Validation of Artificial Intelligence in the Classification of Adolescent Idiopathic Scoliosis and the Compairment to Clinical Manual Handling.

OBJECTIVE: The accurate measurement of Cobb angles is crucial for the effective clinical management of patients with adolescent idiopathic scoliosis (AIS). The Lenke classification system plays a pivotal role in determining the appropriate fusion levels for treatment planning. However, the presence of interobserver variability and time-intensive procedures presents challenges for clinicians. The purpose of this study is to compare the measurement accuracy of our developed artificial intelligence measurement system for Cobb angles and Lenke classification in AIS patients with manual measurements to validate its feasibility. METHODS: An artificial intelligence (AI) system measured the Cobb angle of AIS patients using convolutional neural networks, which identified the vertebral boundaries and sequences, recognized the upper and lower end vertebras, and estimated the Cobb angles of the proximal thoracic, main thoracic, and thoracolumbar/lumbar curves sequentially. Accordingly, the Lenke classifications of scoliosis were divided by oscillogram and defined by the AI system. Furthermore, a man-machine comparison (n = 300) was conducted for senior spine surgeons (n = 2), junior spine surgeons (n = 2), and the AI system for the image measurements of proximal thoracic (PT), main thoracic (MT), thoracolumbar/lumbar (TL/L), thoracic sagittal profile T5-T12, bending views PT, bending views MT, bending views TL/L, the Lenke classification system, the lumbar modifier, and sagittal thoracic alignment. RESULTS: In the AI system, the calculation time for each patient's data was 0.2 s, while the measurement time for each surgeon was 23.6 min. The AI system showed high accuracy in the recognition of the Lenke classification and had high reliability compared to senior doctors (ICC 0.962). CONCLUSION: The AI system has high reliability for the Lenke classification and is a potential auxiliary tool for spinal surgeons.

Automatic Lenke classification of adolescent idiopathic scoliosis with deep learning.

Purpose: The Lenke classification system is widely utilized as the preoperative evaluation protocol for adolescent idiopathic scoliosis (AIS). However, manual measurement is susceptible to observer-induced variability, which consequently impacts the evaluation of progression. The goal of this investigation was to develop an automated Lenke classification system utilizing innovative deep learning algorithms. Methods: Using the database from the First Affiliated Hospital of Sun Yat-sen University, the whole spinal x-rays images were retrospectively collected. Specifically, images collection was divided into AIS and control group. The control group consisted of individuals who underwent routine health checks and did not have scoliosis. Afterwards, relative features of all images were annotated. Deep learning was implemented through the utilization of the key-point based detection method to realize the vertebral detection, and Cobb angle measurement and scoliosis classification were performed based on relevant standards. Besides, the segmentation method was employed to achieve the recognition of lumbar vertebral pedicle to determine the type of lumbar spine modifier. Finally, the model performance was further quantitatively analyzed. Results: In the study, a total of 2082 spinal x-ray images were collected from 407 AIS patients and 227 individuals in the control group. The model for vertebral detection achieved an F1-score of 0.809 for curve type evaluation and an F1-score of 0.901 for thoracic sagittal profile. The intraclass correlation efficient (ICC) of the Cobb angle measurement was 0.925. In the analysis of performance for vertebra pedicle segmentation model, the F1-score of lumbar modification profile was 0.942, the intersection over union (IOU) of the target pixels was 0.827, and the Hausdorff distance (HD) was 6.565 ± 2.583 mm. Specifically, the F1-score for ultimate Lenke type classifier was 0.885. Conclusions: This study has constructed an automated Lenke classification system by employing the deep learning networks to achieve the recognition pattern and feature extraction. Our models require further validation in additional cases in the future.

Bracing in severe skeletally immature adolescent idiopathic scoliosis: does a holding strategy change the surgical plan?

PURPOSE: The purpose of the study was to assess the changes in flexibility during night-time bracing in skeletally immature adolescent idiopathic scoliosis (AIS) with curves in the surgical range. MATERIALS AND METHODS: We included a consecutive cohort of 89 AIS patients with curves ≥ 45° and an estimated growth potential. All patients were eventually treated with fusion surgery, and all patients had side-bending radiographs prior to both bracing and surgery. Curves were classified as structural or non-structural curves according to Lenke at both timepoints. RESULTS: The main curve progressed by a mean of 12 ± 10° and the secondary curve by 8 ± 8°. Flexibility of the main curve decreased from 50 ± 19% to 44 ± 19% (p = 0.001) and the underlying curve from 85 ± 21% to 77 ± 22% (p = 0.005). In 69 patients (79%), the Lenke category did not progress during bracing. In 14 patients (15%), the progression in Lenke type occurred in the thoracic region (i.e., Lenke type 1 to type 2), while six patients (7%) progressed in the lumbar region (i.e., type 1 to type 3). In the 69 patients that did not progress, we found that the last touched vertebra moved distally by one or two levels in 26 patients. CONCLUSIONS: This is the first study to describe that curve flexibility decreases during bracing in severe AIS. However, this had only a modest impact on the surgical strategy. Bracing as a holding strategy can be applied, but the risk of losing flexibility in the lumbar spine should be outweighed against the risks of premature fusion surgery.

