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.

Performing Multiple Posterior Spinal Fusions in 1 Day: A Comparison of Perioperative Outcomes Between Morning and Afternoon Cases.

BACKGROUND: High-volume centers for idiopathic scoliosis (IS) have difficulty in scheduling posterior spinal fusions (PSFs) due to operating room availability, particularly during school vacation. A solution is for 1 surgeon to perform 2 PSF cases back-to-back. This study aims to compare morning and afternoon PSF cases performed by the same surgeon for perioperative outcomes. METHODS: A retrospective review of PSF cases for IS that occurred on the same day as another PSF by the same surgeon between January 2013 and December 2019 was conducted. Perioperative outcomes included surgical time, estimated blood loss, length of stay, and inpatient opioid consumption normalized by the patient's weight. Postoperative outcomes included complications, revision rate, curve correction, and patient-reported outcomes using the Scoliosis Research Society-30. RESULTS: A total of 95 patients (87% female), mean age 15.6 years, were analyzed, with 48 morning cases and 47 afternoon cases. The median follow-up was 1.9 years (range: 0.3 to 6.1 y). Tests for equivalency determined equivalence in median anesthesia and mean surgical duration (P=0.05). The groups had similar initial curve correction (P=0.43) and rate of complications at 90 days postoperative (2 in each group for a total of 4 complications). No significant differences were seen between Scoliosis Research Society-30 scores at 6 months or in those who have reached 2 years postoperative. CONCLUSIONS: Little literature exists on the safety of a surgeon performing 2 PSF cases in 1 day, particularly in regard to pain outcomes, 30- and 90-day complication rates, and quality of life measures. This study indicates that few differences in safety, pain, and quality of life outcomes may appear between morning and afternoon PSF cases. LEVEL OF EVIDENCE: Level II.

Intraoperative Use of O-arm in Pediatric Cervical Spine Surgery.

INTRODUCTION: Traditionally, fluoroscopy and postoperative computed tomographic (CT) scans are used to evaluate screw position after pediatric cervical spine fusion. However, noncontained screws detected postoperatively can require revision surgery. Intraoperative O-arm is a 3-dimensional CT imaging technique, which allows intraoperative evaluation of screw position and potentially avoids reoperations because of implant malposition. This study's objective was to evaluate the use of intraoperative O-arm in determining the accuracy of cervical implants placed by a free-hand technique using anatomic landmarks or fluoroscopic guidance in pediatric cervical spine instrumentation. METHODS: A single-center retrospective study of consecutive examinations of children treated with cervical spine instrumentation and intraoperative O-arm from 2014 to 2018 was performed. In total, 44 cases (41 children, 44% men) with a mean age of 11.9 years (range, 2.1 to 23.5 y) were identified. Instability (n=16, 36%) and deformity (n=10, 23%) were the most frequent indications. Primary outcomes were screw revision rate, neurovascular complications caused by noncontained screws, and radiation exposure. RESULTS: A total of 272 screws were inserted (60 occipital and 212 cervical screws). All screws were evaluated on fluoroscopy as appropriately placed. Four screws (1.5%) in 4 cases (9%) were noncontained on O-arm imaging and required intraoperative revision. A mean of 7.7 levels (range, 5 to 13) were scanned. The mean CT dose index and dose-length product were 15.2±6.87 mGy and 212.3±120.48 mGy×cm. Mean effective dose was 1.57±0.818 mSv. There was no association between screw location and noncontainment (P=0.129). No vertebral artery injuries, dural injuries, or neurologic deficits were related to the 4 revised screws. CONCLUSIONS: Intraoperative non-navigated O-arm is a safe and efficient method to evaluate screw position in pediatric patients undergoing cervical spine instrumentation. Noncontained screws were detected in 9% of cases (n=4). O-arm delivers low radiation doses, allows for intraoperative screw revision, and negates the need for postoperative CT scans after confirmation of optimal implant position. LEVEL OF EVIDENCE: Level IV.

