Background Adolescent Idiopathic Scoliosis (AIS) is a three-dimensional (3D) spinal deformity characterized by coronal curvature and rotational deformity. Predicting curve progression is important ...for the selection and timing of treatment. Although there is a consensus in the literature regarding prognostic factors associated with curve progression, the order of importance, as well as the combination of factors that are most predictive of curve progression is unknown. Objectives (1) create an ordered list of prognostic factors that most contribute to curve progression, and (2) develop and validate a Machine Learning (ML) model to predict the final major Cobb angle in AIS patients. Methods 193 AIS patients were selected for the current study. Preoperative PA, lateral and lateral bending radiographs were retrospectively obtained from the Shriners Hospitals for Children. Demographic and radiographic features, previously reported to be associated with curve progression, were collected. Sequential Backward Floating Selection (SBFS) was used to select a subset of the most predictive features. Based on the performance of several machine learning methods, a Random Forest (RF) regressor model was used to provide the importance rank of prognostic features and to predict the final major Cobb angle. Results The seven most predictive prognostic features in the order of importance were initial major Cobb angle, flexibility, initial lumbar lordosis angle, initial thoracic kyphosis angle, age at last visit, number of levels involved, and Risser "+" stage at the first visit. The RF model predicted the final major Cobb angle with a Mean Absolute Error (MAE) of 4.64 degrees. Conclusion A RF model was developed and validated to identify the most important prognostic features for curve progression and predict the final major Cobb angle. It is possible to predict the final major Cobb angle value within 5 degrees error from 2D radiographic features. Such methods could be directly applied to guide intervention timing and optimization for AIS treatment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Anterior Vertebral Body Tethering (AVBT) is a growing alternative treatment for adolescent idiopathic scoliosis (AIS), offering an option besides spinal fusion. While AVBT aims to correct spinal ...deformity through growth correction, its outcomes have been mixed. To improve surgical outcomes, this study aimed to develop a machine learning-based tool to predict short- and midterm spinal curve correction in AIS patients who underwent AVBT surgery, using the most predictive clinical, radiographic, and surgical parameters. After institutional review board approval and based on inclusion criteria, 91 AIS patients who underwent AVBT surgery were selected from the Shriners Hospitals for Children, Philadelphia. For all patients, longitudinal standing (PA or AP, and lateral) and side bending spinal Radiographs were retrospectively obtained at six visits: preop and first standing, one year, two years, five years postop, and at the most recent follow-up. Demographic, radiographic, and surgical features associated with curve correction were collected. The sequential backward feature selection method was used to eliminate correlated features and to provide a rank-ordered list of the most predictive features of the AVBT correction. A Gradient Boosting Regressor (GBR) model was trained and tested using the selected features to predict the final correction of the curve in AIS patients. Eleven most predictive features were identified. The GBR model predicted the final Cobb angle with an average error of 6.3 ± 5.6 degrees. The model also provided a prediction interval, where 84% of the actual values were within the 90% prediction interval. A list of the most predictive features for AVBT curve correction was provided. The GBR model, trained on these features, predicted the final curve magnitude with a clinically acceptable margin of error. This model can be used as a clinical tool to plan AVBT surgical parameters and improve outcomes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Retrospective review.
To study risk factors for anterior vertebral body tether (VBT) breakage.
VBT is used to treat adolescent idiopathic scoliosis in skeletally immature patients. However, tethers ...break in up to 48% of cases.
We reviewed 63 patients who underwent thoracic and/or lumbar VBT with a minimum five-year follow-up. We radiographically characterized suspected tether breaks as a change in interscrew angle >5°. Demographic, radiographic, and clinical risk factors for presumed VBT breaks were evaluated.
