Parents can reliably and accurately detect trunk asymmetry using an inclinometer smartphone app.

PURPOSE: An inclinometer smartphone application has been developed to enable the measurement of the angle of trunk inclination (ATI) to detect trunk surface asymmetry. The objective was to determine the reliability and validity of the smartphone app in the hands of non-professionals. METHODS: Three non-professional observers and one expert surgeon measured maximum ATI twice in a study involving 69 patients seen in the spine clinics to rule out scoliosis or for regular follow-up (10-18 y.o., Cobb [0°-58°]). Observers were parents not familiar with scoliosis screening nor use of an inclinometer. They received training from a 4-minute video. Intra and inter-observer reliability was determined using the generalizability theory and validity was assessed from intraclass correlation coefficients (ICC), agreement with the expert on ATI measurements using Bland-Altman analysis, and correct identification of the threshold for consultation (set to ≥6° ATI). RESULTS: Intra-observer and inter-observer reliability coefficients were excellent ϕ = 0.92. The standard error of measurement was 1.5° (intra-observer, 2 measurements) meaning that a parent may detect a change of 4° between examinations 95% of the time. Comparison of measurements between non-professionals and the expert resulted in ICC varying from 0.82 [0.71-0.88] to 0.84 [0.74-0.90] and agreement on the decision to consult occurred in 83 to 90% of cases. CONCLUSION: The use of a smartphone app resulted in excellent reliability, sufficiently low standard error of measurement (SEM) and good validity in the hands of non-professionals. The device and the instructional video are adequate means to allow detection and regular examination of trunk asymmetries by non-professionals.

Patient outcomes in idiopathic scoliosis are associated with biological endophenotypes: 2020 SOSORT award winner.

PURPOSE: Bracing is the treatment of choice for idiopathic scoliosis (IS), unfortunately factors underlying brace response remain unknown. Clinicians are currently unable to identify patients who may benefit from bracing, and therefore, better molecular stratification is critically needed. The aim of this study is to evaluate IS patient outcomes at skeletal maturity in relation to biological endophenotypes, and determine specific endophenotypes associated to differential bracing outcomes. This is a retrospective cohort with secondary cross-sectional comparative studies. METHODS: Clinical and radiological data were collected from 563 IS patients, stratified into biological endophenotypes (FG1, FG2, FG3) based on a cell-based test. Measured outcomes were maximum Cobb angle at skeletal maturity, and if severe, spinal deformity (≥ 45°) or surgery was attained. Treatment success/failure was determined by standard progression thresholds (Cobb ≥ 45° or surgery; Cobb angle progression ≥ 6°). Multivariable analyses were performed to evaluate associations between endophenotypes and clinical outcome. RESULTS: Higher Cobb angles at maturity for FG1 and FG2 patients were observed (p = 0.056 and p = 0.05), with increased likelihood of ≥ 45° and/or surgery for FG1 (OR = 2.181 [1.002-4.749] and FG2 (OR = 2.141 [1.038-4.413]) compared to FG3. FG3 was 9.31 [2.58-33.61] and 5.63 [2.11-15.05] times more likely for bracing success at treatment termination and based on the < 6° progression criterion, respectively, compared to FG1. CONCLUSION: Associations between biological endophenotypes and outcomes suggest differences in progression and/or bracing response among IS patients. Outcomes were most favorable in FG3 patients. The results pave the way for establishing personalized treatments, distinguishing who may benefit or not from treatment.

Retrospective analysis of fetal vertebral defects: Associated anomalies, etiologies, and outcome.

