Faculty Bibliography

BACKGROUND AND OBJECTIVES/OBJECTIVE:Adult biomechanical studies suggest a significant reduction in flexion-extension motion after occipitocervical and atlantoaxial fusion. Anecdotal experience in children suggests a lower magnitude of reduction in motion after these procedures, but high-quality quantitative assessments of this motion have not yet been performed. As such, the aim of this study was to determine the magnitude of reduction in cervical spine flexion-extension after O-C2 and C1-2 fusion in pediatric patients. METHODS:The Pediatric Spine Study Group international registry was queried for patients aged 21 years or younger who underwent O-C2 or C1-2 instrumentation and fusion. Patients with cervical spine flexion-extension radiographs preoperatively and ≥6 months postoperatively were included. Flexion, extension, and overall range of motion (ROM) of the cervical spine were measured on radiographs using McGregor line and the inferior endplate of C7. RESULTS:In total, 34 patients were included, with 19 undergoing index O-C2 and 15 undergoing index C1-2 stabilization. The mean age was 9.3 ± 4.5 years with average follow-up of 3.5 ± 2.6 years. The most common etiologies were syndromic (n = 20) and congenital (n = 9). Patients undergoing O-C2 fusion had reduced neck extension (80° vs 69.6°, P = .003) and overall ROM (92.9° vs 80°, P = .002) after stabilization, but no significant reduction in flexion (-12.9° vs -10.4°, P = .324). After C1-2 fusion, there was no significant reduction in overall ROM (85.0° vs 77.5°, P = .079), extension (70.5° vs 63.4°, P = .120), or flexion (-14.6° vs -14.0°, P = .831). CONCLUSION/CONCLUSIONS:In this cohort, children undergoing O-C2 stabilization had a 13.9% reduction in flexion-extension motion of the cervical spine, primarily due to a reduction in extension. There may be a smaller reduction in flexion-extension motion after stabilization in children when compared with adult studies. Further studies with video analysis including axial rotation and lateral bending will be necessary to comprehensively quantify cervical spine motion after fusion across the occipitocervical and atlantoaxial junctions.

BACKGROUND:Congenital early onset scoliosis (C-EOS) often co-occurs with tethered spinal cord syndrome (TSCS), necessitating surgical intervention to address both conditions to prevent worsening neuromuscular function. Detethering can be done concurrently with spinal deformity correction (SDC), before SDC, or not done at all. This study explores perioperative complications in C-EOS patients with and without TSCS who underwent SDC with growing instrumentation or fusion. We hypothesize that C-EOS patients with a history of TSCS who underwent SDC with either growing instrumentation or fusion experienced higher rates of perioperative complications compared with those without TSCS. Among patients with a history of TSCS, we hypothesize that those who were detethered had fewer perioperative complications than those who were not detethered. METHODS:Data from 751 C-EOS patients from an international spine registry were reviewed. After applying inclusion and exclusion criteria, 477 patients were divided into groups: those with TSCS (n=90) and those without (n=387). Among TSCS patients, the majority underwent detethering (n=54), whereas 36 did not. Demographics, magnetic resonance imaging (MRI) findings, treatment history, and surgical complications were assessed. Statistical analyses were conducted to compare demographic and clinical parameters, including complication rates, using appropriate tests. Postoperative complications were further categorized according to the modified Clavien-Dindo-Sink (mCDS) classification system. RESULTS:Comparing C-EOS patients with and without TSCS revealed no significant differences in age at first MRI (P=0.52), pre-index major coronal curve (P=0.43), pre-index maximum sagittal kyphosis (P=0.113), the number of growth-friendly procedures (P=1.00), resection (P=0.071), osteotomy (P=0.081), intraoperative complications (P=0.088), postoperative complications (P=0.41), hardware failure (P=0.78), infections (P=0.26), and neurological complications (P=0.42). Postoperative complications further categorized using the mCDS demonstrated no significant differences between the groups (P=0.144). No significant differences were found in age at first MRI (P=0.60), pre-index major coronal curve (P=0.90), pre-index maximum sagittal kyphosis (P=0.50), resection (P=0.20), or osteotomy (P=0.47) between the detethered and not detethered cohorts. However, a higher percentage of TSCS patients without detethering underwent a growth-friendly procedure (P=0.003). In addition, TSCS patients without detethering experienced higher rates of postoperative complications (P=0.009), hardware failure (P=0.005), and infections (P=0.031) compared with those who underwent detethering. No differences were noted for intraoperative (P=0.059) or neurological (P=0.190) complications based on detethering status. Similarly, postoperative complications using the mCDS revealed that patients who were not detethered had higher rates of complications (P=0.017). CONCLUSIONS:Although there were no significant differences between C-EOS patients with and without TSCS, this study underscores the importance of detethering in C-EOS patients with concurrent TSCS. Detethering significantly reduced the risk of postoperative complications, hardware failure, and infection after SDC with growing instrumentation or fusion. However, given that the not detethered group had a higher frequency of growth-friendly procedures, these findings should be interpreted with caution. These findings highlight the potential benefits of detethering in improving surgical outcomes for C-EOS patients undergoing SDC with growing instrumentation or fusion. LEVEL OF EVIDENCE/METHODS:III.

