Apical stress redistribution during anterior vertebral body tethering for thoracic adolescent idiopathic scoliosis: a finite element analysis of a novel surgical technique.

PURPOSE: Apical stress redistribution (ASR) is proposed to mitigate failure risks after anterior vertebral body tethering for adolescent idiopathic scoliosis. It consists in releasing set-screws at peri-apical levels following curve tensioning to redistribute stresses within the construct. This study determines the biomechanical impact and curve correction obtained with ASR. METHODS: Finite element models of anterior vertebral body tethering were constructed for three typical scoliotic patients with Lenke 1 curves. ASR was simulated by releasing tension on the cable at the level of the three apical set screws (i.e. untightening three consecutive periapical set screws), followed by retightening of the set screws without further tensioning. Cable tension, implant forces and spine geometry were compared before and after performing ASR. RESULTS: Periapical cable tension decreased post-ASR, and ASR also reduced the maximum tensions proximally and distally. Postoperative disc height was similar between conventional and ASR approaches. Apical intervertebral disc stresses were shifted from concave to convex compression intra and postoperatively, with a similar pattern between the conventional and ASR techniques. The ASR technique achieved scoliotic curve corrections of 54%, 68%, and 79%, while the conventional technique resulted in corresponding corrections (54%, 68%, and 80%) for subjects 1, 2, and 3. The periapical coronal curves exhibited similar patterns. CONCLUSION: ASR demonstrated promising apical cable and implant forces re-equilibrium compared to the conventional approach. This novel technique did not impair immediate and postoperative curve correction, while maintaining similar apical intervertebral stress distribution. ASR shows potential to modulate growth while reducing maximum cable tension infra- and supra-apical.

Predicting Complete versus Incomplete Long-Term Functional Independence after Acute AIS Grade D Spinal Cord Injury: A Prospective Cohort Study.

Background: The proportion of patients with American Spinal Injury Association Impairment Scale (AIS) grade D traumatic spinal cord injuries (tSCI) is increasing. Although initial motor deficits can be relatively mild, some individuals fail to recover functional independence. Objectives: This study aims to identify factors associated with failure to reach complete functional independence after AIS grade D tSCI. Methods: An observational prospective cohort study was conducted at a level 1 trauma center specialized in SCI care. A prospective cohort of 121 individuals with an AIS-D tSCI was considered. The baseline characteristics, length of acute stay, need for inpatient rehabilitation, and 12-month functional status were assessed. Univariate and classification and regression tree (CART) analyses were performed to identify factors associated with reaching complete versus incomplete functional independence (defined as perfect total SCIM III score at 12-month follow-up). Results: There were 69.3%, 83.3%, and 61.4% individuals reaching complete independence in self-care, respiration/sphincter management, and mobility, respectively. A total of 64 individuals (52%) reached complete functional independence in all three domains. In the CART analysis, we found that patients are more likely to achieve complete functional independence when they have a baseline motor score ≥83 (65% individuals) and if they present fewer medical comorbidities (70% individuals if Charlson Comorbidity Index [CCI] ≤4). Conclusion: About half of individuals with AIS grade D tSCI can expect complete long-term functional independence. It is important to recognize early during acute care individuals with baseline motor score <83 or a high burden of comorbidities (CCI ≥5) to optimize their rehabilitation plan.

A classification algorithm for prioritizing surgery in Pediatric patients with idiopathic scoliosis when Long Surgical delays are expected.

PURPOSE: To identify the clinical phenotypes associated with the rate of progression while waiting for surgery and propose a classification scheme for identifying subgroups of patients to prioritize for surgery when long surgical delays are expected. METHODS: We reviewed the clinical and radiographic data of a prospective cohort of patients scheduled for IS surgery from 2004 to 2020 with a minimum 1-year wait prior to surgery. Candidate predictors consisted of age, sex, Risser sign, menarchal status, angle of trunk rotation, scoliotic curve type, and main Cobb angle at baseline when scheduled for surgery. Univariate and Regression Tree analysis were performed to identify predictors associated with the annual curve progression rate in the main Cobb angle between baseline and surgery. RESULTS: There were 214 patients (178 females) aged 15 ± 2 years, with a Risser sign 3.4 ± 1.6 and a main Cobb angle 55°±10° at baseline. The average wait prior to surgery was 1.3 ± 0.4 years. Only the Risser sign, menarchal status and sex were significantly associated with the annual progression rate. We have identified 3 clinically and significantly different groups of patients presenting slow (3 ± 4°/yr if Risser sign 3 to 5), moderate (8 ± 4°/yr if female with Risser sign 0 to 2 and post-menarchal), and fast (15 ± 10°/yr if Risser sign 0 to 2 and premenarchal or male) progression rates. CONCLUSION: We present an evidence-based surgical prioritization algorithm for pediatric idiopathic scoliosis that can easily be implemented in clinical practice when long surgical delays are expected.