Escoliosis idiopática del adolescente / Adolescent idiopathic scoliosis

La escoliosis idiopática del Adolescente (EIA) es una deformidad tridimensional de la columna vertebral que aqueja de diversas formas la condición de vida de quien la padece, afectando el desarrollo físico y psicológico del paciente. Proponemos evaluar el resultado clínico, radiológico y el componente de calidad de vida de pacientes tratados quirúrgicamente con EIA, en el servicio de Neurocirugía, Hospital Jesús Yerena del Lídice. Se evaluó patrón de la curva, clasificación según Lenke, ángulo de Cobb pre y postquirúrgico, edad de tratamiento quirúrgico, gradode corrección, calidad de vida según cuestionario SRS-22 pre y postquirúrgica, valoración funcional mediante la escala de discapacidad de Oswestry (ODI) y complicaciones postoperatorias. Se estudiaron 22 casos (95 % femenino), el principal grupo etario fue de 11-14 años (55 %), la escoliosis tipo 1 fue la predominante (60 %), el ángulo de Cobb inicial fue mayor a 50° (50 %) y la madurez esquelética principal fue Risser 3 (55 %). La edad de resolución quirúrgica predominante fue entre 15-18 años (60 %), el grado de corrección postoperatorio fue de 75-100 % (73 %) y la densidad de los tornillos pediculares fue de 1.4-1.7 (64 %). En el cuestionario SRS-22, hubo mayor afectación en las dimensiones de autoimagen con una media de 1.8 y la valoración por ODI mostró un índice de incapacidad mínima, que fue mejorando en los controles sucesivos. Nuestra principal complicación fueron las infecciones (36 %). Concluimos que la cirugía correctiva temprana en la EIA ofrece a una mejoría clínica, radiológica y de la calidadde vida de estos paciente(AU)

Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine that affects the living condition of those who suffer from it in various ways, affecting the physical and psychological development of the patient. We propose to evaluate the clinical and radiological outcome and the quality-of-life component of patients treated surgically with EIA, in the Neurosurgery Service, Hospital Jesús Yerena del Lídice. Curve pattern, Lenke classification, pre-and post-surgical Cobb angle, age at surgical treatment, degree of correction, quality of life according to pre-and post-surgical SRS-22 questionnaire, functional assessment using the Oswestry Disability Scale (ODI) and postoperative complications were evaluated. 22 cases were studied (95% female), the main age group was 11-14 years (55%), type 1 scoliosis was predominant (60%), the initial Cobb angle was greater than 50° (50%) and the main skeletal maturity was Risser 3 (55%). The predominant age of surgical resolution was between 15-18 years (60%), the degree of postoperative correction was 75-100% (73%) and the density of pedicle screws was 1.4-1.7 (64%). In the SRS-22 questionnaire, there was greater impairment in the self-image dimensions with a mean of 1.8 and the ODI assessment showed aminimal disability index, which improved in successive controls. Our main complication was infections (36%). We conclude that early corrective surgery in AIS offers clinical, radiological and quality of life improvement for these patient(AU)

Pedicle Dysplasia in Proximal Thoracic Adolescent Idiopathic Scoliosis Curves: What are We Missing and What are its Possible Surgical Implications? An Observational Retrospective Study on 104 Patients.

STUDY DESIGN: Retrospective cohort study. OBJECTIVES: To assess if pedicle dysplasia is present in proximal thoracic (PT), both structural and nonstructural, compared to main thoracic (MT) curves; and to assess if it is predictive of radiographic outcomes at minimum 2 years of follow-up. METHODS: A retrospective review of surgically-treated Adolescent Idiopathic Scoliosis (AIS) patients with Lenke 1-2-3-4 curves was performed. On preoperative CT-scan, at the apical vertebra, pedicle width on the concavity (PWc) and on the convexity (PWv) and Pedicle Dysplasia Index (PDI, defined as PWc/PWv) were measured. Preoperative and last follow-up (at least 2 years) x-rays were reviewed. RESULTS: 104 patients meeting the inclusion criteria were divided into Structural-PT (S-PT) and Nonstructural-PT (NS-PT) groups based on Lenke criteria. PWc (P < .001). And PDI (P < .001 for S-PT, P = .004 for NS-PT) were significantly smaller in the PT than in MT curves for both groups. PT-PWc significantly correlated with follow-up PT Cobb for both groups (P < .001 and P = .015 respectively). PT-PDI significantly correlated with follow-up PT-Cobb (P < .001), CA (P < .040) and T1 tilt (P < .002), only for NS-PT group. NS-PT patients with PWc PT <1 mm had higher RSHD (P = .021) and T1 tilt (P = .025) at follow-up. NS-PT patients with PDI PT <.3 had higher RSHD (P < .001), CA (P = .002) and T1 tilt (P = .003) at follow-up. CONCLUSION: S-PT and NS-PT curves show significant pedicle dysplasia on the concavity. Pedicle dysplasia significantly correlated with shoulder balance at follow-up, for NS-PT patterns. Patients with a PWc <1 mm or PDI <.30 are at particular risk of postoperative shoulder imbalance.