Our objectives were to describe fetal cases of vertebral defects (VD), assess the diagnostic yield of fetal chromosomal analysis for VD and determine which investigations should be performed when evaluating fetal VD. We performed a retrospective chart review for fetuses with VD seen between 2006 and 2015. Cases were identified from CHU Sainte-Justine's prenatal clinic visits, postmortem fetal skeletal surveys, and medical records. Cases with neural tube defects were excluded. Sixty-six fetuses with VD were identified at a mean gestational age of 20 weeks. Forty-seven (71.2%) had associated antenatal anomalies, most commonly genitourinary, skeletal/limb, and cardiac anomalies. Thirteen mothers (19.7%) had pregestational diabetes (95% CI [10.1%-29.3%]). Fifty-three cases had chromosomal analysis. Three had abnormal results (5.6%): trisomy 13, trisomy 22, and 9q33.1q34.11 deletion. Thirty-four (51.5%) pregnancies were terminated, one led to intrauterine fetal demise and 31 (46.9%) continued to term. Of 27 children who survived the neonatal period, 21 had congenital scoliosis and 3 had spondylocostal dysostosis. Seven had developmental delay. In conclusion, prenatal evaluation of fetuses with VD should include detailed morphological assessment (including fetal echocardiogram), maternal diabetes screening, and chromosomal microarray if non-isolated. Our findings provide guidance about management and counseling after a diagnosis of fetal VD.

Predicting lowest hemoglobin level and risk of blood transfusion in spinal fusion surgery for adolescent idiopathic scoliosis.

PURPOSE: The aim of this study was to evaluate the factors associated with timing of lowest hemoglobin (Hb) level and the need for postoperative blood transfusion in posterior spinal fusion for adolescent idiopathic scoliosis. METHODS: We conducted a retrospective review of all adolescent scoliosis patients undergoing posterior spinal fusion at our institution, 2002-2014. Surgery consisted of segmental pedicle screw fixation using multi-level pedicle screws. Blood-saving techniques were used in all patients. Data included Cobb angle, pre- and postoperative Hb levels, preoperative autologous blood donation (PABD), surgery duration, and allogeneic or autologous transfusion. We used linear and logistic regressions for statistical analysis. RESULTS: There were 456 patients (402 female, 54 male), mean age 16 ± 5 years. Lowest Hb was observed on postoperative Days 2 (32.2%) and 3 (33.3%); 45.1% of postoperative transfusions occurred on Day 2. One hundred and eighty-eight (41%) patients who provided PABD had significantly lower preoperative Hb and received more transfusions intraoperatively (22.6% vs. 5.2%) and postoperatively (20% vs. 6.3%) than others. Probability of transfusion increased 49.6 (95% CI 17.40-141.37) times with preoperative Hb < 11 g/dL as compared to preoperative Hb > 14 g/dL. Probability of transfusion increased 4.3- and 9.8-fold when surgery duration exceeded 5 and 6 h, respectively. Probability of transfusion increased 3.3- and 5.3-fold with Cobb angle > 70° and 80°, respectively. CONCLUSIONS: We identified clear patient-specific perioperative parameters that affect risk of perioperative blood transfusion, including Cobb angle, PABD and preoperative Hb. Hb measurement beyond postoperative Day 3 is considered unnecessary unless clinically indicated. These slides can be retrieved under Electronic Supplementary Material.

Pathways of healthcare utilisation in patients with suspected adolescent idiopathic scoliosis: a cross-sectional study.

BACKGROUND: School screening programs for adolescent idiopathic scoliosis (AIS) have been discontinued in Canada and elsewhere because they were not considered cost-effective. In communities lacking such programs, we expect a significant variety of healthcare pathways and timeframes for patient referrals to orthopaedics. The objectives of this study were: 1) to characterise the healthcare pathways of young children with suspected AIS in a population without school screening; and 2) to investigate the relationships between these healthcare pathways and the appropriateness of referrals to specialised orthopaedic clinics. METHODS: This study concerned all children, ages 10 to 18, referred for an initial visit for suspected AIS to any of the five out-patient paediatric orthopaedic clinics of south-western Quebec (Canada). For the 831 participants, referrals to orthopaedics were characterised as appropriate, late, or inappropriate, based on known risk factors for AIS progression and on treatment indications. Parents documented the circumstances of healthcare use prior to the orthopaedic consultation. Relevant predisposing, enabling, and need variables derived from Andersen's Behavioral Model of Health Services Use were also documented. Healthcare pathways were characterised by developing a taxonomy using multiple correspondence analysis prior to hierarchical classification. Associations between the healthcare pathways and appropriateness of referral were assessed using multinomial regression analyses. RESULTS: We constructed a taxonomy of five distinct healthcare pathways: 1) Lay/regular source of care interrelation, 2) Other professionals, 3) Lay/consultation discontinuity, 4) Other medical doctor, and 5) Regular source of care continuity. Laypersons played an important role in AIS suspicion (53% of cases), but did not prevent late referrals. Continuity of care, as opposed to numerous uncoordinated consultations, was an effective strategy to prevent late referrals (OR = 0.32 [0.17-0.59]), but was related to increased probability of inappropriate referrals. CONCLUSIONS: We identified two cardinal characteristics that distinguished the healthcare pathways and related significantly to appropriateness of referral status, namely the role of laypersons and the involvement of the regular source of care. This suggests directions for intervention such as advocating for access to a regular source of care, increasing awareness of the disease to medical practitioners' and improving their knowledge of AIS detection and referral criteria.

