Patterns of coronal and sagittal deformities in adolescent idiopathic scoliosis

Correlation of the LLRS-AIM Index With LD-SRS and PROMIS in Pediatric Patients With Lower Limb Differences

BACKGROUND

The purpose of this study was to assess the reliability of the Limb Lengthening and Reconstruction Society AIM (LLRS-AIM) index, a scale for grading the severity of lower limb deformities by the physician, and its concordance with 2 patient-reported outcome measures, the Limb Deformity-Scoliosis Research Society (LD-SRS) and Patient-Reported Outcomes Measurement Information System (PROMIS) tools in pediatric patients with lower limb differences.

METHODS

This was a retrospective review of patients 18 years old or younger who presented to our institution with lower limb differences for surgical reconstruction between 2019 and 2024. All patients received the LD-SRS and PROMIS for completion before surgery. The LLRS-AIM index for patients was assessed by 2 independent evaluators, with intraclass correlation coefficients (ICCs) calculated to determine inter-rater agreement. Spearman correlations were performed between the LLRS-AIM Index with all LD-SRS and PROMIS domains. The Benjamini-Hochberg procedure was conducted to reduce the false discovery rate.

RESULTS

A total of 81 patients were included in this study. The LLRS-AIM Index had good and near-perfect inter-rater reliability across different levels of medical training (ICC=0.9). Overall, there were no correlations between the LLRS-AIM Index with LD-SRS and PROMIS domains (LD-SRS function: P=-0.26, P=0.18; PROMIS pain interference: P=0.10, P=0.63). Mental health-related LD-SRS and PROMIS domains showed no correlations with the physician-reported LLRS-AIM index (LD-SRS self image: P=0.10, P=0.63; PROMIS depression: P=-0.05, P=0.63).

CONCLUSIONS

There is a high level of reproducibility for the LLRS-AIM index to evaluate the complexity of lower limb differences in pediatric patients. However, there are no correlations between the LLRS-AIM index with LD-SRS and PROMIS across all relevant domains. Further modifications to the LLRS-AIM index criteria and scoring weights may allow it to better assess patient outcomes in the pediatric population.

LEVEL OF EVIDENCE

Level III.

Relationship between the course of postoperative pelvic axis rotation and shoulder balance in patients with Lenke types 1 and 2 adolescent idiopathic scoliosis

Background

Posteroanterior radiographs of patients with adolescent idiopathic scoliosis (AIS) show bilateral differences in the iliac wings. This is due to pelvic axis rotation (PAR) associated with scoliosis. We often encounter cases wherein the PAR changes with surgery and postoperatively. We investigated the course of preoperative PAR and the relationship between PAR and shoulder balance in patients with Lenke 1,2 AIS.

Methods

In total, 28 patients with Lenke 1,2 AIS undergoing scoliosis correction were included. The PAR and shoulder parameters were measured on posteroanterior radiographs. The correlation between the measured parameters and the extent of changes in each parameter was also examined.

Results

Eleven patients (39.3 %) underwent preoperative PAR. Six patients (21.4 %) showed a greater change in PAR from 1 week to 2 years postoperatively. The rotation did not change significantly from preoperatively to immediately postoperatively but changed during the first three months postoperatively. The rotation group had significantly more balanced shoulders at 2 years (P = 0.025). The rotation group had a greater change in shoulder balance in the postoperative course significantly (P < 0.05). The extent of change in pelvic rotation from 1 week to 2 years postoperatively correlated with the extent of change in shoulder balance.

Conclusion

The PAR in patients with Lenke 1,2 AIS significantly changed during 3 months postoperatively. Patients with Lenke 1,2 AIS with preoperative PAR can be expected to have postoperative shoulder rebalancing.

Correlation between abnormal posture, screen time, physical activity, and suspected scoliosis: a cross-sectional study

BACKGROUND

Scoliosis considerably affects adolescents' physical well-being and quality of life. Current research offers scant data concerning the correlation between abnormal posture, screen time, physical activity, and adolescent scoliosis. This study aimed to investigate their potential correlations with suspected scoliosis in teenagers aged 10-13 years.

METHODS

This is a cross-sectional study. School scoliosis screening was conducted on adolescents aged 10-13 years from nine schools in Guangzhou, China. The survey encompassed demographic attributes, postural traits, and daily lifestyles. Logistic regression analysis was performed to analyze the correlations between various variables and the occurrence of suspected scoliosis.