In confirmed VBT breaks, the average interscrew angle change was 8.1°, and segmental coronal curve change was 13.6°, with a high correlation ( r =0.82). Our presumed VBT break cohort constituted 50 thoracic tethers, four lumbar tethers, and nine combined thoracic/lumbar tethers; the average age was 12.1±1.2 years and the mean follow-up was 73.1±11.7 months. Of 59 patients with thoracic VBTs, 12 patients (20.3%) had a total of 18 breaks. Eleven thoracic breaks (61.1%) occurred between two and five years postoperatively, and 15 (83.3%) occurred below the curve apex ( P <0.05). The timing of thoracic VBT breakage moderately correlated with more distal breaks ( r =0.35). Of 13 patients who underwent lumbar VBT, eight patients (61.5%) had a total of 12 presumed breaks. Six lumbar breaks (50%) occurred between one and two years postoperatively, and seven (58.3%) occurred at or distal to the apex. Age, sex, body mass index, Risser score, and curve flexibility were not associated with VBT breaks, but the association between percent curve correction and thoracic VBT breakage trended toward significance ( P =0.054). Lumbar VBTs were more likely to break than thoracic VBTs ( P =0.016). Seven of the patients with presumed VBT breaks (35%) underwent revision surgery.
Lumbar VBTs broke with greater frequency than thoracic VBTs, and VBT breaks typically occurred at levels distal to the curve apex. Only 15% of all patients required revision.
3.
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.
STUDY DESIGN.Retrospective review.
OBJECTIVE.To report the 2-year results of the initial cohort undergoing anterior vertebral body tethering (VBT).
SUMMARY OF BACKGROUND DATA.Anterior VBT is a ...promising new technique with abundant preclinical studies but very few clinical results. It is a growth modulation technique, which utilizes patientsʼ growth to attain progressive correction of their scoliosis. We report 2-year results of the initial cohort undergoing this procedure.
METHODS.After obtaining institutional review board approval, we retrospectively reviewed our first 11 consecutive patients who underwent anterior VBT with 2-year follow-up. We collected pertinent preoperative, intraoperative, and most recent clinical and radiographical data. Student t test and Fisher exact test were utilized to compare different time points.
RESULTS.Eleven patients with thoracic idiopathic scoliosis (8 females) were identified, with a mean age of 12.3 ± 1.6 years. Preoperatively, all were skeletally immature (Sanders mean = 3.4 ± 1.1; Risser mean = 0.6 ± 1.1). All underwent tethering of an average of 7.8 ± 0.9 (range7–9) levels, with the most proximal being T5 and the most distal L2. Preoperative thoracic Cobb angle averaged 44.2 ± 9.0° and corrected to 20.3 ± 11.0° on first erect, with progressive improvement at 2 years (Cobb angle = 13.5 ± 11.6°, % correction = 70%; P < 0.00002). Similarly, the preoperative lumbar curve of 25.1 ± 8.7° demonstrated progressive correction (first erect = 14.9 ± 4.9°, 2 yr = 7.2 ± 5.1°, % correction = 71%; P < 0.0002). Thoracic axial rotation as measured by a scoliometer went from 12.4 ± 3.3° preoperatively to 6.9 ± 3.4° at the most recent measurement (P < 0.01). No major complications were observed. As anticipated, 2 patients returned to the operating room at 2 years postoperatively for loosening of the tether to prevent overcorrection.
CONCLUSION.Anterior VBT is a promising technique for skeletally immature patients with idiopathic scoliosis. This technique can be performed safely and can result in progressive correction.Level of Evidence4
Purpose
This retrospective chart review evaluates the clinical and radiographic outcomes of anterior vertebral body tethering (VBT) at 1-year follow-up. Anterior VBT offers a fusionless treatment ...option for skeletally immature patients with adolescent idiopathic scoliosis. It is a growth-modulation technique, which utilizes patients’ growth to attain progressive scoliosis correction. Numerous animal models support its promise; however, clinical data remain sparse.
Methods
Clinical and radiographic data were retrospectively analyzed. We reviewed 32 patients who underwent thoracic VBT with a minimum one-year follow-up. Pertinent clinical and radiographic data were collected. ANOVA, Student’s
t
test and Fisher’s exact test were utilized to compare different time points.
Results
32 patients with thoracic idiopathic scoliosis (72 % female) with a minimum one-year follow-up were identified; mean age at surgery was 12 years. All patients were considered skeletally immature pre-operatively; mean Risser score 0.42, mean Sanders score 3.2. Patients underwent tethering of an average of 7.7 levels (range 7–11). Median blood loss was 100 cc. The mean pre-operative thoracic curve magnitude was 42.8° ± 8.0° which corrected to 21.0° ± 8.5° on first erect and 17.9° ± 11.4° at most recent. The pre-operative lumbar curve of 25.2° ± 7.3° demonstrated progressive correction (first erect = 18.0° ± 7.1°, 1 year = 12.6° ± 9.4°,
p
< 0.00001). Thoracic axial rotation measured 13.4° pre-operatively and 7.4° at the most recent measurement (
p
< 0.00001). One patient experienced prolonged atelectasis which required a bronchoscopy; otherwise, no major complications were observed.