A modified position for optimized skeletal maturity assessment of AIS patients and its impact on 3D spinal and pelvic parameters.

PURPOSE: A hands-on-wall (HOW) position for low-dose stereoradiography of adolescent idiopathic scoliosis (AIS) patients would allow for skeletal maturity assessment of the hand and wrist. Our aims were twofold: confirm the reliability and validity of skeletal maturity assessment using the HOW radiographs and compare the spinal and pelvic 3D parameters to those of standard hands-on-cheeks (HOC) stereoradiographs. METHODS: Seventy AIS patients underwent two successive stereoradiographs and a standard hand and wrist radiograph on the same day. Patients were randomly assigned to begin with HOW and follow with HOC, or vice versa. Raters assessed digital skeletal age (DSA), Sanders Simplified Skeletal Maturity (SSMS) and Thumb Ossification Composite Index (TOCI). 3D reconstructions of the spine and pelvis bones were performed for each stereoradiograph to measure nine clinically relevant spinal and pelvic 3D parameters. RESULTS: Inter-rater and intra-rater reliabilities were excellent for DSA, SSMS and TOCI with both standard radiographs and HOW (ICC > 0.95). Strong correlation was found between ratings of both imaging types (ICC > 0.95). In the 3D reconstructions, kyphosis and sacral slope were slightly decreased in the HOW position, but within the clinical margin of error. All other parameters did not differ significantly between positions (p < 0.05). CONCLUSION: The results suggest that HOW stereoradiographs allow clinicians to assess skeletal maturity of the hand and wrist with adequate reliability and validity. We recommend that scoliosis clinics adopt the HOW position to assess skeletal maturity because there is no significant clinical impact on the spinal and pelvic evaluation, and on radiation exposure, cost or time.

Three-dimensional spine parameters can differentiate between progressive and nonprogressive patients with AIS at the initial visit: a retrospective analysis.

BACKGROUND: Knowledge concerning morphology of the spine is reported in 2-dimensional (2D) or focuses on modification of parameters with progression of spinal deformation. The objective of this study was to compare 3-dimensional (3D) morphologic parameters of the spine at the first visit between progressive and a nonprogressive group of immature adolescent idiopathic scoliosis (AIS). METHODS: The first group was made up of surgically corrected AIS patients (E) (n=19), whereas the second group was composed of nonprogressive AIS that had reached skeletal maturity (n=18). Computerized measurements were undertaken on reconstructed 3D spines. There were 5 categories of measurement: Cobb angles (scoliosis, kyphosis, lordosis), 3D wedging (apical vertebra, mean 2 apical disks), rotation (upper and lower junctional vertebra, apical vertebra, and disk), torsion, and slenderness (height/width ratio of T6, L4, and T1-L5). Nonparametric Mann-Whitney tests were also undertaken. RESULTS: There was no statistical difference between the 2 groups for age, 3D Cobb angle, lordosis, and kyphosis. Mean 3D wedging of the apical disks, lower junctional vertebral axial rotation, torsion and T6, and whole spine height/width ratio were all significantly affected. CONCLUSIONS: This study supports the theory that wedging begins in the disks and then in the vertebral body and identifies 3D morphologic parameters that could be used in the prediction of AIS evolution. The findings in the junctional area illustrate that a torsional deformity seems to occur distally from the apex and creates a progressive scoliosis. Curve progression could be predicted based on 3D morphometric parameters, as early as the initial visit.

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.

3D Radiological Outcomes and Quality of Life of Patients With Moderate Idiopathic Scoliosis Treated With Anterior Vertebral Growth Modulation Versus Bracing: Two-Year Follow-up.