Characteristics of back pain in patients with adolescent idiopathic scoliosis: Considerations in candidates for corrective surgery.

BACKGROUND: Previous studies have demonstrated that the point prevalence of back pain ranges from 12 % to 33 % and that the lifetime prevalence of back pain ranges from 28 % to 51 % in adolescents. However, few studies on back pain in patients with Adolescent idiopathic scoliosis (AIS) have been conducted, and these studies had significant limitations, including a lack of comparative controls and detailed information about scoliotic deformity or pain location. This study aimed to determine whether adolescents with AIS experience back pain in specific regions. METHODS: This retrospective case-control study included 189 female adolescents with AIS who underwent corrective fusion from 2008 to 2020. Questionnaires on back pain and health-related quality of life (HRQOL) using the Scoliosis Research Society Outcomes Instrument-22 (SRS-22) were conducted preoperatively. The control group included 2909 general female adolescents. RESULTS: The mean Cobb angles in the main thoracic and thoracolumbar/lumbar curves were 51.4 ± 15.3° and 40.4 ± 12.9°. Back pain characteristics included higher point prevalence (25.9 %) and lifetime prevalence (64.6 %) compared to healthy controls. Adolescents with back pain showed lower scores in the pain and mental health domains of the SRS-22. Adolescents with major thoracic AIS showed more back pain in the upper and middle right back compared to adolescents with major thoracolumbar/lumbar AIS. CONCLUSION: The point and lifetime prevalence of back pain were definitely higher in patients with AIS, which affected their HRQOL. There was a relationship between pain around the right scapula and the right major thoracic curve with a rib hump deformity.

Anterior fusion surgery with overcorrection in the treatment of adolescent idiopathic scoliosis with Lenke 1 AR curve type: how to achieve overcorrection and its effect on postoperative spinal alignment.

BACKGROUND: The efficacy of anterior fusion with overcorrection in the instrumented vertebra for Lenke 1 AR type curves has been reported, but how to achieve overcorrection and how overcorrection affects spinal alignment are unclear. The purpose of this study was to identify the factors that cause overcorrection, and to investigate how overcorrection affects postoperative spinal alignment in the surgical treatment of Lenke 1 AR type curves. METHODS: Patients who had anterior surgery for a Lenke type 1 or 2 and lumbar modifier AR (L4 vertebral tilt to the right) type scoliosis and minimum 2-year follow-up were included. The radiographic data were measured at preoperative, postoperative 1 month, and final follow-up. The UIV-LIV Cobb angle was determined as the Cobb angle between the upper instrumented vertebra (UIV) and the lower instrumented vertebra (LIV), and a negative number for this angle was considered overcorrection. The screw angle was determined to be the sum of the angle formed by the screw axis and the lower and upper endplates in the LIV and UIV, respectively. The change (Δ) in the parameters from postoperative to final follow-up was calculated. The relationships between the UIV-LIV Cobb angle and other radiographic parameters were evaluated by linear regression analyses. RESULTS: Fourteen patients met the inclusion criteria. Their median age was 15.5 years, and the median follow-up period was 53.6 months. The median UIV-LIV Cobb angle was -1.4° at postoperative 1 month. The median screw angle was 4.7°, and overcorrection was achieved in 11 (79%) cases at postoperative 1 month. The screw angle (r2 = 0.42, p = 0.012) and Δ FDUV-CSVL (the deviation of the first distal uninstrumented vertebra from the central sacral vertical line, r2 = 0.53, p = 0.003) were significantly correlated with the UIV-LIV Cobb angle. CONCLUSIONS: Screw placement in the UIV and LIV not parallel to the endplate, but angled, was an effective method to facilitate overcorrection in the instrumented vertebrae. The results of the present study suggest that overcorrection could bring spontaneous improvement of coronal balance below the instrumented segment during the postoperative period.

Surgical Treatment of Adolescent Idiopathic Scoliosis with the ApiFix Minimal Invasive Dynamic Correction System-A Preliminary Report of a 24-Month Follow-Up.