RESULTS

A total of 1297 questionnaires were distributed, and 1231 (94.9%) valid responses were received. All participants with valid responses underwent scoliosis screening. The overall prevalence of suspected scoliosis was 5.1%, with the highest prevalence observed in 11-year-old students, primarily affecting the thoracic spine. Significant correlations were found between suspected scoliosis and right-sided flatfoot, flat upper back, positive forward bend test (FBT), After-school screen time, weekend outdoor time, and weekend TV time.

CONCLUSIONS

The results show a substantial correlation between the incidence of suspected scoliosis and abnormal posture. Moreover, a marked correlation exists between distinct activity patterns, particularly extended usage of electronic devices and television, and the incidence of suspected scoliosis. Screening for abnormal posture and performing the FBT can help detect suspected scoliosis, which requires further clinical assessment to differentiate between postural deviations and scoliosis. We advise middle and primary school kids to modify their daily routines by decreasing sedentary behavior and enhancing physical activity to mitigate the potential occurrence of trunk asymmetries.

Relative anterior spinal overgrowth in mild and moderate adolescent idiopathic scoliosis: a retrospective study

To determine whether relative anterior spinal overgrowth (RASO) occurs regardless of scoliosis segments and severity, and to explore the pattern of vertebral body height changes in adolescent idiopathic scoliosis (AIS). A total of 125 AIS and 179 non-scoliotic adolescents were enrolled. The anterior vertebral body height (VBHa) and posterior vertebral body height (VBHp) were measured on lateral spine radiographs, and the VBHa/VBHp ratio was calculated. The ratios were compared between the two groups and across scoliosis segments in the AIS group. The correlation between scoliosis severity and vertebral ratios, as well as the relationship between the apex vertebra's ratio and Cobb angle, was analyzed. Results showed that the VBHa/VBHp ratios were higher in the AIS group than the control group from T6 to L5 (P < 0.001), with increasing ratios from T7 to T10 and L1 to L5. No significant differences were found across scoliosis segments. Pearson analysis showed positive correlations between scoliosis severity and ratios at T7, T8, and T11 (P < 0.05), and a negative correlation at L5 (P < 0.05). No correlation was found between the apex vertebra's ratio and the Cobb angle. In conclusion, RASO is common in mild to moderate AIS and may help maintain spinal function.

Correlation between coronal wedge deformity and sagittal spinal curvature in adolescent idiopathic scoliosis: a retrospective analysis

The correlation between the Cobb angle and the sagittal spinal curvature (SSC) in adolescent idiopathic scoliosis (AIS) has been reported in some previous studies, but few studies have reported on the relation of coronal wedge deformity (CWD) with sagittal curvature. This study aims to investigate the correlation between CWD and SSC in AIS patients. A retrospective analysis was conducted in 122 AIS patients treated at our hospital from January 2018 to November 2023. Correlation analysis was performed on the Cobb angle, total wedge angle(TW), apical vertebral wedge angle (APW), upper end-vertebral wedge angle (UW), lower end-vertebral wedge angle (LW), total affected structures, average wedge angle(AW), total vertebral wedge angle (TVW), average vertebral wedge angle (AVW), Vertebral Wedge Angle ratio (VWR), total disc wedge angle (TDW), average disc wedge angle (ADW), and disc wedge angle ratio (DWR). Furthermore, out of all cases which underwent lateral spinal radiographs, a correlation analysis between thoracic kyphosis (TK), lumbar lordosis (LL) and CWD was carried out on 102 patients. The Cobb angle exhibited a significant positive correlation with multiple CWD parameters (P < 0.05). TK showed a significant negative correlation with the Cobb angle (r = - 0.221, P = 0.026), TW (r = - 0.199, P = 0.045), AW (r = - 0.262, P = 0.008), TDW (r = - 0.211, P = 0.033), and ADW (r = - 0.278, P = 0.005). LL had no significant correlation with TK and other parameters (P > 0.05). In mild and moderate AIS patients, CWD parameters were positively correlated with the Cobb angle and negatively correlated with thoracic SSC. This may indicate that it's necessary to correct sagittal thoracic curvature when rectifying scoliosis in clinic. This research would not only provide new insights for clinical practice but also offer important evidence for early diagnosis and intervention.

Trunk kinematic analysis of ascent and descent stairs in college students with idiopathic scoliosis: a case-control study

BACKGROUND CONTEXT

Traditional 3D motion analysis typically considers the spine as a rigid entity. Nevertheless, previous single-joint models have proven inadequate in evaluating the movement across different spinal segments in patients with idiopathic scoliosis (IS). Scoliosis significantly impairs movement functions, especially during activities such as ascending and descending stairs. There is a lack of research on the patterns of stair movement specifically for patients with IS.