STUDY DESIGN: Observational cohort study. OBJECTIVE: To test the hypothesis that anterior vertebral body growth modulation (AVBGM) achieves 3D deformity correction after 2-year follow-up while brace treatment limits curve progression for moderate idiopathic scoliosis (30-50°). SUMMARY OF BACKGROUND DATA: For idiopathic scoliosis, bracing and AVBGM have overlapping indications in skeletally immature patients with moderate scoliosis curve angles, creating a grey zone in clinical practice between them. The relative 3D deformity control performance over a 2-year period between these fusionless treatments is still uncertain. METHODS: A retrospective review of a prospective idiopathic scoliosis patients database, recruited between 2013 and 2018 was performed. Inclusion criteria were skeletally immature patients (Risser 0-2), with Cobb angles between 30° and 50° and a 2-year follow-up after bracing or AVBGM. 3D radiological parameters and health related quality of life (HRQoL) scores were evaluated. Unpaired t test was used. RESULTS: Thirty nine patients (12.7 ± 1.3 y.o.) with Cobb angles more than or equal to 30° treated with brace and 41 patients (11.8 ± 1.2 y.o.) with presenting Cobb angles less than or equal to 50° who received AVBGM were reviewed. The statistical analysis of 3D deformity measurements showed that at 2-year follow-up, only the 3D spine length and both sides apical vertebral heights changed significantly with brace treatment. While AVBGM treatment achieved statistically significant correction differences in thoracic and lumbar Cobb angles, TrueKyphosis, 3D spine length, and selective left apical vertebral height ( P < 0.05). 35% of brace patients had a curve progression of more than 5° at final follow-up while it was 0% for AVBGM. HRQoL assessment showed no statistically significant differences between pre and post SRS-22 total scores for each group ( P > 0.05). CONCLUSION: Even though these two cohorts are not fully comparable, bracing seems to control progression for a significant portion of patients with moderate scoliosis curves, while AVBGM significantly corrected and maintained 3D deformity parameters at 2-year follow-up.

Image-Guided Tethering Spine Surgery With Outcome Prediction Using Spatio-Temporal Dynamic Networks.

Recent fusionless surgical techniques for corrective spine surgery such as Anterior Vertebral Body Growth Modulation (AVBGM) allow to treat mild to severe spinal deformations by tethering vertebral bodies together, helping to preserve lower back flexibility. Forecasting the outcome of AVBGM from skeletally immature patients remains elusive with several factors involved in corrective vertebral tethering, but could help orthopaedic surgeons plan and tailor AVBGM procedures prior to surgery. We introduce an intra-operative framework forecasting the outcomes during AVBGM surgery in scoliosis patients. The method is based on spatial-temporal corrective networks, which learns the similarity in segmental corrections between patients and integrates a long-term shifting mechanism designed to cope with timing differences in onset to surgery dates, between patients in the training set. The model captures dynamic geometric dependencies in scoliosis patients, ensuring long-term dependency with temporal dynamics in curve evolution and integrated features from inter-vertebral disks extracted from T2-w MRI. The loss function of the network introduces a regularization term based on learned group-average piecewise-geodesic path to ensure the generated corrective transformations are coherent with regards to the observed evolution of spine corrections at follow-up exams. The network was trained on 695 3D spine models and tested on 72 operative patients using a set of 3D spine reconstructions as inputs. The spatio-temporal network predicted outputs with errors of 1.8 ± 0.8mm in 3D anatomical landmarks, yielding geometries similar to ground-truth spine reconstructions obtained at one and two year follow-ups and with significant improvements to comparative deep learning and biomechanical models.

Automatic bone maturity grading from EOS radiographs in Adolescent Idiopathic Scoliosis.

