Defining multilevel developmental cervical spinal stenosis using MRI.

Aims: Developmental cervical spinal stenosis (DcSS) is a well-known predisposing factor for degenerative cervical myelopathy (DCM) but there is a lack of consensus on its definition. This study aims to define DcSS based on MRI, and its multilevel characteristics, to assess the prevalence of DcSS in the general population, and to evaluate the presence of DcSS in the prediction of developing DCM. Methods: This cross-sectional study analyzed MRI spine morphological parameters at C3 to C7 (including anteroposterior (AP) diameter of spinal canal, spinal cord, and vertebral body) from DCM patients (n = 95) and individuals recruited from the general population (n = 2,019). Level-specific median AP spinal canal diameter from DCM patients was used to screen for stenotic levels in the population-based cohort. An individual with multilevel (≥ 3 vertebral levels) AP canal diameter smaller than the DCM median values was considered as having DcSS. The most optimal cut-off canal diameter per level for DcSS was determined by receiver operating characteristic analyses, and multivariable logistic regression was performed for the prediction of developing DCM that required surgery. Results: A total of 2,114 individuals aged 64.6 years (SD 11.9) who underwent surgery from March 2009 to December 2016 were studied. The most optimal cut-off canal diameters for DcSS are: C3 < 12.9 mm, C4 < 11.8 mm, C5 < 11.9 mm, C6 < 12.3 mm, and C7 < 13.3 mm. Overall, 13.0% (262 of 2,019) of the population-based cohort had multilevel DcSS. Multilevel DcSS (odds ratio (OR) 6.12 (95% CI 3.97 to 9.42); p < 0.001) and male sex (OR 4.06 (95% CI 2.55 to 6.45); p < 0.001) were predictors of developing DCM. Conclusion: This is the first MRI-based study for defining DcSS with multilevel canal narrowing. Level-specific cut-off canal diameters for DcSS can be used for early identification of individuals at risk of developing DCM. Individuals with DcSS at ≥ three levels and male sex are recommended for close monitoring or early intervention to avoid traumatic spinal cord injuries from stenosis.

Effectiveness of bracing to achieve curve regression in adolescent idiopathic scoliosis.

Aims: To systematically evaluate whether bracing can effectively achieve curve regression in patients with adolescent idiopathic scoliosis (AIS), and to identify any predictors of curve regression after bracing. Methods: Two independent reviewers performed a comprehensive literature search in PubMed, Ovid, Web of Science, Scopus, and Cochrane Library to obtain all published information about the effectiveness of bracing in achieving curve regression in AIS patients. Search terms included "brace treatment" or "bracing," "idiopathic scoliosis," and "curve regression" or "curve reduction." Inclusion criteria were studies recruiting patients with AIS undergoing brace treatment and one of the study outcomes must be curve regression or reduction, defined as > 5° reduction in coronal Cobb angle of a major curve upon bracing completion. Exclusion criteria were studies including non-AIS patients, studies not reporting p-value or confidence interval, animal studies, case reports, case series, and systematic reviews. The GRADE approach to assessing quality of evidence was used to evaluate each publication. Results: After abstract and full-text screening, 205 out of 216 articles were excluded. The 11 included studies all reported occurrence of curve regression among AIS patients who were braced. Regression rate ranged from 16.7% to 100%. We found evidence that bracing is effective in achieving curve regression among compliant AIS patients eligible for bracing, i.e. curves of 25° to 40°. A similar effect was also found in patients with major curve sizes ranging from 40° to 60° when combined with scoliosis-specific exercises. There was also evidence showing that a low apical vertebral body height ratio, in-brace correction, smaller pre-brace Cobb angle, and daily pattern of brace-wear compliance predict curve regression after bracing. Conclusion: Bracing provides a corrective effect on scoliotic curves of AIS patients to achieve curve regression, given there is high compliance rate and the incorporation of exercises.

Cross-Cultural Adaptation and Psychometric Properties of the Traditional Chinese Version of the Italian Spine Youth Quality of Life (ISYQOL) Questionnaire.

