OBJECTIVE: To define the risk of curve progression of idiopathic scoliosis (IS) to 35°, 40°, 45°, and 50° based on current curve magnitude and Sanders stage for boys and girls, using a large cohort of patients and encounters, to improve granularity and allow more accurate estimations to guide treatment.
METHODS: Retrospective analysis of a prospectively collected scoliosis database. Generalized estimation equation logistic regression models estimated probabilities of curve progression to 35°, 40°, 45°, and 50° based on starting curve size and Sanders stage. Probabilities and their 95% confidence intervals were calculated for each combination of variables to each endpoint separately for boys and girls.
RESULTS: A total of 309 patients (80% girls) were included. Starting curve size and Sanders stage were significant predictors for progression in both sexes (all P ≤ 0.04). Higher starting curve sizes and lower Sanders stages were associated with greater odds of progression. Risk of progression was still present even at higher Sanders stages.
CONCLUSIONS: IS curves follow a predictable pattern, having more risk for progression when curves are larger and Sanders stages are smaller. Risk of curve progression is a spectrum based on these factors, indicating some risk of progression exists even for many smaller curves with higher Sanders stages. The improved granularity of this analysis compared to prior efforts may be useful for counseling patients about the risks of curve progression to various curve size endpoints and may aid shared decision-making regarding treatments.
UNASSIGNED: Level III: retrospective cohort study.

Background: The progression of scoliosis has been observed in skeletally mature patients with cerebral palsy (CP). The aims of this systematic review were to determine the incidence of curve progression of untreated scoliosis after skeletal maturity, to estimate the average annual increase and to identify factors that influence the progression. Methods: A systematic literature search was performed in PubMed, Embase and the Cochrane Library for original research articles published between 1968 and May 2024 with a retrospective, prospective or cross-sectional design, investigating CP patients that were followed up beyond the age of 15 years. The search was limited to articles in English, French, German and Dutch. Articles were excluded if the study population concerned neuromuscular diseases other than CP. After an assessment of the methodological quality of each study, estimates of annual curve progression and the effect of the investigated risk factors for progression were recorded systematically and synthetized. Results: Fifteen studies met the inclusion criteria, resulting in a total sample size of 2569 participants. The study populations of the included original research articles were small and heterogeneous in terms of patient age and the type and severity of CP. Curve progression after skeletal maturity occurred in all included studies. A greater curve magnitude at the end of adolescence and a severe motor deficit (an inability to walk or GMFCS IV-V) were identified as significant risk factors for the progression of scoliosis after skeletal maturity. If at least one of these risk factors was present, scoliotic curves progressed after skeletal maturity in up to 74% of patients, with an average annual increase of 1.4 to 3.5 degrees per year. No significant association was found between curve progression and the physiologic type of CP, the type of scoliotic curve, previous hip surgery, positioning and gravity, weight and length, sex, epilepsy, or pelvic obliquity. Findings on the effect of hip instability were inconsistent: a positive correlation was found with the progression of scoliosis overall, but not after skeletal maturity in particular. A significant selection bias should be considered in the calculation of average annual curve progression, as patients that received interventions to halt curve progression were excluded from follow-up. Conclusions: The identification of risk factors in patients with CP and scoliosis can aid in predicting curve progression and managing follow-ups in clinical practice. Based on the findings in this review a radiographic follow-up once every 3 years is recommended for skeletally mature CP patients with at least one risk factor, and once every 5 years if no risk factors are present.