Acute Implant-related Complications in Pediatric Cervical Spine Fusion.

BACKGROUND: The use of modern rigid instrumentation in pediatric cervical fusions decreases the risk of implant-related complications, both acute and long term. However, previous studies have indicated that acute implant-related issues still occur in the adult population. Reports of pediatric acute implant complications, occurring within 3 months of surgery, are under-represented in the literature. The purpose of this study is to document the prevalence of acute implant-related complications in a pediatric cervical fusion population. METHODS: A retrospective review of instrumented cervical fusions from August 2002 to December 2018 was conducted. Acute implant-related complications were defined as malposition, fracture, or disengagement of cervical instrumentation, including screws, rods, and plates, within 90 days of surgery. RESULTS: A total of 166 cases were included (55% male individuals) with an average age at surgery of 12.5 years (SD, ±5.28). Acute implant-related complications occurred in 5 patients (3%). All 5 patients had a syndromic diagnosis: Loeys-Dietz (n=1), osteopetrosis (n=1), neurofibromatosis (n=1), trisomy 20 (n=1), and achondroplasia (n=1). One case involved asymptomatic screw protrusion, 1 case lateral mass screw pull-out, 2 more had screw-rod disengagement, and the last experienced dislodgement of the anterior plate. The median time until the presentation was 25 days (range, 1 to 79 d). All patients (n=5) required surgical revision. CONCLUSIONS: This case series suggests that the overall incidence of acute cervical implant failure is low. However, failure is more likely to occur in patients with underlying syndromes compared with patients with different etiologies. Intraoperative use of 3-dimensional computed tomography imaging is recommended to evaluate the screw position and potentially avoid later surgery.

Early Adherence to Prescribed Brace Wear for Adolescent Idiopathic Scoliosis Is Associated With Future Brace Wear.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To assess if initial adherence to prescribed brace wear for adolescent idiopathic scoliosis (AIS) predicts future adherence and curve improvement. SUMMARY OF BACKGROUND DATA: AIS bracing can be effective if patients adhere to prescribed brace wear. Previous research has associated age, sex, and brace prescription length with future adherence. We hypothesize that a patient's initial adherence to brace wear may be associated with future adherence and outcomes. MATERIALS AND METHODS: Consecutive AIS patients who met the Scoliosis Research Society (SRS) criteria for bracing from 2015 to 2019 at a single center were reviewed. Patients were stratified into groups based on their adherence during the initial one-month brace wean-in period-adherent patients were defined as wearing the brace >80% of the daily prescribed amount. Brace wear was recorded by a thermosensor and assessed during the wean-in period, six-, 12-, and 24-month postbracing appointments. Statistical testing was conducted to analyze if initial adherence was associated with future adherence, curve change, and bracing success -defined as reaching Risser stage 4 with a Cobb angle <40°. RESULTS: Sixty patients (mean age=12.5 yr) were included, of which the majority were females (83%) with thoracic curves (70%). Thirty-two patients were considered adherent, and this cohort demonstrated improved adherence relative to the nonadherent group at the six-, 12-, and 24-month appointments ( P <0.001). Adherent patients also showed a significant reduction in their scoliosis at the 12-month appointment, unlike nonadherent patients ( P <0.001). Ninety-seven percent of adherent patients achieved bracing success compared with 71% of nonadherent ( P =0.016). Females were more likely to be adherent than males. CONCLUSIONS: Initial adherence to prescribed AIS brace wear was associated with future adherence, bracing success, and curve improvement. Early recognition of nonadherence may offer an opportunity for supportive intervention to improve brace wear behavior.

Scoliosis with Chiari I malformation without associated syringomyelia.