The Italian Spine Youth Quality of Life (ISYQOL) is a validated health-related quality of life (HRQOL) questionnaire for teenagers with adolescent idiopathic scoliosis (AIS). We culturally-adapted ISYQOL to traditional Chinese (ISYQOL-TC) and then recruited 133 conservatively treated teenagers with AIS to complete the ISYQOL-TC and the Chinese version of the Scoliosis Research Society-22 revised (SRS-22r) questionnaire, nine-item Patient Health Questionnaire (PHQ-9), seven-item Generalized Anxiety Disorder scale (GAD-7), and numeric pain rating scale (NPRS). They repeated ISYQOL-TC two weeks later. The internal consistency, unidimensionality, and test-retest reliability were measured using the Cronbach's alpha, Rasch measurement models, and intra-class correlation coefficients (ICC3,1), respectively. The concurrent validity of the ISYQOL-TC with SRS-22r, and its construct validity with other questionnaires were evaluated using Spearman correlation coefficients. The ISYQOL-TC demonstrated good internal consistency (Cronbach's alpha 0.90 and 0.89 for items 1-13 and items 1-20), and excellent test-retest reliability (ICC3,1 = 0.95-0.96). The Rasch analysis supported the unidimensionality of all 20 items in ISYQOL-TC. The ISYQOL-TC percentage scores were positively correlated with SRS-22r total scores (r = 0.65; p < 0.05), but were negatively related to PHQ-9, GAD-7, and NPRS scores (r = -0.46 to -0.39; p < 0.01). Collectively, the ISYQOL-TC is a reliable and valid instrument for evaluating HRQOL in Chinese teenagers with AIS.

Predicting Progression in Adolescent Idiopathic Scoliosis at the First Visit by Integrating 2D Imaging and 1D Clinical Information.

STUDY DESIGN: Retrospective observational study. OBJECTIVES: The prediction of curve progression in patients with adolescent idiopathic scoliosis (AIS) remains an unresolved area in orthopedic surgery. To make a rapid meaningful prediction, easily accessible multi-dimensional data at the patient's first consultation should be used. Current studies use clinical growth parameters and numerical values extracted from radiographs to compile a predictive model, leaving out the radiographs themselves. Such practice inevitably wastes a lot of information. Thus, this study aims to create a neural network that can predict AIS progression among patients with curves indicated for bracing by integrating both one-dimensional (1D) clinical and two-dimensional (2D) radiological data collected at the patient's first visit in a fully automated manner. METHODS: 513 idiopathic scoliosis patients indicated for and managed with bracing orthosis were recruited. After exclusion, 463 patients were included in deep learning analysis. Processed first-visit growth parameters and posteroanterior radiographs are used as training inputs and the curve progression outcomes obtained in follow ups are used as binary training outputs. The CapsuleNet architecture was modified and trained accordingly to make a prediction. RESULTS: The final model achieved 90% sensitivity with an overall accuracy of 73.9% in the prediction of AIS in-brace curve progression by using first-visit multi-dimensional data, outperforming conventional convolutional neural networks. CONCLUSIONS: This first-ever multidimensional-input model shows promise in serving as a screening tool for AIS in-brace curve progression. The incorporation of such a model into routine AIS diagnostic pipeline can assist orthopedics clinicians in personalizing the most appropriate management for each patient.

Supine correction index as a predictor for brace outcome in adolescent idiopathic scoliosis.

AIMS: The aim of this study was to assess the ability of morphological spinal parameters to predict the outcome of bracing in patients with adolescent idiopathic scoliosis (AIS) and to establish a novel supine correction index (SCI) for guiding bracing treatment. METHODS: Patients with AIS to be treated by bracing were prospectively recruited between December 2016 and 2018, and were followed until brace removal. In all, 207 patients with a mean age at recruitment of 12.8 years (SD 1.2) were enrolled. Cobb angles, supine flexibility, and the rate of in-brace correction were measured and used to predict curve progression at the end of follow-up. The SCI was defined as the ratio between correction rate and flexibility. Receiver operating characteristic (ROC) curve analysis was carried out to assess the optimal thresholds for flexibility, correction rate, and SCI in predicting a higher risk of progression, defined by a change in Cobb angle of ≥ 5° or the need for surgery. RESULTS: The baseline Cobb angles were similar (p = 0.374) in patients whose curves progressed (32.7° (SD 10.7)) and in those whose curves remained stable (31.4° (SD 6.1)). High supine flexibility (odds ratio (OR) 0.947 (95% CI 0.910 to 0.984); p = 0.006) and correction rate (OR 0.926 (95% CI 0.890 to 0.964); p < 0.001) predicted a lower incidence of progression after adjusting for Cobb angle, Risser sign, curve type, menarche status, distal radius and ulna grading, and brace compliance. ROC curve analysis identified a cut-off of 18.1% for flexibility (sensitivity 0.682, specificity 0.704) and a cut-off of 28.8% for correction rate (sensitivity 0.773, specificity 0.691) in predicting a lower risk of curve progression. A SCI of greater than 1.21 predicted a lower risk of progression (OR 0.4 (95% CI 0.251 to 0.955); sensitivity 0.583, specificity 0.591; p = 0.036). CONCLUSION: A higher supine flexibility (18.1%) and correction rate (28.8%), and a SCI of greater than 1.21 predicted a lower risk of progression. These novel parameters can be used as a guide to optimize the outcome of bracing. Cite this article: Bone Joint J 2022;104-B(4):495-503.

