The association of lumbar curve magnitude and spinal range of motion in adolescent idiopathic scoliosis: a cross-sectional study

The effect of spinal range of motion on functional balance, quality of life, and perception of appearance in adolescent idiopathic scoliosis after posterior spinal fusion surgery

OBJECTIVE

Spinal fusion, which is widely used in the surgical treatment of adolescent idiopathic scoliosis (AIS), limits the movements of the vertebral column. In this study, it was aimed to investigate the relationship between spinal mobility in the postoperative period with functional balance, quality of life, and perception of appearance in individuals with AIS.

METHODS

Thirty patients with AIS who underwent posterior spinal fusion surgery 1 to 3 years ago were included in the study. A universal goniometer was used to measure a spinal range of motion (ROM), functional reach test for functional balance, Scoliosis Research Society-30 (SRS-30) for quality of life, and Spinal Appearance Questionnaire (SAQ) for perception of appearance.

RESULTS

Surgical fusion length was significantly correlated with movements in the sagittal and transverse planes (r =  - 0.383-[- 0.608]; p =  < 0.001-0.037). Except for spinal left rotation, there was a significant positive correlation between functional balance level and ROM results (r = 0.374-0.523; p = 0.003-0.42). The SRS-30 total score correlated significantly with all other ROM measures except for rotations (r = 0.434-0.574; p = 0.00-0.016). SAQ total data correlated significantly with all ROM measurements (r =  - 0.553-[- 0.395]; p = 0.002-0.031).

CONCLUSIONS

In AIS, limitation of movement in the coronal, sagittal, and transverse planes is observed after fusion surgery. Spinal ROM is affected by the level of fusion performed at surgery. Postoperative spinal limitation of motion adversely affected functional balance, quality of life, and perception of appearance. We believe that comprehensive rehabilitation approaches that improve postoperative range of motion and increase functionality are important for optimal postoperative recovery.

Comparative analysis of paraspinal muscle imbalance between idiopathic scoliosis and congenital scoliosis from the transcriptome aspect

Background

Previous studies have analyzed paraspinal muscle imbalance in idiopathic scoliosis (IS) with methods including imaging, histology and electromyography. However, whether paraspinal muscle imbalance is the cause or the consequence of spinal deformities in IS remains unclear. Comparison of paraspinal muscle imbalance between IS and congenital scoliosis (CS) may shed some light on the causality of paraspinal muscle imbalance and IS. This study aimed to elucidate the generality and individuality of paraspinal muscle imbalance between IS and CS from gene expression.

Methods

Five pairs of surgical-treated IS and CS patients were matched. Bilateral paraspinal muscles at the apex were collected for transcriptome sequencing. Differentially expressed genes (DEGs) between the convexity and concavity in both IS and CS were identified. Comparison of DEGs between IS and CS was conducted to discriminate IS-specific DEGs from DEGs shared by both IS and CS. Bioinformatics analysis was performed. The top 10 hub genes in the protein-protein interaction (PPI) network of IS-specific DEGs were validated by quantitative PCR (qPCR) in 10 pairs of IS and CS patients.

Results

A total of 370 DEGs were identified in IS, whereas 380 DEGs were identified in CS. Comparison of DEGs between IS and CS identified 59 DEGs shared by IS and CS, along with 311 DEGs specific for IS. These IS-specific DEGs were enriched in response to external stimulus and signaling receptor binding in GO terms and calcium signaling pathway in KEGG pathways. The top 10 hub genes in the PPI network of IS-specific DEGs include BDKRB1, PRH1-TAS2R14, CNR2, NPY4R, HTR1E, CXCL3, ICAM1, ALB, ADIPOQ, and GCGR. Among these hub genes, the asymmetrical expression of PRH1-TAS2R14 and ADIPOQ in IS but not CS were validated by qPCR.

Conclusions

Transcriptomic differences in bilateral paraspinal muscles between the convexity and concavity in IS share few similarities with those in CS.

Scoliosis Without Fusion and Increased Risk of Early Medical and Surgery-Related Complications After Total Hip Arthroplasty: A Propensity-score Analysis

INTRODUCTION

There is a paucity of literature that examines how the abnormal spinopelvic alignment of scoliosis affects outcomes after total hip arthroplasty (THA) in the absence of a lumbar fusion.

METHODS

Patients with a history of scoliosis (idiopathic, adolescent, degenerative, or juvenile) without fusion and those without a history of scoliosis who underwent primary THA were identified using a large national database. Ninety-day incidence of various medical complications, emergency department (ED) visit, and readmission and 1-year incidence of surgery-related complications and cost of care were evaluated in both the scoliosis and control cohorts. Propensity score matching was used to control for patient demographic factors and comorbidities as covariates.

RESULTS

After propensity matching, 21,992 and 219,920 patients were identified in the scoliosis and control cohorts, respectively. Patients with scoliosis were at increased risk of several 90-day medical complications, including pulmonary embolism (odds ratio [OR] 1.96; P < 0.001), deep vein thrombosis (1.49; P < 0.001), transfusion (OR, 1.13; P < 0.001), pneumonia (OR, 1.37; P < 0.001), myocardial infarction (OR, 1.38; P = 0.008), sepsis (OR, 1.59; P < 0.001), acute anemia (OR, 1.21; P < 0.001), and urinary tract infection (OR, 1.1; P = 0.001). Patients with a history of scoliosis were at increased 1-year risk of revision (OR, 1.31; P < 0.001), periprosthetic joint infection (OR, 1.16; P = 0.0089), dislocation (OR, 1.581; P < 0.001), and aseptic loosening (OR, 1.39; P < 0.001) after THA. Patients with scoliosis without a history of fusion were more likely to return to the emergency department (OR, 1.26; P < 0.001) and be readmitted (OR, 1.78; P < 0.001) within 90 days of THA.