Bedside electromyography for clinical assessment of sacral motor and reflex activity adapted for patients hospitalized with acute neurological conditions: a pilot study.

STUDY DESIGN: Pilot cohort study. OBJECTIVE: To develop and implement a sacral electromyographic (sEMG) technique at bedside to ascertain sparing of sacral motor activity and reflexes in patients hospitalized for acute neurological conditions. SETTING: Hôpital du Sacré-Coeur de Montréal a Canadian Level-1 university trauma center specialized in SCI care. METHODS: Nine patients underwent digital rectal examination (DRE) and sEMG, assessing voluntary anal contraction and sacral spinal reflexes (bulbocavernosus reflex and the anal wink). Our sEMG technique utilized surface recording electrodes and tactile elicitation of reflexes. EMG signal was acquired at bedside through the Noraxon MR3 system. RESULTS: It was quick, well accepted and did no harm. We found that contrary to the DRE, sEMG detected subclinical sacral motor activity and reflexes in 20% of cases for voluntary anal contraction and 40% of cases for the anal wink. CONCLUSION: We believe our sEMG technique is a powerful tool able to enhance management of patients suffering from acute neurological impairments and requiring sacral function assessment.

Real-time prediction of postoperative spinal shape with machine learning models trained on finite element biomechanical simulations.

PURPOSE: Adolescent idiopathic scoliosis is a chronic disease that may require correction surgery. The finite element method (FEM) is a popular option to plan the outcome of surgery on a patient-based model. However, it requires considerable computing power and time, which may discourage its use. Machine learning (ML) models can be a helpful surrogate to the FEM, providing accurate real-time responses. This work implements ML algorithms to estimate post-operative spinal shapes. METHODS: The algorithms are trained using features from 6400 simulations generated using the FEM from spine geometries of 64 patients. The features are selected using an autoencoder and principal component analysis. The accuracy of the results is evaluated by calculating the root-mean-squared error and the angle between the reference and predicted position of each vertebra. The processing times are also reported. RESULTS: A combination of principal component analysis for dimensionality reduction, followed by the linear regression model, generated accurate results in real-time, with an average position error of 3.75 mm and orientation angle error below 2.74 degrees in all main 3D axes, within 3 ms. The prediction time is considerably faster than simulations based on the FEM alone, which require seconds to minutes. CONCLUSION: It is possible to predict post-operative spinal shapes of patients with AIS in real-time by using ML algorithms as a surrogate to the FEM. Clinicians can compare the response of the initial spine shape of a patient with AIS to various target shapes, which can be modified interactively. These benefits can encourage clinicians to use software tools for surgical planning of scoliosis.

Is the level of consent to a national research registry associated with patient outcomes following traumatic spinal cord injury? A population-based study from the Rick Hansen Spinal Cord Injury Registry (RHSCIR).

OBJECTIVE: We examined the impact of consenting to the Rick Hansen Spinal Cord Injury Registry (RHSCIR) on outcomes: acute length of stay (LOS), in-hospital mortality, medical complications (pressure injuries and pneumonia), and the final discharge destination following a spinal cord injury (SCI) using the national RHSCIR dataset. DESIGN: A retrospective cohort study was conducted using RHSCIR participant data from 2014 to 2019. Participants approached for enrollment were grouped into 1) PC: provided full consent including community follow-up (CFU) interviews, 2) DWC: declined CFU interviews but accepted minimal data collection that may include initial/final interviews and/or those who later withdrew consent, and 3) DC: declined consent to any participation. As no data was collected for the DC group, descriptive, bivariate, and multivariable regression analysis was limited to the PC and DWC groups. RESULTS: Of 2811 participants, 2101 (74.7%) were PC, 553 (19.7%) were DWC, and 157 (5.6%) were DC. DWC participants had significantly longer acute LOS, more acute pneumonias/pressure injuries, and were less likely to be discharged home than PC participants. All these associations - except pneumonia - remained significant in the multivariable analyses. CONCLUSION: Not participating fully in RHSCIR was associated with more complications and longer hospital stays.

COVID-19 significantly impacted initial consultation for idiopathic scoliosis.