Curve type, flexibility, correction, and rotation are predictors of curve progression in patients with adolescent idiopathic scoliosis undergoing conservative treatment : a systematic review.

AIMS: The aim of this study was to review the current evidence surrounding curve type and morphology on curve progression risk in adolescent idiopathic scoliosis (AIS). METHODS: A comprehensive search was conducted by two independent reviewers on PubMed, Embase, Medline, and Web of Science to obtain all published information on morphological predictors of AIS progression. Search items included 'adolescent idiopathic scoliosis', 'progression', and 'imaging'. The inclusion and exclusion criteria were carefully defined. Risk of bias of studies was assessed with the Quality in Prognostic Studies tool, and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) approach. In all, 6,286 publications were identified with 3,598 being subjected to secondary scrutiny. Ultimately, 26 publications (25 datasets) were included in this review. RESULTS: For unbraced patients, high and moderate evidence was found for Cobb angle and curve type as predictors, respectively. Initial Cobb angle > 25° and thoracic curves were predictive of curve progression. For braced patients, flexibility < 28% and limited in-brace correction were factors predictive of progression with high and moderate evidence, respectively. Thoracic curves, high apical vertebral rotation, large rib vertebra angle difference, small rib vertebra angle on the convex side, and low pelvic tilt had weak evidence as predictors of curve progression. CONCLUSION: For curve progression, strong and consistent evidence is found for Cobb angle, curve type, flexibility, and correction rate. Cobb angle > 25° and flexibility < 28% are found to be important thresholds to guide clinical prognostication. Despite the low evidence, apical vertebral rotation, rib morphology, and pelvic tilt may be promising factors. Cite this article: Bone Joint J 2022;104-B(4):424-432.

Oral Zoledronic acid bisphosphonate for the treatment of chronic low back pain with associated Modic changes: A pilot randomized controlled trial.

To assess the safety and efficacy of oral 50 mg Zoledronic acid (ZA) bisphosphate once-a-week for 6-weeks to placebo among patients with chronic low back pain (cLBP) and Modic changes (MC) on MRI. A parallel, double-blinded randomized controlled study was performed at a single center, consisted of 25 subjects with cLBP and MC that received ZA (n = 13) or placebo (n = 12). Evaluation was at baseline, 2-weeks, 4-weeks, 3-months and 6-months for assessment of LBP/leg pain intensity, disability (Oswestry-Disability-Index: ODI), health-related quality-of-life (RAND-36), and mental component summary scores (MCS). Type 2 MC at baseline (56%) were prevalent. In the ZA group, LBP intensity was lower at 4-weeks in comparison to placebo (5.1 ± 1.9 vs. 6.9 ± 1.8, p = 0.038) (minimal clinically important difference [MCID] = 1.5). LBP intensity reduced at 4-weeks and 3-months in the ZA-treated group in comparison to baseline. Although there was no difference in ODI, subscale RAND-36 metrics for physical function (p = 0.038), energy/fatigue (p = 0.040) and pain (p = 0.003) were improved at 3-months compared to placebo, with moderate significant difference for pain at 6-months (p = 0.051). Correlated MCS scores to baseline also improved at 3-months (p = 0.035) and 6-months (p = 0.028) by 6.9 and 6.8, respectively, (MCID = 3.8). A reduction in MC endplate affected area at 6-month follow-up was noted in the ZA group (-0.67 ± 0.69 cm2 ), while in the placebo group no change in size was observed (0.0 ± 0.15; p = 0.041). Three subjects withdrew from the study and no long-lasting adverse events. Oral ZA was a safe and effective treatment that reduced MC volume, improved LBP symptoms and quality-of-life measures in cLBP subjects with MCs.

Identification of Copy Number Variants in a Southern Chinese Cohort of Patients with Congenital Scoliosis.