DISCUSSION

Patients with even a remote history of scoliosis without fusion are at increased risk of 90-day medical and surgery-related complications after hip arthroplasty. Hip and spine surgeons should collaborate in future studies to best understand how to optimize these patients for their adult reconstructive procedures.

Scoliosis school screening of 139,922 multi-ethnic children in Dali, southwestern China: A large epidemiological study

Idiopathic scoliosis (IS) primarily impacts adolescents and requires early intervention to prevent deformity. Early diagnosis and prediction of spine curvature in children could be aided by school scoliosis screening (SSS). In the Dali Bai Autonomous Prefecture, SSS, including 139,922 children from 18 ethnic groups in 8 counties ranging in age from 6 to 18, was carried out. A medical team conducted the screening with inspection, Adam's test, and angles of trunk rotation (ATR). The overall prevalence of suspected scoliosis was 2.37%, with girls (2.5%) more affected than boys (2.0%). Using penalized regression analysis of LASSO, the variable-selection process was conducted to determine the final regression model. The results showed that age, gender, height, BMI, altitude, latitude, ethnicity, and county were all influencing variables for suspected scoliosis, according to the adjusted final model of multi-factor regression analysis. These results provide substantial information and suggestions for preventative and person-centered healthcare interventions for IS.

Combined Anterior Thoracic Vertebral Body Tethering and Posterior Lumbar Tethering Results in Quicker Return to Sport and Activity Compared to Posterior Spinal Instrumented Fusion in Patients with Adolescent Idiopathic Scoliosis

STUDY DESIGN

Retrospective comparative study.

OBJECTIVE

To compare patient-reported physical activity between anterior thoracic vertebral body tethering and posterior lumbar spine tethering (ATVBT/PLST) and posterior spinal instrumentation and fusion (PSIF) with minimum 2 year follow-up.

METHODS

Consecutive skeletally immature patients with idiopathic scoliosis and a thoracic and lumbar curve magnitude ≥40° who underwent either ATVBT/PLST or PSIF from 2015-2019 were included. The primary outcome was rate of returning to sport. Secondary outcomes included ability to bend and satisfaction with sport performance as well as weeks until return to sport, school, physical education (PE) classes, and running.

RESULTS

Ten patients underwent ATVBT/PLST and 12 underwent PSIF. ATVBT/PLST patients reported significantly faster return to sport (13.5 weeks vs 27.9 weeks, P = .04), running (13.3 weeks vs 28.8 weeks, P = .02), and PE class (12.6 weeks vs 26.2 weeks, P = .04) compared to PSIF patients. ATVBT/PLST patients reported that they had to give up activities due to their ability to bend at lower rates than PSIF patients while reporting "no changes" in their ability to bend after surgery at higher rates than PSIF patients (0% vs 4% giving up activities and 70% vs 0% reporting no changes in bending ability for ATVBT/PLST and PSIF, respectively, P = .01). Compared to PSIF patients, ATVBT/PLST patients experienced less main thoracic and thoracolumbar/lumbar curve correction at most recent follow-up (thoracic: 41 ± 19% vs 69 ± 18%, P = .001; thoracolumbar/lumbar: 59 ± 25% vs 78 ± 15%, P = .02). No significant differences in the number of revision surgeries were observed between ATVBT/PLST and PSIF patients (4 (40%) and 1 (8%) for ATVBT/PLST and PSIF, respectively, P = .221).

CONCLUSIONS

ATVBT/PLST patients reported significantly faster rates of returning to sport, running, and PE. In addition, ATVBT/PLST patients were less likely to have to give up activities due to bending ability after surgery and reported no changes in their ability to bend after surgery more frequently than PSIF patients. However, the overall rate of return to the same or higher level of sport participation was high amongst both groups, with no significant difference observed between ATVBT/PLST and PSIF patients.

Radiographic and perioperative outcomes following anterior thoracic vertebral body tethering and posterior lumbar spine tethering: a pilot series

BACKGROUND AND CONTEXT

 In patients with adolescent idiopathic scoliosis (AIS) of main thoracic and lumbar spine regions, combined anterior thoracic vertebral body tethering and posterior lumbar spine tethering (ATVBT/PLST) is a novel non-fusion treatment option for growth modulation and conservation of motion.

METHODS

 Fourteen patients with AIS who underwent ATVBT/PLST with at least 2-year follow-up were included. Primary outcomes included quality of life as assessed by SRS-22 instruments, radiographic analysis, and revision operations. We secondarily reported perioperative metrics and post-operative opiate morphine equivalents (OME). Clinical success was defined as patients who achieved skeletal maturity with ≤ 30° curve magnitude of both their main thoracic and thoracolumbar/lumbar curves and who did not undergo posterior spine instrumentation and fusion (PSIF).

RESULTS

Patients had a mean age of 11.6 years (range 10-14 years), majority were girls (92%), and mean follow-up was 3.0 years (range 2-4.8 years). All patients were skeletally immature with a Risser ≤ 2. Included curves were Lenke 1C, 3C, or 6C. Mean preoperative curve magnitudes were 53° ± 8° (range 45°-65°) main thoracic and 49° ± 9° (range 40°-62°) thoracolumbar/lumbar curves. At most recent follow-up, patients had a mean main thoracic curve of 29° ± 8° (range 15°-40°) and a mean thoracolumbar/lumbar curve of 20° ± 15° (range 4°-35°). 50% required a revision operation. Cable breakage occurred in 43%, which did not always require revision. One patient progressed to thoracic fusion, but no patient underwent lumbar fusion. Patients had a mean SRS-22 outcome score of 4.2 ± 0.4.