Adolescent idiopathic scoliosis (AIS) is a three-dimensional growth disorder. Corrective surgical procedures are the recommended treatment option for a thoracic angle exceeding 50° and a lumbar major curve of 40°. Over the past few years, dynamic growth modulation implants have been developed as alternatives to permanent fusion. The ApiFix system was designed as a 2D "posterior dynamic device" for curve correction. After implantation in a minimally invasive procedure, it uses polyaxial joints and a self-adjusting rod to preserve the degree of motion and to accommodate the patient's growth. It provides an effective method of controlling deformity and fills the gap between the conservative treatment of major curves that are >35° and the fusion procedure. The objective of the two-center cohort study was the analysis of the correction results of patients, who underwent surgical intervention with the ApiFix system. The inclusion criteria were AIS, Lenke type 1 or type 5, a major curve on bending films of ≤30°, and an angle of the major curve of between 35° and 60°. Postoperative radiograph data were obtained longitudinally for up to 24 months of follow-up and compared to preoperative (preop) values. For comparisons of the different time points, non-parametric tests (Wilcoxon) or paired t-tests for normally distributed values were used to analyze repeated measures. Overall, 36 patients (25 female and 11 male) were treated with the ApiFix system from April 2018 to October 2020. Lenke type 1 was identified in 21 (58%) cases and Lenke type 5 was identified in 15 (42%) cases. The average angle of the thoracic major curve for Lenke 1 was 43°. The preoperative lumbar major curve (Lenke 5) was determined to be 43°. Over a follow-up of 24 months, a correction of the major curve to an average of 20° was observed for Lenke 1 and that to an average of 15° was observed for Lenke 5. Lenke type 1 and type 5 showed significant changes in the major curve over the individual test intervals in the paired comparisons compared to the starting angle (Lenke 1: preop-24 months, 0.002; Lenke 5: preop-24 months, 0.043). Overall, 11 events were recorded in the follow-up period, that required revision surgery. We distinguished between repeated interventions required after reaching the maximum distraction length of the implant due to the continued growth of the patient (n = 4) and complications, such as infections or problems associated with the anchorage of the implant (n = 7). The results from the present cohort revealed a statistically significant improvement in the postoperatively measured angles of the major and minor curves in the follow-up after 24 months. Consequently, the results were comparable to those of the already established vertebral body tethering method. Alignment in AIS via dynamic correction systems in combination with a possible growth modulation has been a treatment alternative to surgical fusing procedures for more than a decade. However, the long-term corrective effect has to be validated in further studies.

Combination of Side-Bending and Traction Radiographs Do Not Influence Selection of Fusion Levels Compared to Either One Alone in Adolescent Idiopathic Scoliosis.

STUDY DESIGN: A retrospective study. OBJECTIVES: Curve flexibility in patients with adolescent idiopathic scoliosis (AIS) can be evaluated using different techniques. This study aimed to determine whether the combination of side-bending (SB) and traction (TX) radiographs influences preoperative planning for AIS than either radiograph alone. METHODS: Thirty-two spine surgeons were asked to review 30 AIS Lenke type 1 cases and select an upper instrumented vertebra (UIV) and lower instrumented vertebra (LIV) for the posterior spinal instrumentation of each case. Each rater reviewed the cases 3 times in each round. The raters were provided with the full-length posteroanterior (PA) and lateral standing and SB radiographs for round 1; PA, lateral, and TX radiographs for round 2; and PA, lateral, SB, and TX radiographs for round 3. Intra- and inter-rater reliabilities were evaluated using Kappa statistics. RESULTS: The intra-rater reliability for UIV and LIV was 0.657 and 0.612 between rounds 1 and 2, 0.634 and 0.692 between rounds 1 and 3, and 0.659 and 0.638 between rounds 2 and 3, respectively, which indicated substantial agreement between rounds. The inter-rater kappa reliabilities for UIV and LIV selection were 0.103 and 0.412 for round 1, 0.121 and 0.380 for round 2, and 0.125 and 0.368 for round 3, indicating slight to moderate agreement between raters. CONCLUSIONS: Whether raters used either SB or TX radiography, or both in addition to PA and lateral standing radiographs, did not influence the decision making for UIV or LIV of AIS Lenke type 1 surgery.

Polymorphisms in paired box 1 gene were associated with susceptibility of adolescent idiopathic scoliosis: A case-control study.

Background: Association of genetic polymorphisms in paired box 1 (PAX-1) gene can influence the development of adolescent idiopathic scoliosis (AIS). PAX-1 is mainly expressed in the region of the vertebral bodies and intervertebral discs, being important for the proper formation of spinal structures. Objectives: The objective of this study was to evaluate the association of polymorphisms in PAX-1 gene with the susceptibility of AIS. Settings and Design: This was an analytical observational case-control study. Materials and Methods: Samples of 59 AIS indicated for surgical treatment, and 119 controls, without spinal disease were genotyped for PAX-1 rs6137473 and rs169311 polymorphisms. Statistical Analysis: The association of the polymorphisms with AIS was evaluated by a multivariable logistic regression model, using odds ratios (OR) and 95% confidence intervals (CI). Results: According to Lenke's classification, 89.8% had Type I and 10.2% II curves. The mean value of the Cobb angle of the proximal thoracic curve was 30.8°, 58.7° thoracic, and 30.4° for the lumbar and on the bending films 14.6°, 40.7°, and 11°, respectively. Among the AIS group, there was a predominance of females (8.8:1). The PAX-1 rs169311 and rs6137473 polymorphisms were positively associated with developing the AIS (OR = 1.98; 95% CI = 1.2-3.3 and OR = 3.16; 95% CI = 1.4-7.3, respectively). The rs6137473 polymorphism was associated with the lumbar modifier B and C compared to A (OR = 2.52; 95% CI = 1.1-5.8). Conclusions: PAX-1 polymorphisms were associated with an increased risk of developing the AIS and with curve severity and can be used as a biomarker to map the risk of developing surgical-grade AIS, guiding the treatment of patients.