Congenital scoliosis (CS) is a lateral curvature of the spine resulting from congenital vertebral malformations (CVMs) and affects 0.5-1/1000 live births. The copy number variant (CNV) at chromosome 16p11.2 has been implicated in CVMs and recent studies identified a compound heterozygosity of 16p11.2 microdeletion and TBX6 variant/haplotype causing CS in multiple cohorts, which explains about 5-10% of the affected cases. Here, we studied the genetic etiology of CS by analyzing CNVs in a cohort of 67 patients with congenital hemivertebrae and 125 family controls. We employed both candidate gene and family-based approaches to filter CNVs called from whole exome sequencing data. This identified 12 CNVs in four scoliosis-associated genes (TBX6, NOTCH2, DSCAM, and SNTG1) as well as eight recessive and 64 novel rare CNVs in 15 additional genes. Some candidates, such as DHX40, NBPF20, RASA2, and MYSM1, have been found to be associated with syndromes with scoliosis or implicated in bone/spine development. In particular, the MYSM1 mutant mouse showed spinal deformities. Our findings suggest that, in addition to the 16p11.2 microdeletion, other CNVs are potentially important in predisposing to CS.

Impact of sleep duration, physical activity, and screen time on health-related quality of life in children and adolescents.

BACKGROUND: Existing studies on health-related quality of life (HRQoL) mainly covered single growth stages of childhood or adolescence and did not report on the trends in the relationships of HRQoL with sleep duration, physical activity, and screen time. This study aimed to establish the population norm of HRQoL in children and adolescents aged 6-17 years and examine the associations of screen time, sleep duration, and physical activity with HRQoL in this population. METHODS: We conducted a large-scale cross-sectional population-based survey study of Hong Kong children and adolescents aged 6 to 17 years. A representative sample of students were interviewed to assess their HRQoL using PedsQL and EQ-5D-Y-5L. Multivariable homoscedastic Tobit regression with linear form or restricted cubic spline of predictors was used to analyze the associations between screen time, sleep duration, and HRQoL. Multiple imputation by chained equations was performed to deal with missing data. RESULTS: A total of 7555 respondents (mean age 11.5, SD 3.2; 55.1% female) were sampled. Their EQ VAS scores, PedsQL physical summary scores, and psychosocial summary scores were positively correlated with sleep duration and moderate/vigorous activity but was negatively correlated with screen time. CONCLUSIONS: Children and adolescents who had longer exposure to screen, shorter sleep duration, and lower physical activity levels appeared to have poorer HRQoL as assessed by PedsQL and EQ-5D-Y-5L. Advice and guidance on screen time allocation for children and adolescents should be provided at the levels of school, community, and family.

Pedigree analysis of lumbar developmental spinal stenosis: Determination of potential inheritance patterns.

Lumbar developmental spinal stenosis (DSS) refers to multilevel pre-existing narrowed spinal canals, which predispose to neural compromise. The objective of this study is to identify any inheritance pattern of DSS by utilizing pedigree charts. This was a case series of 13 families with a total of 80 subjects having magnetic resonance imaging (MRI) from L1 to S1. Cases (subjects with DSS) or controls (subjects without DSS) were identified by measuring their anteroposterior (AP) vertebral canal diameters. Multilevel model analyses were also performed to evaluate whether there is substantial clustering of observations within the families, and the effect of multilevel DSS. The intraclass correlation coefficient (ICC) and Akaike information criteria (AIC) were compared between models. Correlations between subject demographics and AP vertebral canal diameter were statistically insignificant at all levels. Only vertebral canal cross-sectional area, and axial and sagittal vertebral canal diameter were found to be statistically different between cases and controls at all levels (all p < .05). Both males and females were affected by DSS and there was no skipping of generation, which highly suggested DSS followed an autosomal dominant inheritance pattern. After accounting for multilevel DSS, there was a drop of more than 10 in AIC and some variances were also explained within families. This is the first study that suggests multilevel lumbar DSS to have an autosomal dominant inheritance pattern. Within families with a background of DSS, subjects had a smaller canal size, contributed by shortened axial and sagittal AP vertebral canal diameter, and smaller canal cross-sectional area.

Genetic variants of TBX6 and TBXT identified in patients with congenital scoliosis in Southern China.