CONCLUSIONS

ATVBT/PLST is a potential alternative to spine fusion for select immature patients with AIS at a minimum 2-year follow-up. ATVBT/PLST potentially offers motion conservation at the cost of a higher revision rate. Further study and reporting of results are necessary to refine indications and techniques, which in turn will improve outcomes of this procedure.

LEVEL OF EVIDENCE

Level IV-Case series without comparative group.

Deep Learning Model to Classify and Monitor Idiopathic Scoliosis in Adolescents Using a Single Smartphone Photograph

Importance

Adolescent idiopathic scoliosis (AIS) is the most common pediatric spinal disorder. Routine physical examinations by trained personnel are critical to diagnose severity and monitor curve progression in AIS. In the presence of concerning malformation, radiographs are necessary for diagnosis or follow-up, guiding further management, such as bracing correction for moderate malformation and spine surgery for severe malformation. If left unattended, progressive deterioration occurs in two-thirds of patients, leading to significant health concerns for growing children.

Objective

To assess the ability of an open platform application (app) using a validated deep learning model to classify AIS severity and curve type, as well as identify progression.

Design, Setting, and Participants

This diagnostic study was performed with data from radiographs and smartphone photographs of the backs of adolescent patients at spine clinics. The ScolioNets deep learning model was developed and validated in a prospective training cohort, then incorporated and tested in the AlignProCARE open platform app in 2022. Ground truths (GTs) included severity, curve type, and progression as manually annotated by 2 experienced spine specialists based on the radiographic examinations of the participants' spines. The GTs and app results were blindly compared with another 2 spine surgeons' assessments of unclothed back appearance. Data were analyzed from October 2022 to February 2023.

Exposure

Acquisitions of unclothed back photographs using a mobile app.

Main Outcomes and Measures

Outcomes of interest were classification of AIS severity and progression. Quantitative statistical analyses were performed to assess the performance of the deep learning model in classifying the deformity as well as in distinguishing progression during 6-month follow-up.

Results

The training data set consisted of 1780 patients (1295 [72.8%] female; mean [SD] age, 14.3 [3.3] years), and the prospective testing data sets consisted of 378 patients (279 [73.8%] female; mean [SD] age, 14.3 [3.8] years) and 376 follow-ups (294 [78.2%] female; mean [SD] age, 15.6 [2.9] years). The model recommended follow-up with an area under receiver operating characteristic curve (AUC) of 0.839 (95% CI, 0.789-0.882) and considering surgery with an AUC of 0.902 (95% CI, 0.859-0.936), while showing good ability to distinguish among thoracic (AUC, 0.777 [95% CI, 0.745-0.808]), thoracolumbar or lumbar (AUC, 0.760 [95% CI, 0.727-0.791]), or mixed (AUC, 0.860 [95% CI, 0.834-0.887]) curve types. For follow-ups, the model distinguished participants with or without curve progression with an AUC of 0.757 (95% CI, 0.630-0.858). Compared with both surgeons, the model could recognize severities and curve types with a higher sensitivity (eg, sensitivity for recommending follow-up: model, 84.88% [95% CI, 75.54%-91.70%]; senior surgeon, 44.19%; junior surgeon, 62.79%) and negative predictive values (NPVs; eg, NPV for recommending follow-up: model, 89.22% [95% CI, 84.25%-93.70%]; senior surgeon, 71.76%; junior surgeon, 79.35%). For distinguishing curve progression, the sensitivity and NPV were comparable with the senior surgeons (sensitivity, 63.33% [95% CI, 43.86%-80.87%] vs 77.42%; NPV, 68.57% [95% CI, 56.78%-78.37%] vs 72.00%). The junior surgeon reported an inability to identify curve types and progression by observing the unclothed back alone.

Conclusions

This diagnostic study of adolescent patients screened for AIS found that the deep learning app had the potential for out-of-hospital accessible and radiation-free management of children with scoliosis, with comparable performance as spine surgeons experienced in AIS management.

3D Surface Topographic Optical Scans Yield Highly Reliable Global Spine Range of Motion Measurements in Scoliotic and Non-Scoliotic Adolescents

Background: Adolescent idiopathic scoliosis results in three dimensional changes to a patient’s body, which may change a patient’s range of motion. Surface topography is an emerging technology to evaluate three dimensional parameters in patients with scoliosis. The goal of this paper is to introduce novel and reliable surface topographic measurements for the assessment of global coronal and sagittal range of motion of the spine in adolescents, and to determine if these measurements can distinguish between adolescents with lumbar scoliosis and those without scoliosis. Methods: This study is a retrospective cohort study of a prospectively collected registry. Using a surface topographic scanner, a finger to floor and lateral bending scans were performed on each subject. Inter- and intra-rater reliabilities were assessed for each measurement. ANOVA analysis was used to test comparative hypotheses. Results: Inter-rater reliability for lateral bending fingertip asymmetry (LBFA) and lateral bending acromia asymmetry (LBAA) displayed poor reliability, while the coronal angle asymmetry (CAA), coronal angle range of motion (CAR), forward bending finger to floor (FBFF), forward bending acromia to floor (FBAF), sagittal angle (SA), and sagittal angle normalized (SAN) demonstrated good to excellent reliability. There was a significant difference between controls and lumbar scoliosis patients for LBFA, LBAA, CAA and FBAF (p-values < 0.01). Conclusion: Surface topography yields a reliable and rapid process for measuring global spine range of motion in the coronal and sagittal planes. Using these tools, there was a significant difference in measurements between patients with lumbar scoliosis and controls. In the future, we hope to be able to assess and predict perioperative spinal mobility changes.

