Showing papers on "Cobb angle published in 2021"

Prospective Follow-up Report on Anterior Vertebral Body Tethering for Idiopathic Scoliosis: Interim Results from an FDA IDE Study.

Abstract: BACKGROUND Anterior vertebral body tethering (aVBT) has emerged as a novel treatment option for patients with idiopathic scoliosis. We present the results from the first U.S. Food and Drug Administration (FDA) Investigational Device Exemption (IDE) study on aVBT. METHODS In this prospective review of a retrospective data set, eligible patients underwent aVBT at a single center from August 2011 to July 2015. Inclusion criteria included skeletally immature patients with Lenke type-1A or 1B curves between 30° and 65°. Clinical and radiographic parameters were collected, with the latter measured by an independent reviewer. RESULTS Fifty-seven patients (49 girls and 8 boys), with a mean age (and standard deviation) of 12.4 ± 1.3 years (range, 10.1 to 15.0 years), were enrolled in the study. The patients had a mean of 7.5 ± 0.6 levels tethered, the mean operative time was 223 ± 79 minutes, and the mean estimated blood loss was 106 ± 86 mL. The patients were followed for an average of 55.2 ± 12.5 months and had a mean Risser grade of 4.2 ± 0.9 at the time of the latest follow-up. The main thoracic Cobb angle was a mean of 40.4° ± 6.8° preoperatively and was corrected to 18.7° ± 13.4° at the most recent follow-up. In the sagittal plane, T5-T12 kyphosis measured 15.5° ± 10.0° preoperatively, 17.0° ± 10.1° postoperatively, and 19.6° ± 12.7° at the most recent follow-up. Eighty percent of patients had curves of <30° at the most recent follow-up. The most recent Scoliosis Research Society (SRS) scores averaged 4.5 ± 0.4, and scores on the self-image questionnaire averaged 4.4 ± 0.7. No major neurologic or pulmonary complications occurred. Seven (12.3%) of 57 patients had a revision: 5 were done for overcorrection and 2, for adding-on. CONCLUSIONS Anterior VBT is a promising technique that has emerged as a treatment option for patients with immature idiopathic scoliosis. We present the results from the first FDA-approved IDE study on aVBT, which formed the basis for the eventual Humanitarian Device Exemption approval. The findings affirm the safety and efficacy of this technique and suggest opportunities for improvement, particularly with respect to reoperation rates. LEVEL OF EVIDENCE Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Anterior Vertebral Body Tethering (AVBT) for Treatment Of Idiopathic Scoliosis in the Skeletally Immature: Results of 112 Cases.

Abstract: STUDY DESIGN Prospective case series. OBJECTIVE Determine the efficacy of anterior vertebral body tethering (AVBT) in skeletally immature patients. SUMMARY OF BACKGROUND DATA The value of AVBT is currently unclear given the paucity of available data. METHODS Consecutive skeletally immature patients with idiopathic scoliosis were treated with AVBT between 2012 and 2018 by one of two surgeons working at two independent centers and followed up for >2 years. Data were collected prospectively and supplemented retrospectively where necessary. Outcomes were measured preoperatively, at first erect radiograph (FE), 1-year postoperatively and at most recent follow up (FU). RESULTS One hundred twelve patients underwent 116 primary tethering procedures (108 thoracic and eight lumbar tethers). Four patients had primary tethering of both lumbar and thoracic curves. At surgery mean age was 12.7 ± 1.4 years (8.2-16.7) and Risser 0.5 ± 0.9 (0-3). Follow up was mean 37 ± 9 months (15-64). Preoperative mean coronal Cobb angle of the 130 tethered curves was 50.8° ± 10.2 (31-81) and corrected significantly to 26.6° ± 10.1 (-3-61) at FE radiograph (P < 0.001). Further significant improvement was seen from FE to 1-year, to mean 23.1° ± 12.4 (-37-57) (P < 0.001). There was a small but significant increase between 1-year and FU to 25.7° ± 16.3 (-32-58) (P < 0.001), which appeared to reflect tether breakage. Untethered minor curves were corrected from 31.0° ± 9.5 (3-57) to 20.3° ± 10.3 (0-52) at FU (P < 0.001). Rib hump was corrected from 14.1 ± 4.8 (0-26) to 8.8° ± 5.4 (0-22) at FU (P < 0.01). Twenty-five patients (22%) had 28 complications. Fifteen patients (13%) requiring 18 revision operations including six completed and one awaited fusions. CONCLUSION AVBT of immature cases is associated with satisfactory deformity correction in the majority of cases. However, complication and revision rates suggest the need for improved implants and patient selection. Long-term follow-up remains crucial to establish the true efficacy of this procedure.Level of Evidence: 3.

Complications, Reoperations, and Mid-Term Outcomes Following Anterior Vertebral Body Tethering Versus Posterior Spinal Fusion: A Meta-Analysis.

