Showing papers on "Cobb angle published in 2019"

Cobb Angle Measurement of Spine from X-Ray Images Using Convolutional Neural Network

Abstract: Scoliosis is a common spinal condition where the spine curves to the side and thus deforms the spine. Curvature estimation provides a powerful index to evaluate the deformation severity of scoliosis. In current clinical diagnosis, the standard curvature estimation method for assessing the curvature quantitatively is done by measuring the Cobb angle, which is the angle between two lines, drawn perpendicular to the upper endplate of the uppermost vertebra involved and the lower endplate of the lowest vertebra involved. However, manual measurement of spine curvature requires considerable time and effort, along with associated problems such as interobserver and intraobserver variations. In this article, we propose an automatic system for measuring spine curvature using the anterior-posterior (AP) view spinal X-ray images. Due to the characteristic of AP view images, we first reduced the image size and then used horizontal and vertical intensity projection histograms to define the region of interest of the spine which is then cropped for sequential processing. Next, the boundaries of the spine, the central spinal curve line, and the spine foreground are detected by using intensity and gradient information of the region of interest, and a progressive thresholding approach is then employed to detect the locations of the vertebrae. In order to reduce the influences of inconsistent intensity distribution of vertebrae in the spine AP image, we applied the deep learning convolutional neural network (CNN) approaches which include the U-Net, the Dense U-Net, and Residual U-Net, to segment the vertebrae. Finally, the segmentation results of the vertebrae are reconstructed into a complete segmented spine image, and the spine curvature is calculated based on the Cobb angle criterion. In the experiments, we showed the results for spine segmentation and spine curvature; the results were then compared to manual measurements by specialists. The segmentation results of the Residual U-Net were superior to the other two convolutional neural networks. The one-way ANOVA test also demonstrated that the three measurements including the manual records of two different physicians and our proposed measured record were not significantly different in terms of spine curvature measurement. Looking forward, the proposed system can be applied in clinical diagnosis to assist doctors for a better understanding of scoliosis severity and for clinical treatments.

Fully automated radiological analysis of spinal disorders and deformities: a deep learning approach.

Abstract: We present an automated method for extracting anatomical parameters from biplanar radiographs of the spine, which is able to deal with a wide scenario of conditions, including sagittal and coronal deformities, degenerative phenomena as well as images acquired with different fields of view. The location of 78 landmarks (end plate centers, hip joint centers, and margins of the S1 end plate) was extracted from three-dimensional reconstructions of 493 spines of patients suffering from various disorders, including adolescent idiopathic scoliosis, adult deformities, and spinal stenosis. A fully convolutional neural network featuring an additional differentiable spatial to numerical (DSNT) layer was trained to predict the location of each landmark. The values of some parameters (T4–T12 kyphosis, L1–L5 lordosis, Cobb angle of scoliosis, pelvic incidence, sacral slope, and pelvic tilt) were then calculated based on the landmarks’ locations. A quantitative comparison between the predicted parameters and the ground truth was performed on a set of 50 patients. The spine shape predicted by the models was perceptually convincing in all cases. All predicted parameters were strongly correlated with the ground truth. However, the standard errors of the estimated parameters ranged from 2.7° (for the pelvic tilt) to 11.5° (for the L1–L5 lordosis). The proposed method is able to automatically determine the spine shape in biplanar radiographs and calculate anatomical and posture parameters in a wide scenario of clinical conditions with a very good visual performance, despite limitations highlighted by the statistical analysis of the results. These slides can be retrieved under Electronic Supplementary Material.

Mean 6-Year Follow-up of Magnetically Controlled Growing Rod Patients With Early Onset Scoliosis: A Glimpse of What Happens to Graduates.