BACKGROUND: Prior reviews investigating the impact of pregnancy on adolescent idiopathic scoliosis (AIS) have reached different conclusions and a meta-analysis of curve progression among pregnant females with AIS and its effects on clinical outcomes has not previously been performed.
METHODS: A comprehensive search of major bibliographic databases (PubMed, Embase, and Scopus) was conducted for articles pertaining to spinal curve progression during pregnancy among patients with AIS. Patient demographics, scoliotic curve outcomes, and patient-reported quality of life measures were extracted.
RESULTS: Ten studies, including 857 patients with a mean age of 28.7 years, were included. Before pregnancy, 42.1% had undergone spinal fusion and 59.0% had a thoracic curve. Based on pre-pregnancy and post-pregnancy radiographs, the curve increased from 33.9° to 38.5° and meta-analysis revealed a curve progression of 3.6° (range=-5.85--1.25, p=0.003), primarily arising from loss of correction in the unfused group (Unfused=-5.0, p=0.040; Fused=-3.0, p=0.070). At the same time, 45.9% patients reported increased low back pain and many reported a negative body self-image and limitations in sexual function. However, five studies noted that pregnancy and number of pregnancies were not associated with curve progression, and multiple studies identified similar quality of life-related changes in non-pregnant patients with AIS.
CONCLUSIONS: Among unfused pregnant females with AIS, the spinal curvature increased significantly by 5.0° from before to after pregnancy. However, these changes may be independent of pregnancy status and occur with time. Such curve progression can contribute to a negative body self-image, low back pain, and functional limitations irrespective of pregnancy state.

Accurate prediction of scoliotic curve progression is crucial for guiding treatment decisions in adolescent idiopathic scoliosis (AIS). Traditional methods of assessing the likelihood of AIS progression are limited by variability and rely on static measurements. This study developed and validated machine learning models for classifying progressive and non-progressive scoliotic curves based on gait analysis using wearable inertial sensors. Gait data from 38 AIS patients were collected using seven inertial measurement unit (IMU) sensors, and hip-knee (HK) cyclograms representing inter-joint coordination were generated. Various machine learning algorithms, including support vector machine (SVM), random forest (RF), and novel deep convolutional neural network (DCNN) models utilizing multi-plane HK cyclograms, were developed and evaluated using 10-fold cross-validation. The DCNN model incorporating multi-plane HK cyclograms and clinical factors achieved an accuracy of 92% in predicting curve progression, outperforming SVM (55% accuracy) and RF (52% accuracy) models using handcrafted gait features. Gradient-based class activation mapping revealed that the DCNN model focused on the swing phase of the gait cycle to make predictions. This study demonstrates the potential of deep learning techniques, and DCNNs in particular, in accurately classifying scoliotic curve progression using gait data from wearable IMU sensors.

Low bone mineral density and impaired bone quality have been shown to be important prognostic factors for curve progression in adolescent idiopathic scoliosis (AIS). There is no evidence-based integrative interpretation method to analyze high-resolution peripheral quantitative computed tomography (HR-pQCT) data in AIS. This study aimed to (1) utilize unsupervised machine learning to cluster bone microarchitecture phenotypes on HR-pQCT parameters in girls with AIS, (2) assess the phenotypes\' risk of curve progression and progression to surgical threshold at skeletal maturity (primary cohort), and (3) investigate risk of curve progression in a separate cohort of girls with mild AIS whose curve severity did not reach bracing threshold at recruitment (secondary cohort). Patients were followed up prospectively for 6.22 ± 0.33 years in the primary cohort (n = 101). Three bone microarchitecture phenotypes were clustered by fuzzy C-means at time of peripubertal peak height velocity (PHV). Phenotype 1 had normal bone characteristics. Phenotype 2 was characterized by low bone volume and high cortical bone density, and phenotype 3 had low cortical and trabecular bone density and impaired trabecular microarchitecture. The difference in bone quality among the phenotypes was significant at peripubertal PHV and continued to skeletal maturity. Phenotype 3 had significantly increased risk of curve progression to surgical threshold at skeletal maturity (odd ratio [OR] = 4.88; 95% CI, 1.03-28.63). In the secondary cohort (n = 106), both phenotype 2 (adjusted OR = 5.39; 95% CI, 1.47-22.76) and phenotype 3 (adjusted OR = 3.67; 95% CI, 1.05-14.29) had increased risk of curve progression ≥6° with mean follow-up of 3.03 ± 0.16 years. In conclusion, 3 distinct bone microarchitecture phenotypes could be clustered by unsupervised machine learning on HR-pQCT-generated bone parameters at peripubertal PHV in AIS. The bone quality reflected by these phenotypes was found to have significant differentiating risk of curve progression and progression to surgical threshold at skeletal maturity in AIS.
Adolescent idiopathic scoliosis (AIS) is an abnormal spinal curvature that commonly presents during puberty growth. Evidence has shown that low bone mineral density and impaired bone quality are important risk factors for curve progression in AIS. High-resolution peripheral quantitative computed tomography (HR-pQCT) has improved our understanding of bone quality in AIS. It generates a large amount of quantitative and qualitative bone parameters from a single measurement, but the data are not easy for clinicians to interpret and analyze. This study enrolled girls with AIS and used an unsupervised machine-learning model to analyze their HR-pQCT data at the first clinic visit. The model clustered the patients into 3 bone microarchitecture phenotypes (ie, phenotype 1: normal; phenotype 2: low bone volume and high cortical bone density; and phenotype 3: low cortical and trabecular bone density and impaired trabecular microarchitecture). They were longitudinally followed up for 6 years until skeletal maturity. We observed the 3 phenotypes were persistent and phenotype 3 had a significantly increased risk of curve progression to severity that requires invasive spinal surgery (odds ratio = 4.88, p = .029). The difference in bone quality reflected by these 3 distinct phenotypes could aid clinicians to differentiate risk of curve progression and surgery at early stages of AIS.