Adolescent Idiopathic Scoliosis (AIS) is a deformation of the spine and it is routinely diagnosed using posteroanterior and lateral radiographs. The Risser sign used in skeletal maturity assessment is commonly accepted in AIS patient's management. However, the Risser sign is subject to inter-observer variability and it relies mainly on the observation of ossification on the iliac crests. This study proposes a new machine-learning-based approach for Risser sign skeletal maturity assessment using EOS radiographs. Regions of interest including right and left humeral heads; left and right femoral heads; and pelvis are extracted from the radiographs. First, a total of 24 image features is extracted from EOS radiographs using a ResNet101-type convolutional neural network (CNN), pre-trained from the ImageNet database. Then, a support vector machine (SVM) algorithm is used for the final Risser sign classification. The experimental results demonstrate an overall accuracy of 84%, 78%, and 80% respectively for iliac crests, humeral heads, and femoral heads. Class activation maps using Grad-CAM were also investigated to understand the features of our model. In conclusion, our machine learning approach is promising to incorporate a large number of image features for different regions of interest to improve Risser grading for skeletal maturity. Automatic classification could contribute to the management of AIS patients.

Brace prescription patterns in patients referred to orthopaedic clinics for adolescent idiopathic scoliosis (AIS).

Even if braces for scoliosis are broadly used, there are no data on the orthopaedic medical practice to evaluate the circumstances of brace prescription. This study aims at comparing scoliosis brace prescription patterns with generally recognized standards. A cross-sectional study was carried out in 2006-2007 on all confirmed AIS patients referred to a paediatric scoliosis clinic for a first visit. Agreement between the actual brace prescription patterns and standards for immediate prescription was analyzed, following the recommendations of the Quebec Scoliosis Network (QSN), as well as the Scoliosis Research Society (SRS) therapeutic inclusion criteria. In addition, chi-2 tests and logistic regression models were used to identify variables related to brace prescription. Amongst the 321 AIS patients, immediate brace treatment was recommended in 70 cases, for about 50% of concordance with the defined criteria. Variables describing the patients' maturity (age, Risser, onset of menses) and deformity magnitude (Cobb angle and rib hump), as well as the treating physician, were the main determinants of brace prescription. Despite the professional consensus on immediate bracing norms, under and over-prescription of brace were documented in this study. Better understanding of these patterns would require documentation of motives associated with prescription at the individual level.

A Predictive Model of Progression for Adolescent Idiopathic Scoliosis Based on 3D Spine Parameters at First Visit.

MINI: The aim of this prospective cohort study was to improve the prediction of curve progression in AIS. By adding the 3D morphology parameters at first visit, the predictive model explains 65% of the variability. It is one of the greatest advances in the understanding of scoliosis progression in the last 30 years. STUDY DESIGN: Prospective cohort study. OBJECTIVE: The objective of the present study was to design a model of AIS progression to predict Cobb angle at full skeletal maturity, based on curve type, skeletal maturation, and 3D spine parameters available at first visit. SUMMARY OF BACKGROUND DATA: Adolescent idiopathic scoliosis (AIS) is a three-dimensional (3D) spinal deformity that affects 1% of adolescents. Curve severity is assessed using the Cobb angle. Prediction of scoliosis progression remains challenging for the treating physician and is currently based on curve type, severity, and maturity. The objective of this study was to develop a predictive model of final Cobb angle, based on 3D spine parameters at first visit, to optimize treatment. METHODS: A prospective cohort of AIS patients at first orthopedic visit was enrolled between 2006 and 2010, all with 3D reconstructions. Measurements of five types of descriptors were obtained: angle of plane of maximum curvature, Cobb angles, 3D wedging, rotation, and torsion. A general linear model analysis with backward selection was done with final Cobb angle (either just before surgery or at skeletal maturity) as outcome and 3D spine parameters and clinical parameters as predictors. RESULTS: Of 195 participants, 172 (88%) were analyzed; average age at presentation was 12.5 ±â€Š1.3 years and mean follow-up to outcome, 3.2 years. The final model includes significant predictors: initial skeletal maturation, curve type, frontal Cobb angle, angle of plane of maximal curvature, and 3D disk wedging (T3-T4, T8-T9) and achieved a determination coefficient (R) = 0.643. Positive and negative predictive values to identify a curve of 35 degrees are 79% and 94%. CONCLUSION: This study developed a predictive model of spinal curve progression in scoliosis based on first-visit information. The model will help the treating physician to initiate appropriate treatment at first visit. LEVEL OF EVIDENCE: 3.