PURPOSE

This study aims to investigate trunk kinematics in college students with IS during stair ascent and descent tasks. A total of 56 participants, 28 with IS and 28 with healthy controls, were recruited for this case-control study. The trunk movements were analyzed using a motion analysis system that incorporated a multisegment spine model. Understanding the multi-segment spine kinematics during stair tasks can contribute to the development of effective rehabilitation programs for individuals with IS.

STUDY DESIGN

Case-control study.

SAMPLE SIZE

Twenty-eight IS and 28 controls.

OUTCOME MEASURES

Cobb angle, spinal curvature, spinal active range of motion (ROM), Kinematics.

METHODS

The Qualisys system (Gothenburg, Sweden) was utilized in this study with a sampling frequency of 150 Hz. It recorded the kinematics in the thoracic, lumbar, thoracic cage, and pelvis while ascending and descending stairs for both the 28 IS individuals and the 28 control participants. Additionally, clinical parameters such as the Cobb angle, curvature of the spine, spinal range of motion (ROM), and other relevant factors were concurrently assessed among the subjects. Project supported by the National Natural Science Foundation of China (Grant No. 82205306). The authors declare no conflict of interest in preparing this article.

RESULTS

The findings of this study revealed that IS individuals exhibited reduced kyphotic curvature in the sagittal plane (p<.05) when compared to the control group. In contrast, these IS patients displayed greater coronal curvature (Cobb angle) in the frontal plane and a more substantial difference in thoracic side bending range of motion in comparison to the control group (p.05). Moreover, during the ascending stair activity, IS patients showed reduced thoracic cage flexion-extension range of motion (p<.05), while displaying increased lumbar rotation range of motion and anterior-posterior pelvic tilt range of motion (p<.05) in contrast to the control group. Notably, the kinematic analysis during the descent of stairs indicated that IS patients exhibited a larger range of motion in thoracic flexion-extension, thoracic side bending, thoracic cage side bending, thoracic rotation, and thoracic cage rotation when compared to the control group (p<.05).

CONCLUSIONS

The results showed significant differences in trunk kinematics between the two groups during both stair ascent and descent tasks. The utilization of the "multisegment spine model" facilitates the acquisition of motion information across multiple segments of the spine in patients diagnosed with IS, effectively enhancing the assessment outcomes derived from imaging information. The three-dimensional structural deformity in the trunk affects both static and dynamic activity patterns. In different activity states, IS patients demonstrate stiff movements in certain segments while experiencing compensatory instability in others. In the future, clinical rehabilitation programs for IS should prioritize stair-related activity training.

Patient-Specific Rods in Adolescent and Adult Spinal Deformity Surgery: A Narrative Review

Spinal deformity surgery often requires complex surgical interventions that can have a drastic effect on both patient quality of life and functional capacity. Modern-day corrective solutions for these deformities include spinal osteotomies, pedicle screw instrumentation, and dual/multirod constructs. These solutions are efficacious and are currently considered standard practice for spinal surgeons, but they lack individualization. Patient-specific rods (PSRs) are a novel technology that attempts to offer a personalized approach to spinal deformity correction based on preoperative computerized tomography scans. Moreover, PSRs may offer several advantages to conventional rods, which include achievement of desired rod contour angles according to surgical planning alignment goals, reduced operative time, and reduced blood loss. In adolescent idiopathic scoliosis, those instrumented with PSR have observed coronal Cobb reductions up to 74%. In adult spinal deformity, PSRs have offered superior correction in radiographic parameters such as sagittal vertical axis and pelvic incidence minus lumbar lordosis. However, there still remains a paucity of research in this area, mainly in health care expenditure, cost-effectiveness, and longitudinal clinical outcomes. The purpose of this article is to survey the current body of knowledge of PSR instrumentation in both adolescent and adult spinal deformity populations. The current strength, limitations, and future directions of PSRs are highlighted throughout this article.

Adolescent Idiopathic Scoliosis Minimum Data Set: Towards Standardization of Data Elements in History and Physical Examination

INTRODUCTION

Nonoperative care represents a cornerstone of adolescent idiopathic scoliosis (AIS) management, although no consensus exists for a minimal data set. We aimed to determine a consensus in critical data points to obtain during clinical AIS visits.