Abstract: Background Anterior vertebral body tethering (AVBT) is a growth-modulation technique theorized to correct adolescent idiopathic scoliosis (AIS) without the postoperative stiffness imposed by posterior spinal fusion. However, data are limited to small series examining short-term outcomes. To assess AVBT's potential as a viable alternative to posterior spinal fusion (PSF), a comprehensive comparison is warranted. The purpose of this meta-analysis was to compare postoperative outcomes between patients with AIS undergoing PSF and AVBT. Our primary objective was to compare complication and reoperation rates at available follow-up times. Secondary objectives included comparing mid-term Scoliosis Research Society (SRS)-22 scores, and coronal and sagittal-plane Cobb angle corrections. Methods We performed a systematic review of outcome studies following AVBT and/or PSF procedures. The inclusion criteria included the following: AVBT and/or PSF procedures; Lenke 1 or 2 curves; an age of 10 to 18 years for >90% of the patient population; <10% non-AIS scoliosis etiology; and follow-up of ≥1 year. A single-arm, random-effects meta-analysis was performed. Deformity corrections, complication and reoperation rates, and postoperative SRS-22 scores were recorded. Results Ten AVBT studies (211 patients) and 14 PSF studies (1,069 patients) were included. The mean follow-up durations were similar for both groups. Pooled complication rates were 26% for AVBT versus 2% for PSF, and reoperation rates were 14.1% for AVBT versus 0.6% for PSF with nonoverlapping confidence intervals (CIs). The pooled reoperation rate among studies with follow-up times of ≥36 months was 24.7% in AVBT versus 1.8% in PSF. Deformity correction, clinical outcomes, and mid-term SRS-22 scores were similar. Conclusions Our study showed greater rates of complications and reoperations with AVBT compared with PSF. Reoperation rates were significantly greater in AVBT studies with longer follow-up (≥36 months). Deformity correction, clinical outcomes, and mid-term SRS-22 scores were similar. While a potential fusionless treatment for AIS merits excitement, clinicians should consider AVBT with caution. Future long-term randomized prospective studies are needed. Level of Evidence Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Initial intraoperative experience with robotic-assisted pedicle screw placement with stealth navigation in pediatric spine deformity: an evaluation of the first 40 cases

Abstract: Pedicle screw fixation in pediatric spine surgery has become common practice given the fixation stability and improved curve correction. However, due to proximity to vital structures, accuracy is paramount. Literature has reported accuracy rates from 87.5 to 90% using traditional freehand techniques. This study presents our initial experience with pedicle screw placement using the newest generation of spinal robotics for treatment of pediatric spinal deformity. A cohort of patients, aged 8–21 years, undergoing spinal fusion surgery using robotic-assisted technology was reviewed. Diagnoses, Cobb angles, surgical time, robot time, number of screws placed, and complications were recorded. Accuracy of screw placement was assessed based on analysis of successful screw execution, evaluation screw position using intraoperative fluoroscopy and post-operative radiographs, and clinical evaluation. The average age was 14.5 years. Prevalent diagnoses included idiopathic (65%) and neuromuscular scoliosis (13%). Mean preoperative curve measured 66.8°. The median time for operation was 235 minutes with medians of 8 levels fused and 5 screws placed per patient. Of the 314 screws placed, we recorded a 98.7% accuracy rate. Lateral deviation was the most common cause of malpositioning. Post-operative plain films revealed no grossly misplaced screws. There were no perioperative neurologic deficits or malpositioned screws requiring reoperation. This is the first reported series of navigated spinal robotics used for pedicle screw placement in children. Our clinical success rate was 98.7% and there were no clinically relevant screw related complications. The study shows promising initial results of combined robotic-navigation techniques in pediatric patients.

Multicenter assessment of surgical outcomes in adult spinal deformity patients with severe global coronal malalignment: determination of target coronal realignment threshold

Abstract: OBJECTIVE The impact of global coronal malalignment (GCM; C7 plumb line-midsacral offset) on adult spinal deformity (ASD) treatment outcomes is unclear. Here, the authors' primary objective was to assess surgical outcomes and complications in patients with severe GCM, with a secondary aim of investigating potential surgical target coronal thresholds for optimal outcomes. METHODS This is a retrospective analysis of a prospective multicenter database. Operative patients with severe GCM (≥ 1 SD above the mean) and a minimum 2-year follow-up were identified. Demographic, surgical, radiographic, health-related quality of life (HRQOL), and complications data were analyzed. RESULTS Of 691 potentially eligible operative patients (mean GCM 4 ± 3 cm), 80 met the criteria for severe GCM ≥ 7 cm. Of these, 62 (78%; mean age 63.7 ± 10.7 years, 81% women) had a minimum 2-year follow-up (mean follow-up 3.3 ± 1.1 years). The mean ASD-Frailty Index was 3.9 ± 1.5 (frail), 50% had undergone prior fusion, and 81% had concurrent severe sagittal spinopelvic deformity with GCM and C7-S1 sagittal vertical axis (SVA) positively correlated (r = 0.313, p = 0.015). Surgical characteristics included posterior-only (58%) versus anterior-posterior (42%) approach, mean fusion of 13.2 ± 3.8 levels, iliac fixation (90%), 3-column osteotomy (36%), operative duration of 8.3 ± 3.0 hours, and estimated blood loss of 2.3 ± 1.7 L. Final alignment and HRQOL significantly improved (p < 0.01): GCM, 11 to 4 cm; maximum coronal Cobb angle, 43° to 20°; SVA, 13 to 4 cm; pelvic tilt, 29° to 23°; pelvic incidence-lumbar lordosis mismatch, 31° to 5°; Oswestry Disability Index, 51 to 37; physical component summary of SF-36 (PCS), 29 to 37; 22-Item Scoliosis Research Society Patient Questionnaire (SRS-22r) Total, 2.6 to 3.5; and numeric rating scale score for back and leg pain, 7 to 4 and 5 to 3, respectively. Residual GCM ≥ 3 cm was associated with worse SRS-22r Appearance (p = 0.04) and SRS-22r Satisfaction (p = 0.02). The minimal clinically important difference and/or substantial clinical benefit (MCID/SCB) was met in 43%-83% (highest for SRS-22r Appearance [MCID 83%] and PCS [SCB 53%]). The severity of baseline GCM (≥ 2 SD above the mean) significantly impacted postoperative SRS-22r Satisfaction and MCID/SCB improvement for PCS. No significant partial correlations were demonstrated between GCM or SVA correction and HRQOL improvement. There were 89 total complications (34 minor and 55 major), 45 (73%) patients with ≥ 1 complication (most commonly rod fracture [19%] and proximal junctional kyphosis [PJK; 18%]), and 34 reoperations in 22 (35%) patients (most commonly for rod fracture and PJK). CONCLUSIONS Study results demonstrated that ASD surgery in patients with substantial GCM was associated with significant radiographic and HRQOL improvement despite high complication rates. MCID improvement was highest for SRS-22r Appearance/Self-Image. A residual GCM ≥ 3 cm was associated with a worse outcome, suggesting a potential coronal realignment target threshold to assist surgical planning.