Semi-automatic method for pre-surgery scoliosis classification on X-ray images using Bending Asymmetry Index.

PURPOSE: Bending Asymmetry Index (BAI) has been proposed to characterize the types of scoliotic curve in three-dimensional ultrasound imaging. Scolioscan has demonstrated its validity and reliability in scoliosis assessment with manual assessment-based X-ray imaging. The objective of this study is to investigate the ultrasound-derived BAI method to X-ray imaging of scoliosis, with supplementary information provided for the pre-surgery planning. METHODS: About 30 pre-surgery scoliosis subjects (9 males and 21 females; Cobb: 50.9 ± 19.7°, range 18°-115°) were investigated retrospectively. Each subject underwent three-posture X-ray scanning supine on a plain mattress on the same day. BAI is an indicator to distinguish structural or non-structural curves through the spine flexibility information obtained from lateral bending spinal profiles. BAI was calculated semi-automatically with manual annotation of vertebral centroids and pelvis level inclination adjustment. BAI classification was validated with the scoliotic curve type and traditional Lenke classification using side-bending Cobb angle measurement (S-Cobb). RESULTS: 82 curves from 30 pre-surgery scoliosis patients were included. The correlation coefficient was R2 = 0.730 (p < 0.05) between BAI and S-Cobb. In terms of scoliotic curve type classification, all curves were correctly classified; out of 30 subjects, 1 case was confirmed as misclassified when applying to Lenke classification earlier, thus has been adjusted. CONCLUSION: BAI method has demonstrated its inter-modality versatility in X-ray imaging application. The curve type classification and the pre-surgery Lenke classification both indicated promising performances upon the exploratory dataset. A fully-automated of BAI measurement is surely an interesting direction to continue our endeavor. Deep learning on the vertebral-level segmentation should be involved in further study.

Use of Temporary Rod and Intraoperative Neuroimaging for Correction of Adolescent Idiopathic Scoliosis: 2-Dimensional Operative Video.

Adolescent idiopathic scoliosis (AIS) is an abnormal lateral curvature of the spine that arises during the pubescent growth spurt. AIS mainly affects females in the age group of 10 to 16 yr, with a prevalence of about 1% to 3% in the at-risk population.1 Treatment options vary depending on disease presentation and severity. Mild curvature mainly requires periodic observation for disease progression, whereas more moderate curvature can necessitate bracing or corrective surgery.2 Here, we present the use of a temporary rod and neuroimaging for the correction of Lenke type 1 spinal curvature in an AIS patient. An inferior facetectomy is performed, and a Lenke probe is used for entry into the pedicle and vertebral body. The channel is sounded before and after tapping to check for adequate walls prior to insertion of the pedicle screw. The ARTIS pheno is brought into the field, which uses fluoroscopy to create a 3-dimensional (3D) representation of the instrumentation within the spine. A temporary rod is placed in the concavity, and a combination of corrective techniques, including a rod roll, apical translation, and reduction, is performed to bring up the concavity, derotate the spine, and translate the spine. The permanent rod is then placed in the convexity, and compression is performed to bring down the scapular prominence. The temporary rod is then removed, and a final rod is placed to complete the 3D correction. The patient consented to the procedure, and an informed written consent was obtained from the patient to use her photographs and video recordings for publication.