Prospective cohort study. The objective of the present study was to design a model of AIS progression to predict Cobb angle at full skeletal maturity, based on curve type, skeletal maturation, and 3D spine parameters available at first visit. Adolescent idiopathic scoliosis (AIS) is a three-dimensional (3D) spinal deformity that affects 1% of adolescents. Curve severity is assessed using the Cobb angle. Prediction of scoliosis progression remains challenging for the treating physician and is currently based on curve type, severity, and maturity. The objective of this study was to develop a predictive model of final Cobb angle, based on 3D spine parameters at first visit, to optimize treatment. A prospective cohort of AIS patients at first orthopedic visit was enrolled between 2006 and 2010, all with 3D reconstructions. Measurements of five types of descriptors were obtained: angle of plane of maximum curvature, Cobb angles, 3D wedging, rotation, and torsion. A general linear model analysis with backward selection was done with final Cobb angle (either just before surgery or at skeletal maturity) as outcome and 3D spine parameters and clinical parameters as predictors. Of 195 participants, 172 (88%) were analyzed; average age at presentation was 12.5 ±â€Š1.3 years and mean follow-up to outcome, 3.2 years. The final model includes significant predictors: initial skeletal maturation, curve type, frontal Cobb angle, angle of plane of maximal curvature, and 3D disk wedging (T3-T4, T8-T9) and achieved a determination coefficient (R2) = 0.643. Positive and negative predictive values to identify a curve of 35 degrees are 79% and 94%. This study developed a predictive model of spinal curve progression in scoliosis based on first-visit information. The model will help the treating physician to initiate appropriate treatment at first visit. Level of Evidence: 3.

Association between lay perception of morbidity and appropriateness of specialized health care use in adolescent idiopathic scoliosis.

In absence of school scoliosis screening programs (SSSP) in Canada, this study examined the relationships between the lay person's perception of morbidity and the appropriateness of referral in orthopedics. A cross-sectional study was conducted with all children consecutively referred in orthopedics for suspected scoliosis. The 831 participants were classified as Appropriate, Late, or Inappropriate referrals for the orthopedic setting. Perceived morbidity was operationalized by: the scoliosis detection originator, the perceptions of the seriousness of the condition and urgency to consult a physician, the perception of the general health, as well as Visible Back Deformity, Self-image, and Pain. Direct associations between the perceived morbidity and the appropriateness of referral were found in all scoliosis-specific measures; the most discriminant variable was Visible Back Deformity. Lay perceived morbidity is a good indicator of the objective morbidity, and thus reflects in the appropriateness of referral status. The important role of the lay persons in symptoms appraisal does not however insure appropriate referral. Searching for alternatives to SSSP would wisely include a health promotion and medical management program. Statement of Clinical Significance: Perceived morbidity by the lay persons is strongly associated with the objectively evaluated severity of scoliosis deformity. Therefore, in absence of SSSP, lay person awareness plays an important role in symptom recognition and search for care. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

Prediction of spinal curve progression in Adolescent Idiopathic Scoliosis using Random Forest regression.

BACKGROUND: The progression of the spinal curve represents one of the major concerns in the assessment of Adolescent Idiopathic Scoliosis (AIS). The prediction of the shape of the spine from the first visit could guide the management of AIS and provide the right treatment to prevent curve progression. METHOD: In this work, we propose a novel approach based on a statistical generative model to predict the shape variation of the spinal curve from the first visit. A spinal curve progression approach is learned using 3D spine models generated from retrospective biplanar X-rays. The prediction is performed every three months from the first visit, for a time lapse of one year and a half. An Independent Component Analysis (ICA) was computed to obtain Independent Components (ICs), which are used to describe the main directions of shape variations. A dataset of 3D shapes of 150 patients with AIS was employed to extract the ICs, which were used to train our approach. RESULTS: The approach generated an estimation of the shape of the spine through time. The estimated shape differs from the real curvature by 1.83, 5.18, and 4.79° of Cobb angles in the proximal thoracic, main thoracic, and thoraco-lumbar lumbar sections, respectively. CONCLUSIONS: The results obtained from our approach indicate that predictions based on ICs are very promising. ICA offers the means to identify the variation in the 3D space of the evolution of the shape of the spine. Another advantage of using ICs is that they can be visualized for interpretation.

Dynamic ensemble selection of learner-descriptor classifiers to assess curve types in adolescent idiopathic scoliosis.