Congenital scoliosis (CS) is a spinal deformity present at birth due to underlying congenital vertebral malformation (CVM) that occurs during embryonic development. Hemivertebrae is the most common anomaly that causes CS. Recently, compound heterozygosity in TBX6 has been identified in Northern Chinese, Japanese, and European CS patient cohorts, which explains about 7%-10% of the affected population. In this report, we recruited 67 CS patients characterized with hemivertebrae in the Southern Chinese population and investigated the TBX6 variant and risk haplotype. We found that two patients with hemivertebrae in the thoracic spine and one patient with hemivertebrae in the lumbar spine carry the previously defined pathogenic TBX6 compound heterozygous variants. In addition, whole exome sequencing of patients with CS and their family members identified a de novo missense mutation (c.G47T: p.R16L) in another member of the T-box family, TBXT. This rare mutation compromised the binding of TBXT to its target sequence, leading to reduced transcriptional activity, and exhibited dominant-negative effect on wild-type TBXT. Our findings further highlight the importance of T-box family genes in the development of congenital scoliosis.

Predicting spondylolisthesis correction with prone traction radiographs.

AIMS: To determine the effectiveness of prone traction radiographs in predicting postoperative slip distance, slip angle, changes in disc height, and lordosis after surgery for degenerative spondylolisthesis of the lumbar spine. METHODS: A total of 63 consecutive patients with a degenerative spondylolisthesis and preoperative prone traction radiographs obtained since 2010 were studied. Slip distance, slip angle, disc height, segmental lordosis, and global lordosis (L1 to S1) were measured on preoperative lateral standing radiographs, flexion-extension lateral radiographs, prone traction lateral radiographs, and postoperative lateral standing radiographs. Patients were divided into two groups: posterolateral fusion or posterolateral fusion with interbody fusion. RESULTS: The mean changes in segmental lordosis and global lordosis were 7.1° (SD 6.7°) and 2.9° (SD 9.9°) respectively for the interbody fusion group, and 0.8° (SD 5.1°) and -0.4° (SD 10.1°) respectively for the posterolateral fusion-only group. Segmental lordosis (ρ = 0.794, p < 0.001) corrected by interbody fusion correlated best with prone traction radiographs. Global lumbar lordosis (ρ = 0.788, p < 0.001) correlated best with the interbody fusion group and preoperative lateral standing radiographs. The least difference in slip distance (-0.3 mm (SD 1.7 mm), p < 0.001), slip angle (0.9° (SD 5.2°), p < 0.001), and disc height (0.02 mm (SD 2.4 mm), p < 0.001) was seen between prone traction and postoperative radiographs. Regression analyses suggested that prone traction parameters best predicted correction of slip distance (Corrected Akaike's Information Criterion (AICc) = 37.336) and disc height (AICc = 58.096), while correction of slip angle (AICc = 26.453) was best predicted by extension radiographs. Receiver operating characteristic (ROC) cut-off showed, with 68.3% sensitivity and 64.5% specificity, that to achieve a 3.0° increase in segmental lordotic angle, patients with a prone traction disc height of 8.5 mm needed an interbody fusion. CONCLUSION: Prone traction radiographs best predict the slip distance and disc height correction achieved by interbody fusion for lumbar degenerative spondylolisthesis. To achieve this maximum correction, interbody fusion should be undertaken if a disc height of more than 8.5 mm is attained on preoperative prone traction radiographs. Level of Evidence: Level II Prognostic Study Cite this article: Bone Joint J 2020;102-B(8):1062-1071.

Comparative study of the use of Paediatric Quality Of Life Inventory 4.0 generic core scales in paediatric patients with spine and limb pathologies.

AIMS: The health-related quality of life (HRQoL) of paediatric patients with orthopaedic conditions and spinal deformity is important, but existing generic tools have their shortcomings. We aim to evaluate the use of Paediatric Quality of Life Inventory (PedsQL) 4.0 generic core scales in the paediatric population with specific comparisons between those with spinal and limb pathologies, and to explore the feasibility of using PedsQL for studying scoliosis patients' HRQoL. METHODS: Paediatric patients attending a speciality outpatient clinic were recruited through consecutive sampling. Two groups of patients were included: idiopathic scoliosis, and paediatric orthopaedic upper and lower limb condition without scoliosis. Patients were asked to complete PedsQL 4.0 generic core scales, Youth version of 5-level EuroQol-5-dimension questionnaire, and Refined Scoliosis Research Society 22-item (SRS-22r) questionnaire. Statistical analyses included scores comparison between scoliosis and limb pathology patients using independent-samples t-test, and correlation tests of PedsQL and SRS-22r. RESULTS: A total of 566 paediatric patients were recruited: 357 (63.0%) having idiopathic scoliosis, and 209 (37.0%) with limb conditions. Patients with limb pathology had lower functioning scale, summary, and total scores of PedsQL than scoliosis patients (p < 0.05 to p < 0.001). No floor or ceiling effects (< 15%) were detected for PedsQL Psychosocial Health Summary and total scores in both groups. PedsQL was sensitive in differentiating patients with/without problems in their daily lives (p < 0.05 to p < 0.01). PedsQL summary and total scores correlated with SRS-22r total score. CONCLUSION: PedsQL is an effective HRQoL measure for both paediatric orthopaedic groups with minimal ceiling and floor effects, and is capable of detecting worse HRQoL in patients with limb pathology. The multidimensional PedsQL is sensitive in differentiating among those with daily life problems, especially for scoliosis patients. Cite this article: Bone Joint J 2020;102-B(7):890-898.

