Larson, A Noelle

ABSTRACT Background Intrathecal opioids are widely used for postoperative analgesia in pediatric spine surgery, but optimal dosing remains undefined. We evaluated the relationship between intrathecal hydromorphone (ITH) dose, analgesia, and adverse effects in adolescents undergoing posterior spinal fusion (PSF). Methods In this single‐center, prospective, blinded dose‐escalation study using a biased‐coin up‐down sequential allocation design, patients aged 10–17 years undergoing PSF received ITH starting at 3.5 mcg kg −1 , with dose adjustments based on analgesic response (range 2.0 to 7 mcg kg −1 with a maximum of 400 mcg). The primary outcome was maximum postoperative pain within 18 h. Secondary outcomes included pain burden (area under the curve), 24‐h systemic opioid consumption (oral morphine equivalents [OME], excluding ITH), adverse effects, supplemental diazepam use, and rescue opioid use. Associations between dose and outcomes were assessed using Spearman correlation and logistic regression. Results Twenty‐seven patients completed the study. The median ITH dose received was 5.5 mcg kg −1 (IQR, 3.5–7.0), with a median absolute dose of 370 mcg (IQR, 180–400). No significant association was observed between ITH dose and maximum pain ( r = 0.16, p = 0.41), pain burden ( r = 0.32, p = 0.10), or 24‐h OME ( r = 0.13, p = 0.52). ITH dose was not significantly associated with the time to rescue opioid (HR = 1.24; 95% CI 0.68–2.25; p = 0.485) or diazepam (HR = 1.10; 95% CI 0.72–1.71; p = 0.655). Adverse respiratory events occurred at doses > 5 mcg kg −1 without improved analgesia. Conclusions Increasing ITH dose was not associated with improved analgesia or change in supplemental opioid or diazepam use. Doses > 5 mcg kg −1 were associated with adverse respiratory effects. These findings support conservative dosing strategies and underscore the need to define the minimum effective dose in pediatric populations.

Background: Vertebral body tethering (VBT) for adolescent idiopathic scoliosis (AIS) is an alternative to posterior fusion. There are limited prospective, multicenter data available on VBT following US Food and Drug Administration approval. We hypothesize that curve correction on first postoperative standing (first erect, FE) imaging is associated with higher rates of successful correction at final follow-up. Methods: All qualifying patients with AIS who underwent thoracic and lumbar VBT between 2019 and 2022 were prospectively enrolled from 9 institutions. Radiographic and clinical data were compared preoperatively, at FE, and at final follow-up with minimum of 2 years. Success was defined as major curve magnitude of ≤35° at final follow-up and no fusion surgery. Results: One hundred twenty-seven patients were enrolled (79.5% female), with mean follow-up 2.4 years. Mean age at surgery was 12.9 ± 1.4 years, most had bone age of Sanders 4 or lower (93/112, 83.0%). In average, 7.6 ± 1.7 levels were tethered. Mean preoperative major curve magnitude was 50 ± 8°, with mean initial correction at FE of 29 ± 8° (% correction, 39 ± 18%). At final follow-up, mean curve magnitude was maintained at 26 ± 11° (% correction, 45 ± 23%) despite 29% of tether breakage. Patients who had mean FE curve magnitude of ≤35° were 88% successful compared with only 60% in those with >35° on FE (p = 0.0021). Patients showed stable sagittal alignment across all timepoints. Scoliosis Research Society-22 scores improved significantly by 2 years (p < 0.0001). Conclusion: This was the first prospective, multicenter study to assess outcomes of VBT for patients with AIS. VBT shows promise, but optimal results may depend on careful patient selection and surgical technique. FE major curve magnitude of ≤35° was associated with 88% success rate compared with only 60% success for those with poor correction. Level of Evidence: Level II . See Instructions for Authors for a complete description of levels of evidence.

