Decoding pulsatile patterns of cerebrospinal fluid dynamics through enhancing interpretability in machine learning.

Analyses of complex behaviors of Cerebrospinal Fluid (CSF) have become increasingly important in diseases diagnosis. The changes of the phase-contrast magnetic resonance imaging (PC-MRI) signal formed by the velocity of flowing CSF are represented as a set of velocity-encoded images or maps, which can be thought of as signal data in the context of medical imaging, enabling the evaluation of pulsatile patterns throughout a cardiac cycle. However, automatic segmentation of the CSF region in a PC-MRI image is challenging, and implementing an explained ML method using pulsatile data as a feature remains unexplored. This paper presents lightweight machine learning (ML) algorithms to perform CSF lumen segmentation in spinal, utilizing sets of velocity-encoded images or maps as a feature. The Dataset contains 57 PC-MRI slabs by 3T MRI scanner from control and idiopathic scoliosis participants are involved to collect data. The ML models are trained with 2176 time series images. Different cardiac periods image (frame) numbers of PC-MRIs are interpolated in the preprocessing step to align to features of equal size. The fivefold cross-validation procedure is used to estimate the success of the ML models. Additionally, the study focusses on enhancing the interpretability of the highest-accuracy eXtreme gradient boosting (XGB) model by applying the shapley additive explanations (SHAP) technique. The XGB algorithm presented its highest accuracy, with an average fivefold accuracy of 0.99% precision, 0.95% recall, and 0.97% F1 score. We evaluated the significance of each pulsatile feature's contribution to predictions, offering a more profound understanding of the model's behavior in distinguishing CSF lumen pixels with SHAP. Introducing a novel approach in the field, develop ML models offer comprehension into feature extraction and selection from PC-MRI pulsatile data. Moreover, the explained ML model offers novel and valuable insights to domain experts, contributing to an enhanced scholarly understanding of CSF dynamics.

Adolescent Idiopathic Scoliosis in Siblings Treated by Surgical Deformity Correction.

Adolescent idiopathic scoliosis (AIS) in siblings reflects genetic hypothesis; however, few studies have been published. Furthermore, to the best of our knowledge, there have been no reports in the literature of both siblings with AIS who underwent deformity corrections. A 15-year-old adolescent girl visited our clinic with back pain after recognition of the incidental findings of a scoliotic curve in the spine. Whole spine radiographs detected Lenke classification type 3CN. The patient underwent deformity correction with posterior instrumented fusion from T4 to L3 with thoracoplasty of the right 7th to 10th rib. Four years later, her 16-year-old younger brother also visited our clinic with back pain after recognition of the incidental findings of a scoliotic curve in the spine. Whole spine radiographs detected Lenke classification type 2AN. The patient underwent deformity correction with posterior instrumented fusion from T5 to L2 with thoracoplasty of the right 8th to 10th rib. In conclusion, we report on two siblings with AIS who underwent surgical treatment for different types of curves. They showed favorable outcomes after performing deformity correction with posterior instrumented fusion. Our rare case supports the underlying basis of genetic heterogeneity as a complex polygenic model.

Comparison of three artificial intelligence algorithms for automatic cobb angle measurement using teaching data specific to three disease groups.

Spinal deformities, including adolescent idiopathic scoliosis (AIS) and adult spinal deformity (ASD), affect many patients. The measurement of the Cobb angle on coronal radiographs is essential for their diagnosis and treatment planning. To enhance the precision of Cobb angle measurements for both AIS and ASD, we developed three distinct artificial intelligence (AI) algorithms: AIS/ASD-trained AI (trained with both AIS and ASD cases); AIS-trained AI (trained solely on AIS cases); ASD-trained AI (trained solely on ASD cases). We used 1612 whole-spine radiographs, including 1029 AIS and 583 ASD cases with variable postures, as teaching data. We measured the major and two minor curves. To assess the accuracy, we used 285 radiographs (159 AIS and 126 ASD) as a test set and calculated the mean absolute error (MAE) and intraclass correlation coefficient (ICC) between each AI algorithm and the average of manual measurements by four spine experts. The AIS/ASD-trained AI showed the highest accuracy among the three AI algorithms. This result suggested that learning across multiple diseases rather than disease-specific training may be an efficient AI learning method. The presented AI algorithm has the potential to reduce errors in Cobb angle measurements and improve the quality of clinical practice.