INTRODUCTION: Since the outbreak of the COVID-19 pandemic, reduction of social activities and rapid adoption of telemedicine, decreasing face-to-face encounters seems to have negatively affected the timely Idiopathic Scoliosis (IS) referral with a spine specialist. We aim to document the progression of IS curves during COVID-19 pandemic reflected by the late presentation of patients at the initial visit with higher Cobb angles and to evaluate its influence on health-related quality of life scores. MATERIALS AND METHODS: All IS patients scheduled for surgery between April 2019 and September 2021 were recruited in a prospective cohort study. The patients were divided into five cohorts of 6 month duration each according to their booking date: 2 periods before the 1st COVID-19 wave, one period during and two periods afterwards. In each cohort, patients were divided into 3: those who were scheduled for posterior spinal fusion (PSF) at 1st visit, those booked for vertebral body tethering (VBT) at 1st visit, and those scheduled for surgery but who have failed brace treatment. Variables included age, gender, Risser grade and preoperative SRS-22 scores. Chi2 and ANOVA tests were used for comparison. RESULTS: 173 patients were analyzed. 33 patients (13.1 ± 3 y.o.) were scheduled between Apr and Sept 2019; 38 (13.1 y.o. ± 2) between Oct 2019 and Mar 2020; 31 (13.4 ± 3 y.o.) between Apr and Sept 2020; 30 (14.3 ± 2 y.o.) between Sept 2020 and Mar 2021; and 41 patients (13.8 ± 2 y.o.) between Apr and Sept 2021. Non-statistically significant differences were found between periods before, during or after the COVID-19 first wave regarding patients' age, gender, Risser grade and SRS-22 scores. Average Cobb angles of patients at their 1st visit after the beginning of the COVID-19 pandemic were significantly higher than those before COVID-19 (52.2° ± 7° and 56.6° ± 13° vs 47.8° ± 12° and 45.2° ± 13°; p = 0.0001). More patients were booked for PSF (p < 0.0000) through the five evaluated periods, while the indication of VBT or surgery in patients previously braced progressively decreased. CONCLUSION: Patients presented at the scoliosis clinic for the 1st time after the 1st COVID-19 wave with significantly larger Cobb angles, and likely contributed to an increased proportion of PSF, as the potential window for bracing or VBT was missed due to a delayed consultation.

Clinical and radiological outcomes of gradual reduction and circumferential fusion of high-grade spondylolisthesis in adolescents: a prospective cohort study of 29 young patients.

AIM: The objective of this study was to evaluate the safety and efficacy of a novel technique of formal reduction and circumferential fusion for pediatric high-grade spondylolisthesis (HGS). PURPOSE: The safety and efficacy of formal reduction for high-grade spondylolisthesis (HGS) has never been thoroughly examined. This study reports the outcomes of 29 children with HGS who underwent a procedure of gradual reduction and circumferential fusion. METHODS: 29 children (13 males, 16 females) were recruited between 2006 and 2010. Radiographic measurements (including % of slip, lumbosacral angle-LSA, pelvic incidence-PI, pelvic tilt-PT, sacral slope-SS, and proximal femoral angle-PFA) and quality of life assessment (SRS-22 questionnaire) were prospectively obtained at baseline and at the last post-operative follow-up (> 2 years post-op). Radiological measurements were used to classify patients according to the Spine Deformity Study Group (SDSG) classification. RESULTS: Mean baseline slip % was 69.9 ± 16.5%. There were 13 patients with a balanced pelvic (SDSG Type 4) and 16 with an unbalanced pelvis (SDSG Type 5 and 6). On average, a reduction of 45.5 ± 15.3% (range 20-86%) was achieved safely with no major complication. In particular, of the 29 patients, only 3 had a L5 radiculopathy postoperatively that was self-resolved at follow-up. From a radiological standpoint, we observed a mean improvement of LSA from 80.3 ± 17.9° to 91.7 ± 13.6°. We also observed a statistically significant improvement in global HRQOL, and in the function and body image domains. CONCLUSION: This prospective study suggests that formal reduction of HGS followed by circumferential fusion is safe when using a standardized surgical technique based on gradual reduction. Performing this intervention could also help improve QOL in some patients.

Classifying clinical phenotypes of functional recovery for acute traumatic spinal cord injury. An observational cohort study.