Measurable Thoracic Motion Remains at 1 Year Following Anterior Vertebral Body Tethering, with Sagittal Motion Greater Than Coronal Motion.

Abstract: Background Anterior vertebral body tethering is an alternative to fusion surgery for the treatment of adolescent idiopathic scoliosis (AIS) that is purported to preserve spinal motion. There is limited information regarding the measurable motion that is maintained over the instrumented levels following thoracic anterior vertebral body tethering surgery in humans. The purpose of the present study was to assess radiographic spinal motion 1 year after anterior vertebral body tethering. Methods As part of a prospective U.S. Food and Drug Administration investigational device exemption study, 32 patients were treated with thoracic anterior vertebral body tethering. At 1 year postoperatively, patients were evaluated with standing flexion-extension and side-bending radiographs in a microdose biplanar slot scanning imaging system. The angle subtended by the screws at the upper instrumented vertebra (UIV) and lower instrumented vertebra (LIV) was measured on left and right-bending radiographs to evaluate the coronal arc of motion and was compared with preoperative values over the same levels. At 1 year postoperatively, the sagittal Cobb angle was measured over the instrumented levels on flexion and extension radiographs. Results Side-bending radiographs revealed that the mean angle subtended by the screws changed from 15° ± 8° on left-bending radiographs to 8° ± 6° on right-bending radiographs. The mean coronal arc of motion on bending was 7° ± 6°, with 20 (62.5%) of 32 patients having a coronal arc of motion of >5°. The mean preoperative coronal arc of motion over the instrumented segments was 30° ± 9°. On flexion-extension lateral radiographs made at 1 year postoperatively, the mean kyphotic angle over the instrumented segments was 33° ± 13° in flexion and 11° ± 14° in extension, for a mean postoperative arc of motion of 21° ± 12° between flexion and extension radiographs. Conclusions At 1 year following thoracic anterior vertebral body tethering for the treatment of AIS, the thoracic spine showed a measurable range of coronal and sagittal plane motion over the instrumented levels without evidence of complete autofusion. Motion in the coronal plane decreased by 77% following anterior vertebral body tethering. These findings provide proof of concept that sagittal spinal motion is preserved after thoracic anterior vertebral body tethering, although the functional importance remains to be determined. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Cervical Spine Alignment in the Sagittal Axis: A Review of the Best Validated Measures in Clinical Practice.

Abstract: Study Design:Review of the best-validated measures of cervical spine alignment in the sagittal axis.Objective:Describe the C2-C7 Cobb Angle, C2-C7 sagittal vertical axis, chin-brow to vertical angl...

Automatic Detection and Measurement of Spinous Process Curve on Clinical Ultrasound Spine Images

Abstract: The ultrasound (US) imaging technique has been applied to scoliosis assessment, and the proxy Cobb angle can be acquired on the US coronal images. The spinous process angle (SPA) is a valuable parameter to indicate 3-D deformity of spine. However, the SPA cannot be measured on US images since the spinous process (SP) is merged in the soft tissue layer and impossible to be identified on the coronal view directly. A new method based on the gradient vector flow (GVF) snake model was proposed to automatically locate SP position on the US transverse images, and the density-based spatial clustering of application with noise (DBSCAN) was used to remove the outliers out of the detected location results. With marking the SP points on the US coronal image, the SP curve was interpolated and the SPA was measured. The algorithm was evaluated on 50 subjects with various severity of scoliosis, and two raters measured the SPA on both US images and radiographs manually. The mean absolute differences (MADs) of SPAs obtained from the two modalities were 3.4° ± 2.4° and 3.6° ± 2.8° for the two raters, respectively, which were less than the clinical acceptance error (5°), and the results reported a good linear correlation ( ${r} > 0.85$ ) between the US method and radiography. It indicates that the proposed method can be a promising approach for SPA measurement using the US imaging technique.