Impact of Physical Flexibility Changes on Respiratory Function after Posterior Spinal Fusion for Adolescent Idiopathic Scoliosis Surgery

Introduction

Corrective scoliosis surgery in patients with adolescent idiopathic scoliosis (AIS) increases thoracic volume but does not improve respiratory function (RF). This study evaluates the effect of physical flexibility (PF) improvement after scoliosis surgery on RF.

Methods

This study reviewed the records of 61 consecutive patients with AIS (56 female and 5 male; mean±standard deviation age: 14.8±2.2 years, range: 11-20 years) who had undergone posterior spinal fusion (PSF) of the thoracic curve. PF evaluated as finger-floor distance (FFD) was measured preoperatively and one year after surgery. After dividing the cohort into the PF improvement group and the PF nonimprovement group, RF changes at two years postoperative were statistically compared. Using logistic regression analysis, we evaluated the impact of a PF improvement on % forced vital capacity (%FVC) two years after surgery.

Results

The rate of patients with increased FVC, %FVC, and forced expiratory volume 1.0 second two years after surgery was 79%, 51%, and 80%, respectively. The PF improvement group exhibited a significantly higher gain in %FVC versus the PF nonimprovement group (P=0.043). Moreover, PF improvement significantly prevented a %FVC decrease (odds ratio 8.43, 95% confidence interval 1.92-59.70; P<0.001), with an adjusted odds ratio of 11.86 (P<0.001).

Conclusions

Patients with diminished PF after PSF for AIS may be less likely to achieve postoperative %FVC improvement. As increased postsurgical %FVC had a positive effect on physical function, treatment strategies that focus on maintaining and increasing PF are desirable from an RF viewpoint.

Contribution of coronal vertebral and IVD wedging to Cobb angle changes in adolescent idiopathic scoliosis during growth

STUDY DESIGN

Prospective study BACKGROUND: Vertebral and intervertebral disc (IVD) wedging are often seen in patients with adolescent idiopathic scoliosis (AIS). However, the relationship between wedging and curve progression, and the change of wedging before bracing to final weaning is unknown. The aim of this study was to investigate the pattern and sequence of vertebral and IVD wedging development, and to determine the relationship between the change of wedging and curve progression in AIS during growth.

METHODS

This was a prospective study of 32 AIS females with right-sided thoracic curves and/or left-sided lumbar curves who completed brace treatment. They were classified into progression and non-progression groups. Vertebral and IVD wedging were calculated for each spinal segment. The wedging pattern was first identified and then used to determine the sequence of wedging development. Percentage change in the sum of wedging during growth was calculated and compared.

RESULTS

The sum of vertebral wedging for both groups was 2.4° to 8.7° more than that of IVD wedging in the thoracic spine but 8.7° to 17.7° less in the lumbar spine. Out of the 20 curves assessed, 5 thoracic curves and 1 lumbar curve developed vertebral wedging before IVD wedging, and 3 thoracic curves and 4 lumbar curves had the opposite pattern. The progression group had larger increases in sum of vertebral (40%) and IVD (28.6%) wedging as compared to the non-progression group (both 16.7%). A significant difference in wedging between the first and the latest visits was found in the progression group only (p < 0.05).

CONCLUSION

Pattern and sequence of vertebral and IVD wedging were related to the location of the curve rather than the presence of curve progression. Progressed curves were associated with increased wedging during growth.

LEVEL OF EVIDENCE

II.

Predictive factors for successful non-operative treatment and achieving MCID improvement in health-related quality of life in adult spinal deformity

Background

Adult spinal deformity is a spectrum of degenerative spinal diseases with increasing prevalence and healthcare burden worldwide. Identification of patients who are more likely to improve through conservative management may reduce cost and potentially prevent surgery and its associated costs and complications. This study aims to identify predictive factors for MCID in improvement of ODI and SRS-22r questionnaires in patients with adult spinal deformity treated with conservative treatment.

Methods

A prospective, observational cohort study of 46 patients was conducted at a spine specialist clinic. Inclusion criteria were 30–80 years of age, diagnosis of neglected adolescent idiopathic scoliosis, de-novo scoliosis, degenerative spondylolisthesis, and sagittal plane deformities (thoracic hypokyphosis, lumbar hypolordosis), presenting with mechanical back pain with or without radicular leg pain. All patients received conservative management including medication and physiotherapy. Radiological and clinical parameters were measured at baseline and at 1-year follow-up. Primary outcomes were ODI and SRS-22r scores. Secondary outcomes were EQ-5D-5L scores and requiring spine surgery during conservative treatment. Predictors for MCID improvement in ODI and SRS-22r were identified using multivariate regressions and receiver operating characteristic (ROC) analyses.

Results

At baseline, patients who reached MCID in ODI and/or SRS-22r showed less comorbidities (diabetes mellitus, hypertension, ischemic heart disease, osteoarthritis, cancer), smaller range of lateral spinal flexion, larger trunk shift, larger pelvic incidence, a higher EQ-5D-5L anxiety/depression dimension score, a lower SRS-22r total score, and presence of spondylolisthesis. Lateral flexion range < 25 degrees, trunk shift > 14 mm, pelvic incidence > 50 degrees, EQ-5D-5L anxiety/depression dimension score > 1, and SRS-22r total score < 3.5 were the cut-off values generated by ROC analysis.