PURPOSE: Identify patient subgroups with different functional outcomes after SCI and study the association between functional status and initial ISNCSCI components. METHODS: Using CART, we performed an observational cohort study on data from 675 patients enrolled in the Rick-Hansen Registry(RHSCIR) between 2014 and 2019. The outcome was the Spinal Cord Independence Measure (SCIM) and predictors included AIS, NLI, UEMS, LEMS, pinprick(PPSS), and light touch(LTSS) scores. A temporal validation was performed on data from 62 patients treated between 2020 and 2021 in one of the RHSCIR participating centers. RESULTS: The final CART resulted in four subgroups with increasing totSCIM according to PPSS, LEMS, and UEMS: 1)PPSS < 27(totSCIM = 28.4 ± 16.3); 2)PPSS ≥ 27, LEMS < 1.5, UEMS < 45(totSCIM = 39.5 ± 19.0); 3)PPSS ≥ 27, LEMS < 1.5, UEMS ≥ 45(totSCIM = 57.4 ± 13.8); 4)PPSS ≥ 27, LEMS ≥ 1.5(totSCIM = 66.3 ± 21.7). The validation model performed similarly to the original model. The adjusted R-squared and F-test were respectively 0.556 and 62.2(P-value <0.001) in the development cohort and, 0.520 and 31.9(P-value <0.001) in the validation cohort. CONCLUSION: Acknowledging the presence of four characteristic subgroups of patients with distinct phenotypes of functional recovery based on PPSS, LEMS, and UEMS could be used by clinicians early after tSCI to plan rehabilitation and establish realistic goals. An improved sensory function could be key for potentiating motor gains, as a PPSS ≥ 27 was a predictor of a good function.

After a traumatic Spinal Cord Injury (SCI), early neurological examination using the International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) is recommended to determine initial injury severity and prognosis.This study identified three initial ISNCSCI components defining four subgroups of SCI patients with different expectations in functional outcomes, namely the initial pinprick sensory score, the Lower Extremity Motor Score, and the Upper Extremity Motor Score.Clinicians could use these subgroups early after tSCI to plan rehabilitation and set realistic therapeutic goals regarding functional outcomes.In clinical practice, careful and accurate assessment of pinprick sensation early after the SCI is crucial when predicting function or stratifying patients based on the expected function.

Clinical Relevance of Painful Congenital Early-onset Scoliosis: A Magnetic Resonance Image-based Study.

BACKGROUND: Back pain, as a clinical marker in scoliosis, has been associated with underlying pathology for many years, warranting further magnetic resonance imaging (MRI). Failures of segmentation, mixed defects, female gender, rib anomalies, congenital thoracic anomalies, and neurocutaneous markers are known risk factors for abnormal MRI pathology findings in patients with congenital early-onset scoliosis (Congenital-EOS). Yet, back pain has not been evaluated as a risk factor for underlying MRI pathology in patients with Congenital-EOS. This study aimed to assess back pain as a risk factor for underlying pathology in Congenital-EOS using MRI as a diagnostic tool. METHODS: A retrospective database review from the Pediatric Spine Study Group (PSSG) of all patients with Congenital-EOS who reported a back pain complaint, and underwent a spinal MRI study before surgical intervention was performed. Patients were divided into those with an underlying MRI pathology and those without. Demographics were compared between groups. RESULTS: From a total of 2355 patients with Congenital-EOS registered in PSSG, 107 patients reported a back pain complaint, with only 42 patients fulfilling the inclusion criteria (being evaluated with an MRI study). Overall group mean age was 8.1±4.5 years, with 25 of the 42 patients (60%) being females. Twenty-four of 42 patients (57%) had a comorbidity reported such as cardiac problems, musculoskeletal complaints, neurological deficits/myelopathy, gastrointestinal symptoms, developmental delay, respiratory problems, craniofacial abnormalities, and chromosomal conditions. An underlying MRI pathology was found in 21 of 42 patients with Congenital-EOS (50%) with back pain. The underlying MRI pathologies found were tethered spinal cord, spinal canal stenosis, syringomyelia, Arnold-Chiari malformation, and arachnoid cyst. CONCLUSIONS: Abnormal MRI findings are common in patients with Congenital-EOS who report back pain. Gender, age, major coronal curve angle, thoracic or lumbar predominance deformity, and comorbidities type or amount were not associated with abnormal MRI findings. LEVEL OF EVIDENCE: Level II-Prognostic study.

Does Improvement in American Spinal Injury Association Impairment Scale Grade Correlate With Functional Recovery in All Patients With a Traumatic Spinal Cord Injury?