Magnetically controlled growing rods in early onset scoliosis: radiological results, outcome, and complications in a series of 22 patients

Abstract: Magnetically controlled growing rods (MCGR) for the surgical treatment of early onset scoliosis (EOS) allow non-invasive outpatient based distractions during spinal growth The purpose of this study is to present the results of a single center case series of 22 patients, evaluate the effect of MCGR treatment on the development of spino-pelvic parameters during growth, and report initial outcomes after end of treatment Prospectively collected data of 22 EOS patients with MCGR treatment has been analyzed The following radiological parameters were measured before index surgery, after index surgery, 1 year after index surgery, and at last follow-up: Cobb angle of the major curves, thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic incidence (PI), pelvic tilt (PT), and sacral slope (SS) Mean age at index surgery was 95 years (range: 4–14 years) Mean length of follow-up was 476 months (range: 25–121 months) Etiology of diagnosis was idiopathic in 14 patients, associated with neurofibromatosis in 2 patients, and neuromuscular or syndromic in 6 patients Mean Cobb angle of the major curve was 57° preoperatively and 29° at last follow-up (p 005) Mean LL was 528° preoperatively and 532° at last follow-up (p > 005) Mean PI was 432° preoperatively and 463° at last follow-up (p > 005) Mean PT was 41° preoperatively and 58° at last follow-up (p > 005) Mean SS was 392° preoperatively and 417° at last follow-up (p > 005) 14 patients finished treatment: nine received final fusion and five received rod removal without fusion Twelve complications occurred: one deep wound infection, six patients developed proximal junctional kyphosis (PJK), one rod fracture, two rods failed to distract, one deformity progressed after rod removal and required spinal fusion, and one patient developed autofusion of the spine prior to end of treatment MCGR treatment is able to control deformity progression Complication rate was 545% Sagittal balance was not altered and treatment does not seem to have a negative impact on the development of spino-pelvic parameters during growth Optimal end of treatment for the individual patient still has to be defined

Risk Factor Analysis of Proximal Junctional Kyphosis after Surgical Treatment of Adult Spinal Deformity with Oblique Lateral Interbody Fusion.

Abstract: Study design A single-center retrospective study. Purpose To investigate the prevalence of proximal junctional kyphosis (PJK) and its risk factors after surgical treatment of adult spinal deformity (ASD) with oblique lateral interbody fusion (OLIF). Overview of literature Correction of ASD using OLIF has been developed because it is less invasive, and enables correction of severe deformities. Although PJK is a well-recognized complication after the correction of spinal deformity, few studies have evaluated the prevalence and risk factors for PJK after OLIF for ASD. Methods We reviewed 74 patients who underwent surgery for ASD. PJK was defined as a proximal junction sagittal Cobb angle exceeding 10°, and at least 10° greater than the preoperative measurement. We investigated the following as risk factors: age, sex, body mass index, medical history, number of fused segments, number of interbody fusions, number of OLIFs, number of osteotomies, level of upper instrumented vertebrae, lowest instrumented vertebrae, and radiographic parameters. Results The mean follow-up duration was 22.4 months and the mean age of the patients was 73.6 years. PJK was present in 19/74 patients (25.7%) and absent in 55/74 (74.3%). In the univariate analysis, those with PJK had a significantly higher proportion of patients with a history of vertebral compression fracture (7/19 patients [36.8%] vs. 6/55 patients [10.9%], p=0.027). Those with PJK had a significantly higher proportion of patients with fusion to the pelvis (18/19 patients [94.7%] vs. 34/55 patients [61.8%], p=0.016). According to the multivariate analysis, fusion to the pelvis was a significant risk factor for PJK. Conclusions Fusion to the pelvis was the most important risk factor for PJK. A history of vertebral compression fracture served as an additional risk factor for PJK. Clinicians should consider these factors before treating ASD patients with OLIF.

Radiographic scoliosis angle estimation: spline-based measurement reveals superior reliability compared to traditional COBB method

Abstract: Although being standard for scoliosis curve size estimation, COBB angle measurement is well known to be inaccurate, due to a high interobserver variance in end vertebra selection and end plate contour delineation. We propose a stepwise improvement by using a spline constructed from vertebra centroids to resemble spinal curve characteristics more closely. To enhance precision even further, a neural net was trained to detect the centroids automatically. Vertebra centroids in AP spinal X-ray images of varying quality from 551 scoliosis patients were manually labeled by 4 investigators. With these inputs, splines were generated and the computed curve sizes were compared to the manually measured COBB angles and to the curve estimation obtained from the neural net. Splines achieved a higher interobserver correlation of 0.92–0.95 compared to manual COBB measurements (0.83–0.92) and showed 1.5–2 times less variance, depending on the anatomic region. This translates into an average of 1° of interobserver measurement deviation for spline-based curve estimation compared to 3°–8° for COBB measurements. The neural net was even more precise and achieved mean deviations below 0.5°. In conclusion, our data suggest an advantage of spline-based automated measuring systems, so further investigations are warranted to abandon manual COBB measurements.

Exploring thoracic kyphosis and incident fracture from vertebral morphology with high-intensity exercise in middle-aged and older men with osteopenia and osteoporosis: a secondary analysis of the LIFTMOR-M trial