Background: Scoliosis has various etiologies, ranging from idiopathic, congenital, to those with spinal cord abnormalities. Advanced imaging is not always feasible and limited by cost, low-yield, and anesthesia risks in children. Given artificial intelligence's potential, we hypothesize that a deep learning (DL)–based image classifier will demonstrate superior performance in radiographic classification of scoliosis etiology compared witht experienced spine surgeons based on spine radiographs. Methods: One thousand thirty-six pediatric patients from single institution with scoliosis diagnosis and paired anterior-posterior - lateral images were included. Patients were manually classified based on their scoliosis etiology from chart review, including previous spine imaging studies when available. Categories included idiopathic, congenital, and spinal cord pathology. Images were randomized and assigned for training, validation, and testing. A DL-classifier using EfficientNet B4 architecture was trained on the radiographs. Accuracy and positive predictive value as defined by precision, recall, and F1-score were calculated to assess final performance metrics. Results: The trained classifier performed well at identifying correct etiologies, with F1-Score (harmonic mean of precision-recall) of 0.97. Model precision was 0.99 for adolescent idiopathic scoliosis, 0.89 for congenital, and 0.78 for spinal cord pathology. Performance was higher on more common classes, with lower performance observed in class with fewer images. The algorithm has highest overall precision (0.96), recall (0.96), and F1 (0.96), while Surgeons 1 and 2 have lower accuracies (precision 0.80, recall 0.79, and F1 0.79 and precision 0.76, recall 0.67, and F10.71, respectively). There was no clear pattern identified regarding the surgeons' errors and poor agreement on which X-rays corresponded to underlying spinal cord pathology. Conclusion: A DL-convolutional-neural-network classifier has been trained to high degree of accuracy to distinguish between 3 scoliosis etiologies on pediatric spine radiographs. This model could provide a novel tool to clinicians to decide when to refer for axial imaging. It had superior diagnostic performance compared with experienced spine surgeons. After further validation and refinement, a clinician could put a patient's X-rays into the predictive tool for analysis and use the results to discuss with the family the risk of finding spinal cord pathology, helping them determine together the best timing for an MRI. Level of Evidence: Level III . See Instructions for Authors for a complete description of levels of evidence.

Artificial intelligence (AI) is increasingly shaping pediatric spine care, leveraging its rapid advancements in healthcare to improve efficiency, accuracy, and disease understanding. Moreover, machine learning and deep learning excel at detecting complex patterns. This holds promise in processing spinal deformity data, with the potential to surpass traditional statistical methods in predictive accuracy. Challenges persist, however, including unclear clinical implementation guidelines, limited model transparency, and ethical concerns surrounding data privacy and bias. Small sample sizes and the need for larger, diverse datasets further complicate integration. In order to realize AI’s transformative potential in pediatric spine care, these critical obstacles must be addressed for effective and ethical clinical adoption. This review examines the role of AI through applications such as image sorting, surgical outcome prediction, forecasting of spinal curve progression, and vertebral volumetric analysis using deep reasoning. It also explores possible intraoperative contributions from AI, including robotics and optimized screw trajectory planning, and the potential of large language models in clinical practice.

Background: Motion-sparing approaches to scoliosis surgery such as vertebral body tethering (VBT) are growing in popularity. There is limited data evaluating motion preserving after the different tether approaches. We hypothesized that spinal motion would be preserved in both the sagittal and coronal planes in patients after thoracic, lumbar, and bilateral vertebral body tethering procedures. Methods: This was a retrospective comparison study of adolescent idiopathic scoliosis (AIS) patients who underwent VBT. Preoperative and postoperative coronal range of motion across the instrumented levels were compared using a standing microdose slot-scanning protocol. Flexion/extension radiographs were evaluated postoperatively to assess preserved sagittal arc of motion. Patients with known cord breakage were excluded. Results: The mean age at surgery was 12.9 years (range: 9.4 to 16.5) with mean follow-up period of 2.8 years. Skeletal maturity, defined as Risser sign ≥5, was observed in 29 patients. (26.9%). Overall, mean thoracic coronal arc of motion for postoperative VBT patients was 10 degrees in the thoracic spine and 20 degrees in the lumbar. This was a 59% (24 to 10 deg.) decrease in thoracic range of motion and a 51% (40 to 20 deg.) decrease in lumbar range of motion. Right-sided motion was greater in patients with thoracic instrumentation, whereas left-sided motion was greater in patients with lumbar instrumentation. In addition, patients also retained sagittal motion. Patients with single thoracic tethers had a total arc of motion of 22 degrees, whereas patients with single lumbar tethers had a total arc of motion of 25 degrees. It was noted that both groups had a greater degree of flexion than extension. Conclusions: Patients with single thoracic tethers saw a 60% decrease in the total coronal arc of motion. Patients with single lumbar tethers saw a 57% decrease in coronal motion. Patients had around 20 to 25-degree arc of motion preserved over the instrumented segments in the sagittal plane. Further work is needed to outline the functional benefits of motion preservation after VBT. Level of Evidence: Level III (retrospective cohort study).