Abstract: BACKGROUND There is no agreement on frequency of distractions of magnetically controlled growing rods (MCGRs) but more frequent and smaller amounts of distractions mimic physiological spine growth. The mid- to long-term follow-up and management at skeletal maturity is unknown. OBJECTIVE To analyze patients with mean 6 yr of follow-up and describe the fate of MCGR graduates. METHODS Early onset scoliosis (EOS) patients treated with MCGRs with minimum 4 yr of follow-up and/or at graduation were studied. Parameters under study included Cobb angle, spine and instrumented lengths, and rod distraction gains. Relationship between timing of rod exchanges with changes in rate of lengthening was studied. RESULTS Ten EOS patients with mean 6.1 yr of follow-up were studied. The greatest Cobb angle correction occurred at the initial implantation surgery and was stable thereafter. Consistent gains in T1-12, T1-S1, and instrumented segment were observed. Rate of lengthening reduced after the first year of use but improved back to initial rates after rod exchange. Seven of the ten patients experienced complications with reoperation rate of 40% for rod distraction failure and proximal foundation problems. Only mild further improvements in all radiological parameters were observed pre- and postfinal surgery. No clinically significant curve progression was observed for rod removal only. All postfinal surgery parameters remained similar at postoperative 2 yr. CONCLUSION This study provides an outlook of the end of MCGR treatment. Although this is a fusionless procedure, instrumented segments do experience stiffness limiting further correction and length gain during final surgery whether fusion or rod removal is performed.

Evaluation of a computer-aided method for measuring the Cobb angle on chest X-rays

Abstract: To automatically measure the Cobb angle and diagnose scoliosis on chest X-rays, a computer-aided method was proposed and the reliability and accuracy were evaluated. Two Mask R-CNN models as the core of a computer-aided method were used to separately detect and segment the spine and all vertebral bodies on chest X-rays, and the Cobb angle of the spinal curve was measured from the output of the Mask R-CNN models. To evaluate the reliability and accuracy of the computer-aided method, the Cobb angles on 248 chest X-rays from lung cancer screening were measured automatically using a computer-aided method, and two experienced radiologists used a manual method to separately measure Cobb angles on the aforementioned chest X-rays. For manual measurement of the Cobb angle on chest X-rays, the intraclass correlation coefficients (ICC) of intra- and inter-observer reliability analysis was 0.941 and 0.887, respectively, and the mean absolute differences were 10° as a reference standard for scoliosis, the computer-aided method achieved a high level of sensitivity (89.59%) and a relatively low level of specificity (70.37%) for diagnosing scoliosis on chest X-rays. The computer-aided method has potential for automatic Cobb angle measurement and scoliosis diagnosis on chest X-rays. These slides can be retrieved under Electronic Supplementary Material.

Comparison of full-endoscopic and minimally invasive decompression for lumbar spinal stenosis in the setting of degenerative scoliosis and spondylolisthesis.

Abstract: OBJECTIVEThe management of lumbar spinal stenosis (LSS) with concurrent scoliosis and/or spondylolisthesis remains controversial. Full-endoscopic unilateral laminotomy for bilateral decompression (ULBD) facilitates neural decompression while preserving stabilizing osseoligamentous structures and may be uniquely suited for the treatment of LSS with concurrent mild to moderate degenerative deformity. The safety and efficacy of full-endoscopic versus minimally invasive surgery (MIS) ULBD in this patient population is studied here for the first time.METHODSA retrospective analysis of prospectively collected data was conducted on 45 consecutive LSS patients with concurrent scoliosis (≥ 10° coronal Cobb angle) and/or spondylolisthesis (≥ 3 mm). Patient demographics, operative details, complications, and imaging characteristics were reviewed. Outcomes were quantified using back and leg visual analog scale (VAS) scores and the Oswestry Disability Index (ODI) at 2 weeks, 3 months, and 1 year.RESULTSA total of 26 patients underwent full-endoscopic and 19 underwent MIS-ULBD with an average follow-up period of 12 months. The endoscopic cohort experienced a significantly shorter hospital length of stay (p = 0.014) and fewer adverse events (p = 0.010). Both cohorts experienced significant improvements in VAS and ODI scores at all time points (p < 0.001), but the endoscopic cohort demonstrated significantly better early ODI scores (p = 0.024).CONCLUSIONSEndoscopic and MIS-ULBD result in similar functional outcomes for LSS with mild to moderate deformity, while the endoscopic approach demonstrates a favorable rate of complications. Further studies are required to better delineate the characteristics of spinal deformities amenable to this approach and the durability of functional results.