OBJECTIVE: The aim of the study is to determine what improvement on the American Spinal Injury Impairment Scale correlates with functional status after a traumatic spinal cord injury. DESIGN: We performed an observational cohort study, analyzing prospective data from 168 patients with traumatic spinal cord injury admitted to a single level 1 trauma center. A multivariable analysis was performed to assess the relationship between functional status (from the Spinal Cord Independence Measure) at 1-year follow-up and American Spinal Injury Impairment Scale grade (baseline and 1-yr follow-up), while taking into account covariables describing the sociodemographic status, trauma severity, and level of neurological injury. RESULTS: Individuals improving to at least American Spinal Injury Impairment Scale grade D had significantly higher Spinal Cord Independence Measure score compared with those not reaching American Spinal Injury Impairment Scale D (89.3 ± 15.2 vs. 52.1 ± 20.4) and were more likely to reach functional independence (68.5% vs. 3.6%), regardless of the baseline American Spinal Injury Impairment Scale grade. Higher final Spinal Cord Independence Measure was more likely with an initial American Spinal Injury Impairment Scale grade D (ß = 1.504; 95% confidence interval = 0.46-2.55), and a final American Spinal Injury Impairment Scale grade D (ß = 3.716; 95% CI = 2.77-4.66) or E (ß = 4.422; 95% CI = 2.91-5.93). CONCLUSIONS: Our results suggest that reaching American Spinal Injury Impairment Scale grade D or better 1 yr after traumatic spinal cord injury is highly predictive of significant functional recovery, more so than the actual improvement in American Spinal Injury Impairment Scale grade from the injury to the 1-yr follow-up.

OBJECTIVE: The aim of the study is to determine what improvement on the American Spinal Injury Impairment Scale correlates with functional status after a traumatic spinal cord injury. DESIGN: We performed an observational cohort study, analyzing prospective data from 168 patients with traumatic spinal cord injury admitted to a single level 1 trauma center. A multivariable analysis was performed to assess the relationship between functional status (from the Spinal Cord Independence Measure) at 1-year follow-up and American Spinal Injury Impairment Scale grade (baseline and 1-yr follow-up), while taking into account covariables describing the sociodemographic status, trauma severity, and level of neurological injury. RESULTS: Individuals improving to at least American Spinal Injury Impairment Scale grade D had significantly higher Spinal Cord Independence Measure score compared with those not reaching American Spinal Injury Impairment Scale D (89.3 ± 15.2 vs. 52.1 ± 20.4) and were more likely to reach functional independence (68.5% vs. 3.6%), regardless of the baseline American Spinal Injury Impairment Scale grade. Higher final Spinal Cord Independence Measure was more likely with an initial American Spinal Injury Impairment Scale grade D (ß = 1.504; 95% confidence interval = 0.46­2.55), and a final American Spinal Injury Impairment Scale grade D (ß = 3.716; 95% CI = 2.77­4.66) or E (ß = 4.422; 95% CI = 2.91­5.93). CONCLUSIONS: Our results suggest that reaching American Spinal Injury Impairment Scale grade D or better 1 yr after traumatic spinal cord injury is highly predictive of significant functional recovery, more so than the actual improvement in American Spinal Injury Impairment Scale grade from the injury to the 1-yr follow-up.

A data-driven approach to categorize patients with traumatic spinal cord injury: cluster analysis of a multicentre database.

Background: Conducting clinical trials for traumatic spinal cord injury (tSCI) presents challenges due to patient heterogeneity. Identifying clinically similar subgroups using patient demographics and baseline injury characteristics could lead to better patient-centered care and integrated care delivery. Purpose: We sought to (1) apply an unsupervised machine learning approach of cluster analysis to identify subgroups of tSCI patients using patient demographics and injury characteristics at baseline, (2) to find clinical similarity within subgroups using etiological variables and outcome variables, and (3) to create multi-dimensional labels for categorizing patients. Study design: Retrospective analysis using prospectively collected data from a large national multicenter SCI registry. Methods: A method of spectral clustering was used to identify patient subgroups based on the following baseline variables collected since admission until rehabilitation: location of the injury, severity of the injury, Functional Independence Measure (FIM) motor, and demographic data (age, and body mass index). The FIM motor score, the FIM motor score change, and the total length of stay were assessed on the subgroups as outcome variables at discharge to establish the clinical similarity of the patients within derived subgroups. Furthermore, we discussed the relevance of the identified subgroups based on the etiological variables (energy and mechanism of injury) and compared them with the literature. Our study also employed a qualitative approach to systematically describe the identified subgroups, crafting multi-dimensional labels to highlight distinguishing factors and patient-focused insights. Results: Data on 334 tSCI patients from the Rick Hansen Spinal Cord Injury Registry was analyzed. Five significantly different subgroups were identified (p-value ≤0.05) based on baseline variables. Outcome variables at discharge superimposed on these subgroups had statistically different values between them (p-value ≤0.05) and supported the notion of clinical similarity of patients within each subgroup. Conclusion: Utilizing cluster analysis, we identified five clinically similar subgroups of tSCI patients at baseline, yielding statistically significant inter-group differences in clinical outcomes. These subgroups offer a novel, data-driven categorization of tSCI patients which aligns with their demographics and injury characteristics. As it also correlates with traditional tSCI classifications, this categorization could lead to improved personalized patient-centered care.