Background/Objectives: Accurate assessment of spinal bone density is essential for evaluating bone health, particularly in preoperative planning. Conventional manual methods for Hounsfield unit (HU) measurements rely on single-slice measurements within the region of interest, limiting their precision and reproducibility in patients with severe vertebral deformities. We hypothesize that a novel deep-reasoning and learning model (DR-AI) can fully automate spinal bone density assessment volumetrically, with high correlations to spinal bone mineral density (BMD) obtained from dual-energy X-ray absorptiometry (DXA), as well as to the T- and Z-scores. Methods: A cross-sectional study was conducted on patients who had BMD assessment of their lumbar spine and lumbar CT scans within 1 year. The fully-automated DR model was utilized to analyze the soft-tissue window of the lumbar vertebrae CT scans. Spearman correlation coefficients were calculated to assess the strength of relationships between the computed volumetric HUs and the BMD, T-, and Z-scores from each vertebra. Results: 84 patients (67 females, mean age 74.1 ± 10.3 years; 17 males, mean age 68.1 ± 12.4 years) meeting inclusion criteria. Correlation analyses for L1 to L4 showed significant positive relationships (p < 0.0001), with the strongest correlation at L2 between HU and BMD (ρ = 0.75). Conclusions: the DR model for automated assessment of volumetric HUs offers a highly reliable, efficient, and precise alternative to DXA measurements.

Background/Objectives: Traditional fusion leads to a loss of spine mobility across the fused vertebrae. Vertebral body tethering (VBT) was developed with the goal of increasing flexibility and maintaining some spinal mobility. However, it is not known if the additional mobility leads to significant functional improvement. This prospective motion analysis study evaluates functional outcomes, specifically gait stability, in pre-operative, post-fusion, and post-VBT patients by using postural perturbations on a treadmill. Methods: Overall, 79 subjects underwent a computer-controlled treadmill study with postural perturbations, which simulated trips and slips. The subjects were harnessed for safety. Overall, 21 subjects were healthy controls, 18 patients were at least one-year post-VBT, 15 patients were at least one-year post-fusion, and 25 were pre-operative scoliosis patients. Subject weight, height, and treadmill acceleration were recorded and used to determine anteroposterior single (ASSTs, PSSTs) and multiple (AMSTs, PMSTs) stepping thresholds to describe the maximum torque a patient could withstand before failing to recover from the simulated trip. Independent t-tests were run to compare groups under the advice of a master statistician with expertise in orthopedic surgery. Results: Pre-operative scoliosis patients had lower PSSTs than healthy controls (uncorrected p = 0.036). No significant differences were observed between pre-operative and post-operative groups for both fusion and VBT. There was no significant difference in ASST, AMST, or PMST between any of the groups. Conclusions: The lower PSST in pre-operative scoliosis patients compared to healthy controls may reflect impaired reactive balance and potentially increased fall risk. Interestingly, there was no significant difference in reactive balance measures between pre-operative and post-operative scoliosis patients or between post-fusion and post-VBT patients.