OBJECTIVE:In cases of complex pediatric spinal deformity, posterior spinal instrumentation crossing the cervicothoracic junction (CTJ) may be required. This is most frequently encountered for revision surgery to address proximal junctional kyphosis (PJK). In the cervical spine, lateral mass screws are most commonly used, although they may result in biomechanically weak proximal constructs and predispose to instrumentation failure. The use of supplemental anterior constructs has recently been reported with promising results, but this necessitates an additional surgical procedure. Subaxial cervical pedicle screws can provide good biomechanical fixation without the need for an anterior approach, but outcome data have been very limited. The purpose of this study was to assess radiographic and clinical outcomes at two years in pediatric patients who have undergone posterior spinal instrumentation and fusion (PSIF) crossing the CTJ using subaxial cervical spine pedicle screws. METHODS:The Pediatric Spine Study Group (PSSG) registry was queried to identify patients ≤ 21 years old who underwent PSIF crossing the CTJ with two-year minimum clinical and radiographic follow-up. Patients were excluded if they had a history of anterior stabilization or if their fusion construct with subaxial pedicle screws started below C6. Clinical, surgical, and radiographic parameters were assessed, and measurements were compared statistically. RESULTS:Then, 8 patients (6 female and 2 male) met inclusion criteria, with a mean age at surgery of 11.2 ± 3.3 years. All patients underwent PSIF crossing the CTJ (mean levels fused 15.6 ± 6.6). The mean density of subaxial cervical pedicle screws was 61.9% ± 27.8 (range 28.5 to 100%). The major coronal curve averaged 54.7° ± 19.6 preoperatively and 34.5° ± 13.6 postoperatively (41.5% ± 26.5 correction; p = 0.03). The average major sagittal curve was 55.9° ± 20.6 preoperatively and 29.6° ± 9.6 (44.2% ± 18.0 correction; p = 0.01) postoperatively. There were no major intraoperative or postoperative complications. Deformity parameters remained stable without radiographic evidence of PJK in 8/8 patients at minimum 2-year follow-up. CONCLUSIONS:In this small preliminary international series of pediatric patients with spinal deformity, the inclusion of subaxial cervical pedicle screws in constructs that span the cervicothoracic junction resulted in good clinical and radiographic outcomes without major complications. Subaxial cervical spine pedicle screws provide enhanced biomechanical stability and may eliminate the need for additional anterior support in pediatric patients.

The pediatric cervical spine is structurally and biomechanically unique in comparison to adults. Guidelines to assess for cervical spine instability and standard of care treatments in the pediatric population have yet to be delineated. This is due to the rarity of the condition and the lack of multicenter data published on the topic. Our review explores the biomechanics of the pediatric cervical spine and highlights evolving concepts/research over the last several decades, with special attention to the Down syndrome and complex Chiari malformation cohorts.