While classification is important for assessing adolescent idiopathic scoliosis (AIS), it however suffers from low interobserver and intraobserver reliability. Classification using ensemble methods may contribute to improving reliability using the proper 2D and 3D images of spine curvature features. In this study, we present two new techniques to describe the spine, namely, leave-one-out and fan leave-one-out. Using these techniques, three descriptors are computed from a stereoradiographic 3D reconstruction to describe the relationship between a vertebra and its neighbors. A dynamic ensemble selection method is introduced for automatic spine classification. The performance of the method is evaluated on a dataset containing 962 3D spine models categorized according to three curve types. With a log loss of 0.5623, the dynamic ensemble selection outperforms voting and stacking ensemble learning techniques. This method can improve intraobserver and interobserver reliability, identify the best combination of descriptors for characterizing spine curve types, and provide assistance to clinicians in the form of information to classify borderline curvature types. Graphical abstract ᅟ.

3-D Morphology Prediction of Progressive Spinal Deformities From Probabilistic Modeling of Discriminant Manifolds.

We introduce a novel approach for predicting the progression of adolescent idiopathic scoliosis from 3-D spine models reconstructed from biplanar X-ray images. Recent progress in machine learning has allowed to improve classification and prognosis rates, but lack a probabilistic framework to measure uncertainty in the data. We propose a discriminative probabilistic manifold embedding where locally linear mappings transform data points from high-dimensional space to corresponding low-dimensional coordinates. A discriminant adjacency matrix is constructed to maximize the separation between progressive (P) and nonprogressive (NP) groups of patients diagnosed with scoliosis, while minimizing the distance in latent variables belonging to the same class. To predict the evolution of deformation, a baseline reconstruction is projected onto the manifold, from which a spatiotemporal regression model is built from parallel transport curves inferred from neighboring exemplars. Rate of progression is modulated from the spine flexibility and curve magnitude of the 3-D spine deformation. The method was tested on 745 reconstructions from 133 subjects using longitudinal 3-D reconstructions of the spine, with results demonstrating the discriminatory framework can identify between P and NP of scoliotic patients with a classification rate of 81% and the prediction differences of 2.1° in main curve angulation, outperforming other manifold learning methods. Our method achieved a higher prediction accuracy and improved the modeling of spatiotemporal morphological changes in highly deformed spines compared with other learning methods.

Measurement Properties of the Scoliosis Research Society Outcomes Questionnaire in Adolescent Patients With Spondylolisthesis.

STUDY DESIGN: Prospective validation of the Scoliosis Research Society Outcomes Questionnaire French-Canadian version (SRS-22fv) in adolescent patients with spondylolisthesis. OBJECTIVE: To determine the measurement properties of the SRS-22fv. SUMMARY OF BACKGROUND DATA: The SRS-22 is widely used for the assessment of health-related quality of life in adolescent idiopathic scoliosis (AIS) and other spinal deformities. Spondylolisthesis has an important effect on quality of life. The instrument was previously used in this population, although its measurement properties remained unknown. We aim to determine its reliability, factorial, concurrent validity, and its discriminant capacity in an adolescent spondylolisthesis population. METHODS: The SRS-22fv was tested in 479 subjects (272 patients with spondylolisthesis, 143 with AIS, and 64 controls) at a single institution. Its reliability was measured using the coefficient of internal consistency, concurrent validity by the short form-12 (SF-12v2 French version) and discriminant validity using multivariate analysis of variance, analysis of covariance, and multivariate linear regression. RESULTS: The SRS-22fv showed a good global internal consistency (spondylolisthesis: Cronbach α = 0.91, AIS: 0.86, and controls: 0.78) in all its domains for spondylolisthesis patients. It showed a factorial structure consistent with the original questionnaire, with 60% of explained variance under four factors. Moderate to high correlation coefficients were found for specifically corresponding domains between SRS-22fv and SF-12v2. Boys had higher scores than do girls, scores worsened with increasing age and body mass index. Analysis of covariance showed statistically significant differences between patients with spondylolisthesis, patients with AIS, and controls when controlling for age, sex, body mass index, pain, function, and self-image scores. In the spondylolisthesis group, scores on all domains and mean total scores were significantly lower in surgical candidates and in patients with high-grade spondylolisthesis. Low to moderate ceiling effects were shown in function (1.1%), self-image (10.7%), and pain (13.6%). CONCLUSION: The SRS-22fv can discriminate between healthy and spondylolisthesis subjects. It can be used in spondylolisthesis patients to assess health-related quality of life. LEVEL OF EVIDENCE: 4.