Attention-gated U-Net networks for simultaneous axial/sagittal planes segmentation of injured spinal cords.

Magnetic resonance imaging is currently the gold standard for the evaluation of spinal cord injuries. Automatic analysis of these injuries is however challenging, as MRI resolutions vary for different planes of analysis and physiological features are often distorted around these injuries. This study proposes a new CNN-based segmentation method in which information is exchanged between two networks analyzing the scans from different planes. Our aim was to develop a robust method for automatic segmentation of the spinal cord in patients having suffered traumatic injuries. The database consisted of 106 sagittal MRI scans from 94 patients with traumatic spinal cord injuries. Our method used an innovative approach where the scans were analyzed in series under the axial and sagittal plane by two different convolutional networks. The results were compared with those of Deepseg 2D from the Spinal Cord Toolbox (SCT), which was taken as state-of-the-art. Comparisons were evaluated using K-Fold cross-validation combined with statistical t-test results on separate test data. Our method achieved significantly better results than Deepseg 2D, with an average Dice coefficient of 0.95 against 0.88 for Deepseg 2D (p <0.001). Other metrics were also used to compare the segmentations, all of which showed significantly better results for our approach. In this study, we introduce a robust method for spinal cord segmentation which is capable of adequately segmenting spinal cords affected by traumatic injuries, improving upon the methods contained in SCT.

Validation of a New Tool to Detect and Characterize Spinal Cord Injury in the Acute Trauma Patient: The Montreal Acute Classification of Spinal Cord Injury.

STUDY DESIGN: Retrospective validation protocol. OBJECTIVE: The International Standards for Neurological Classification of Spinal Cord Injury (ISNCSCI) is the most comprehensive tool for classifying spinal cord injuries (SCI), but it is not adapted for the evaluation of trauma patients. The objective is to develop and validate a streamlined tool, the Montreal Acute Classification of Spinal Cord Injury (MAC-SCI) that can be integrated in the evaluation of trauma patients to detect and characterize traumatic SCI (tSCI). METHODS: The completion rate of the ISCNSCI during initial evaluation after tSCI was estimated at a Level-1 trauma center specialized in SCI care. Using a modified Delphi technique, we designed the MAC-SCI, a new tool to detect and characterize the severity grade and level of SCI in the polytrauma patient. A cohort consisting of 35 consecutive tSCI patients with complete ISNCSCI documentation was used to validate the MAC-SCI. The severity grade and neurological level of injury (NLI) were assessed using the MAC-SCI, and compared to those obtained with the ISNCSCI. RESULTS: Only 33% of 148 patients admitted after a tSCI had a complete ISNCSCI performed at initial presentation. The MAC-SCI retains 53 of the 134 elements from the ISNCSCI. There was a 100% concordance in severity grade between the MAC-SCI and ISNCSCI. The NLI were within 2 levels between the MAC-SCI and ISNCSI for 100% of patients. CONCLUSION: The MAC-SCI is a streamlined tool that accurately detects and characterizes tSCI in the acute trauma setting. It could be implemented in trauma protocols to guide the management of SCI patients. LEVEL OF EVIDENCE: Level III Diagnostic criteria.

Pre-operative parameters influencing vertebral body tethering outcomes: patient's characteristics play an important role in determining the outcomes at a minimum of 2 years post-op.

PURPOSE: The aim of this study is to determine preoperative predictors of good radiographic outcomes in VBT patients at a minimum 2-year follow-up. METHODS: From a single-center dataset, we reviewed patients who underwent VBT from January 2014 to November 2018. Data analysis included age, gender, Risser grade and biometric data. Radiographically, maximum Cobb angle, C-DAR and apical vertebral and disc wedging were measured preop and at a minimum 2-year follow-up. Patients were divided into two cohorts following two different outcome measures: (1) vertebral growth modulation, those patients that growth modulated or corrected ≥ 5° and those who did not; and (2) Maximum Cobb angle at 2 years, < and ≥ 40°. Student T and Chi2 tests were used for comparison and a multiple linear correlation test was implemented between statistically significant variables. RESULTS: 79 patients were recruited. 26 patients (33%) did growth modulate their spine at 2-year follow-up. These patients were significantly younger, and more skeletally immature with less height (147 cm vs 155 cm; p < 0.0001), weight (38 kg vs. 45 kg; p = 0.0009) and BMI (17 vs 18.8; p = 0.0229) as those who did not. Multiple linear regression model with these variables resulted in a moderate correlation (r2 = 0.234). 67 patients (85%) finished at a 2-year follow-up with a maximum Cobb angle < 40°. These patients were also younger and skeletally immature. We found significant differences in outcome 2 regarding the average preoperative maximum Cobb angle (48.5° ± 9.5 vs. 59.1° ± 10), average C-DAR (7 ± 1.5 vs. 8.5 ± 2.1), average apical vertebral wedging (6.5° vs. 8.3°), average vertebral/disc wedging ratio (1.5 vs. 2.4) and the average immediate postoperative Cobb angle (25° vs. 38°). These variables predicted a 36% of the variation in final Cobb angle measurement at a 2-year follow-up (r2 = 0.362). CONCLUSION: Curve severity determined by a preoperative C-DAR, preoperative Cobb angles and immediate postoperative Cobb angle are significantly related to curves < 40° at a minimum 2-year follow-up, while the potential to growth modulate the spine is more dependent on skeletal maturity, lower body weight and lower BMI. These patients' characteristics should be considered preoperatively.