METHODS

A REDCap-based survey was distributed to Pediatric Orthopedic Society of America (POSNA), Pediatric Spine Study Group (PSSG), and International Society on Scoliosis Orthopedic and Rehabilitation Treatment (SOSORT). Respondents ranked the importance of data points in history, physical examination, and bracing during AIS visits.  Results: One hundred eighty-one responses were received (26% response rate), of which 86% were physicians and 14% were allied health professionals. About 80% of respondents worked at pediatric hospitals or pediatric spaces within adult hospitals, and 82% were academic, with the majority (57%) seeing 150+ unique AIS patients annually. Most respondents recommended six-month follow-up for patients under observation (60%) and bracing (54%). Most respondents (75%) considered family history and pain important (69%), with the majority (69%) asking about pain at every visit. Across all time points, Adam's forward bend test, shoulder level, sagittal contour, trunk shift, and curve stiffness were all considered critically important (>60%). At the first visit, scapular prominence, leg lengths, motor and neurological examination, gait, and iliac crest height were also viewed as critical. At the preoperative visit, motor strength and scapular prominence should also be documented. About 39% of respondents use heat sensors to monitor bracing compliance, and average brace wear since the prior visit was considered the most important (85%) compliance data point.

CONCLUSIONS

This study establishes recommendations for a 19-item minimum data set for clinical AIS evaluation, including history, physical exam, and bracing, to allow for future multicenter registry-based studies.

The effect of Providence night-time bracing on the sagittal profile in adolescent idiopathic scoliosis

PURPOSE

Adolescent idiopathic scoliosis (AIS) is characterized by coronal scoliosis and often a sagittal hypokyphosis. The effect of bracing on the sagittal profile is not well understood. The aim of this study is to assess the effect of night-time bracing on the sagittal profile in patients with AIS.

METHODS

We retrospectively included AIS patients with a main curve of 25-45° treated with a night-time brace in our institution between 2005 and 2018. Patients with estimated growth potential based on either Risser stage, hand X-rays, or menarchal status were included. Coronal and sagittal radiographic parameters were recorded at both brace- initiation and -termination. Patients were followed until surgery or one year after brace termination. Results were compared to a published cohort of full-time braced patients.

RESULTS

One hundred forty-six patients were included. Maximum thoracic kyphosis (TK) increased 2.5° (± 9.7) (p = 0.003), corresponding to a 3.5-fold relative risk increase post bracing in TK compared to a full-time brace cohort. Twenty-seven percent (n = 36) of the patients were hypokyphotic (T4/T12 < 20°) at brace initiation compared with 19% (n = 26) at brace termination (p = 0.134). All other sagittal parameters remained the same at follow-up. We found no association between progression in the coronal plane and change in sagittal parameters.

CONCLUSION

This is the first study to indicate that night-time bracing of AIS does not induce hypokyphosis. We found a small increase in TK, with a substantially lower risk of developing flat back deformity compared to full-time bracing. The coronal curve progression was not coupled to a change in TK.

Analysis of Correlation between Spinal Deformation and Pelvic Asymmetry in High School Girls with Idiopathic Scoliosis

The Article Abstract is not available.    

Patient-Specific Surgical Correction of Adolescent Idiopathic Scoliosis: A Systematic Review

The restoration of sagittal alignment is fundamental to the surgical correction of adolescent idiopathic scoliosis (AIS). Despite established techniques, some patients present with inadequate postoperative thoracic kyphosis (TK), which may increase the risk of proximal junctional kyphosis (PJK) and imbalance. There is a lack of knowledge concerning the effectiveness of patient-specific rods (PSR) with measured sagittal curves in achieving a TK similar to that planned in AIS surgery, the factors influencing this congruence, and the incidence of PJK after PSR use. This is a systematic review of all types of studies reporting on the PSR surgical correction of AIS, including research articles, proceedings, and gray literature between 2013 and December 2023. From the 28,459 titles identified in the literature search, 81 were assessed for full-text reading, and 7 studies were selected. These included six cohort studies and a comparative study versus standard rods, six monocentric and one multicentric, three prospective and four retrospective studies, all with a scientific evidence level of 4 or 3. They reported a combined total of 355 AIS patients treated with PSR. The minimum follow-up was between 4 and 24 months. These studies all reported a good match between predicted and achieved TK, with the main difference ranging from 0 to 5 degrees, p > 0.05, despite the variability in surgical techniques and the rods' properties. There was no proximal junctional kyphosis, whereas the current rate from the literature is between 15 and 46% with standard rods. There are no specific complications related to PSR. The exact role of the type of implants is still unknown. The preliminary results are, therefore, encouraging and support the use of PSR in AIS surgery.