Supine flexibility predicts curve progression for patients with adolescent idiopathic scoliosis undergoing underarm bracing.

AIMS: The aim of this study was to assess whether supine flexibility predicts the likelihood of curve progression in patients with adolescent idiopathic scoliosis (AIS) undergoing brace treatment. METHODS: This was a retrospective analysis of patients with AIS prescribed with an underarm brace between September 2008 to April 2013 and followed up until 18 years of age or required surgery. Patients with structural proximal curves that preclude underarm bracing, those who were lost to follow-up, and those who had poor compliance to bracing (<16 hours a day) were excluded. The major curve Cobb angle, curve type, and location were measured on the pre-brace standing posteroanterior (PA) radiograph, supine whole spine radiograph, initial in-brace standing PA radiograph, and the post-brace weaning standing PA radiograph. Validation of the previous in-brace Cobb angle regression model was performed. The outcome of curve progression post-bracing was tested using a logistic regression model. The supine flexibility cut-off for curve progression was analyzed with receiver operating characteristic curve. RESULTS: A total of 586 patients with mean age of 12.6 years (SD 1.2) remained for analysis after exclusion. The baseline Cobb angle was similar for thoracic major curves (31.6° (SD 3.8°)) and lumbar major curves (30.3° (SD 3.7°)). Curve progression was more common in the thoracic curves than lumbar curves with mean final Cobb angles of 40.5° (SD 12.5°) and 31.8° (SD 9.8°) respectively. This dataset matched the prediction model for in-brace Cobb angle with less mean absolute error in thoracic curves (0.61) as compared to lumbar curves (1.04). Reduced age and Risser stage, thoracic curves, increased pre-brace Cobb angle, and reduced correction and flexibility rates predicted increased likelihood of curve progression. Flexibility rate of more than 28% has likelihood of preventing curve progression with bracing. CONCLUSION: Supine radiographs provide satisfactory prediction for in-brace correction and post-bracing curve magnitude. The flexibility of the curve is a guide to determine the likelihood for brace success. Cite this article: Bone Joint J 2020;102-B(2):254-260.

Underarm bracing for adolescent idiopathic scoliosis leads to flatback deformity: the role of sagittal spinopelvic parameters.

AIMS: The aim of this study was to determine the influence of pelvic parameters on the tendency of patients with adolescent idiopathic scoliosis (AIS) to develop flatback deformity (thoracic hypokyphosis and lumbar hypolordosis) and its effect on quality-of-life outcomes. PATIENTS AND METHODS: This was a radiological study of 265 patients recruited for Boston bracing between December 2008 and December 2013. Posteroanterior and lateral radiographs were obtained before, immediately after, and two-years after completion of bracing. Measurements of coronal and sagittal Cobb angles, coronal balance, sagittal vertical axis, and pelvic parameters were made. The refined 22-item Scoliosis Research Society (SRS-22r) questionnaire was recorded. Association between independent factors and outcomes of postbracing ≥ 6° kyphotic changes in the thoracic spine and ≥ 6° lordotic changes in the lumbar spine were tested using likelihood ratio chi-squared test and univariable logistic regression. Multivariable logistic regression models were then generated for both outcomes with odds ratios (ORs), and with SRS-22r scores. RESULTS: Reduced T5-12 kyphosis (mean -4.3° (sd 8.2); p < 0.001), maximum thoracic kyphosis (mean -4.3° (sd 9.3); p < 0.001), and lumbar lordosis (mean -5.6° (sd 12.0); p < 0.001) were observed after bracing treatment. Increasing prebrace maximum kyphosis (OR 1.133) and lumbar lordosis (OR 0.92) was associated with postbracing hypokyphotic change. Prebrace sagittal vertical axis (OR 0.975), prebrace sacral slope (OR 1.127), prebrace pelvic tilt (OR 0.940), and change in maximum thoracic kyphosis (OR 0.878) were predictors for lumbar hypolordotic changes. There were no relationships between coronal deformity, thoracic kyphosis, or lumbar lordosis with SRS-22r scores. CONCLUSION: Brace treatment leads to flatback deformity with thoracic hypokyphosis and lumbar hypolordosis. Changes in the thoracic spine are associated with similar changes in the lumbar spine. Increased sacral slope, reduced pelvic tilt, and pelvic incidence are associated with reduced lordosis in the lumbar spine after bracing. Nevertheless, these sagittal parameter changes do not appear to be associated with worse quality of life. Cite this article: Bone Joint J 2019;101-B:1370-1378.