Preoperative supine traction radiographs often result in higher Lenke classifications than supine bending radiographs in adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective chart and radiographic review. OBJECTIVE: The purpose of this study is to determine if both traction and side-bending radiographs yield the same Lenke classification. Supine side-bending radiographs are used to evaluate curve flexibility and assign Lenke classification in Adolescent Idiopathic Scoliosis (AIS). Supine traction radiographs are another tool used by treating surgeons to gauge flexibility and appropriate levels for spinal fusion in AIS. METHODS: Retrospective chart and radiographic review were performed on AIS patients that underwent a posterior spinal fusion from 2008 to 2017. Cobb angles and Lenke classifications were determined on all upright posterioanterior (PA) spine radiographs, supine traction radiographs, and four supine bending radiographs. Statistical analysis using independent t tests and chi-square tests as appropriate were compared between patients with or without discordant Lenke classifications with p value set at < 0.05 for statistical significance. RESULTS: 184 patients met inclusion criteria, 36 males and 148 females. The average Cobb angle for the proximal thoracic (PT) curve was 27.2°, main thoracic (MT) curve was 60.5°, and thoracolumbar/lumbar (TL/L) curve was 48.0°. Significantly less curve correction was found with supine traction radiographs compared with bending radiographs: PT (23.1° vs 18.9°, p < 0.001), MT (38.9° vs 37.9°, p = 0.015), and TL/L (25.9° vs. 18.0°, p < 0.001). Lenke Classification was found concordant in 151/184 (82.1%). Traction views in the discordant Lenke classification group demonstrated less curve correction than those in the concordant group: PT (27.4° vs. 22.1°, p = 0.011), MT (45.3° vs. 37.5°, p < 0.001), and TL/L (29.3° vs 25.1°, p = 0.019). CONCLUSION: Supine traction and supine bending radiographs provided a concordant Lenke classification 82.1% of the time. However, supine traction radiographs demonstrate less curve correction, a higher Lenke classification, and underestimated the TL/L curve correction to a greater degree. A single supine traction film is not an adequate substitute to side-bending radiographs when determining Lenke classification in patients with Adolescent Idiopathic Scoliosis. LEVEL OF EVIDENCE: III.

Choosing the Distal Fusion Levels in Lenke Type 1 Adolescent Idiopathic Scoliosis: How Do the Existing Classifications and Recommendations Guide Us?

STUDY DESIGN: Retrospective cohort. OBJECTIVE: (a) To compare the recommendations of Lenke and Peking Union Medical College (PUMC) classifications in choosing distal fusion levels in Lenke 1 adolescent idiopathic scoliosis (AIS) curves and (b) to analyze whether the variability in distal fusion levels influences treatment outcomes. METHODS: Hospital records of Lenke 1 AIS patients operated for single stage, posterior-only deformity correction were analyzed. Distal fusion levels recommended by Lenke and PUMC classifications were calculated and were compared with the actual distal fusion levels. The study population was divided based on whether the actual distal fusion levels were in agreement, shorter or longer than those recommended by Lenke classification. Subgroup analysis of Lenke 1C curves was done. The groups were compared with regard to the following outcome measures: Cobb angle correction, postoperative sagittal vertical axis, postoperative C7 offset, and Scoliosis Research Society-22r (SRS-22r) score at 24 months. RESULTS: The distal fusion levels recommended by the 2 classifications were in agreement in 92 of 104 cases. In all the cases with disparity, Lenke classification recommended shorter fusions than the PUMC classification. No statistically significant difference was observed in the outcome measures-whether the actual distal fusion levels were in agreement, shorter, or longer than those recommended by the Lenke classification or whether or not the recommendations for selective fusion of any of these classifications were adhered to. CONCLUSION: Lenke classification can save fusion levels without compromising on treatment outcomes when compared with PUMC classification. Variability in choice of distal fusion levels is not clinically significant at 24-month follow-up.

Association Between Vertebral Rotation Pattern and Curve Morphology in Adolescent Idiopathic Scoliosis.

OBJECTIVES: Although rotation is an important aspect of pathogenesis of adolescent idiopathic scoliosis (AIS), there are no studies demonstrating rotation pattern by directly measuring rotation angle in computed tomography (CT) images. The present retrospective comparative radiographic study was conducted to evaluate the rotation pattern in AIS and its relation to curve morphology and Lenke classification. METHODS: The study included 245 patients diagnosed with AIS and evaluated with a preoperative CT scan. Rotation angle of each vertebrae was measured using reconstructed axial CT images. Lenke classification of scoliosis curvature, Cobb angle, location of apical vertebra and end vertebra, level of most rotated vertebra (MRV), and rotational shift vertebra were recorded. Student's t-test, analysis of variance test, and correlation analysis were performed to identify the characteristics of rotation patterns in each Lenke type. RESULTS: The rotation angle of MRV was significantly correlated with the Cobb angle. The level of MRV and rotation angle of MRV demonstrated significant correlation in both the main thoracic curve and lumbar curve, which signified that MRV located near the thoracolumbar junction is related to more severe rotational deformity. The level of MRV was also significantly correlated to the Cobb angle in both the main thoracic curve and lumbar curve. The types of structural curves proximal to major structural curves, such as type 2, 4, and 6, demonstrated more severe rotational and coronal plane deformities as compared with types 1, 3, and 5. CONCLUSIONS: Curves with different Lenke types demonstrated different levels of MRV and severity of rotation. The results suggest that different center levels of rotation, signified by MRV, are a factor determining curve morphology. The findings would be a basis of connection between 2-dimensional classification and transverse plane deformity.

Impact of pelvic obliquity on coronal alignment in patients with adolescent idiopathic scoliosis.

