knowledge and classification of vertebral artery anatomy in SKD patients is important for safe surgical planning. We aimed to determine if predictably abnormal vertebral artery anatomy exists in pediatric SKD. METHODS: We performed a retrospective review of CTAs of the neck for pediatric patients at a single institution from 2006 to 2018. CTAs in SKD and controls were reviewed independently in blinded fashion by two radiologists who classified dominance, vessel curvature at C2, direction at C3, and presence of fenestration and intersegmental artery. RESULTS: 14 skeletal dysplasia patients were compared to 32 controls. The path of the vertebral artery at C2 foramen was no different between the cohorts or by side, right (p = 0.43) or left (p = 0.13), nor for medial or lateral exiting direction from C3 foramen on right (p = 0.82) or left (p = 0.60). Dominance was most commonly neutral in both groups (71% in SKD and 63% in controls). There were no fenestrated nor first intersegmental arteries in our cohort. CONCLUSION: No systematic differences were detected between SKD and control patients with respect to vertebral artery anatomy. Nonetheless, surgically relevant variability was observed in both groups. Paying particular attention to the direction of exit at C3 and curvature at C2 with respect to the foramen and vessel dominance are important and easily classifiable abnormalities that both surgeons and radiologists can use to communicate and employ in pre-operative planning. LEVEL OF EVIDENCE: III.

NSQIP versus institutional morbidity and mortality conference: complementary complication reporting in pediatric spine fusion.

PURPOSE: Other fields of medicine have demonstrated underreported surgical complication rates by institutional M&M compared to NSQIP. However, a study comparing surgical complication rates in the pediatric spine population, using an identical set of patients rather than nationally extrapolated, has not been performed. METHODS: A single institution's ASC-NSQIP Pediatric spine fusion cases and its departmental team-reported M&M database for the same were reviewed for January 1, 2012 to December 31, 2018. Differences in surgical complication reporting between the two databases for the identical patient cohort were recorded. RESULTS: NSQIP identified 50 pediatric spine fusion patients with complications out of 386 NSQIP-algorithm-sampled cases (13%). Of these complications, 23 were not reported in the M&M conference database (6% of NSQIP-sampled cases, 2.5% of all M&M cases). The most common under-reported complication categories include pneumonia (100% under-reported), clostridium difficile (100%), urinary tract infection (83%), and superficial wound disruption (67%). During the same 7 years, M&M covered 924 spine fusions and identified 162 complications. Of these 162 patients, 22 were included in the NSQIP sampling and were not reported as complications (6% of NSQIP sampled patients). CONCLUSION: Recognizing complication rates is central to implement strategies for delivering better quality care. NSQIP data may serve as an important quality check for pediatric spine institutional M&M data, but both may not include all complications even within its sampled patients. In general, NSQIP's protocols identified more medical complications, while M&M has a surgical focus, benefits from the limitless follow-up, and involves timely departmental awareness of complications.

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.

Delayed Postoperative Spinal Cord Ischemia After Posterior Spinal Fusion in a Pediatric Patient with Syrinx and Decompressed Chiari: A Case Report.

CASE: We present a case of delayed postoperative neurologic deficits 1 day after posterior spinal fusion in a pediatric patient with syrinx and previous Chiari decompression, which reversed with urgent rod removal. CONCLUSION: There is limited literature on delayed cord injury occurring after surgery in a patient with scoliosis of neuromuscular origin. Patients with syrinx and a history of Chiari decompression may have spinal cords more sensitive to injury including delayed ischemia after deformity treatment and should be paid extra perioperative attention including considering prolonged mean arterial pressure goals or more conservative deformity correction.

What Should I Wear to Clinic? A National Survey of Pediatric Orthopaedic Patients and Parents.

BACKGROUND: A number of factors have been shown to affect how surgeons are subjectively viewed, including their appearance in clinic. Patient preference for pediatric orthopaedic surgeon attire has not previously been studied, nor has its influence on initial perception of the surgeon. METHODS: At 5 pediatric regional sites across the United States, parents and patients presenting to the pediatric orthopaedic clinic were given anonymous surveys showing 8 photos of surgeons in different clinical dress including in business or scrub dress, each with or without white coat (WC). Subjects reported their demographics, single preferred photo, rated characteristics of the surgeons in each photo on a 5-point Likert scale, and answered specific questions on scrubs and WCs. The first consecutively completed 100 parent and 100 patient surveys were included from each site. RESULTS: One thousand surveys were collected from patients (500) and parents (500). The majority felt a surgeon's clinical dress would not affect how they are cared for (83%), and that it was ok to wear scrubs in clinic (90%). Overall, WC was preferred to those without no matter the age, but there was no difference between scrub and business choices. Of those stating a preference, woman in business and WC (24%) and woman in scrubs and WC (21%) were most selected, with the only geographic difference being the midwest's preference for man in business and WC. Females were more likely to prefer women photographs (P<0.0001). CONCLUSIONS: In general, pediatric orthopaedic patients and parents do not have a strong specific preference toward what their surgeon wears to clinic, including whether or not we are dressed in scrubs, but some initial biases exist. When asked to choose, the traditional WC worn over any attire is preferred, and female patients and parents uncover a preference for a surgeon of their own sex. LEVEL OF EVIDENCE: Level III.