Spontaneous Resolution of Kyphoscoliosis Secondary to Guillain-Barre Syndrome: A Case Report.

CASE: Spinal deformity associated with Guillain-Barre syndrome (GBS) is not commonly reported. We present a 6-year-old girl who developed kyphoscoliosis after being diagnosed GBS. She had extensive motor deficits requiring 2 hospitalizations and treatment with IV immunoglobulin therapy. Five months after diagnosis, she presented to our clinic with a 15° coronal scoliosis and a 65° thoracic kyphosis. At 6-month follow-up, kyphosis progressed to 77° with no significant change in the coronal curve. At 1 year, sagittal alignment was within normal limits and the coronal curve had completely resolved. CONCLUSION: Spinal deformity in GBS can resolve spontaneously.

The application of machine learning methods for predicting the progression of adolescent idiopathic scoliosis: a systematic review.

Predicting curve progression during the initial visit is pivotal in the disease management of patients with adolescent idiopathic scoliosis (AIS)-identifying patients at high risk of progression is essential for timely and proactive interventions. Both radiological and clinical factors have been investigated as predictors of curve progression. With the evolution of machine learning technologies, the integration of multidimensional information now enables precise predictions of curve progression. This review focuses on the application of machine learning methods to predict AIS curve progression, analyzing 15 selected studies that utilize various machine learning models and the risk factors employed for predictions. Key findings indicate that machine learning models can provide higher precision in predictions compared to traditional methods, and their implementation could lead to more personalized patient management. However, due to the model interpretability and data complexity, more comprehensive and multi-center studies are needed to transition from research to clinical practice.

Fetal Scoliosis: Natural History and Outcomes.

INTRODUCTION: Scoliosis can be detected on prenatal ultrasonography and may be associated with structural and syndromic abnormalities. Associations and pregnancy outcomes related to the prenatal diagnosis of scoliosis are poorly understood. METHODS: A retrospective cohort study was undertaken at a tertiary referral center in London. Referred cases with spinal deformities between 1997 and 2021 were identified from the prenatal ultrasonography database. Outcomes were ascertained from the database and electronic notes. RESULTS: One hundred twenty-three cases of fetal spinal deformities (scoliosis, kyphosis, or kyphoscoliosis) were identified from a referral population of 660,000 pregnancies, giving an incidence of approximately 0.2 per 1000 fetuses. Fifty-eight live births (47.2%) and 65 cases (52.8%) of fetal or neonatal demise or termination were observed. Most live births were isolated spinal deformities with a good postnatal outcome (n = 35, 60.3%). The commonest syndromic diagnosis in this group was VACTERL association (n = 7, 12.1%). Most cases of fetal loss were associated with severe malformations, most commonly spina bifida, body stalk anomaly and amniotic band sequence, or chromosomal abnormalities, except in 2 cases (3.1%). CONCLUSIONS: This is the largest reported cases series to date of prenatally diagnosed fetal spinal deformity. This confirms that fetal scoliosis and associated vertebral abnormalities are underdiagnosed prenatally, with the reported incidence (0.2 per 1000) lower than the recognized incidence of congenital scoliosis (1 in 1,000). The concurrent finding of severe malformations was strongly associated with fetal loss. When an isolated finding, most fetal spinal deformities had a good postnatal outcome, while 1:8 live births were diagnosed with VACTERL association.

A horizontal and perpendicular interlaminar approach for intrathecal nusinersen injection in patients with spinal muscular atrophy and scoliosis: an observational study.