PURPOSE: Many patients with presumed idiopathic scoliosis are found to have Chiari I malformation (CM-I) on MRI. The objective of this study is to report on scoliosis progression in CM-I with no syringomyelia. METHODS: A retrospective review of patients with scoliosis and CM-I was conducted from 1997 to 2015. Patients with syringomyelia and/or non-idiopathic scoliosis were excluded. Clinical and radiographic characteristics were recorded at presentation and latest follow-up. CM-I was defined as the cerebellar tonsil extending 5 mm or more below the foramen magnum on MRI. RESULTS: Thirty-two patients (72% female) with a mean age of 11 years (range 1-16) at scoliosis diagnosis were included. The average initial curve was 30.3° ± SD 16.3. The mean initial Chiari size was 9.6 mm SD ± 4.0. Fifteen (46.9%) experienced Chiari-related symptoms, and three (9%) patients underwent Posterior Fossa Decompression (PFD) to treat these symptoms. 10 (31%) patients went on to fusion, progressing on average 13.6° (95% CI 1.6-25.6°). No association was detected between decompression and either curve progression or fusion (p = 0.46, 0.60). For those who did not undergo fusion, curve magnitude progressed on average 1.0° (95% CI - 4.0 to 5.9°). There was no association between age, Chiari size, presence of symptoms, initial curve shape, or bracing treatment and fusion. CONCLUSION: Patients with CM-I and scoliosis may not require surgical treatment, including PFD and fusion. Scoliosis curvature stabilized in the non-surgical population at an average progression of 1.0°. These results suggest that CM-I with no syringomyelia has minimal effect on scoliosis progression.

SIMDiscovery: a simulation-based preparation program for adolescents undergoing spinal fusion surgery.

PURPOSE: Spinal fusion surgery is associated with high levels of stress and anxiety for patients and their caregivers. Medical simulation has demonstrated efficacy in improving preparedness, knowledge, and overall experience prior to other medical procedures. The current study examines the utility of a multi-faceted preparation program (SIMDiscovery) using simulation techniques to reduce anxiety and increase preparedness among patients undergoing spinal fusion surgery and their caregivers. METHODS: Participants attended SIMDiscovery where they received hands-on preparation about what to expect before, during, and after their surgery. Anxiety, preparedness, and knowledge about the procedure were assessed pre- and post-participation using self-report measures. Participants also completed a questionnaire at their first post-operative medical appointment. Differences from pre to post and between patients and caregivers were calculated with paired and independent sample t-tests. RESULTS: Participants included 22 patients and 29 caregivers. Post-SIMDiscovery, both groups demonstrated increased knowledge for the surgical process and lower state anxiety. Patients reported increased feelings of preparedness in all areas while caregivers reported increased feelings of preparedness in most areas. Families continued to report positive impact of the program 30 days after surgery; however, they also identified areas where they desired increased preparation. CONCLUSIONS: SIMDiscovery increased patients' and caregivers' knowledge regarding spinal fusion surgery and helped them feel less anxious and more prepared regarding most aspects of the surgical process. These changes were generally maintained throughout the post-operative period. Participants identified areas for increased preparation, highlighting the importance of continuing to adapt programs based on patient and family feedback. LEVEL OF EVIDENCE: Level III.

Use of recombinant human bone morphogenetic protein for revision cervical spine fusion in children with Down syndrome: a case series.