Background: The implications of delaying surgical intervention for patients with adolescent idiopathic scoliosis (AIS) wishing to undergo vertebral body tethering (VBT) have not yet been explored. It is important to understand how these delays can impact surgical planning and patient outcomes. Methods: This was a retrospective review that analyzed all AIS patients treated between 2015 and 2021 at a single tertiary center. Time to surgery from initial surgical consultation and ultimate surgical plan were assessed. Patient characteristics, potential risk factors associated with increased curve progression, and reasons for delay were also analyzed. Results: 174 patients were evaluated and 95 were scheduled for VBT. Four patients later required a change to posterior spinal fusion (PSF) due to excessive curve progression. Patients requiring PSF were shown to have significantly longer delays than those who received VBT. Additionally, longer delays, younger age, greater curve progression, and lower skeletal maturity were correlated with significant curve progression (≥5 degrees). Conclusions: Surgical delays for AIS patients awaiting VBT may lead to significant curve progression and necessitate more invasive procedures. Patients with longer delays experienced an increased risk of needing PSF instead of VBT. Of those requiring PSF, the majority were due to insurance denials. Optimizing surgical timing and shared decision-making among patients, families, and healthcare providers are essential for achieving the best outcomes.

UNASSIGNED: (1) Compare the cross-sectional thickness (CST) and shear wave speed (SWS) of paraspinal muscles (PSM) in adolescent idiopathic scoliosis (AIS) with and without curve progression; (2) investigate the relationship between CST/SWS and radiographic characteristics in AIS with curve progression; (3) compare the CST/SWS between AIS and non-scoliosis controls.
UNASSIGNED: This cross-sectional study analyzed the CST and SWS of PSM in 48 AIS with mild to moderate curvature and 24 non-scoliosis participants. Participants with scoliosis greater than 45° of Cobb angles were excluded. The Change of Cobb angles within the last 6-months was retrieved to allocate AIS into progression and non-progression groups. The SWS and CST of multifidus; longissimus and iliocostalis of the major curve were measured using B-mode ultrasound image with an elastography mode. Discrepancies of the SWS (SWS-ratio: SWS on the convex side divided by SWS on the concave side) and CST (CST-ratio: CST on the convex side divided by CST on the concave side) at the upper/lower end and apical vertebrae were studied.
UNASSIGNED: A higher SWS at the apical vertebrae on the concave side of the major curve (multifidus: 3.9 ± 1.0 m/s vs. 3.1 ± 0.6 m/s; p < 0.01, longissimus: 3.3 ± 1.0 m/s vs. 3.0 ± 0.9 m/s; p < 0.01, iliocostalis: 2.8 ± 1.0 m/s vs. 2.5 ± 0.8 m/s; p < 0.01) was observed in AIS with curve progression. A lower SWS-ratio at apical vertebrae was detected with a greater vertebral rotation in participants with curve progression (multifidus [grade II]: 0.7 ± 0.1 vs. grade I: 0.9 ± 0.2; p = 0.03, longissimus [grade II]: 0.8 ± 0.2 vs. grade I: 1.1 ± 0.2; p < 0.01). CST was not different among the progressive, non-progressive AIS and non-scoliosis controls.
UNASSIGNED: Increased SWS of PSM without change of CST was observed on the concave side of the major curve in participants with progressive AIS.