Novel compression rat model for developmental spinal stenosis.

Developmental spinal stenosis (DSS) is characterized by pre-existing circumferential narrowing of the bony spinal canal which predisposes neural tissue to compression. This study aims to create a reproducible animal model mimicking DSS for investigation of its pathoanatomy. Developmental spinal canal constriction was simulated using circumferential compression. Eighteen female Sprague-Dawley rats (13.0-14.5 weeks-old) underwent circumferential compression at L4-L5 using silicone sheets; or dorsal compression using overlapping silicone sheets; or as controls. A series of outcome scores were used for locomotor function assessment, together with electrophysiological and histological assessment. Assessment time-points were at preoperative, postoperative 1-week, 2-weeks, 3-weeks, 1-month, and pre-sacrifice. Statistical analyses were performed. At all postoperative time-points, circumferential group had the worst mean Basso, Beattie and Bresnahan locomotor scores with significant difference from the control group (p < 0.05), as well as the lowest mean Louisville Swim Scale scores, as compared to the dorsal (p < 0.05) and to the control (p < 0.01) groups. Circumferential group had worse mean foot fault score for both hindlimbs (p < 0.01 to p < 0.05) and highest error rate in foot placement accuracy, especially higher than dorsal (p < 0.05) and control (p < 0.05) groups at pre-sacrifice. Electrophysiological assessment revealed postoperative increase in P1 latency was higher in circumferential than dorsal compression. Highest postoperative mean P1 latency was observed for both paws at all postoperative time-points for circumferential group (except at postoperative 1-week). Circumferential group had lower myelin-to-axonal area ratio and higher g-ratio than both the dorsal and control groups (p < 0.001). For each study group, hindlimb P1 latency and P1-N1 amplitude were each correlated with g-ratio (p < 0.05); and mean myelin-to-axonal area ratio correlated with P1 latency of both hindlimbs (p < 0.05). Based on these more severe axonal demyelination and neurological deficits, a valid DSS rat model is created with somatosensory evoked potential neuro-monitoring technique. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.

How Common Is Back Pain and What Biopsychosocial Factors Are Associated With Back Pain in Patients With Adolescent Idiopathic Scoliosis?