BACKGROUND: Lumbar puncture is challenging for patients with scoliosis. Previous ultrasound-assisted techniques for lumbar puncture used the angle of the probe as the needle trajectory; however, reproducing the angle is difficult and increases the number of needle manipulations. In response, we developed a technique that eliminated both the craniocaudal and lateromedial angulation of the needle trajectory to overall improve this technique. We assessed the feasibility and safety of this method in patients with scoliosis and identify factors related to difficult lumbar puncture. METHODS: Patients with spinal muscular atrophy and scoliosis who were referred to the anesthesia department for intrathecal nusinersen administrations were included. With a novel approach that utilized patient position and geometry, lumbar puncture was performed under ultrasound guidance. Success rates, performance times and adverse events were recorded. Clinical-demographic and spinal radiographic data pertaining to difficult procedures were analyzed. RESULTS: Success was achieved in all 260 (100%) lumbar punctures for 44 patients, with first pass and first attempt success rates of 70% (183/260) and 87% (226/260), respectively. Adverse events were infrequent and benign. Higher BMI, greater skin dural sac depth and smaller interlaminar size might be associated with greater difficulty in lumbar puncture. CONCLUSIONS: The novel ultrasound-assisted horizontal and perpendicular interlaminar needle trajectory approach is an effective and safe method for lumbar puncture in patients with spinal deformities. This method can be reliably performed at the bedside and avoids other more typical and complex imaging such as computed tomography guided procedure.

Adolescent idiopathic scoliosis: a prospective randomised trial protocol comparing clinical and radiological outcomes in minimally invasive surgery versus standard posterior spinal fusion in a single-centre, the Rizzoli Orthopaedic Institute, Bologna, Italy.

INTRODUCTION: Minimally invasive spine surgery (MISS) has been shown to be safe and effective in adolescent idiopathic scoliosis (AIS) correction, even though there is no consensus on which treatment provides the best results. METHODS AND ANALYSIS: The present study will be a randomised controlled trial with allocation 1:1. We will enrol 126 patients with Cobb≤70° undergoing AIS surgery. Patients will be divided into two groups, according to a randomisation list unknown to the surgeons. Group 1 will be treated with posterior spine fusion and group 2 with MISS. MISS technique: two midline noncontiguous skin incisions of 3 cm in length, 3-4 segments (6-8 pedicles screws) instrumented per skin incision, uniplanar and polyaxial pedicle screws inserted bilaterally on each side of the proximal and distal levels, rod translation manoeuvre and C-D manoeuvre performed on the distal part. Clinical and radiological follow-ups will be performed for 5 years. Values of Cobb angles degrees will be collected to study the correction rate of the structural major curve. Postoperative and preoperative anterior-posterior (AP) direct radiography will be compared with the last follow-up examination. Operative time, preoperative haemoglobin (Hb) and second postoperative day Hb, full length of hospitalisation, time to achieve verticalisation and time to remove the drainage will be recorded. Numeric Rating Scale (NRS) medium score will be assessed immediately after surgery and during the whole postoperative rehabilitation treatment to estimate pain reduction. Complications will be collected postoperatively and throughout the whole follow-up period.Moreover, questionnaires will be administered at follow-up (NRS, Scoliosis Research Society-22 and Oswestry Disability Index) for the clinical assessment. ETHICS AND DISSEMINATION: The study protocol has been approved by the local ethic committee Area Vasta Emilia Romagna Centro. Written informed consent will be collected for all the participants. Findings of this study will be disseminated through peer-reviewed publications and conference presentations. TRIAL REGISTRATION NUMBER: NCT05860673.

The selection of a surgical strategy for the treatment of adult degenerative scoliosis with "pear-shaped" decompression under open spinal endoscopy.