Conclusions

Both radiological and clinical predictive factors for MCID improvement in health-related quality of life were identified. Future research should identify subgroups of patients who are responsive to specific conservative treatment modalities, so as to provide information for personalized medicine.

Level of evidence

II

The Effects of Adolescent Idiopathic Scoliosis on Axial Rotation of the Spine: A Study of Twisting Using Surface Topography

Axial twisting of the spine has been previously shown to be affected by scoliosis with decreased motion and asymmetric twisting. Existing methods for evaluating twisting may be cumbersome, unreliable, or require radiation exposure. In this study, we present an automated surface topographic measurement tool to evaluate global axial rotation of the spine, along with two measurements: twisting range of motion (TROM) and twisting asymmetry index (TASI). The aim of this study is to evaluate the impact of scoliosis on axial range of motion. Adolescent idiopathic scoliosis (AIS) patients and asymptomatic controls were scanned in a topographic scanner while twisting maximally to the left and right. TROM was significantly lower for AIS patients compared to control patients (69.1° vs. 78.5°, p = 0.020). TASI was significantly higher for AIS patients compared to control patients (29.6 vs. 19.8, p = 0.023). After stratifying by scoliosis severity, both TROM and TASI were significantly different only between control and severe scoliosis patients (Cobb angle > 40°). AIS patients were then divided by their major curve region (thoracic, thoracolumbar, or lumbar). ANOVA and post hoc tests showed that only TROM is significantly different between thoracic AIS patients and control patients. Thus, we demonstrate that surface topographic scanning can be used to evaluate twisting in AIS patients.

Lumbopelvic postural differences in adolescent idiopathic scoliosis: A pilot study

BACKGROUND

A primary etiology of adolescent idiopathic scoliosis (AIS) is currently unknown, but poor postural control of the spinal extensor musculature has been identified as an AIS risk factor. Identifiable postural differences would aid in advancing the precise postural behaviors that should be modified during Physiotherapy Scoliosis Specific Exercise (PSSE) to help limit the progression of AIS.

RESEARCH QUESTION

Are there any determinable differences in lumbopelvic posture or range of motion between subjects with AIS and controls?

METHODS

This prospective cohort pilot study consisted of 53 subjects (27 AIS and 26 control) aged 11-17 years. Subjects had their lumbopelvic posture assessed and monitored using the ViMove DorsaVi sensor package. All subjects underwent a live assessment to obtain initial lumbopelvic (LP) range of motion (ROM) measurements. Subjects were then monitored while continuing with normal activities of daily living (ADLs) for 12 h. With an alpha level of 0.05, nonparametric analyses were performed for each variable via a Mann-Whitney U-test.

RESULTS

During the live assessment, controls exhibited a significantly greater anterior pelvic tilt ROM in the sitting position than the AIS group (p = 0.0433). When compared to female controls, females with AIS had a sitting pelvic tilt ROM that was significantly more retroverted (p = 0.0232) and less anteverted (p = 0.0010). During ADLs, female controls exhibited a higher total number of extension events than their female with AIS (p = 0.0263). These associations did not strengthen with greater spinal deformity.

SIGNIFICANCE

This work demonstrates postural differences between patients with AIS and controls. Further study is necessary to determine why patients with AIS adopt these postures, and if PSSEs can be utilized to limit the progression of AIS.

Global Spine Range of Motion in Patients With Adolescent Idiopathic Scoliosis Before and After Corrective Surgery

Given the importance of the spine in carrying out daily movements, adolescent idiopathic scoliosis (AIS) can significantly limit the range of motion (ROM). Severe forms of AIS are treated surgically, most commonly with posterior spinal fusion and instrumentation, which may also reduce spine ROM. This review is the first to describe the literature on total spine ROM in patients with AIS before and after corrective surgery. A systematic literature search was performed using PubMed and Google Scholar to identify articles reporting global spine ROM in AIS patients. Following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA), 486 articles were initially identified. Two independent reviewers (YM and JH) assessed eligibility for inclusion.

A total of 11 articles fit the inclusion criteria. AIS in untreated patients seems to limit axial and coronal plane ROM based on the degree of curve severity, with more severe curves having less ROM. More research comparing total spine ROM in untreated AIS patients to that of healthy controls is needed. In those undergoing spinal fusions, the lowest instrumented vertebra and surgical approach appear to minimize further reductions in ROM; however, the findings are mixed. Vertebral body tethering (VBT) shows promising preliminary results in treating AIS while preserving motion; however, long-term outcomes have yet to be assessed for this novel procedure. The results of this systematic review suggest that further research is required before treatment strategies can be modified for surgically treating patients with AIS to take into account the effects of treatment on changes in spine mobility.

Correlation between age, coronal and sagittal parameters and spine flexibility in patients with adolescent idiopathic scoliosis

PURPOSE

To investigate the correlation between spine flexibility and age, skeletal maturity, coronal and sagittal parameters for adolescent idiopathic scoliosis (AIS).

METHODS

All AIS patients evaluated for surgery were included. Following parameters were obtained: age, gender, skeletal maturity (Risser and Sanders), Cobb angle at high thoracic (HT), mean thoracic (MT) and thoracolumbar/lumbar (TL/L) level, flexibility of HT, MT and TL/L curves, coronal and sagittal parameters. A multivariate diagnostic through the Pearson Product-Moment Correlation Coefficient ([Formula: see text]) was performed.