STUDY DESIGN: Retrospective study. OBJECTIVE: To investigate pelvic obliquity prevalence and its coronal alignment effects in patients with adolescent idiopathic scoliosis (AIS). Pelvic obliquity observed on standing radiographs could affect coronal alignment; however, its incidence or relationship with coronal alignment remains unclear. METHODS: Data of 141 patients with AIS (11 men, 130 women; mean age, 14.2 years) were retrospectively analyzed. Pelvic obliquity (pelvic coronal obliquity angle (PCOA) value ≥ 3°) was evaluated on standing radiographs; PCOAs were classified into two groups: right-upward and left-upward. Cobb angle and flexibility of proximal thoracic, main thoracic, thoracolumbar/lumbar curve, radiographic shoulder height (RSH), L4 tilt, and coronal balance were measured. Iliac crest and femoral head height differences were measured to evaluate correlations between pelvic obliquity and leg length discrepancy. We compared patients with and without pelvic obliquity according to Lenke classifications. RESULTS: Among 141 patients, 33 (23%) showed pelvic obliquity: 12 were type 1, 3 were type 2, 1 was type 3, 13 were type 5, and 4 were type 6. Right-upward obliquity was observed in 25 patients (76%), all B or C curves; left-upward obliquity was observed in 8 (24%) and most were lumbar modifier A curves. PCOA and iliac crest height difference correlated with femoral head height difference. Among patients with Lenke type 1 with and without pelvic obliquity, those with right-upward pelvic obliquity showed significantly greater absolute RSH values, while those with left-upward pelvic obliquity showed significant smaller absolute RSH values. Among patients with Lenke types 5 and 6, those with pelvic obliquity showed significantly greater L4 tilt absolute values. CONCLUSIONS: Pelvic obliquity was frequently observed in patients with AIS, especially lumbar scoliosis. Right-upward pelvic obliquity influenced by lumbar curves promoted shoulder imbalance and left-upward obliquity compensated for shoulder imbalance in Lenke type 1. LEVEL OF EVIDENCE: Level 3.

An ontology-based module of the information system ScolioMedIS for 3D digital diagnosis of adolescent scoliosis.

BACKGROUND AND OBJECTIVE: Conventional information systems are built on top of a relational database. The main weakness of these systems is impossibility to define stable data schema ahead when the knowledge of the system is evolving and dynamic. The widely accepted alternatives to relational databases are ontologies that can be used for designing information systems. Many research papers describe various methods for improving reliability and precision in generating the type of the Lenke classification based on the image processing techniques or a computer program, but all of them require radiograph images. The main objective of this paper is to demonstrate the development of an ontology-based module of the information system ScolioMedIS for adolescent idiopathic scoliosis (AIS) diagnosis and monitoring, which uses optical 3D methods to determine the Lenke classification of AIS and to avoid harmful effects of traditional radiation diagnosis. METHODS: For creating an ontology-based module of the ScolioMedIS we used the following steps: specification, conceptualization, formalization and implementation. In the specification and conceptualization phase we performed data collection and analysis to define domain, concepts and relationships for ontology design. In the formalization and implementation stage we developed the OBR-Scolio ontology and the ontology-based module of the ScolioMedIS. The module employs the Protégé-OWL API, as a collection of Java interfaces for the OBR-Scolio ontology, which enables the creating, deleting, and editing of the basic elements of the OBR-Scolio ontology, as well as the querying of the ontology. RESULTS: The ontology-based module of ScolioMedIS is tested on the datasets of 20 female and 15 male patients with AIS between the ages of 11 and 18, to categorize spinal curvatures and to automatically generate statistical indicators about the frequency of the basic spinal curvatures, degree of progression or regression of deformity and statistical indicators about curvature characteristics according to the Lenke classification system and Lenke scoliosis types. Results are then compared with analysis of the Lenke classification of 315 observed patients, performed using traditional radiation techniques. CONCLUSIONS: This part of the system allows continuous monitoring of the progression/regression of spinal curvatures for each registered patient, which may provide a better management of scoliosis (diagnosis and treatment).

Comparison of Extending Fusion to Thoracic Curve Versus Thoracolumbar/Lumbar Fusion in Posterior Fusion of Patients with Lenke 5C: Variation in Upper End Vertebrae Tilt Affected Coronal Balance.