Abstract: Our aim was to explore change in kyphosis and vertebral fracture incidence following 8 months of high-intensity resistance and impact training (HiRIT) or machine-based isometric axial compression (IAC) training in men with osteopenia and osteoporosis. HiRIT and IAC improved posture. HiRIT participants did not experience progression or incident vertebral fracture. IAC participants did experience progression and incident vertebral fracture. The Lifting Intervention For Training Muscle and Osteoporosis Rehabilitation for Men (LIFTMOR-M) trial examined efficacy and safety of an eight-month, supervised, high-intensity progressive resistance and impact training (HiRIT) program compared with machine-based isometric axial compression (IAC) training in middle-aged and older men with low areal bone mineral density (aBMD). The primary purpose of the current work was to explore change in thoracic kyphosis and incident fracture from vertebral morphology following eight-months of HiRIT or IAC training. The secondary purpose was to explore change in clinical kyphosis measures for HiRIT, IAC and a non-randomized, matched control group. Men (≥ 45 yrs), with low aBMD, were recruited and randomized to HiRIT or IAC, or designated control. Clinical measures of thoracic kyphosis with inclinometry were determined. Cobb angle of kyphosis and vertebral fracture assessment using the Genant semi-quantitative method were determined from lateral thoracolumbar DXA (Medix DR, Medilink, France). Per-protocol (n = 40) and intention-to-treat (n = 93) analyses were conducted. Forty participants (HiRIT n = 20, IAC n = 20; 66.1 ± 7.8 yrs.; lumbar spine T-score − 0.1 ± 0.8; femoral neck T-score − 1.5 ± 0.5) underwent clinical kyphosis measures and thoracolumbar DXA at baseline and follow-up. No between-group differences were detected in kyphosis change, however, within-group improvements in neutral (HiRIT − 2.3 ± 0.8°; IAC − 2.5 ± 0.8°) and ‘standing tall’ (HiRIT − 2.4 ± 0.8°; IAC − 2.0 ± 0.8°) postures were observed (p < 0.05). HiRIT improved Cobb angle (− 3.5 ± 1.5°, p = 0.027) from baseline. Over the 8 months, no incident vertebral fractures nor progression of prevalent vertebral fractures occurred for HiRIT participants. Five incident fractures of thoracic vertebrae occurred for IAC and one wedge fracture progressed. Ninety-three participants underwent clinical kyphosis measures at both time-points (HiRIT n = 34, IAC n = 33, control n = 26). HiRIT exhibited a reduction in ‘standing tall’ kyphosis compared to control (− 2.3 ± 0.6° versus 1.4 ± 0.7°, p < 0.05), but no other between-group differences were detected. Although there was no difference in change between intervention groups, thoracic kyphosis appeared to improve in both HiRIT and IAC with exercise exposure. HiRIT improved 'standing tall' posture in comparison to usual activities. HiRIT was not associated with vertebral fracture progression or incident vertebral fracture, but for some IAC participants there was evidence of progression of vertebral fracture severity and incident vertebral fractures, in our small sample. Larger trials are required to confirm the observations of the current work, which was exploratory in nature.

The effectiveness of two different exercise approaches in adolescent idiopathic scoliosis: A single-blind, randomized-controlled trial

Abstract: Objectives The purpose of this study was to compare the efficacy of two different types of exercise methods in patients with adolescent idiopathic scoliosis. Methods In total, 28 subjects with adolescent idiopathic scoliosis with a mild curve magnitude (10°–26°) were randomly divided into two groups: the Schroth group (n = 14) and the core group (n = 14). The patients in the Schroth group were treated with supervised Schroth exercises, and the patients in the core group were treated with supervised core stabilization exercises; both groups performed the exercises for three days per week for a total of 10 weeks, and both were given additional traditional exercises to perform. Assessment included Cobb angle (Radiography), trunk rotation (Adam’s test), cosmetic trunk deformity (Walter Reed Visual Assessment Scale), spinal mobility (Spinal Mouse), peripheral muscle strength (Biodex System 4-Pro), and quality of life (Scoliosis Research Society-22 questionnaire). Results It was found that patients in the Schroth group showed greater improvement in Cobb angles, thoracic trunk rotation angle, cosmetic trunk deformity, spinal mobility, and quality of life than those in the core group (p<0.05), except for in lumbar trunk rotation angle. Peripheral muscle strength improvement was greater in the core group than in the Schroth group (p<0.05). Conclusion Schroth exercises are more effective than core stabilization exercises in the correction of scoliosis and related problems in mild adolescent idiopathic scoliosis, and core stabilization exercises are more effective than Schroth exercises in the improvement of peripheral muscle strength. Trial registration NCT04421157

Seg4Reg+: Consistency Learning Between Spine Segmentation and Cobb Angle Regression.

Abstract: Automated methods for Cobb angle estimation are of high demand for scoliosis assessment. Existing methods typically calculate the Cobb angle from landmark estimation, or simply combine the low-level task (e.g., landmark detection and spine segmentation) with the Cobb angle regression task, without fully exploring the benefits from each other. In this study, we propose a novel multi-task framework, named Seg4Reg+, which jointly optimizes the segmentation and regression networks. We thoroughly investigate both local and global consistency and knowledge transfer between each other. Specifically, we propose an attention regularization module leveraging class activation maps (CAMs) from image-segmentation pairs to discover additional supervision in the regression network, and the CAMs can serve as a region-of-interest enhancement gate to facilitate the segmentation task in turn. Meanwhile, we design a novel triangle consistency learning to train the two networks jointly for global optimization. The evaluations performed on the public AASCE Challenge dataset demonstrate the effectiveness of each module and superior performance of our model to the state-of-the-art methods.

An automated estimator for Cobb angle measurement using multi-task networks

Abstract: Scoliosis is a medical condition where a person’s spine has a sideways curve. The Cobb angle quantifying the degree of spinal curvature is the gold standard for a scoliosis assessment. Recently, the deep learning methods based on segmentation and landmark estimation both achieve high performance for automated Cobb angle measurement on X-rays. However, we notice that these methods utilize segmentation and landmark information separately. In this light, we propose an automated architecture that uses combined segmentation with landmark information to estimate 68 landmarks of 17 vertebrae. In addition, we consider spinal curvature described by 68 landmarks as a constraint to estimate the Cobb angle. Extensive experiment results which test on 240 X-rays demonstrate that our method improves the landmark estimation performance effectively and reduces the Cobb angle error.