Background: The purpose of this study was to report on 2-year results of vertebral body tethering (VBT), performed under a Food and Drug Administration protocol, to obtain insight into outcomes and complications. Methods: Forty prospectively enrolled patients with adolescent idiopathic scoliosis (AIS) who had a Sanders score of ≤4 or a Risser score of ≤2 underwent VBT for curves between 40° and 70°. Surgical, radiographic, and patient-reported outcomes were reviewed at a minimum 2-year follow-up. Results: Mean age at surgery was 13 (range, 10 to 16) years. The 40 patients were 90% female; 95% White, 2.5% other, and 2.5% unreported; and 92.5% non-Hispanic, 5% Hispanic, and 2.5% unreported. A mean of 8 (range, 5 to 12) levels were instrumented. Most patients were at Sanders 4 (65%) and Risser 0 (63%). Mean length of stay was 3 ± 1 days, estimated blood loss was 236 ± 158 (range, 25 to 740) mL, and operative time was 4.4 ± 1.4 hours. Mean correction of the major curve was 44% (range, 22% to 95%) on the 3-month standing radiograph, 49% at 1 year, and 46% (range, −10% to 93%) at 2 years. The mean major Cobb angle improved from 51° ± 8° (range, 40° to 70°) preoperatively to 27° ± 11° (range, 3° to 56°) at 2 years. Success at 2 years, defined by a Cobb angle of <35° and no reoperation, was seen in 30 patients (75%) and was associated with a mean Cobb angle of <35° on the first postoperative standing radiograph (p < 0.001). Twelve patients (30%) demonstrated improvement in the curve with growth. By 2 years, 2 (5%) of the patients underwent repeat surgery (1 release for overcorrection, 1 lumbar VBT for lumbar curve progression after thoracic VBT). The Scoliosis Research Society (SRS) satisfaction score improved 2 years following surgery (p < 0.001), but other SRS domains only remained stable over time. Beyond 2 years, 1 additional lumbar tether was required after thoracic VBT, 1 implant was removed, and 3 fusions were performed, for a 10% fusion rate and overall 20% reoperation rate at a mean of 3.8 ± 1.1 years of follow-up. The rate of cord breakage in the study population was 20%. Conclusions: In skeletally immature patients treated in the U.S. under a prospective Investigational Device Exemption, there was a 75% rate of successful outcomes at 2 years. Most correction was obtained at the time of surgery, and inadequate intraoperative curve correction was associated with a higher Cobb angle on the first postoperative standing radiograph and failure by 2 years. Level of Evidence: Therapeutic Level II . See Instructions for Authors for a complete description of levels of evidence.

Background/Objectives: The burden of scoliosis care extends beyond treatment costs and includes missed school for patients and lost income for parents. Chronic absenteeism, defined as more than 18 days of missed school, can have a significant impact on a child’s educational progression, but missed school and work due to scoliosis treatment are not well quantified in the literature. This study investigates absenteeism among scoliosis patients and their caregivers. Methods: We conducted a retrospective comparative study of survey results based on surgery timing and surgery type. Patients and caregivers presenting for clinic visits for scoliosis treatment at a single large tertiary care center from 2014 to 2022 were queried. Results: We collected 2772 surveys from 1104 unique patients. Of these, 223 surveys from 132 patients were within one year of surgery: 140 post-fusion surveys, 71 post-nonfusion surveys, and 11 post-halo/multistage surgery surveys. A total of 2280 surveys were from 1022 nonoperatively treated patients. School absenteeism was significantly higher for surgeries during the school year compared to summer in both the fusion and nonfusion groups, though work absenteeism showed no significant differences. Halo/multistage surgery patients had the highest rates of absenteeism. Conclusions: This study highlights the impacts of scoliosis surgery timing and type on absenteeism among patients and their caregivers. Surgery during summer breaks reduces school absenteeism and academic disruption. Halo/multistage surgery patients face the greatest risk of chronic absenteeism from school, indicating a need for targeted interventions. Optimized surgical timing and planning can help families navigate the educational and financial challenges of scoliosis treatment.

Study Design Prospective Cohort Study. Objective The present study aims to determine if the racial representation of patients enrolled in a large prospective scoliosis registry is reflective of the general United States population. Further, we studied whether there was an association between race, pre-operative parameters, outcomes and loss to follow-up. Methods Prospectively collected data for patients who underwent spinal fusion for adolescent idiopathic scoliosis (AIS) was reviewed, including self-reported race/ethnicity. The U.S. pediatric population and U.S. patients enrolled in the prospective registry were compared. The data obtained was analyzed for variations between races, for pre-operative variables and follow-up. Results Of the 2210 included patients in the registry 66% of patients reported as White, while 52% of the 2018 U.S. pediatric population reported as White. 15% of the registry reported as Hispanic/Latino compared to 22% of the U.S. pediatric population, 13% Black compared to 14% of the U.S. pediatric population, and 4% Asian compared to 5% of the U.S. pediatric population. Asian and White patients had statistically significant higher 2-year follow-up in all but one of six enrollment sites ( P < 0.001). Native American, Other, and Hispanic/Latino patients had the highest BMIs. Native American and Black patients had the highest pre-op thoracic Cobb angles. Pre-op ages of Black, Hispanic, and Native American patients were statistically lower ( P < 0.01). Conclusion This study demonstrates the association between race and patient follow-up and pre-operative factors in patients who underwent surgery for AIS. Black, Native American, and Hispanic populations were underrepresented both at pre-op and follow-up when compared to their relative proportion in the U.S. pediatric population.