The prognoses of patients who undergo open spinal endoscopy (OSE) decompression significantly differ by scoliosis type and symptom despite the use of uniform standards and procedures for the decompression surgery. These differences may be directly related to the selection and formulation of surgical strategies but their cause remains unclear. The aim of this study was to verify and evaluate the efficacy of the "Symptom, Stenosis and Segment classification (SSS classification)" in determining an appropriate surgical strategy and to analyze the differences in the outcomes of different patients after receiving the selected surgical strategy. The results of this study ultimately provide a theoretical basis for the specific optimization of surgical strategies guided by the "SSS classification". This work was a retrospective study. We reviewed 55 patients with scoliosis and spinal stenosis who underwent "pear-shaped" decompression under OSE from May 2021 to June 2023 treated by our surgical team. To classify different types of patients, we defined the "SSS classification" system. The permutation and combination of subtypes in Symptom (including three subtypes: Convex = v, Concave = c and Bilateral = b), Stenosis (including three subtypes: Convex = v, Concave = c and Bilateral = b), and Segment (including two subtypes: Edge = e and Inside = i) yields 18 possible types (details in Table 1) in this classification system. To classify different types of surgeries, we also defined the operation system. The VAS Back and VAS Leg scores after surgical treatment were significantly lower in all patients 3 months after surgery than before surgery. (**P < 0.05). The Svve type accounted for the greatest proportion of patients (62.50%) in the VAS back remission group, and the Scce type accounted for the greatest proportion (57.14%) in the VAS back ineffective group. According to the VAS leg score, the percentage of patients in whom Svve was detected in the VAS leg remission group reached 60.87%, and the percentage of patients in whom Svve was detected in the VAS leg ineffective group reached 44.44%. Svve accounted for the greatest proportion of cases (61.22%) in the JOA-effective group, and Scce accounted for the greatest proportion of cases (50.00%) in the JOA-ineffective group. In the JOA-effective group, the Ovv type accounted for the greatest proportion (up to 79.59%), while in the JOA-ineffective group, Occ and Ovv accounted for 50.00% of the cases each. The proportions of Svve type were the highest in the healthy group (up to 60.00%) and the ODI-effective group (up to 50.00%). The Ovv type accounted for the greatest proportion of patients in the ODI-effective group (up to 80.00%), and the Occ type accounted for the greatest proportion of patients in the ODI-ineffective group (up to 60.00%). Most of the surgical plans formulated by the "SSS classification" method were considered appropriate, and only when the symptoms of patients were located on the concave side did the endoscopic decompression plan used in the present study have a limited ability to alleviate symptoms.

[Imaging characteristics and surgical effect for symmetrical lumbar hemivertebrae].

Objective: To analyze the imaging characteristics and surgical effect for symmetrical lumbar hemivertebrae in pediatric patients. Methods: The data of 13 patients with hemivertebrae locating in the lumbar spine symmetrically were retrospectively analyzed, and all the patients were treated in Beijing Children's Hospital from January 2015 to September 2021. The mean age of the patients was 6.2 (2.9, 9.3) years. There were 8 males and 5 females. The data of coronal/sagittal plane including segmental Cobb angle, cranial/caudal compensatory curve, thoracic kyphosis, thoracolumbar kyphosis, sacral obliquity, and lumbar lordosis were recorded through long cassette spinal radiographs. Associated anomalies and the relationship between hemivertebrae and posterior component were recorded through computerized tomography (CT) and magnetic resonance imaging (MRI). All the patients received surgery, and their pre-and postoperative imaging data were compared. Results: A total of 26 hemivertebraes were found, in which 80.8% (21/26) located below L2. Hemivertebraes in 10 patients were separated by a mean 1-2 normal vertebrae. Most hemivertebraes along with the corresponding posterior component were unison (21/26, 80.8%). The Cobb angles of cranial compensatory curve (13.9°±7.2°) was more serious than that of caudal compensatory curve (5.5°±5.0°)(P=0.04). The lumbar lordosis and thoracic kyphosis was 20.2°±15.0° and 18.7°±9.2°, respectively. Six patients complicated with sacral obliquity, while 7 patients complicated with thoracolumbar lordosis. Associated anomalies were found in 6 (46.2%) patients through CT and MRI. Eleven patients received one-or two-stage posterior hemivertebrae resection with short segmental fusion, and 2 patients received one-stage hemivertebrae resection with long segmental fusion. All the surgery were completed successfully without serious complications such as nerve injury, infection, and implant failure. The mean follow-up period was (42.4±10.2) months. At the last follow-up point, the correction rate of segmental Cobb angle and cranial compensatory curve was 83.3%±15.6% and 38.1%±10.4%, respectively, showing significant improvement (P<0.05). Although the caudal compensatory curve, sacral obliquity, and thoracic kyphosis improved after surgery, the data showed no significant difference compared to that before surgery. Thoracolumbar lordosis in all patients were corrected. Conclusions: Most hemivertebraes in such spinal deformity locate in lower lumbar region with a high incidence of anomalies. Individualized treatment based on patients' condition is essential for the complicated spinal deformity.