Imaging study of coccygeal morphology in adolescent idiopathic scoliosis

The correlation between scoliosis and sagittal curvature of the cervical, thoracic, and lumbar spine have already been reported in previous studies. However, as a part of the spine, the change in coccygeal morphology in AIS patients has not yet been studied. In this study, a retrospective analysis was performed on 400 patients who were divided into a non-scoliotic group (206 patients) and an AIS group (194 patients). The Postacchini coccygeal radiological classification that was modified by Nathan was used to observe and compare the sagittal coccygeal morphology between the two groups. The results showed that the non-scoliotic group had the highest percentage (52.4%) of patients with type I and the lowest (3.4%) proportion of patients with type V; moreover, the AIS group had the highest percentage (69.1%) of patients with type I and the lowest (1.5%) proportion of patients with type V. The coccygeal morphology was significantly different between the non-scoliotic group and the AIS group (P = 0.001). No significant differences in coccygeal morphology were found between the males and females in the two groups (mild and moderate scoliosis and different segmental scoliosis). In addition, a significant correlation between coccygeal morphology and scoliosis (P = 0.035) was found. In conclusion, coccygeal morphology significantly differs between AIS patients and non-scoliotic adolescents. There was a smaller proportion of patients with a type I coccyx and a larger proportion of patients with a type II or type III coccyx in the AIS group than in the non-scoliotic group. In other words, the presence of a more pronounced coccygeal curve in AIS patients may be caused by an incorrect sitting position and an imbalance in the contraction of the pelvic muscles. It should be further studied whether correcting the sitting position and muscular imbalances could change coccygeal morphology and subsequently affect the development of AIS.

Is sagittal spinopelvic alignment a cause of low back pain in pediatric spine pathologies? A review

Purpose

Altered spinopelvic morphology is observed in many spine pathologies occurring during growth. The aim of the study is to better understand the sagittal compensatory mechanisms and their possible influence on the occurrence of pain in selected pediatric spine pathologies.

Methods

A bibliographic search in the PubMed database included articles published between September 1965 and July 2023. The keywords contained in the search were "spondylolysis," "spondylolisthesis," "scoliosis," "kypho," "sagittal," "pediatric," "child," "adolescent," "grow," "development," and "pain."

Results

The largest diversity in sagittal alignment patterns was reported in idiopathic scoliosis, with global flattening of the spine being the most common. Kyphotic deformations occurring during growth are characterized by structural thoracic or thoracolumbar kyphosis compensated by lumbar hyperlordosis and lower pelvic incidence. Whereas in spondylolisthesis, altered morphology of the spinopelvic junction with high values of pelvic incidence is observed. Pain does not seem to be related to sagittal alignment in idiopathic scoliosis. In Scheuermann disease, it is localized at the apex of the deformity and is associated with the curve pattern, whereas in spondylolisthesis, sagittal alignment correlates with pain scores only in high-grade slips.

Conclusion

Most of the patients with spine disorders that occurred during growth present a clinically balanced posture in the sagittal plane. It suggests that compensatory mechanisms before achieving skeletal maturity are really significant. A comprehension of sagittal alignment in spine deformities and its relationship to pain is essential for the proper assessment and treatment of these disorders.

Directed Versus Nondirected Standing Postures in Adolescent Idiopathic Scoliosis: Its Impact on Curve Magnitude, Alignment, and Clinical Decision-Making

STUDY DESIGN

Prospective study.

OBJECTIVE

To investigate the difference in major curve Cobb angle and alignment between directed and nondirected positioning for adolescent idiopathic scoliosis (AIS) and to evaluate implications on treatment decision-making.

SUMMARY OF BACKGROUND DATA

Proper positioning of patients with spinal deformities is important for assessing usual functional posture in standing, so management strategies can be customized accordingly. Whether postural variability affects coronal and sagittal radiologic parameters and the impact of posture on management decisions remains unknown.