RESULTS

Data from 200 patients were obtained (30 males, age 15 ± 1.9 years). No significant correlation was found between curve flexibility and age or gender. A negative correlation was observed between flexibility of MT curves and magnitude of HT ([Formula: see text] = - 0.4) and MT curves ([Formula: see text] = - 0.4). A weak correlation among curve flexibility at different levels was observed: the flexibility of HT curves correlated with the flexibility of MT and TL/L curves, and the flexibility of MT curves correlated with flexibility TL/L curves. A negative correlation between flexibility of MT curves and AVT-T (thoracic apical vertebral translation) ([Formula: see text] = - 0.2) was evidenced. No correlations between flexibility and sagittal parameters were observed.

CONCLUSIONS

No strong correlation were observed between curve flexibility and age or skeletal maturity. A negative correlation between curve magnitude and flexibility at thoracic level was demonstrated. Furthermore, a weak positive correlation between flexibility of PT, MT and TL/L curves was observed.

Physical Functioning in Adolescents with Idiopathic Scoliosis: A Systematic Review of Outcome Measures and Their Measurement Properties

STUDY DESIGN

A systematic review.

OBJECTIVE

To summarize evidence on measurement properties of Outcome Measures (OM) used to assess physical functioning in adolescents with idiopathic scoliosis (AIS).

SUMMARY OF BACKGROUND DATA

The AIS is a common spine deformity in those aged 10 to 18 years old. Associated health problems (e.g., back pain) significantly impact the quality of life (QoL). One important domain in QoL is physical functioning, which can be measured with patient-reported outcome measures (PROM), performance-based outcome measures (PBOM), and body structure and function OM. Adequate measurement properties of OM are important for precision in research and practice.

METHODS

A two-staged search strategy was performed on electronic databases up to December 2019. Search one revealed a list of OM was used for physical functioning assessment in AIS. Search two identified studies that evaluated the measurement properties of OM in AIS; using the list identified in search one. Two independent reviewers determined study eligibility, risk of bias assessment (COnsensus-based Standards for the selection of health Measurement INstruments [COSMIN] checklist), and performed data extraction. The level of evidence was established using a modified GRADE approach.

RESULTS

Search one yielded: 28 PROM, 20 PBOM, and 10 body structure and function OM. Search two revealed: 16 measurement properties studies for PROM, one for PBOM, and three for body structure and function measures. Construct validity, reliability, and responsiveness of most PROM has been established in AIS, but not content validity or internal consistency (moderate evidence). Construct validity was sufficient for the Timed Up and Go test and body structure and function measures (very low to low evidence).

CONCLUSION

Currently, physical functioning is evaluated with a variety of measures in AIS. The majority of measurement properties studies evaluated PROM with a paucity of information on measurement properties of PBOM and body structure and function OM. Based on COSMIN methodology, none of the OM identified in this review can be recommended with confidence in individuals with AIS.Level of Evidence: 2.

What determines immediate postoperative coronal balance and delayed global coronal balance after anterior spinal fusion for Lenke 5C curves?

PURPOSE

To determine the factors associated with 6-week postoperative global coronal balance and delayed global coronal balance at 2-year follow-up after anterior spinal fusion for Lenke 5C curves.

METHODS

A total of 124 consecutive Lenke 5C curves with minimum 2-year follow-up was studied. Radiographic parameters were studied preoperatively, 6 weeks postoperatively, and 2 years postoperatively. Coronal balance was measured by C7-CSVL and trunk shift < 20 mm. The study outcomes were patients with early coronal balance and those who had immediate imbalance but developed delayed balance. Multivariate regression analyses of associated factors were performed with cutoffs determined by receiver operating characteristic curve.

RESULTS

31.5% patients attained global coronal balance immediate postoperatively and 89.4% of the early imbalance cases showed spontaneous coronal balance at 2-year follow-up. Increased preoperative UIV tilt (OR 1.093; p = 0.026; 95% CI: 1.011-1.182) and reduced immediate postoperative RSH difference (OR 0.963; p = 0.015; 95% CI: 0.935-0.993) were associated with immediate postoperative balance. For those with immediate imbalance, larger preoperative major Cobb angle (OR 1.226; p = 0.047; 95% CI: 1.003-1.499), less preoperative C7-CSVL (OR 0.829; p = 0.016; 95% CI: 0.712-0.966), and less immediate postoperative LIV tilt (OR 0.728; p = 0.013; 95% CI: 0.567-0.934) were associated with 2-year coronal balance. There was significant improvement in function (p = 0.006), self-image (p = 0.039) and total score domains (p = 0.014) in immediate imbalance to 2-year balance and imbalance groups.

CONCLUSION

Successful balance is achieved with a parallel fusion mass when performing anterior spinal fusion for Lenke 5C curves. Patients should be reassured that most attain eventual coronal balance despite the early imbalance. Level of evidence Therapeutic III.

Proper positioning of mice for Cobb angle radiographic measurements

Background

There is no recommended standard for positioning of a mouse for radiographic assessment of the spine. This is necessary to have reproducible radiographic data and avoid false positive results. The objective of this study was to investigate the impact of various postures on Cobb angle measurements and to set up a positioning standard for imaging mouse spines.

Methods

This study was conducted in three parts. Firstly, we identified the problem of lack of posture standardization for radiographs. We collected 77 C57BL/6 J mice for spine radiographs and found a scoliosis prevalence of 28.6% with large variations in curve magnitude. Secondly, 24 C57BL/6 J mice underwent 4 consecutive weekly radiographs and observed high variations (relative standard deviation: 125.3%) between radiographs. Thirdly, we collected another 82 C57BL/6 J mice and designed 14 different postures that could take place during imaging. These postures were related to curling of the limbs, and head, pelvic and tail tilting.