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.

The effectiveness of a protocol without routine radiographs for follow-up of adolescent idiopathic scoliosis patients (CURVE): a study protocol.

BACKGROUND AND PURPOSE: Current follow-up protocols for adolescent idiopathic scoliosis (AIS) are based on consensus and consist of regular full-spine radiographs to monitor curve progression and surgical complications. Consensus exists to avoid inappropriate use of radiographs in children. It is unknown whether a standard radiologic follow-up (S-FU) approach is necessary or if a patient-empowered follow-up (PE-FU) approach can reduce the number of radiographs without treatment consequences. METHODS AND ANALYSES: A nationwide multicenter pragmatic randomized preference trial was designed for 3 follow-up subgroups (pre-treatment, post-brace, post-surgery) to compare PE-FU and S-FU. 812 patients with AIS (age 10-18 years) will be included in the randomized trial or preference cohorts. Primary outcome is the proportion of radiographs with a treatment consequence for each subgroup. Secondary outcomes consist of the proportion of patients with delayed initiation of treatment due to non-routine radiographic follow-up, radiation exposure, societal costs, positive predictive value, and interrelation of clinical assessment, quality of life, and parameters for initiation of treatment during follow-up. Outcomes will be analyzed using linear mixed-effects models, adjusted for relevant baseline covariates, and are based on intention-to-treat principle. Study summary: (i) a national, multicenter pragmatic randomized trial addressing the optimal frequency of radiographic follow-up in patients with AIS; (ii) first study that includes patient-empowered follow-up; (iii) an inclusive study with 3 follow-up subgroups and few exclusion criteria representative for clinical reality; (iv) preference cohorts alongside to amplify generalizability; (v) first study conducting an economic evaluation comparing both follow-up approaches.

Identification of Predictors for Progression of Scoliosis in Rett Syndrome.

Rett syndrome is a neurodevelopmental disorder in which scoliosis is a common orthopedic complication. This explorative study aims to identify predictors for rapid progression of scoliosis in Rett syndrome to enable variable selection for future prediction model development. A univariable logistic regression model was used to identify variables that discriminate between individuals with and without rapid progression of scoliosis (>10 ∘Cobb angle/6 months) based on multi-center data. Predictors were identified using univariable logistic regression with OR (95% CI) and AUC (95% CI). Age at inclusion, Cobb angle at baseline and epilepsy have the highest discriminative ability for rapid progression of scoliosis in Rett syndrome.

In idiopathic scoliosis distances of spinal cord to thoracic pedicle are within 2 mm in a large region of the thoracic apex.

Despite a 15% misplacement rate of screws in idiopathic scoliosis surgery, little is known about the relationship between pedicles and nerve structures in the entire thoracic curve. This study aimed to explore the spinal cord's proximity to the pedicle wall at each thoracic vertebra in the entire thoracic curve, while considering different anatomical changes. Spinal cord to medial pedicle distances were measured on magnetic resonance imaging in 73 patients who underwent posterior spinal fusion with pedicle screw instrumentation. Associations with different variables were examined. A total of 51 patients (69.9%) showed a distance within 2 mm at the apex vertebra on the concave side, more than 50% had a distance within 2 mm in the next thoracic vertebra level above and below, and more than 25% two levels above and below. Weak correlations were found between proximity of the spinal cord at the apex vertebra and vertebra's level and Cobb angle on the concave side (r = - 0.310, P = 0.008, r = 0.380, P = 0.001, respectively). These results emphasize the importance of thorough assessment when placing thoracic pedicle screws in idiopathic scoliosis patients. Further research is warranted to develop surgical strategies aimed at preventing potentially neurological complications resulting from screw misplacement.