PATIENTS AND METHODS

Patients with adolescent idiopathic scoliosis presenting for an initial consultation at a tertiary scoliosis clinic were recruited. They were asked to stand in two positions: passive, nondirected position; and directed position by the radiographer. Radiologic assessment included major and minor Cobb angle, coronal balance, spinopelvic parameters, sagittal balance, and alignment. Cobb angle difference >5° between directed and nondirected positioning was considered clinically impactful. Patients with or without such differences were compared. Overestimation or underestimation of the major curve (at 25° or 40°) by nondirected positioning were examined due to its relevance to bracing and surgical indications.

RESULTS

This study included 198 patients, with 22.2% experiencing Cobb angle difference (>5°) between positioning. The major curve Cobb angle was smaller in nondirected than directed positioning (median difference: -6.0°, upper and lower quartile: -7.8, 5.8), especially for curves ≥30°. Patients with a Cobb angle difference had changes in shoulder balance ( P =0.007) when assuming a directed position. Nondirected positioning had 14.3% of major Cobb 25° underestimated and 8.8% overestimated, whereas 11.1% of curves >40° were underestimated.

CONCLUSION

Strict adherence to a standardized radiographic protocol is mandatory for reproducing spine radiographs reliable for curve assessment, as a nondirected position demonstrates smaller Cobb angles. Postural variation may lead to overestimation, or underestimation, of the curve size which is relevant to both bracing and surgical decision-making.

LEVEL OF EVIDENCE

Level-II.

Electromyographic Discrepancy in Paravertebral Muscle Activity Predicts Early Curve Progression of Untreated Adolescent Idiopathic Scoliosis

STUDY DESIGN

This study adopted a prospective cohort study design.

PURPOSE

This study aimed to examine electromyogram (EMG) discrepancy in paravertebral muscle activity and scoliosis progression, determine how vertebral morphology and EMG discrepancy evolve during scoliosis progression, and identify differences in EMG activity between individuals with and without adolescent idiopathic scoliosis (AIS).

OVERVIEW OF LITERATURE

Higher EMG activity is observed in the convex side of scoliotic curves, but not in populations without scoliosis, suggesting that higher EMG activity is a causative factor for curve progression.

METHODS

In this study, 267 matched pairs of AIS and controls were recruited. The participants underwent EMG measurements at their first presentation and did not receive any treatment for 6 months at which point they underwent EMG and radiographs. Early curve progression was defined as >5° in Cobb angle at 6 months. The root mean square of the EMG (rms-EMG) signal was recorded with the participants in sitting and back extension. The rms-EMG ratio at the upper end vertebrae, apical vertebrae (AV), and lower end vertebrae (LEV) of the major curve was calculated.

RESULTS

The rms-EMG ratio in the scoliosis cohort was high compared with that in the controls (sitting: 1.2±0.3 vs. 1.0±0.1, p<0.01; back extension: 1.1±0.2 vs. 1.0±0.1, p<0.01). An AV rms-EMG ratio in back extension, with a cutoff threshold of ≥1.5 in the major thoracic curve and ≥1.3 in the major lumbar curve, was a risk factor for early curve progression after 6 months without treatment (odds ratio, 4.1; 95% confidence interval, 2.8-5.9; p<0.01). Increases in side deviation (SD) (distance between the AV and the central sacral line) were related to a higher rms-EMG ratio in LEV of the major thoracic curve (baseline: rs=0.2, p=0.03; 6 months: rs=0.3, p<0.01).

CONCLUSIONS

An EMG discrepancy was detected in the scoliosis cohort, which was related to increases in SD in the major thoracic curve. The AV rms-EMG ratio in back extension was correlated with curve progression after 6 months of no treatment.

The post-surgical transition in adolescents who have idiopathic scoliosis. A qualitative study

OBJECTIVE

To know the process experienced by adolescents suffering from idiopathic scoliosis when undergoing surgery to correct the physical deformity.

METHOD

Qualitative study with a symbolic interactionism approach. 22 semi-structured interviews were conducted with adolescents who underwent posterior spinal fusion in a third-level hospital in Madrid between May 2019 and January 2021. Taylor and Bogdan's analysis in progress was carried out.

RESULTS

Patients with adolescent idiopathic scoliosis present with a complex simultaneous health/illness and developmental transition. The main inhibitory conditions of the transition are the meanings about: their identity, social, beliefs about surgery, ignorance about the pathology, the surgical process, and their recovery. As facilitating conditions, we find: a positive attitude towards physical, aesthetic, and social change, socioeconomic level, and family support.