Results

The results showed that head and pelvic tilting significantly affects the curve magnitude with effect size (Glass’s delta) over 1.50. Avoiding these incorrect positions during radiographs is warranted. The standard recommended posture for mouse imaging entails positioning the snout, interorbital space, neck and whole spine in one line, and with the limbs placed symmetrical to the trunk, whilst avoiding stretching the body of the mouse.

Conclusions

Our work exemplified the importance of standard protocol during imaging when using an animal model in the scoliosis study. We recommend utilizing this standard in studying various disorders of the spine to avoid technical causes for the appearance of a curve.

Patterns of coronal and sagittal deformities in adolescent idiopathic scoliosis

BACKGROUND

Thoracic scoliosis has been shown to be associated with hypokyphosis in adolescent idiopathic scoliosis (AIS). However, the relationship of sagittal spino-pelvic parameters with different coronal curve patterns and their influence on patient-perceived quality of life is unknown. This study aims to determine the association between coronal and sagittal malalignment in patients with AIS and to determine their effects on SRS-22r scores.

METHODS

A cross-sectional study was conducted on 1054 consecutive patients with AIS. The coronal Cobb angle, thoracic kyphosis (TK), lumbar lordosis (LL), pelvic incidence (PI), PI-LL mismatch (PI-LL), pelvic tilt (PT), and sacral slope (SS) were measured on standing radiographs. The coronal Cobb angle (mild: 10-20°; moderate: > 20-40°; severe: > 40°) and PI (low: < 35°; average: 35-50°; high: > 50°) were divided into 3 sub-groups for comparison. Relationship between coronal curve magnitudes and sagittal parameters was studied as was their association with SRS-22r scores.

RESULTS

Low PI had smaller SS (30.1 ± 8.3° vs 44.8 ± 7.7°; p < 0.001), PT (- 0.3 ± 8.1° vs 14.4 ± 7.5°; p < 0.001), and LL (42.0 ± 13.2° vs 55.1 ± 10.6°; p < 0.001), negative PI-LL mismatch (- 12.1 ± 13.1° vs 4.1 ± 10.5°; p < 0.001) as compared to large PI. There were no significant relationships with PI and TK (p = 0.905) or curve magnitude (p = 0.431). No differences in sagittal parameters were observed for mild, moderate or severe coronal Cobb angles. SRS-22r scores only correlated with coronal Cobb angle and larger Cobb angles were negatively correlated with the function, appearance and pain domains.

CONCLUSIONS

The sagittal profile for AIS is associated with the pelvic parameters especially PI but not with the coronal curve pattern. All patients have a similar TK regardless of coronal curve type. However, it appears that the coronal deformity is a greater influence on quality of life outcomes especially those > 40°.

Stress distribution changes in growth plates of a trunk with adolescent idiopathic scoliosis following unilateral muscle paralysis: A hybrid musculoskeletal and finite element model

This study aimed to investigate changes occurred in the stress distribution in the growth plates (GPs) of a trunk with adolescent idiopathic scoliosis (AIS) following unilateral muscle paralysis. We hypothesized that weakening the appropriately chosen muscles on the concave side can decelerate AIS deformity progression. Muscle forces and reaction loads were estimated by an optimization-driven musculoskeletal (MS) model of adolescents with a normal- and an AIS trunk, and then applied on the finite element model of GPs of L1 through L4. Different set patterns of 95% reduction in the strength of the concave-side longissimus thoracis pars thoracic (LGPT), multifidus lumborum (MFL), and LGPT + MFL muscles were performed in the MS models. Results of this study showed that weakening of the concave-side MFL and LGPT muscles rendered a 35% correction in the symptomatic axial rotation of the AIS spine, and a reduction of about 25% in the compressive von Mises stress on the concave side of GPs, respectively, which can decelerate the deformity progression. It was observed that unilateral muscle weakening caused a compensatory activation of the rest of muscles to retain the spine stability. The intradiscal pressures and ratio between the rotations toward either side of the scoliotic spine, found here, matched well with some recent in-vivo investigations. One of the applications of the stability-based MS model of AIS spine with unilaterally weakened muscles presented in this study is to optimize the performance of the currently used braces. To fortify the presented therapeutic approach, experiments should be done on scoliotic animals.

Flexibility Measurement Affecting the Reduction Pattern of Back Muscle Activation during Trunk Flexion

Numerous studies have been conducted on lower back injury caused by deeper stooped posture, which is associated with the back muscle flexion–relaxation phenomenon (FRP). Individual flexibility also affects FRP; individuals with high flexibility have the benefit of delayed FRP occurrence. This study attempted to determine the most efficient measurement of flexibility for evaluating the occurrence and degree of FRP when participants flexed their trunk forward. We recruited 40 male university students who were grouped on the basis of three flexibility measurements (toe-touch test, TTT; sit-and-reach test, SRT; modified Schober’s test, MST) into three levels (high, middle and low). Muscle activation (thoracic and lumbar erector spinae, TES and LES, respectively; hamstring, HMS) and lumbosacral angle (LSA) were recorded when the trunk flexed forward from 0° (upright) to 15°, 30°, 45°, 60°, 75° and 90°. The results indicated that trunk angle had a significant effect on three muscle activation levels and LSA. The effects of muscles and LSA varied depending on flexibility measurement. TTT significantly discriminated LES electromyography findings between high and low flexibility groups, whereas MST and SRT distinguished between high and non-high flexibility groups. The TTT values positively correlated with the time of LES FRP occurrence, showing that the higher the TTT, the slower the occurrence of FRP. This is beneficial in delaying or avoiding excessive loading on the passive tissue of the lumbar spine when performing a deeper trunk flexion.