The minimally invasive interbody selection algorithm for spinal deformity.

Abstract: Objective Minimally invasive surgery (MIS) for spinal deformity uses interbody techniques for correction, indirect decompression, and arthrodesis. Selection criteria for choosing a particular interbody approach are lacking. The authors created the minimally invasive interbody selection algorithm (MIISA) to provide a framework for rational decision-making in MIS for deformity. Methods A retrospective data set of circumferential MIS (cMIS) for adult spinal deformity (ASD) collected over a 5-year period was analyzed by level in the lumbar spine to identify surgeon preferences and evaluate segmental lordosis outcomes. These data were used to inform a Delphi session of minimally invasive deformity surgeons from which the algorithm was created. The algorithm leads to 1 of 4 interbody approaches: anterior lumbar interbody fusion (ALIF), anterior column release (ACR), lateral lumbar interbody fusion (LLIF), and transforaminal lumbar interbody fusion (TLIF). Preoperative and 2-year postoperative radiographic parameters and clinical outcomes were compared. Results Eleven surgeons completed 100 cMISs for ASD with 338 interbody devices, with a minimum 2-year follow-up. The type of interbody approach used at each level from L1 to S1 was recorded. The MIISA was then created with substantial agreement. The surgeons generally preferred LLIF for L1-2 (91.7%), L2-3 (85.2%), and L3-4 (80.7%). ACR was most commonly performed at L3-4 (8.4%) and L2-3 (6.2%). At L4-5, LLIF (69.5%), TLIF (15.9%), and ALIF (9.8%) were most commonly utilized. TLIF and ALIF were the most selected approaches at L5-S1 (61.4% and 38.6%, respectively). Segmental lordosis at each level varied based on the approach, with greater increases reported using ALIF, especially at L4-5 (9.2°) and L5-S1 (5.3°). A substantial increase in lordosis was achieved with ACR at L2-3 (10.9°) and L3-4 (10.4°). Lateral interbody arthrodesis without the use of an ACR did not generally result in significant lordosis restoration. There were statistically significant improvements in lumbar lordosis (LL), pelvic incidence-LL mismatch, coronal Cobb angle, and Oswestry Disability Index at the 2-year follow-up. Conclusions The use of the MIISA provides consistent guidance for surgeons who plan to perform MIS for deformity. For L1-4, the surgeons preferred lateral approaches to TLIF and reserved ACR for patients who needed the greatest increase in segmental lordosis. For L4-5, the surgeons' order of preference was LLIF, TLIF, and ALIF, but TLIF failed to demonstrate any significant lordosis restoration. At L5-S1, the surgical team typically preferred an ALIF when segmental lordosis was desired and preferred a TLIF if preoperative segmental lordosis was adequate.

Effects of 8 years of growth hormone treatment on scoliosis in children with Prader-Willi syndrome.

Abstract: Objective Scoliosis is frequently seen in children with Prader-Willi syndrome (PWS). There is still concern that growth hormone (GH) treatment might increase the risk of onset or progression of scoliosis. Short-term data suggested no adverse effects of GH on scoliosis, but long-term effects of GH treatment on development of scoliosis in PWS are unknown. This study investigated the effects of 8 years of GH treatment on scoliosis in children with PWS. Design Open-label, prospective cohort study in 103 children with PWS receiving GH for 8 years was analyzed. Prevalence and severity of scoliosis were compared to a group of 23 age-matched GH-untreated children with PWS. Methods Spine X-rays and DEXA-scans were performed, and Cobb angel was measured by two independent observers. Results After 8 years of GH treatment, at median age of 10.8 years, prevalence of scoliosis was 77.7%. No difference in prevalence or severity of scoliosis was found between GH-treated and age-matched untreated children with PWS (P = 0.409 and P = 0.709, respectively). Height SDS and trunkLBM were significantly higher in GH-treated children. Higher bone mineral density of the lumbar spine was found in children without scoliosis after 8 years of GH. Bone mineral apparent density of lumbar spine (BMADLS) SDS was associated with lower Cobb angle (r = -0.270, P = 0.008). Conclusions Eight years of GH treatment has no adverse effects on the prevalence and severity of scoliosis in children with PWS until 11 years of age. As BMADLS SDS is inversely associated with Cobb angle, it is pivotal to optimize the BMD status in children with PWS.

Asymmetrical activation and asymmetrical weakness as two different mechanisms of adolescent idiopathic scoliosis.