Optimization of traction parameters for lumbar scoliosis.

BACKGROUND: Scoliosis is a high incidence disease that endangers the physical and mental health of adolescents. Traction therapy, as a conservative treatment plan, is helpful to improve the recovery speed of patients by studying the influence of different traction factors on the therapeutic effect. METHODS: Based on the thin layer CT data of the lumbar spine of a 16-year-old patient with scoliosis, Mimics21.0 was used to extract the 3D digital model, and Geomagic Wrap2021 was used to perform the smooth surface. After that, SolidWorks was used to manually construct the structures, such as the intervertebral disc, and Ansys17.0 was used to add constraints, ligaments, and other features. Three-factor ANOVA was carried out after an orthogonal experiment that considered traction mode, traction angle, and traction force was finished. RESULTS: ① A three-dimensional biomechanical model of lumbar scoliosis was created. ② The model's correctness was confirmed by comparing it to the corpse and other finite element models, as well as by verifying it under a range of working settings. ③ Traction force (P = 0.000), traction angle (P = 0.000), the interaction between traction force and traction angle (P = 0.000), and the interaction between traction mode and traction angle (P = 0.045) were all significant. ④ The interaction between traction force and traction angle has the most significant effect on Cobb, and traction with a certain angle is better than traditional axial traction. ⑤ Traction mode is not significant, but the interaction between traction mode and traction angle is significant. CONCLUSIONS: A certain angle of traction can aid in improving outcomes and the traction force can be suitably decreased in the clinical formulation of the traction plan. The uniformity of correcting effect is more favorable when higher fixation techniques like positive suspension or traction bed traction are used, as opposed to overhanging traction.

Ultrasound Rounds: Intraoperative Point-of-Care Ultrasound Identifies Intracardiac Thrombus and Pulmonary Embolism Allowing for Alteration in Surgical Management.

Most of the cases demonstrating describing acute findings using point-of-care ultrasound (POCUS) have been described in emergency medicine and critical care medicine. While the use of POCUS has become more prevalent in anesthesia practice, documentation of acute findings resulting in alteration in management based on real-time ultrasound findings during pediatric anesthesia remains limited. This case highlights the use of POCUS during cardiopulmonary collapse occurring during correction of neuromuscular scoliosis. POCUS excluded the presumed diagnosis of venous air embolism and identified an intracardiac thrombus leading to the diagnosis and treatment of pulmonary embolism.

Accuracy and postoperative assessment of robot-assisted placement of pedicle screws during scoliosis surgery compared with conventional freehand technique: a systematic review and meta-analysis.

STUDY DESIGN: A systematic review and meta-analysis. BACKGROUND: The complexity of human anatomical structures and the variability of vertebral body structures in patients with scoliosis pose challenges in pedicle screw placement during spinal deformity correction surgery. Through technological advancements, robots have been introduced in spinal surgery to assist with pedicle screw placement. METHODS: A systematic search was conducted using PubMed, Cochrane, Embase, and CNKI databases and comparative studies assessing the accuracy and postoperative efficacy of pedicle screw placement using robotic assistance or freehand techniques in patients with scoliosis were included. The analysis evaluated the accuracy of screw placement, operative duration, intraoperative blood loss, length of postoperative hospital stay, and complications. RESULTS: Seven studies comprising 584 patients were included in the meta-analysis, with 282 patients (48.3%) in the robot-assisted group and 320 (51.7%) in the freehand group. Robot-assisted placement showed significantly better clinically acceptable screw placement results compared with freehand placement (odds ratio [OR]: 2.61, 95% confidence interval [CI]: 1.75-3.91, P < 0.0001). However, there were no statistically significant differences in achieving "perfect" screw placement between the two groups (OR: 1.52, 95% CI: 0.95-2.46, P = 0.08). The robot-assisted group had longer operation durations (mean deviation [MD]: 43.64, 95% CI: 22.25-64.74, P < 0.0001) but shorter postoperative hospital stays (MD: - 1.12, 95% CI: - 2.15 to - 0.08, P = 0.03) than the freehand group. There were no significant differences in overall complication rates or intraoperative blood loss between the two groups. There was no significant difference in Cobb Angle between the two groups before and after operation. CONCLUSION: Robot-assisted pedicle screw placement offers higher accuracy and shorter hospital stay than freehand placement in scoliosis surgery; although the robotics approach is associated with longer operative durations, similar complication rates and intraoperative blood loss.