Is it safe to initiate activity-based therapy within days following traumatic spinal cord injury? Preliminary results from the PROMPT-SCI trial.

CONTEXT: Activity-based therapy initiated within days of the accident could prevent complications and improve neurofunctional outcomes in patients with traumatic spinal cord injury (TSCI). However, it has never been attempted in humans with TSCI because of practical obstacles and potential safety concerns. The PROMPT-SCI trial is the first attempt at implementing ABT within the first days following a TSCI (i.e. very early ABT; VE-ABT). The objective is to determine if VE-ABT can be initiated safely in the intensive care unit (ICU) within 48 h of early decompressive surgery. DESIGN: As part of the PROMPT-SCI trial, 15 adult patients with severe TSCI were enrolled between April and November of 2021. The intervention consisted of 30-minute sessions of motor-assisted in-bed leg cycling starting within 48 h of early spinal surgery. Safety was assessed through continuous monitoring of vital signs and recording of adverse events during and after sessions. The main outcome measure was the achievement (yes or no) of a full and safe session within 48 h of early surgery. FINDINGS: Out of the 15 participants, 10 (66.6%) achieved this outcome. Out of the remaining 5, 2 were not cleared to engage in cycling within 48 h of surgery and 3 initiated cycling within 48 h but stopped prematurely. All 5 eventually completed a full and safe session within the next 1-2 days. In all 15 participants, there were no neurological deteriorations after the first completed session. CONCLUSION: Our results suggest that it is safe and feasible to perform a first session of VE-ABT within days of a severe TSCI with no serious adverse events and excellent completion rates.

How do early perioperative changes in AIS grade correlate with long-term neurological recovery? A retrospective cohort study.

CONTEXT/OBJECTIVE: Providing accurate counseling on neurological recovery is crucial after traumatic spinal cord injury (TSCI). The early neurological changes that occur in the subacute phase of the injury (i.e. within 14 days of early decompressive surgery) have never been documented. The objective of this study was to assess peri-operative neurological improvements after acute TSCI and determine their relationship with long-term neurological outcomes, measured 6-12 months following the injury. METHODS: A retrospective cohort study of 142 adult TSCI patients was conducted. Early peri-operative improvement was defined as improvement of at least 1 AIS grade between the pre-operative and follow-up (6-12 months post-TSCI) assessment. neurological improvement of at least 1 AIS grade. RESULTS: Out of the 142 patients, 18 achieved a peri-operative improvement of at least 1 AIS grade. Presenting a pre-operative AIS grade B and having shorter surgical delays were the main factors associated with stronger odds of achieving this outcome. Out of the 140 patients who still had potential for improvement at the time of the post-operative assessment, 44 achieved late neurological recovery (improvement of at least 1 AIS grade between the post-operative assessment and follow-up). Patients who presented a perioperative improvement seemed more likely to achieve later neurological improvement as well, although this was not statistically significant. CONCLUSION: Our results suggest that it is important to assess early perioperative neurological changes within 14 days of surgery because it can provide beneficial insight on long-term neurological outcomes for some patients. In addition, earlier surgery may promote early neurological recovery.

A Surgical Treatment Algorithm for Restoring Pelvic Balance and Health-related Quality of Life in High-grade Lumbosacral Spondylolisthesis: Prospective Multicenter Cohort of 61 Young Patients.