Abstract: There have been many studies on adolescent idiopathic scoliosis related abnormal muscle contractions of the spine. However, previous studies using surface electromyography to investigate paraspinal muscle asymmetry are controversial, lacking in clarity of results, and hindered by methodological limitations. The purpose of this study was to investigate the relationship between imbalance factors including surface electromyography activity according to the scoliosis curve type and leg length discrepancy and adolescent idiopathic scoliosis curve types. Seventy-nine patients with scoliosis were prospectively enrolled and were divided into five types: single thoracic, thoracolumbar, lumbar, double thoracic, and double major. Cobb angle and structural variables were measured. Surface electromyography examinations were conducted at the 7th, 12th thoracic erector spinae, 3rd lumbar erector spinae, and multifidus muscles during the superman position keeping prone spinal extension to lift the arms and legs off the floor. Whole spine radiographs were obtained to measure the Cobb angle, coronal imbalance, pelvic height and angle, and femoral head height. In the double major, thoracolumbar, and lumbar types, the mean root mean squared (RMS) EMG amplitudes were significantly higher on the convex side than the concave side (P < 0.005). In the DM type, the mean RMS EMG amplitudes of EST7 and ESL3 where the apex was located were significantly higher at the convex side than those of the concave side (P < 0.005, effect size (Cohen's d) for EST7/ESL3: 0.517/0.573). The TL and L types showed a similar pattern. The mean RMS EMG amplitudes of the EST12 concave side and MuL3 and ESL3 concave sides were significantly lower than those of the convex side in the TL and L types, respectively (P < 0.008, effect size (Cohen's d) for EST12/MuL3/ESL3: 0.960/0.264/0.448). Conversely, there were no significant differences in the single thoracic and double thoracic types. All structural variables (coronal imbalance, pelvic height and angle, and femur head height) were higher in the lumbar type, but only coronal imbalance was significantly different (P < 0.05). Different patterns of asymmetry of paraspinal muscles and structural variables were described based on the curvature of the spine. L type showed that EMG activity was asymmetric in the paraspinalis muscles where the apex was located and that structural asymmetry, such as coronal imbalance was significantly greater than other types. DM type showed similar paraspinalis asymmetry pattern to the ST type but there was no structural asymmetry in DM and ST types. TL type has the features of both thoracic and lumbar origins. Understanding these could contribute to the management in correcting scoliosis.

Minimally Invasive Surgery for Neuromuscular Scoliosis: Results and Complications at a Minimal Follow-up of 5 Years.

Abstract: STUDY DESIGN A prospective study. OBJECTIVE The aim of this study was to report the results of an alternative technique to growing rods (GR) for neuromuscular scoliosis using a minimally invasive fusionless surgery with a minimum of 5 years' follow-up. SUMMARY OF BACKGROUND DATA Conservative treatment is not effective in progressive neuromuscular scoliosis. Early surgery using GR is increasingly advocated to control the deformity while preserving spinal and thoracic growth before arthrodesis. These techniques still provide a high rate of complications. METHODS The technique relies on a bilateral double rod sliding instrumentation anchored proximally by four hooks claws and distally to the pelvis by iliosacral screws through a minimally invasive approach. The clinical and radiological outcomes of 100 consecutive patients with neuromuscular scoliosis who underwent this fusionless surgery with a minimum follow-up of 5 years were reviewed. RESULTS 6.5 ± 0.7 years after initial surgery, six patients were lost of follow-up and 11 died of unrelated raison. Of the 83 remaining patients at latest follow-up, mean Cobb angle was stable to 35.0° which correspond to 61% correction of the initial deformation. Mean pelvic obliquity was 29.6° (0.3°-80.0°) preoperatively and 7.2 (0.2°-23.5°) at latest follow-up. Correction of the hyper kyphosis remained stable. Skeletal maturitywas reached in 42 of 83 patients (50.6%). None of these patients has required spinal fusion. The global complication rate was 31.3%. CONCLUSION The outcomes of this minimally invasive fusionless technique at 5 years follow-up showed a stable correction of spinal deformities and pelvic obliquity over time, with a reduced rate of complication. The arthrodesis was not required for all patients at skeletal maturity. This technique could be a good alternative to arthrodesis for neuromuscular scoliosis.Level of Evidence: 3.

Does preoperative and intraoperative imaging for anterior vertebral body tethering predict postoperative correction

Abstract: Anterior vertebral body tethering (AVBT) is an emerging approach for idiopathic scoliosis. However, overcorrection and under-correction are common causes of revision surgery, and intraoperative tensioning of the cord is one key component to achieve appropriate curve correction. We sought to determine whether preoperative flexibility radiographs or intraoperative radiographs would predict correction at first erect imaging for scoliosis patients undergoing anterior vertebral body tethering (AVBT). Single-center retrospective review. Fifty-one patients with a diagnosis of idiopathic scoliosis underwent anterior body tethering. Preoperative flexibility films and intraoperative radiographs were compared to first erect standing radiographs to determine if there was a correlation in Cobb angle. Preoperative major Cobb angle measured 52° ± 9°. Major Cobb angle on bending films was 24° ± 8°. Intraoperative imaging showed correction to a mean of 17° ± 8°. Postoperative first erect standing radiographs showed correction to a mean of 26° ± 10°. The mean difference in major Cobb angle between intraoperative radiograph and a first erect radiograph was 10° ± 4°, whereas the mean difference from preoperative bending radiograph at first erect was 2° ± 7°. Thus, correction on preoperative flexibility films correlated with the first erect radiograph. Preoperative bending radiographs provide a reasonable estimate of postoperative correction for patients undergoing AVBT with tensioning of the cord. Surgeons should expect the major Cobb angle to increase on first erect radiographs compared to intraoperative radiographs. These findings may guide patient selection and assist surgeons in achieving appropriate correction intraoperatively.

Schroth exercises improve health-related quality of life and radiographic parameters in adolescent idiopathic scoliosis patients.