A multipurpose, adolescent idiopathic scoliosis-specific, short MRI protocol: A feasibility study in volunteers.

INTRODUCTION: Visualization of scoliosis typically requires ionizing radiation (radiography and CT) to visualize bony anatomy. MRI is often additionally performed to screen for neural axis abnormalities. We propose a 14-minutes radiation-free scoliosis-specific MRI protocol, which combines MRI and MRI-based synthetic CT images to visualize soft and osseous structures in one examination. We assess the ability of the protocol to visualize landmarks needed to detect 3D patho-anatomical changes, screen for neural axis abnormalities, and perform surgical planning and navigation. METHODS: 18 adult volunteers were scanned on 1.5 T MR-scanner using 3D T2-weighted and synthetic CT sequences. A predefined checklist of relevant landmarks was used for the parameter assessment by three readers. Parameters included Cobb angles, rotation, torsion, segmental height, area and centroids of Nucleus Pulposus and Intervertebral Disc. Precision, reliability and agreement between the readers measurements were evaluated. RESULTS: 91 % of Likert-based questions scored ≥ 4, indicating moderate to high confidence. Precision of 3D dot positioning was 1.0 mm. Precision of angle measurement was 0.6° (ICC 0.98). Precision of vertebral and IVD height measurements was 0.4 mm (ICC 0.99). Precision of area measurement for NP was 8 mm2 (ICC 0.55) and for IVD 18 mm2 (ICC 0.62) for IVD. Precision of centroid measurement for NP was 1.3 mm (ICC 0.88-0.92) and for IVD 1.1 mm (ICC 0.88-91). CONCLUSIONS: The proposed MRI protocol with synthetic CT reconstructions, has high precision, reliability and agreement between the readers for multiple scoliosis-specific measurements. It can be used to study scoliosis etiopathogenesis and to assess 3D spinal morphology.

Radiological Outcomes of Re-tethering for Adolescent Idiopathic Scoliosis: A 2-to-5-year Follow-Up Case Series After Index Vertebral Body Tethering Failure.

PURPOSE: Vertebral Body Tethering (VBT) has been shown to have a less predictable outcome compared to spinal fusion in patients with adolescent idiopathic scoliosis (AIS). Tether breakage is a common mechanical event that sometimes leads to loss of correction. No data has been published that evaluates the outcome of re-tethering in patients who underwent revision surgery for failed VBT, which was the purpose of this study. METHODS: This is an analysis of a prospectively collected single center database of 290 patients who have had VBT. Patients for this study were included if they have had re-tethering after failed VBT and a minimum follow up of 24 months after index surgery as well as a minimum follow up of 12 months after revision surgery. Revision surgeries included tether exchange, tether reinforcement and/or mono- and bisegmental lateral fusion. Main outcome of interest was curve magnitude at latest follow up. RESULTS: 11 patients were identified who received VBT for 16 curves of which 13 curves have had failed index surgery. Mean follow up from index surgery was 40 months, time between index and revision surgery was 22 months and latest follow up after revision surgery 19 months. Re-tethering resulted in an additional correction of 42% for thoracic and 63% for thoracolumbar curves. These results remained clinically stable with only minor loss of correction at final follow up. No patient underwent or was indicated for spinal fusion. CONCLUSION: Re-tethering is feasible and able to achieve additional correction and a sustainable result.