Non-Fusion Surgical Correction of Thoracic Idiopathic Scoliosis Using a Novel, Braided Vertebral Body Tethering Device: Minimum Follow-up of 4 Years.

Abstract: Anterior vertebral body tethering to effect scoliosis correction in a growing spine has been shown to work with varying degrees of success. This report describes the mid-term results of this technique using a new device composed of a braided ultra-high molecular weight polyethylene (UHMWPE) cord anchored to bone screws applied without segmental compression. Methods This was a single-center prospective observational study of an investigational device. Five female patients aged 9 to 12 years with thoracic scoliosis underwent thoracoscopic insertion of the UHMWPE tether. Radiographs and magnetic resonance imaging (MRI) were performed, and the Scoliosis Research Society (SRS)-22 was administered, preoperatively and at regular intervals after surgery, with a minimum of 4 years of follow-up. Results All tethering devices spanning the end vertebrae (range, 7 to 8 vertebrae) were implanted successfully. Mean blood loss was 136 mL, and the mean operative time was 205 minutes. The mean preoperative main thoracic Cobb angle was 40.1°. Curve correction of the tethered segment ranged from 0% to 133.3% at 4 years. We observed greater correction in 2 patients with open triradiate cartilage (TRC), achieving full scoliosis correction at 2 years and 121.5% at 4 years. MRI showed improvement in periapical disc wedging morphology and 55% improvement of rotation at 3 years. There were 20 adverse events, of which 16 were mild and 4 were moderate in severity. The 4 moderate events of pneumonia, distal decompensation, curve progression, and overcorrection occurred in 3 patients, 2 of whom required fusion. Conclusions Anterior vertebral body tethering resulted in scoliosis deformity correction in the coronal and axial planes, with preservation of curve flexibility. Actual correction by growth modulation was noted only in patients with open TRC, whereas curve stabilization was noted in patients with closed TRC. Overcorrection, curve progression, and distal decompensation are problems with this technique. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

High-intensity exercise did not cause vertebral fractures and improves thoracic kyphosis in postmenopausal women with low to very low bone mass: the LIFTMOR trial.

Abstract: Our aim was to assess risk of vertebral fracture during high-intensity resistance and impact training (HiRIT) for postmenopausal women with low bone mass. HiRIT did not induce vertebral fracture, as evidenced by a reduction in kyphosis following 8 months of training and a lack of change in vertebral morphology. The LIFTMOR trial demonstrated a novel, HiRIT program notably improved bone mass in postmenopausal women with osteopenia and osteoporosis. While no clinical signs or symptoms of vertebral crush fracture were evident during the trial, anecdotal feedback suggests that concerns about safety of HiRIT in the osteoporosis demographic remain. The aim of the current work was to assess vertebral body morphology, Cobb angle, and clinical measures of thoracic kyphosis in participants in the LIFTMOR trial for evidence of vertebral fracture following 8 months of supervised HiRIT. Participants were randomized to either 8 months of 30-min, twice-weekly, supervised HiRIT or unsupervised, low-intensity, home-based exercise (CON). Lateral thoracolumbar DXA scans (Medix DR, Medilink, France) were performed at baseline and follow-up. Cobb angle was determined, and vertebral fracture identification was performed using the semiquantitative Genant method. Clinical kyphosis measurements were performed in relaxed standing (neutral posture) and standing tall using an inclinometer and a flexicurve. The HiRIT group exhibited a reduction in inclinometer-determined standing tall thoracic kyphosis compared to CON (− 6.7 ± 8.2° vs − 1.6 ± 8.1°, p = 0.031). Both the HiRIT and CON groups exhibited within-group improvement in kyphosis in relaxed standing as measured by both inclinometer and flexicurve (p < 0.05). There were no changes in vertebral fracture classification in the HiRIT group post-intervention. A single, new, wedge deformity was observed for CON. Supervised HiRIT was not associated with an increased risk of vertebral fracture in postmenopausal women with low bone mass. Indeed, a clinically relevant improvement in thoracic kyphosis was observed following 8 months of supervised HiRIT, further supporting its efficacy as an osteoporosis intervention for postmenopausal women with low to very low bone mass.