OBJECTIVE: Patients with trisomy 21 (Down syndrome; DS) often have atlantoaxial instability (AAI), which, if severe, causes myelopathy and neurological deterioration. Children with DS and AAI who undergo cervical spine fusion have a high rate of nonunion requiring revision surgery. Recombinant human bone morphogenetic protein-2 (rhBMP-2) is a TGF-ß growth factor that is used to induce bone formation in spine fusion. Although previous studies in the adult population have reported no reduction in pseudarthrosis rates with the use of rhBMP-2, there is a lack of literature in the pediatric DS population. This study describes the use of rhBMP-2 in children with DS and AAI during revision to treat nonunion. METHODS: A retrospective review of a cervical spine fusion database (n = 175) was conducted. This database included all cervical spine fusions using modern instrumentation at the authors' institution from 2002 to 2019. Patients with DS who underwent a revision utilizing rhBMP-2 were included in the study. The number of prior fusions, use of rhBMP-2 in fusions, length of stay, halo use, and surgical data were collected. Postoperative complications and length of follow-up were also recorded. RESULTS: Eight patients (75% female) met the inclusion criteria. The average age at revision with rhBMP-2 was 11 years (range 3-19 years). All patients were diagnosed with nonunion after an initial cervical fusion. All revisions were posterior fusions of C1-2 (n = 2) or occiput to cervical (n = 6). All revisions included implant revisions, iliac crest bone grafting, and rhBMP-2 use. One patient required irrigation and debridement of an rhBMP-induced seroma. Another patient required return to the operating room to repair a dural tear. There were no neurological, infectious, airway, or implant-related complications. Revision utilizing rhBMP-2 achieved fusion in 100% (n = 8) of patients. The average length of follow-up was 42.6 months. All patients demonstrated solid fusion mass on the last radiograph. CONCLUSIONS: This is the first case series reporting the successful use of rhBMP-2 to facilitate cervical spine fusion in patients with DS after previous nonunion. In addition, few rhBMP-2-related postoperative complications occurred.

Halo-gravity traction for the treatment of pediatric cervical spine disorders.

OBJECTIVE: Halo-gravity traction (HGT) is an effective and safe method for gradual correction of severe cervical deformities in adults. However, the literature is limited on the use of HGT for cervical spine deformities that develop in children. The objective of the present study was to evaluate the safety and efficacy of HGT for pediatric cervical spine deformities. METHODS: Twenty-eight patients (18 females) whose mean age was 11.3 ± 5.58 years (range 2-24.9 years) underwent HGT. Common indications included kyphosis (n = 12), rotatory subluxation (n = 7), and basilar invagination (n = 6). Three children (11%) received traction to treat severe occipitocervical instability. For these 3 patients, traction combined with a halo vest, with bars attached rigidly to the vest, but with the ability to slide through the connections to the halo crown, was used to guide the corrective forces and moments in a specific and controlled manner. Patients ambulated with a wheelchair or halo walker under constant traction. Imaging was done before and during traction to evaluate traction efficacy. The modified Clavien-Dindo-Sink classification was used to categorize complications. RESULTS: The mean duration of HGT was 25 days (IQR 13-29 days), and the mean traction was 29% ± 13.0% of body weight (IQR 19%-40% of body weight). The mean kyphosis improved from 91° ± 20.7° (range 64°-122°) to 56° ± 17.6° (range 32°-96°) during traction and corresponded to a mean percentage kyphosis correction of 38% ± 13.8% (range 21%-57%). Twenty-five patients (89%) underwent surgical stabilization, and 3 patients (11%) had rotatory subluxation that was adequately reduced by traction and were treated with a halo vest as their definitive treatment. The mean hospital stay was 35 days (IQR 17-43 days).Nine complications (32%) occurred: 8 grade I complications (28%), including 4 cases of superficial pin-site infection (14%) and 4 cases of transient paresthesia (14%). One grade II complication (4%) was seen in a child with Down syndrome and a preexisting neurological deficit; this patient developed flaccid paralysis that rapidly resolved with weight removal. Six cases (21%) of temporary neck discomfort occurred as a sequela of a preexisting condition and resolved without treatment within 24-48 hours. CONCLUSIONS: HGT in children is safe and effective for the gradual correction of cervical kyphosis, atlantoaxial subluxation, basilar invagination, and os odontoideum. Cervical traction is an additional tool for the pediatric spine surgeon if uncertainties exist that the spinal alignment required for internal fixation and deformity correction can be safely achieved surgically. Common complications included grade I complications such as superficial pin-site infections and transient paresthesias. Halo vest gravity traction may be warranted in patients with baseline neurological deficits and severe occipitocervical instability to reduce the chance of catastrophic movement.