CONCLUSIONS

The informants of this study refer that aesthetic affectation and physical limitations are the main elements that cause them discomfort. Surgical intervention is presented as the solution to this situation. Recovery is a critical point in the transition process mainly due to pain. They accept the discomfort suffered during the recovery because they hope to obtain an improvement in the image and physical limitations. The changes and differences they experience during the transition make them think that they will be able to lead a «normal life» to which they constantly refer in their speeches.

Radiograph-comparable image synthesis for spine alignment analysis using deep learning with prospective clinical validation

Background

Adolescent idiopathic scoliosis (AIS) is the most common type of spinal disorder affecting children. Clinical screening and diagnosis require physical and radiographic examinations, which are either subjective or increase radiation exposure. We therefore developed and validated a radiation-free portable system and device utilising light-based depth sensing and deep learning technologies to analyse AIS by landmark detection and image synthesis.

Methods

Consecutive patients with AIS attending two local scoliosis clinics in Hong Kong between October 9, 2019, and May 21, 2022, were recruited. Patients were excluded if they had psychological and/or systematic neural disorders that could influence the compliance of the study and/or the mobility of the patients. For each participant, a Red Green Blue-Depth (RGBD) image of the nude back was collected using our in-house radiation-free device. Manually labelled landmarks and alignment parameters by our spine surgeons were considered as the ground truth (GT). Images from training and internal validation cohorts (n = 1936) were used to develop the deep learning models. The model was then prospectively validated on another cohort (n = 302) which was collected in Hong Kong and had the same demographic properties as the training cohort. We evaluated the prediction accuracy of the model on nude back landmark detection as well as the performance on radiograph-comparable image (RCI) synthesis. The obtained RCIs contain sufficient anatomical information that can quantify disease severities and curve types.

Findings

Our model had a consistently high accuracy in predicting the nude back anatomical landmarks with a less than 4-pixel error regarding the mean Euclidian and Manhattan distance. The synthesized RCI for AIS severity classification achieved a sensitivity and negative predictive value of over 0.909 and 0.933, and the performance for curve type classification was 0.974 and 0.908, with spine specialists' manual assessment results on real radiographs as GT. The estimated Cobb angle from synthesized RCIs had a strong correlation with the GT angles (R² = 0.984, p < 0.001).

Interpretation

The radiation-free medical device powered by depth sensing and deep learning techniques can provide instantaneous and harmless spine alignment analysis which has the potential for integration into routine screening for adolescents.

Funding

Innovation and Technology Fund (MRP/038/20X), Health Services Research Fund (HMRF) 08192266.

Clinical Application of the Roussouly Classification in the Sagittal Balance Reconstruction of 101 Adolescent Idiopathic Scoliosis Patients

PURPOSE

Although Roussouly classification has been widely used in spinal surgery, it was mainly applied to degenerative scoliosis patients and correlational studies concerning adolescent idiopathic scoliosis (AIS) are still insufficient. This retrospective study explored the clinical application of Roussouly classification in surgeries and prognosis prediction for AIS.

METHODS

This clinical research selected 101 AIS patients who received surgeries between August 2005 and November 2019. Whole spine standing radiographs were obtained for each patient preoperatively, postoperatively, and at the last follow-up (>24 months). All patients were classified into "theoretical types" and "current types." Patients were further divided into mismatch or match groups based on the consistency of their current type and theoretical type. The main parameters include: proximal junctional angle (PJA), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), fixed thoracic kyphosis (TK), global TK, fixed lumbar lordosis (LL), global LL, thoracic tilt, proximal thoracic alignment (PTA), lumbar tilt, spino-sacral angle (SSA), and spinal tilt (ST).

RESULTS

A total of 47.5% of AIS patients were subject to a preoperative mismatch of Roussouly classification. There was a significant difference in PI-LL between the preoperative mismatch and match groups (p = 0.008). There was a significant difference in the rate of PI-LL deformity between the match and mismatch groups with a preoperative mismatch (p = 0.037). A significant difference in thoracic tilt was observed between the postoperative mismatch and match groups (p = 0.019). The preoperative mismatch group has a higher risk of postoperative PI-LL malformation than match group (OR = 2.303, 95% CI: 1.026, 5.165). When mismatch occurred postoperatively, there were significant differences between groups in the rate of pelvic deformity (p = 0.002) and PI-LL deformity (p = 0.025) at the last follow-up. Compared with the postoperative match group, mismatch group had an increased risk of pelvic deformity (OR = 5.029, 95% CI: 1.618, 15.629) and PJK deformity (OR = 3.017, 95% CI: 1.709, 11.375) at the last follow-up. Short Form-36 and Scoliosis Research Society 22 score of the match group was significantly higher than that of the mismatch group at the last follow-up.