Conclusions
Our early results indicate that anterior VBT is a safe and potentially effective treatment option for skeletally immature patients with idiopathic scoliosis. These patients experienced an improvement of their scoliosis with minimal major complications. However, longer term follow-up of this cohort will reveal the true benefits of this promising technique.
Level of evidence
IV.
Retrospective, single-center study.
To examine pulmonary function tests (PFTs) in patients undergoing anterior vertebral body tethering (AVBT).
The effect of AVBT on pulmonary status remains unclear.
...The authors examined preoperative and postoperative PFTs following AVBT in a retrospective, single-center cohort of patients. Outcomes were compared using percent predicted values as continuous and categorical variables (using 10% change as significant) and divided into categorical values based on the American Thoracic Society standards.
Fifty-eight patients with adolescent idiopathic scoliosis were included, with a mean age of 12.5±1.4 years and a follow-up of 4.2±1.1 years. The mean thoracic curve was 47°±9°, which improved to 21°±12°. At baseline, the mean forced expiratory volume in one second (FEV1%) and forced vital capacity (FVC%) values were 79% and 82%, respectively. Four patients had normal FEV1% (≥100%), 67% had mild restrictive disease (70%-99%) and the rest had worse FEV1%. Mean FEV1 improved from 2.2 to 2.6 L ( P <0.05) and FVC improved from 2.5 to 3.0 L ( P <0.05); however, % predicted values remained unchanged (FEV1%: 79%-80%; FVC%: 82-80%, P >0.05) with mean postoperative PFTs at 37±12 months postoperative. The use of miniopen thoracotomy was not associated with worsening PFTs, but extension of the lowest instrumented vertebra below T12 was correlated with decreasing FEV1% in the bivariate analysis ( P <0.05). Patients with worse preoperative FVC% (80±13% vs. 90±11%, P =0.03) and FEV1% (77±17% vs. 87±12%, P =0.06) also had a greater likelihood of declining postoperative FEV1%.
Pulmonary function in most patients undergoing AVBT remained stable (76%) or improved (14%); however, a subset may worsen (10%). Further studies are needed to identify the risk factors for this group, but worse preoperative PFTs and extension below T12 may be risk factors for worsening pulmonary function.
Three groups of 6 rats received subtotal cervical spinal cord hemisections followed with marrow stromal cell (MSC) transplants by lumbar puncture (LP), intravenous delivery (IV), or direct injection ...into the injury (control). Animals survived for 4 or 21 days.
Cell therapy is a promising strategy for the treatment of spinal cord injury (SCI). The mode of cell delivery is crucial for the translation to the clinic. Injections directly into the parenchyma may further damage already compromised tissue; therefore, less invasive methods like LP or IV delivery are preferable.
Human MSC are multipotent mesenchymal adult stem cells that have a potential for autologous transplantation, obviating the need for immune suppression. Although previous studies have established that MSC can be delivered to the injured spinal cord by both LP and IV, the efficacy of cell delivery has not been directly compared with respect to efficacy of delivery and effects on the host.
Purified MSC from a human donor were transplanted into the CSF at the lumbar region (LP), into the femoral vein (IV), or directly into the injury (control). After sacrifice, spinal cord sections were analyzed for MSC graft size, tissue sparing, host immune response, and glial scar formation, using specific antibodies and Nissl-myelin staining.
LP delivery of MSC to the injured spinal cord is superior to IV delivery. Cell engraftment and tissue sparing were significantly better after LP delivery, and host immune response after LP delivery was reduced compared with IV delivery.
LP is an ideal minimally invasive technique to deliver cellular transplants to the injured spinal cord. It is superior to IV delivery and, together with the potential for autologous transplantation, lends itself for clinical application.