BACKGROUND: Adolescent idiopathic scoliosis (AIS) is the most common spine deformity in adolescent patients. Although structural deformity may affect spinal biomechanics of patients with AIS, little is known regarding various period prevalence proportions of back pain and chronic back pain and factors associated with back pain in such patients. QUESTIONS/PURPOSES: (1) What are the period prevalence rates of back pain among teenagers with AIS? (2) Is back pain in patients with AIS associated with curve severity? METHODS: A total of 987 patients with AIS who were treated without surgery were recruited from a single center's scoliosis clinic. Between December 2016 and July 2017, this center treated 1116 patients with suspected AIS. During that time, patients were offered surgery when their Cobb angle was at least 50° and had evidence of curve progression between two visits, and most of the patients who were offered surgery underwent it; other patients with AIS were managed nonsurgically with regular observation, brace prescription, posture training, and reassurance. To be included in this prospective, cross-sectional study, a patient needed to be aged between 10 and 18 years with a Cobb angle > 10°. No followup data were required. A total of 1097 patients with AIS were managed nonsurgically (98.3% of the group seen during the period in question). After obtaining parental consent, patients provided data related to their demographics; physical activity levels; lifetime, 12-month, 30-day, 7-day, and current thoracic pain and low back pain (LBP); chronic back pain (thoracic pain/LBP); brace use; and treatments for scoliosis/back pain. Pain was rated on a 10-point numeric rating scale for pain. The Insomnia Severity Index, Epworth Sleepiness Scale, and Depression Anxiety Stress Scales were also assessed. These features and radiologic study parameters between patients with and without back pain were also compared. Factors associated with current and 12-month back pain as well as chronic back pain were analyzed by multivariate analyses. RESULTS: Depending on the types of period prevalence, the prevalence of thoracic pain ranged from 6% (55 of 987) within 12 months to 14% (139 of 987) within 7 days, whereas that of LBP ranged from 6% (54 of 987) to 29% (289 of 987). Specifically, chronic thoracic pain or LBP had the lowest prevalence. Compared with the no pain group, patients with current back pain had more severe insomnia (odds ratio [OR], 1.80; p = 0.02; 95% confidence interval [CI], 1.10-2.93) and daytime sleepiness (OR, 2.41; p < 0.001, 95% CI, 1.43-4.07). Those with chronic back pain had the same problems along with moderate depression (OR, 2.49; p = 0.03; 95% CI, 1.08-5.71). Older age (OR range, 1.17-1.42; all p values ≤ 0.030) and Cobb angle > 40° (OR range, 2.38-3.74; all p values ≤ 0.015), daytime sleepiness (OR range, 2.39-2.41; all p values ≤ 0.011), and insomnia (OR range, 1.76-2.31; all p values ≤ 0.001) were associated with episodic and/or chronic back pain. Females were more likely to experience back pain in the last 12 months than males. Moderate depression (OR, 3.29; 1.45-7.47; p = 0.004) and wearing a brace (OR, 3.00; 1.47-6.15; p = 0.003) were independently associated with chronic back pain. CONCLUSIONS: Biopsychosocial factors are associated with the presence and severity of back pain in the AIS population. Our results highlight the importance of considering back pain screening/management for patients with AIS with their psychosocial profile in addition to curve magnitude monitoring. In particular, sleep quality should be routinely assessed. Longitudinal changes and effects of psychotherapy should be determined in future studies. LEVEL OF EVIDENCE: Level II, prognostic study.

Learning Curve in Monitoring Magnetically Controlled Growing Rod Distractions With Ultrasound.

STUDY DESIGN: Prospective study. OBJECTIVE: To determine whether a learning curve exists for ultrasound measurement of magnetically controlled growing rod (MCGR) distractions. SUMMARY OF BACKGROUND DATA: For patients managed by MCGRs, close monitoring of interval distraction length gains is important to determine whether the distractions are translating into actual spine growth. Radiographs are the criterion standard for measuring length gains, but ultrasound has been shown to be effective in monitoring distraction lengths without radiation exposure. It is, however, an operator-dependent tool and thus the accuracy of ultrasound measurement of distracted length may improve with experience. METHODS: This is a prospective correlation analysis of patients who underwent MCGR treatment for scoliosis. The study period was inclusive of 19th February 2013 to 31st March 2015. All subjects were consecutively recruited in a prospective manner. Data regarding date of the distraction visit, and the interval radiograph and ultrasound measurements of the distracted lengths were collected. Only those episodes with both radiograph and ultrasound performed were used for analysis. The mean differences in change of radiograph and ultrasound measurements were plotted to determine correlation differences and to observe for a learning curve. RESULTS: A total of 379 distraction episodes were analyzed. The mean differences between ultrasound and radiograph measurements per distraction episode were -0.3 mm for the right rod and -0.1 mm for the left rod. For learning curve analysis, there were three distinct timepoints in which the difference of correlation became significantly better and were described as clusters. The correlation in the first cluster (19th February 2013 to 15th October 2013) was 0.612 (right rod) and 0.795 (left rod), the second cluster (16th October 2013 to 20th May 2014) was 0.879 (right rod) and 0.918 (left rod), and the third cluster (21st May 2014 to 31st March 2015) was 0.956 (right rod) and 0.932 (left rod). Thus, a plateau was observed at the second cluster, which translated to 97 to 146 rod measurements. CONCLUSION: Correlation between radiograph and ultrasound measurements is reasonable to begin with but improves with time. During initial use, successful distractions should correlate between the clinical feel and ultrasound confirmation. Although the absolute value may not be accurate and may require radiographs to confirm, with time and experience, ultrasound measurements can then be more reliable. LEVEL OF EVIDENCE: 3.