BACKGROUND AND OBJECTIVES/OBJECTIVE:Pediatric spine surgery has evolved considerably over the past century. No previous study conducted a bibliometric analysis of the corpus of pediatric spine surgery. We used big data and advanced bibliometric analyses to evaluate trends in the progression of pediatric spine surgery as a distinct field since the beginning of the 20th century. METHODS:A Web of Science query was designed to capture the representative corpus of pediatric spine literature. Statistical and bibliometric analyses were performed using various Python packages and the Bibliometrix R package. RESULTS:The collection, published from 1902 to 2023, comprised a total of 11 861 articles from 61 journals and 32 715 unique authors. The overall growth rate annually for publications was 5.08%. An upsurge in publications was seen in the 1980s, after the advent of specialty and subspecialty journals. Illustratively, over 90% of all articles pertaining to pediatric spine surgery were published in the past 3 decades. International and domestic collaboration also increased exponentially over this time period. Reference publication year spectroscopy allowed us to identify 75 articles that comprise the historical roots of modern pediatric spine surgery. There was a recent lexical evolution of topics and terms toward alignment, outcomes, and patient-centric terms. Coauthorship among under-represented groups increased since 1990, but remains low, with disparities persisting across journals. CONCLUSION/CONCLUSIONS:This comprehensive bibliometric analysis on the corpus of pediatric spine surgery offers insight into the evolving landscape of research, authorship, and publication trends over the past century. Advancements in the understanding of the natural history and technology have led the field to become increasingly outcomes focused, all of which have been fueled by pioneering authors. While diversity among authors improves, under-representation of various groups continues to persist, indicating a critical role for further outreach and promotion.

Cervical spine injuries (CSIs) in pediatric patients with traumatic brain injury (TBI) pose unique diagnostic and management challenges. Current studies on the intricate overlap between pediatric TBI and CSI are limited. This paper explores the existing literature as well as the epidemiology, mechanisms of injury, diagnostic criteria, treatment strategies, and outcomes associated with CSI in pediatric TBI patients.

OBJECTIVE:The purpose of this study was to identify factors associated with fusion success among pediatric patients undergoing occiput-C2 rigid instrumentation and fusion. METHODS:The Pediatric Spine Study Group registry was queried to identify patients ≤ 21 years of age who underwent occiput-C2 posterior spinal rigid instrumentation and fusion and had a 2-year minimum clinical and radiographic (postoperative lateral cervical radiograph or CT scan) follow-up. Fusion failure was defined clinically if a patient underwent hardware revision surgery > 30 days after the index procedure or radiographically by the presence of hardware failure or screw haloing on the most recent follow-up imaging study. Univariate comparisons and multivariable logistic regression analyses were subsequently performed. RESULTS:Seventy-six patients met inclusion criteria. The median age at surgery was 9 years (range 1.5-17.2 years), and 51% of the cohort was male. Overall, 75% of patients had syndromic (n = 41) or congenital (n = 15) etiologies, with the most frequent diagnoses of Down syndrome (28%), Chiari malformation (13%), and Klippel-Feil syndrome (12%). Data were available to determine if there was a fusion failure in 97% (74/76) of patients. Overall, 38% (28/74) of patients had fusion failure (95% CI 27%-50%). Univariate analysis demonstrated that use of a rigid cervical collar postoperatively (p = 0.04) and structural rib autograft (p = 0.02) were associated with successful fusion. Multivariable logistic regression analysis determined that patients who had rib autograft used in surgery had a 73% decrease in the odds of fusion failure (OR 0.27, 95% CI 0.09-0.82; p = 0.02). Age, etiology including Down syndrome, instrumentation type, unilateral instrumentation, use of recombinant human bone morphogenetic protein, and other variables did not influence the risk for fusion failure. CONCLUSIONS:In this multicenter, multidisciplinary, international registry of children undergoing occiput-C2 instrumentation and fusion, fusion failure was seen in 38% of patients, a higher rate than previously reported in the literature. The authors' data suggest that postoperative immobilization in a rigid cervical collar may be beneficial, and the use of structural rib autograft should be considered, as rib autograft was associated with a 75% higher chance of successful fusion.