Geometric Torsion in Adolescent Idiopathic Scoliosis: A New Method to Differentiate Between Lenke 1 Subtypes.

STUDY DESIGN: Consecutive case series. OBJECTIVE: To study geometric torsion in thoracic adolescent idiopathic scoliosis (AIS) to propose it as a numerical three-dimensional (3D) parameter that quantifies the scoliosis deformity. SUMMARY OF BACKGROUND DATA: AIS is a 3D deformity of the spine. The most widely accepted and used classification systems, however, still rely on two-dimensional aspects of x-rays. Yet, a 3D classification of AIS remains elusive because there is no widely accepted 3D parameter in the clinical practice. METHODS: Analysis of 141 patients with Lenke type-1 deformity recruited in our institution. The Lenke classification was identified by two observers and 3D reconstructions were obtained using biplanar radiographs. Geometric torsion measuring the twisting effect of the spine was computed using a novel technique by approximating local arc lengths at the neutral vertebra in the thoracolumbar segment. An inter- and intragroup statistical analysis was performed to evaluate the torsion index, and how it relates to other 3D indices. RESULTS: A statistically significant increase in torsion was observed between Lenke 1A (1.15 mm) and Lenke 1C (2.10 mm) subgroups. No differences were found between the Lenke 1B (1.75 mm) subgroup with either of the other two subgroups. An automatic classification based on torsion indices identified two groups: one with high torsion values (3.02 mm) and one with low torsion values (0.82 mm). Statistically significant differences were found between the main thoracic planes of maximum curvature (PMC) orientation of the high-torsion group (73.72°) and the low-torsion group (79.85°). Statistically significant differences were also found for the thoracolumbar/lumbar PMC orientation between the high-torsion group (56.41°) and the low-torsion group (49.25°). CONCLUSION: These results suggest that a numerical method of describing scoliosis in 3D is within reach. They also suggest the existence of two subgroups of 3D deformations based on torsion values (high and low) with links to PMC orientation. LEVEL OF EVIDENCE: 4.

Three-dimensional spinal morphology can differentiate between progressive and nonprogressive patients with adolescent idiopathic scoliosis at the initial presentation: a prospective study.

STUDY DESIGN: This is a prospective case-control study. OBJECTIVE: The objective of this study was to compare 3-dimensional (3D) morphological parameters of the spine at the first visit between a nonprogressive (NP) and a progressive (P) group of immature adolescent idiopathic scoliosis (AIS). SUMMARY OF BACKGROUND DATA: Prediction of curve progression remains challenging in AIS at the first visit. Prediction of progression is based on curve type, curve magnitude, and skeletal or chronological age. METHODS: A prospective cohort of 133 AIS was followed from skeletal immaturity to maturity (mean, 37 mo). The first group was made up of patients with AIS with a minimum 6-degree progression of the major curve between the first and last follow-up (P) (n = 53) and the second group was composed of patients with NP who reached maturity with less than 6-degree progression (n = 81). Computerized measurements were taken on reconstructed 3-dimensional (3D) spine radiographs of the first visit. There were 6 categories of measurements: angle of plane of maximum curvature, Cobb angles (kyphosis, lordosis), 3D wedging (apical vertebra, apical disks), rotation (upper and lower junctional vertebra, apical vertebra, and thoracolumbar junction), torsion, and slenderness (height/width ratio). t tests were also conducted. RESULTS: There was no statistical difference between the 2 groups for age and initial Cobb angle. P presented significant hypokyphosis, and parameters related to rotation presented significant statistical differences between NP and P (plane of maximal curvature, torsion, and apical axial rotation). Depth slenderness also presented statistical differences. CONCLUSION: This study confirms that even at the initial visit, 3D morphological differences exist between P and NP AIS. It supports the use of 3D reconstructions of the spine in the initial evaluation of AIS to help predict outcome.