Abstract: BACKGROUND Finding an optimal treatment strategy for adolescent idiopathic scoliosis (AIS) patients remains challenging because of its intrinsic complexity. For mild to moderate scoliosis patients with lower skeletal growth potential (Risser 3-5), most clinicians agree with observation treatment; however, the curve progression that occurs during puberty, the adolescent period, and even in adulthood, remains a challenging issue for clinicians. The aim of the study is to investigate the efficacy of Schroth exercise in AIS patients with lower skeletal growth potential (Risser 3-5) and moderate scoliosis (Cobb angle 20°-40°). METHODS From 2015 to 2017, data of 64 patients diagnosed with AIS in Peking University Third Hospital were reviewed. Forty-three patients underwent Schroth exercise were classified as Schroth group, and 21 patients underwent observation were classified as observation group. Outcomes were measured by health-related quality of life (HRQOL) and radiographic parameters. HRQOL was assessed using the visual analog scale (VAS) scores for back, Scoliosis Research Society-22 (SRS-22) patient questionnaire. Radiographic spinopelvic parameters were obtained from anteroposterior and lateral X-rays. The pre-treatment and post-treatment HRQOL and radiographic parameters were tested to validate Schroth exercise efficacy. The inter-rater reliability of the radiographic parameters was tested using the interclass correlation coefficient (ICC). The paired t test was used to examine HRQOL and radiographic parameters. Clinical relevance between C2-C7 sagittal vertical axis (SVA) and thoracic kyphosis was analyzed using Spearman correlation. RESULTS In Schroth group, VAS back score, SRS-22 pain, and SRS-22 self-image domain were significantly improved from pre-treatment 3.0 ± 0.8, 3.6 ± 0.5, and 3.5 ± 0.7 to post-treatment 1.6 ± 0.6 (t = 5.578, P = 0.013), 4.0 ± 0.3 (t = -3.918, P = 0.001), and 3.7 ± 0.4 (t = -6.468, P < 0.001), respectively. No significant improvements of SRS-22 function domain (t = -2.825, P = 0.088) and mental health domain (t = -3.174, P = 0.061) were observed. The mean Cobb angle decreased from 28.9 ± 5.5° to 26.3 ± 5.2° at the final follow-up, despite no statistical significance was observed (t = 1.853, P = 0.102). The mean C2-C7 SVA value decreased from 21.7 ± 8.4 mm to 17.0 ± 8.0 mm (t = -1.224 P = 0.049) and mean T1 tilt decreased from 4.9 ± 4.2 ° to 3.5 ± 3.1° (t = 2.913, P = 0.011). No significant improvement of radiographic parameters and HRQOL were observed in observation group. CONCLUSIONS For AIS patients with a Risser 3-5 and a Cobb angle 20°-40°, Schroth exercises improved HRQOL and halted curve progression during the follow-up period. Both cervical spine alignment and shoulder balance were also significantly improved after Schroth exercises. We recommend Schroth exercises for patients with AIS.

Trends in Incidence of Adolescent Idiopathic Scoliosis: A Modern US Population-based Study.

Abstract: Background A successful disease screening strategy requires a high incidence of the condition, efficacy of early treatment, and efficient detection. There is limited population-based data describing trends in incidence of adolescent idiopathic scoliosis (AIS) in the United States and potential role of school screening programs on the incidence of AIS. Thus, we sought to evaluate the incidence of AIS over a 20-year period between 1994 and 2013 using a population-based cohort. Methods The study population comprised 1782 adolescents (aged 10 to 18 y) with AIS first diagnosed between January 1, 1994 and December 31, 2013. The complete medical records and radiographs were reviewed to confirm diagnosis and coronal Cobb angles at first diagnosis. Age-specific and sex-specific incidence rates were calculated and adjusted to the 2010 United States population. Poisson regression analyses were performed to examine incidence trends by age, sex, and calendar period. Results The overall age-adjusted and sex-adjusted annual incidence of AIS was 522.5 [95% confidence interval (CI): 498.2, 546.8] per 100,000 person-years. Incidence was about 2-fold higher in females than in males (732.3 vs. 338.8/100,000, P 10 degrees was 181.7 (95% CI: 167.5, 196.0) per 100,000 person-years. The overall incidence of AIS decreased significantly after discontinuation of school screening in 2004 (P Conclusions Overall population-based incidence of AIS decreased after school screening was discontinued. However, incidence of patients with a Cobb angle >10 degrees, initiation of bracing and surgery did not change significantly over time. This provides further data to help determine the role of scoliosis screening. Level of evidence Level III.

Comparison of manual versus automated measurement of Cobb angle in idiopathic scoliosis based on a deep learning keypoint detection technology

Abstract: The present study compared manual and automated measurement of Cobb angle in idiopathic scoliosis based on deep learning keypoint detection technology. A total of 181 anterior–posterior spinal X-rays were included in this study, including 165 cases of idiopathic scoliosis and 16 normal adult cases without scoliosis. We labeled all images and randomly chose 145 as the training set and 36 as the test set. Two state-of-the-art deep learning object detection models based on convolutional neural networks were used in sequence to segment each vertebra and locate the vertebral corners. Cobb angles measured from the output of the models were compared to manual measurements performed by orthopedic experts. The mean Cobb angle in test cases was 27.4° ± 19.2° (range 0.00–91.00°) with manual measurements and 26.4° ± 18.9° (range 0.00–88.00°) with automated measurements. The automated method needed 4.45 s on average to measure each radiograph. The intra-class correlation coefficient (ICC) for the reliability of the automated measurement of the Cobb angle was 0.994. The Pearson correlation coefficient and mean absolute error between automated positioning and expert annotation were 0.990 and 2.2° ± 2.0°, respectively. The analytical result for the Spearman rank-order correlation was 0.984 (p < 0.001). The automated measurement results agreed with the experts’ annotation and had a high degree of reliability when the Cobb angle did not exceed 90° and could locate multiple curves in the same scoliosis case simultaneously in a short period of time. Our results need to be verified in more cases in the future.