Pediatric spine trauma is rare but presents unique challenges to clinical management. Special considerations include but are not limited to the need to minimize ionizing radiation in this patient population, anatomic immaturity, physiologic variants, and injuries seen only in the pediatric population. Here we review the epidemiology of pediatric spine trauma, presentation, diagnosis, and treatment of the most common injuries and discuss specific medical and surgical strategies for treatment.

BACKGROUND AND IMPORTANCE:Although rare, severe congenital cervical spine deformity can present with limited treatment options and potentially catastrophic outcomes. The use of halter traction for cervical deformity correction in children has been well described, but it has not been previously reported in the management of neonates. CLINICAL PRESENTATION:A baby girl born at full-term gestation presented with generalized hypotonia, bilateral club feet, and significant right upper extremity weakness. Imaging demonstrated a severe congenital swan-neck deformity with spinal cord compression. Halter traction was initiated in the neonatal intensive care unit with subsequent neurological and radiographic improvement. After 7 days, traction was discontinued and she was placed in a custom-fitted cervico-thoracic orthosis. At 2 years of follow-up, she remains neurologically stable with maintained cervical alignment. CONCLUSION:Halter traction followed by external bracing is technically possible in the neonatal period. For children with severe cervical congenital deformity, this technique can reduce spinal cord compression, provide significant deformity correction, and delay the need for definitive operative spinal stabilization.

PURPOSE/OBJECTIVE:In children with early onset scoliosis (EOS) who have tethered spinal cord (TSC), spinal cord detethering is commonly performed prior to spinal deformity correction (SDC). The purpose of this study was to investigate whether age or curve magnitude at the time of detethering is associated with curve progression at a follow-up of at least 2 years. It was hypothesized that patients who undergo detethering at a younger age, or those with a smaller curve magnitude, would experience a reduced rate of curve progression when compared with those who are older or with larger curves. METHODS:Patients with EOS who underwent detethering at least 2 years prior to SDC were identified in a multicenter international registry. Radiographs were assessed just prior to the detethering procedure (pre-detether) and at the most recent visit prior to SDC (most recent post-detether). The rate of curve progression > 10° was examined. Owing to unequal follow-up in individual patients, Cox regression was used to investigate associations between primary variables (age and magnitude of major coronal curve) and rate of curve progression. RESULTS:37 patients met inclusion criteria and 18 (mean age: 3.7 ± 2.9 years, 66.7% female, mean follow-up: 3.4 ± 1.3 years) had radiographic data available for analysis. Pre-detether and most recent post-detether major coronal curves were 44.8° ± 18.5° and 47.6° ± 23.9°, respectively. 5 (27.8%) patients had curve progression > 10° at a follow-up of 3.2 ± 1.2 years. Patients with progression > 10° were older at the time of detethering when compared with those without (5.6 ± 2.8 vs. 3 ± 2.7 years, p = 0.084). Regression analysis demonstrated that as age at detethering increased by 1 year, the rate of curve progression > 10° increased by 28.6% [95% confidence interval (CI) 0.899; 1.839, p = 0.169]. There was no evidence of an association between pre-detethering curve magnitude and rate of curve progression > 10° [HR: 1.027, 95% CI 0.977; 1.079, p = 0.297]. CONCLUSION/CONCLUSIONS:In a small multicenter cohort of EOS patients with TSC, younger age, but not curve size, at the time of detethering was associated with a lower rate of scoliosis progression. Although these results indicate a potential role for early spinal cord detethering in the EOS population, they require further prospective investigation with a larger number of patients. LEVEL OF EVIDENCE/METHODS:Level II.