Introduction: Bracing is one of the first-line treatment for early-onset idiopathic scoliosis (EOIS) to control curves from progression. This study aimed to explore the determinants that govern bracing effectiveness in EOIS. Methods: One hundred and eleven patients with EOIS (mean age of 8.6 ± 1.25 at diagnosis) received bracing treatment and had a final follow-up beyond skeletal maturity were identified from records between 1988 and 2021. Demographic data and clinical features of spinal curvature were obtained for correlation analyses to determine the associations between curve outcomes and clinical features. Results: Most patients were female (85.6%) and had a major curve on the left side (67%). The mean baseline Cobb angle of major curves was 21.73 ± 7.92°, with a mean Cobb angle progression of 18.05 ± 19.11°. The average bracing duration was 5.3 ± 1.9 years. Only 26 (23.4%) of them underwent surgery. The final Cobb angle and curve progression at the final follow-up with a Cobb angle of ≥50° were positively correlated with the initial Cobb angle (r = 0.206 and r = 0.313, respectively) and negatively correlated with maturity parameters. The lumbar curve type was found to correlate with a smaller final Cobb angle. Conclusions: The majority of patients had a final Cobb angle < 50°, which was considered a successful bracing outcome. The final Cobb angle correlated with the initial Cobb angle and curve types observed in EOIS.

The diagnosis of adolescent idiopathic scoliosis requires clinical and radiographic evaluation; the management options vary depending on the severity of the curve and potential for progression. Identifying predictors of scoliosis progression is crucial to avoid incorrect management; clinical and radiographic factors have been studied as potential predictors. The present study aims to review the literature on radiological indexes for the peak height velocity or curve acceleration phase to help clinicians manage treatment of patients with adolescent idiopathic scoliosis.
This systematic review was carried out in accordance with Preferential Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. The search was carried out including only peer-reviewed articles written in English that described the radiological indexes assessing skeletal maturity in patients with adolescent idiopathic scoliosis and evaluated their correlation with curve progression, expressed as peak height velocity and/or curve acceleartion phase.
Thirteen studies were included and showed promising results in terms of reliable radiological indexes. Risser staging gives a general measure of skeletal maturity, but it cannot be used as a primary index for driving the treatment of patients with adolescent idiopathic scoliosis since more reliable indexes are available.
Skeletal maturity quantification for adolescent idiopathic scoliosis has the potential to significantly modify disease management. However, idiopathic scoliosis is a complex and multifactorial disease: therefore, it is unlikely that a single index will ever be sufficient to predict its evolution. Therefore, as more adolescent idiopathic scoliosis progression-associated indexes are identified, a collective scientific effort should be made to develop a therapeutic strategy based on reliable and reproducible algorithms.

BACKGROUND: To evaluate the sex-based differences in clinical and radiological presentation of patients with degenerative lumbar scoliosis (DLS) and to explore whether the difference is helpful in investigating the etiology and progression of DLS.
METHODS: A retrospective review of 199 patients (41 males, 158 females) with DLS was included. Patient demographics including age, gender, bone mineral density were collected. Back and leg pain was assessed by visual analog scale, and general physical condition was assessed by Oswestry Disability Index. Cobb\'s angle was measured, and direction of scoliosis, position of the superior, inferior and apex vertebrae, number of vertebrae included in the scoliosis, rotation of apex vertebrae (Nash-Mo index), translation of apex vertebrae were recorded. Sagittal longitudinal axis, thoracolumbar kyphosis, lumbar lordosis (LL), pelvic incidence angle (PI), sacral slope, apex of lumbar lordosis and coronal balance distance were measured by whole spine lateral radiographs, and type of coronal imbalance was evaluated in all patients. Fat infiltration rate (FIR) of the paraspinal muscles at the vertebral apex was measured by MRI.
RESULTS: Compared to female patients, male patients showed more back and leg pain on clinical presentation and smaller Cobb angle, less parietal rotation, larger LL, smaller PI-LL and lower paravertebral muscle FIR on radiologic features.
CONCLUSIONS: Gender differences do exist in DLS patients with regard to clinical and radiological presentation, low back pain was more pronounced in male patients, and scoliosis was more severe in female patients based on this cross-sectional study.