CONCLUSION

The Roussouly classification mismatch before or after operation leads to increased risks of PI-LL deformity and pelvis deformity postoperatively or at the follow-up, which seriously worsens the clinical symptoms and prognosis of patients. Therefore, recovering to the theoretical type in Roussouly classification may effectively improve patients' prognosis.

Association of FBN1 polymorphism with susceptibility of adolescent idiopathic scoliosis: a case-control study

BACKGROUND

Fibrillin-1 (FBN1) is an extracellular matrix glycoprotein essential to the structural component of microfibrils and FBN1 gene polymorphisms can be associated with adolescent idiopathic scoliosis (AIS) susceptibility. This study aimed to evaluate the potential role of the FBN1 rs12916536 polymorphism in AIS development or severity and the variation in Cobb angle in relation to patient's characteristics.

METHODS

DNA from 563 subjects (185 AIS patients and 378 controls) were genotyped using a validated TaqMan allelic discrimination assay. A multivariate logistic regression model evaluated the association between polymorphism and AIS, using the adjusted odds ratios (OR) with their respective 95% confidence intervals (95% CI). A linear regression analysis evaluated the variation in Cobb angle according to the patient's age and body mass index (BMI).

RESULTS

Among the AIS group there was a predominance of females (12:1), low or normal BMI (90%), 58% had a Cobb angle greater than 45° and 74% were skeletally mature. Age was a risk factor (4-fold) for curve progression higher than BMI (P < 0.001). The allelic frequency of the rs12916536 G > A polymorphism was 40% in controls and 31% in AIS cases; and this difference was statistically significant (P = 0.004). FBN1 rs12916536 GA + AA genotypes were associated with a lower risk of AIS susceptibility (OR = 0.58 and 95% CI = 0.35-0.98), after adjustment for age, sex and BMI. However, no significant differences were detected in polymorphism distribution with the severity of the disease (Cobb < 45° or ≥ 45°).

CONCLUSION

Age was a risk factor for progression of the scoliotic curve and FBN1 rs12916536 polymorphism a protective factor for AIS susceptibility.

An artificial intelligence powered platform for auto-analyses of spine alignment irrespective of image quality with prospective validation

BACKGROUND

Assessment of spine alignment is crucial in the management of scoliosis, but current auto-analysis of spine alignment suffers from low accuracy. We aim to develop and validate a hybrid model named SpineHRNet+, which integrates artificial intelligence (AI) and rule-based methods to improve auto-alignment reliability and interpretability.

METHODS

From December 2019 to November 2020, 1,542 consecutive patients with scoliosis attending two local scoliosis clinics (The Duchess of Kent Children's Hospital at Sandy Bay in Hong Kong; Queen Mary Hospital in Pok Fu Lam on Hong Kong Island) were recruited. The biplanar radiographs of each patient were collected with our medical machine EOS™. The collected radiographs were recaptured using smartphones or screenshots, with deidentified images securely stored. Manually labelled landmarks and alignment parameters by a spine surgeon were considered as ground truth (GT). The data were split 8:2 to train and internally test SpineHRNet+, respectively. This was followed by a prospective validation on another 337 patients. Quantitative analyses of landmark predictions were conducted, and reliabilities of auto-alignment were assessed using linear regression and Bland-Altman plots. Deformity severity and sagittal abnormality classifications were evaluated by confusion matrices.

FINDINGS

SpineHRNet+ achieved accurate landmark detection with mean Euclidean distance errors of 2·78 and 5·52 pixels on posteroanterior and lateral radiographs, respectively. The mean angle errors between predictions and GT were 3·18° and 6·32° coronally and sagittally. All predicted alignments were strongly correlated with GT (p < 0·001, R2 > 0·97), with minimal overall difference visualised via Bland-Altman plots. For curve detections, 95·7% sensitivity and 88·1% specificity was achieved, and for severity classification, 88·6-90·8% sensitivity was obtained. For sagittal abnormalities, greater than 85·2-88·9% specificity and sensitivity were achieved.

INTERPRETATION

The auto-analysis provided by SpineHRNet+ was reliable and continuous and it might offer the potential to assist clinical work and facilitate large-scale clinical studies.

FUNDING

RGC Research Impact Fund (R5017-18F), Innovation and Technology Fund (ITS/404/18), and the AOSpine East Asia Fund (AOSEA(R)2019-06).