BACKGROUND: Extended fusion can be performed in patients with Lenke 5C adolescent idiopathic scoliosis (AIS) with a large and relatively rigid thoracic curve. Progression of the thoracic curve is related to coronal imbalance. We aimed to determine the correlation between the upper instrumented vertebra choice and coronal balance in patients with Lenke 5C AIS. METHODS: A total of 61 patients with Lenke 5C AIS underwent posterior fusion from 2009 to 2015 in a single institution with ≥2 years of follow-up data available. The extended fusion group (n = 32) and thoracolumbar/lumbar (TL/L) fusion group (n = 29) were compared for the correction rates for the main TL/L and thoracic curves, coronal balance, upper end vertebra (UEV) tilt, and Scoliosis Research Society-22 questionnaire score. RESULTS: Both groups had excellent correction of the main TL/L curve, and the extended fusion group had a significantly greater correction rate of the thoracic curve than the TL/L fusion group (70.2% vs. 57.3%). The incidence of coronal imbalance was similar in both groups. The spontaneous change in UEV tilt was associated with the change in coronal balance from the first to the final follow-up examination. In the TL/L fusion group, the increase in UEV tilt from the first to final follow-up visit resulted in improved coronal balance at the final follow-up examination. Both groups had similar Scoliosis Research Society-22 questionnaire scores at 2 years postoperatively. CONCLUSIONS: In patients with Lenke 5C AIS, thoracic curve fusion results in better correction of the thoracic curve but no improvement in coronal balance. With TL/L fusion, a postoperative UEV tilt >5° leads to better coronal balance.

Three-Dimensional Radiographic Analysis of Two Distinct Lenke 1A Curve Patterns.

STUDY DESIGN: Retrospective review of three-dimensional (3D) imaging from a multicenter database of surgically treated adolescent idiopathic scoliosis (AIS) patients. OBJECTIVE: To use 3D analysis software to compare Lenke 1AR and 1AL curves in the coronal, sagittal, and axial planes. BACKGROUND DATA: The Lenke 1AR and AL curve patterns have been shown to be two distinct curve types, with 1AL curves being more likely to add on after fusion. Analysis in 3D may help define some of the intricacies of these two curves. METHODS: Ninety-four AIS patients with Lenke 1A curves and upright biplanar scanned radiographs were reviewed. Analysis was performed using 3D reconstruction software to evaluate the 3D coronal, sagittal and axial plane deformities. Coronal L4 tilt was used to distinguish between the two curve patterns. RESULTS: The main thoracic Cobb was not significantly different between the AR (n = 43) and AL (n = 51) curves (52° ± 8° vs. 50° ± 5°; p = .25). The thoracolumbar/lumbar Cobb was significantly smaller in the AR curves (28° ± 8° vs. 32° ± 7°; p = .02). In the sagittal plane, T5-T12 kyphosis and T12-S1 lordosis were not significantly different (p >.2); however, the T10-L2 alignment was significantly more lordotic in the AR curves (11° ± 8° vs. 4° ± 10° lordosis; p <.001). In the axial plane, thoracic apical rotation was significantly greater in AR curves (21° ± 6° vs. 14° ± 6°; p <.001) and lumbar apical rotation was significantly smaller in AR curves (1° ± 5° vs. 6° ± 5°; p <.001). CONCLUSION: 3D spinal analysis demonstrates that 1AR and AL curves are distinctly different in all three planes. Although the treatment-based Lenke classification system combines these two curve patterns into one curve type, the 3D assessment suggests there are clear features that differentiate these curve patterns. The differing features of the nonstructural lumbar curves may help define the variance in fusion level selection and risk of adding-on for these two curve patterns. LEVEL OF EVIDENCE: Level II, prognostic.

Coronal Imbalance in Lenke 5C Adolescent Idiopathic Scoliosis Regarding Selecting the Lowest Instrumented Vertebra: Lower End Vertebra versus Lower End Vertebra +1 in Posterior Fusion.

BACKGROUND: Choosing the fusion level for posterior fusion in patients with Lenke 5C adolescent idiopathic scoliosis (AIS) is highly associated with coronal balance. Previous studies indicated that in patients with lowest end vertebra tilt >25°, surgeons could extend distal fusion to avoid coronal imbalance (CIB). This study aimed to assess the risk factors for CIB in Lenke 5C scoliosis and to discuss how to select fusion level. METHODS: We reviewed 59 patients with Lenke 5C AIS in 1 institution with at least 2 years follow-up from 2010 to 2015. Preoperative and 3-month and 2-year postoperative follow-up radiographs were measured using several specific measurements related to coronal balance. Patients were categorized into an LEV (lower end vertebra) group and an LEV+1 group. RESULTS: CIB was found in 6/31 patients in the LEV+1 group at final follow-up and not found in the LEV group at the first or final follow-up. The C7 plumb line shifted to the convex side of the central sacral vertical line in 47/59 patients, including all of the 19 patients with CIB after surgery. Patients who underwent fusion at LEV+1 with >25° LEV tilt also showed poor results regarding CIB. Statistically, coronal balance at the final follow-up was correlated with preoperative bending lumbosacral hemicurve (P = 0.002) and all 6 patients with CIB had bending lumbosacral hemicurve >15°. No significant difference was found in Scoliosis Research Society-22 questionnaire scores between the 2 groups at 2-year-follow-up. CONCLUSIONS: Distal fusion extension at LEV+1 is more likely to result in CIB at the first and final follow-up, especially when the bending lumbosacral hemicurve is >15°. Fusion at LEV+1 should not be chosen when LEV is at L4.