OBJECTIVE Intraoperative neuromonitoring (IONM) involves the use of somatosensory evoked potentials (SSEPs) and transcranial electric motor evoked potentials (TceMEPs). In this retrospective study ...the authors examined the sensitivity and specificity of both SSEPs and TceMEPs during pediatric spinal deformity surgeries. METHODS The authors performed a retrospective quantitative analysis of data obtained in 806 patients (197 males and 609 females) treated from December 2011 until October 2015. All patients were diagnosed with scoliosis that was classified as one of the following: adolescent idiopathic scoliosis (AIS) (38%), congenital scoliosis (22%), or syndromic scoliosis (40%). Also, 53 patients underwent vertebral column resection (VCR). All surgeries were monitored by high-level neuromonitoring specialists and were performed with total intravenous anesthesia. Alerts were described as a decrease in amplitude by 50% or greater (bilateral or unilateral) in SSEPs, TceMEPs, or both. RESULTS True-positive alerts for TceMEPs were observed in 60 of the 806 patients (7.4%). True-positive alerts for SSEPs were observed in 7 of the 806 patients (0.9%). In contrast, there were no false-positive or false-negative outcomes. Only 1 case (0.1%) was reported with a permanent postoperative deficit. No reported false negatives or false positives were observed, and thus sensitivity was 100% and specificity was 93%-100% for TceMEPs. The rate of sensitivity was 13.2% and the rate of specificity was 100% for SSEPs. The breakdown of total alert was as follows: 6.6% in AIS cases, 24.5% in congenital scoliosis cases, and 10.2% in syndromic scoliosis cases. Neurological injury rates were significantly lower than in previous studies, as there were 0% for AIS cases (p = 0.12), 0.6% for congenital scoliosis cases (p = 0.17), and 0% for syndromic scoliosis cases (p = 0.07). One injury in a patient with congenital scoliosis occurred during a VCR procedure, which brought the injury rate to 1.9% (p < 0.005). IONM alerts occurred during 34% of rod/correction cases, 25% of thoracic screw placements, 20% of the osteotomies, 17% of the resections, 3% of the cage insertions, and 2% of the sublaminar wiring procedures. CONCLUSIONS The authors hypothesize that the results of this study will support the necessity, as a standard of care, of multimodality neuromonitoring during high-risk pediatric spinal deformity surgery because of the decrease in postoperative deficits. Their data suggest that the TceMEPs are more sensitive than SSEPs, but when used in combination, they offer the patient a level of safety that would otherwise not exist. Last, these findings support the notion that better outcomes are achieved with high-level IONM professionals.
OBJECTIVE Postoperative complications are one of the most significant concerns in surgeries of the spine, especially in higher-risk cases such as neuromuscular scoliosis. Neuromuscular scoliosis is a ...classification of multiple diseases affecting the neuromotor system or musculature of patients leading to severe degrees of spinal deformation, disability, and comorbidity, all likely contributing to higher rates of postoperative complications. The objective of this study was to evaluate deformity correction of patients with neuromuscular scoliosis over a 12-year period (2004-2015) by looking at changes in postsurgical complications and management. METHODS The authors queried the Scoliosis Research Society (SRS) Morbidity and Mortality (M&M) database for neuromuscular scoliosis cases from 2004 to 2015. The SRS M&M database is an international database with thousands of self-reported cases by fellowship-trained surgeons. The database has previously been validated, but reorganization in 2008 created less-robust data sets from 2008 to 2011. Consequently, the majority of analysis in this report was performed using cohorts that bookend the 12-year period (2004-2007 and 2012-2015). Of the 312 individual fields recorded per patient, demographic analysis was completed for age, sex, diagnosis, and preoperative curvature. Analysis of complications included infection, bleeding, mortality, respiratory, neurological deficit, and management practices. RESULTS From 2004 to 2015, a total of 29,019 cases of neuromuscular scoliosis were reported with 1385 complications, equating to a 6.3% complication rate when excluding the less-robust data from 2008 to 2011. This study shows a 3.5-fold decrease in overall complication rates from 2004 to 2015. A closer look at complications shows a significant decrease in wound infections (superficial and deep), respiratory complications, and implant-associated complications. The overall complication rate decreased by approximately 10% from 2004-2007 to 2012-2015. CONCLUSIONS This study demonstrates a substantial decrease in complication rates from 2004 to 2015 for patients with neuromuscular scoliosis undergoing spine surgery. Decreases in specific complications, such as surgical site infection, allow us to gauge our progress while observing how trends in management affect outcomes. Further study is needed to validate this report, but these results are encouraging, helping to reinforce efforts toward continual improvement in patient care.
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