A novel tool to provide predictable alignment data irrespective of source and image quality acquired on mobile phones: what engineers can offer clinicians

PURPOSE

Existing automated spine alignment is based on original X-rays that are not applicable for teleradiology for spinal deformities patients. We aim to provide a novel automated vertebral segmentation method enabling accurate sagittal alignment detection, with no restrictions imposed by image quality or pathology type.

METHODS

A total of 428 optical images of original sagittal X-rays taken by smartphones or screenshots for consecutive patients attending our spine clinic were prospectively collected. Of these, 300 were randomly selected and their vertebrae were labelled with Labelme. The ground truth was specialists measured sagittal alignment parameters. Pre-trained Mask R-CNN was fine-tuned and trained to predict the vertebra level(s) on the remaining 128 testing cases. The sagittal alignment parameters including the thoracic kyphosis (TK), lumbar lordosis (LL) and sacral slope (SS) were auto-detected, based on the segmented vertebra. Dice similarity coefficient (DSC) and mean intersection over union (mIoU) were calculated to evaluate the accuracy of the predicted vertebra. The detected sagittal alignments were then quantitatively compared with the ground truth.

RESULTS

The DSC was 84.6 ± 3.8% and mIoU was 72.1 ± 4.8% indicating accurate vertebra prediction. The sagittal alignments detected were all strongly correlated with the ground truth (p < 0.001). Standard errors of the estimated parameters had a small difference from the specialists' results (3.5° for TK and SS; 3.4° for LL).

CONCLUSION

This is the first study using fine-tuned Mask R-CNN to predict vertebral locations on optical images of X-rays accurately and automatically. We provide a novel alignment detection method that has a significant application on teleradiology aiding out-of-hospital consultations. These slides can be retrieved under Electronic Supplementary Material.

A head-to-head comparison of five-level (EQ-5D-5L-Y) and three-level EQ-5D-Y questionnaires in paediatric patients

PURPOSE

The aim of this study was to assess the psychometric properties of a youth version of the EQ-5D five-level questionnaire (5LY) and its three-level version (3LY) in a sample of Chinese paediatric patients.

METHODS

A consecutive sample of idiopathic scoliosis patients were recruited from a referral outpatient scoliosis center at Hong Kong, China in October 2017 and completed the two versions of EQ-5D-Y. Redistribution properties in each dimension of EQ-5D-Y were analyzed between 5LY and 3LY by logistics regressions. Absolute reduction and relative reduction in ceiling effects from the 3LY to the 5LY were calculated. Test-retest reliability was assessed by examining the Gwet's agreement coefficient (Gwet's AC) for five individual dimension responses over the 2-week period.

RESULTS

A total of 129 idiopathic scoliosis patients completed the two versions of EQ-5D-Y at baseline assessment, among which 70 patients completed the test-retest interview in 2-3 weeks after baseline assessment. For redistribution properties, the proportion of inconsistency was low in all the dimensions, ranging from 0.0% ("Usual activities") to 3.9% ("Pain/discomfort"). Ceiling effects were reduced in four dimensions. "Usual activities" dimension showed significant reduction (absolute and relative reductions: 3.9% and 4.3%; p = 0.025) and the "worried/sad/unhappy" dimension showed the largest significant reduction in ceiling effects (absolute and relative reductions: 7.8% and 9.8%; p = 0.012). The 3LY and 5LY showed very good agreement (> 80%) of individual dimension responses between two assessments, except for the "worried/sad/unhappy" dimension in 3LY.

CONCLUSION

Through this head-to-head comparison, the 5LY had significant improvements in ceiling effects in two dimensions when compared to 3LY but other measurement properties of 3LY and 5LY performed similar in the idiopathic scoliosis patient group.

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.

APSS-ASJ Best Clinical Research Award: Predictability of Curve Progression in Adolescent Idiopathic Scoliosis Using the Distal Radius and Ulna Classification

Study Design

Prospective study.

Purpose

To determine the risk of clinically significant curve progression in adolescent idiopathic scoliosis (AIS) based on the initial Cobb angle and to test the utility of the distal radius and ulna (DRU) classification in predicting these outcomes.

Overview of Literature

Determining the remaining growth potential in AIS patients is necessary for predicting prognosis and initiating treatment. Limiting the maturity Cobb angle to <40° and <50° reduces the risk of adulthood progression and need for surgery, respectively. The risk of curve progression is the greatest with skeletally immature patients and thus warrants close monitoring or early intervention. Many parameters exist for measuring the skeletal maturity status in AIS patients, but the DRU classification has been shown to be superior in predicting peak growth and growth cessation. However, its predictive capabilities for curve progression are unknown.

Methods

Totally, 513 AIS patients who presented with Risser 0–3 were followed until either skeletal maturity or the need for surgery, with a minimum 2-year follow-up period. Outcomes of 40° and 50° were used for probability analysis based on the cut-offs of adulthood progression risk and surgical threshold, respectively.

Results

At the R6/U5 grade, most curves (probability of ≥48.1%–55.5%) beyond a Cobb angle of 25° progressed to the 40° threshold. For curves of ≥35°, there was a high risk of unfavorable outcomes, regardless of skeletal maturity. Most patients with the R9 grade did not progress, regardless of the initial curve magnitude (probability of 0% to reach the 50° threshold for an initial Cobb angle of ≥35°).

Conclusions

This large-scale study illustrates the utility of the DRU classification for predicting curve progression and how it may effectively guide the timing of surgery. Bracing may be indicated for skeletally immature patients at an initial Cobb angle of 25°, and those with a scoliosis ≥35° are at an increased risk of an unfavorable outcome, despite being near skeletal maturity.