STUDY DESIGN: Retrospective multicenter cohort-study. OBJECTIVE: We propose an evidence-based surgical algorithm for achieving normal pelvic balance while optimizing health-related quality of life (HRQoL) in high-grade spondylolisthesis. SUMMARY OF BACKGROUND DATA: The principles of surgical treatment for young patients with high-grade L5-S1 spondylolisthesis remain unclear. There is a growing body of evidence supporting the central role of pelvic balance in the postural control and biomechanics of subjects with high-grade spondylolisthesis. METHODS: This retrospective study assessed a multicenter cohort of 61 patients with high-grade L5-S1 spondylolisthesis. Classification and regression tree analysis was used to identify objective criteria associated with pelvic balance and HRQoL after surgery. RESULTS: The most important predictor of a postoperative balanced pelvis was a postoperative L5 incidence ≤63.5 degrees. With postoperative L5 incidence ≤63.5 degrees,a residual slip percentage 9% and performing an L5-S1 posterior lumbar interbody fusion (PLIF)/transforaminal lumbar interbody fusion (TLIF) increased the likelihood of achieving a balanced pelvis postoperatively. When L5 incidence was 63.5 degrees,a balanced pelvis was most likely achieved with fusion limited to L5 proximally, residual slip percentage ≤40%, and residual lumbosacral angle 98 degrees. Predictors of postoperative HRQoL were the preoperative HRQoL score, L5 incidence and slip percentage. CONCLUSIONS: A surgical algorithm is proposed to achieve normal pelvic balance, while optimizing HRQoL. The first step during surgery is to assess L5 incidence and if L5 incidence is <65 degrees, the next step depends on the pelvic balance. With a preoperative balanced pelvis, it is important not to reduce completely the slip percentage by leaving a slip percentage ≥10%. When the preoperative pelvis is unbalanced, a TLIF/PLIF at L5-S1 is recommended to facilitate correcting the angular deformity at L5-S1. If L5 incidence is ≥65 degrees,a TLIF/PLIF at L5-S1 should be performed to correct the angular deformity at L5-S1, and fusion should ideally end at L5 proximally, in addition to performing gradual reduction of the slip percentage. If fusion up to L4 is required, a lumbosacral angle ≥100 degrees is key.

Do all patients with functional motor-incomplete (AIS-D) traumatic spinal cord injury need specialized inpatient functional rehabilitation? A prospective observational cohort study proposing clinical criteria for home-based rehabilitation after acute care.

CONTEXT/OBJECTIVE: Functional motor-incomplete AIS-D traumatic spinal cord injury (tSCI) represents an important growing population in neuro-traumatology. There is thus an important need for establishing strategies to optimize SCI rehabilitation resources. This study aims at proposing eligibility criteria to select individuals who could be discharged home (home-based rehabilitation) after acute care following an AIS-D tSCI and investigate its impact on the long-term functional status and quality of life (QOL), as compared to transfer to inpatient functional rehabilitation (IFR) resources. DESIGN: An observational prospective cohort study. SETTING: A single Level-1 specialized trauma center. PARTICIPANTS: 213 individuals sustaining an AIS-D tSCI. INTERVENTIONS: Home-based rehabilitation based on clinical specific criteria to be assessed by the acute care team. OUTCOME MEASURES: Functional status and QOL as assessed by the Spinal Cord Independence Measure version 3 and WHOQOL-BREF questionnaire one year following the injury, respectively. RESULTS: A total 37.9% of individuals fulfilled proposed criteria for home-based rehabilitation after acute care. As expected, this group was significantly younger, experienced lesser comorbidities and acute complications, and showed higher motor and sensory function compared to the IFR group. Home-rehabilitation was associated with a higher long-term functional status, physical and psychological QOL, when accounting for relevant confounding factors after an acute AIS-D tSCI. There was no readmission due to failure of home-based rehabilitation. CONCLUSION: Home-based rehabilitation in selected individuals sustaining an acute AIS-D tSCI is a safe and interesting strategy to optimize the long-term outcome in terms of functional recovery, physical and psychological QOL, as well as to optimize inpatient rehabilitation resources. The proposed eligibility criteria can be used by the acute care team to select the optimal discharge orientation in this important subpopulation.

Optoelectronic Pressure Sensor Based on the Bending Loss of Plastic Optical Fibers Embedded in Stretchable Polydimethylsiloxane.

We report the design and testing of a sensor pad based on optical and flexible materials for the development of pressure monitoring devices. This project aims to create a flexible and low-cost pressure sensor based on a two-dimensional grid of plastic optical fibers embedded in a pad of flexible and stretchable polydimethylsiloxane (PDMS). The opposite ends of each fiber are connected to an LED and a photodiode, respectively, to excite and measure light intensity changes due to the local bending of the pressure points on the PDMS pad. Tests were performed in order to study the sensitivity and repeatability of the designed flexible pressure sensor.