Comparing short-term AIS post-operative complications between ACS-NSQIP and a surgeon study group.

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.

Prospective spine at risk program for prevalence of intracanal spine lesions in pediatric hereditary multiple osteochondromas.

STUDY DESIGN: Retrospective cohort study OBJECTIVES: To determine prevalence of hereditary multiple osteochondromas (HMO) and utility of MRI surveillance in a prospective Spine at Risk (SAR) program. Unidentified intraspinal exostoses in HMO can lead to neurologic injury in children during sedated procedures but no MRI guidelines exist. We sought to determine the prevalence and age of intraspinal exostoses from MRIs, and indications for MRI surveillance. METHODS: Retrospective review was performed of pediatric HMO patients who underwent total spine MRIs at a single institution after a prospective SAR program was instituted. Charts were reviewed for MRI indication and findings, symptoms, surgery, and location of other exostoses. Fisher's exact test was used to compare categorical variables and T test to compare continuous variables. Predictive value of pelvic/rib exostoses was calculated for intraspinal lesions. RESULTS: Forty-three patients with HMO underwent total spine MRIs with average age of 11.5 years. Fifteen (35%) patients had exostoses on vertebral column, eight (19%) had intra-canal spinal exostoses. Higher prevalence of spine lesions occurred in symptomatic patients than asymptomatic (any spinal lesion: 73% prevalence in symptomatic vs 22% in asymptomatic, p < 0.005; intra-canal spinal lesion: 46% vs 9%, p < 0.05). Only two of the 11 'symptomatic presentations' could be attributable to intracanal spinal exostoses. Only one intra-canal exostosis found on asymptomatic surveillance was treated surgically. Presence of pelvic or rib exostoses were not strongly predictive of intra-canal lesions (23% PPV, 85% NPV, 63% sensitivity, 51% specificity). CONCLUSIONS: Even with the presence of intra-canal exostoses, true symptomatic lesions are rare. Rib and pelvic lesions were not predictive of intra-canal lesions in our population. We recommend obtaining MRIs at time of preoperative evaluation in asymptomatic children old enough to not need sedation, or in patients with true neurologic symptoms to prevent unnecessary sedation of younger children for surveillance MRI. LEVEL OF EVIDENCE: III.

Cerebral palsy - beyond hip deformities.

Cerebral palsy is a neurologic condition with myriad musculoskeletal and articular manifestations. While every patient is unique with innumerable variations in presentation, symptoms and treatments, there are broad themes and recognizable patterns of development. Many of these findings spill over to other neurodevelopmental disorders, and lessons learned from children with cerebral palsy translate well to multiple neurologic conditions. This review focuses on the more common manifestations involving the spine, knee, foot and ankle, with an emphasis on collecting and describing imaging features, along with clinical and radiologic pearls and pitfalls.

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.

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.

Pelvic Incidence in Spines With 4 and 6 Lumbar Vertebrae.

STUDY DESIGN: Anatomical study. OBJECTIVES: This study was conducted to determine the prevalence of abnormal lumbar vertebrae (4 and 6) and note any differences in pelvic incidence (PI) between spines with 4, 5, and 6 lumbar vertebrae. METHODS: We screened 2980 dry cadaveric specimens from an osteological collection. Pelvises were reconstructed by articulating the sacra and innominate bones. PI was measured in all specimens via lateral photographs. L6-pelvic incidence (L6PI) was also measured, by articulating L6 to the sacrum and measuring PI from the superior aspect of the L6 vertebral body. RESULTS: Of the specimens screened, 969 specimens were evaluated. Average age of death for all specimens was 50.4 ± 15.4 years. The prevalence of 6 lumbar vertebrae was 0.8% (n = 23), and the prevalence of 4 lumbar vertebrae was 1.8% (n = 54). PI measured 38.5° in specimens with 4 lumbar vertebrae, and 46.7° and 47.1° in specimens with 5 and 6 lumbar vertebrae, respectively. PI was significantly different between specimens with 4 and 5 lumbar vertebrae (P < .001) but not between specimens with 5 and 6 lumbar vertebrae (P = .38). For specimens with 6 lumbar vertebrae, when L6 was added to the sacrum, mean L6PI was 27.4°. CONCLUSIONS: In our large cadaveric study of full spines, we reported a lower prevalence of spines with 4 and 6 lumbar vertebrae compared to previous studies. PI was significantly decreased in subjects with 4 lumbar vertebrae compared with those with normal spines, and special caution should be taken when managing sagittal balance in these patients.