Sequential correction technique to avoid postoperative global coronal decompensation in rigid adult spinal deformity: a technical note and preliminary results.

Abstract: This study aims to evaluate this new sequential correction technique for preventing postoperative coronal imbalance. Adult Spinal deformity (ASD) patients were stratifies into two types: primary thoracolumbar/lumbar (TL/L) curve with compensatory lumbosacral (LS) curve (Type I) and primary LS curve with compensatory TL/L curve (Type II): for Type I patients: correction of major TL/L curve and one- or two-level segmental rod installed at the convexity of the TL/L curve, L4-S1 TLIF to correct fractional curve and a short rod installed on the contralateral side and installation of long rods; for Type II patients: horizontalize L4 and L5, short rod installation at the convexity of the LS curve, distraction of curve with regional rod and installation of long rods. ASD patients were enrolled with inclusion criteria: with pre-op TL/L Cobb angle more than 30°, with pelvic fixation and with UIV over T10. Radiographic parameters were analyzed. Twenty-one patients were recruited (14 patients Type I and 7 Type II patients). Both Cobb angle and coronal offset were significantly improved after surgery. In Type I patients, Cobb angle was improved from 50.48° to 26.91° and coronal offset from 2.94 to 0.95 cm; in Type II patients, Cobb angle was improved from 61.42° to 28.48° and coronal offset from 2.82 to 1.38 cm. In the 10 patients with baseline coronal imbalance, 9 were corrected to coronal balance after surgery. The sequential correction technique allows decomposing the complex correction surgery into several steps, and each step focuses only on one task. It can also reduce the difficulty of rod installation due to the separated maneuvers and multi-rod system. IV These slides can be retrieved under Electronic Supplementary Material.

Patients with adolescent idiopathic scoliosis perceive positive improvements regardless of change in the Cobb angle - Results from a randomized controlled trial comparing a 6-month Schroth intervention added to standard care and standard care alone. SOSORT 2018 Award winner.

Abstract: The Cobb angle is proposed as the “disease process” outcome for scoliosis research because therapies aim to correct or stop curve progression. While the Scoliosis Research Society recommends the Cobb angle as the primary outcome, the Society on Scoliosis Orthopaedic and Rehabilitation Treatment prioritises, as a general goal, patient related outcomes over Cobb angle progression. To determine the threshold of change in the Cobb angle in adolescents with idiopathic scoliosis (AIS) who perceive improvement in a 6-months randomized controlled trial comparing a Schroth exercise intervention added to the standard of care to the standard of care alone. This is a secondary analysis of data from a randomized controlled trial of 50 patients with AIS, with curves ranging from 10° to 45°, with or without a brace. Participants with diagnoses other than AIS, surgical candidates or patients who had scoliosis surgery were excluded. The 6-month interventions consisted of Schroth exercises added to standard-of-care (observation or bracing) with daily home exercises and weekly therapy sessions (Schroth) or standard-of-care alone (Control). The anchor method for estimating the minimal important difference (MID) in the largest Cobb angles (LC) was used. Patient-reported change in back status over the 6-month treatment period was measured using the Global Rating of Change (GRC) scale as anchor varying from − 7 (“great deal worse”) to + 7 (“great deal better”). Participants were divided into two groups based on GRC scores: Improved (GRC ≥2) or Stable/Not Improved (GRC ≤1). MID was defined as the change in the LC that most accurately predicted the GRC classification as per the receiver operating characteristic curve (ROC). The average age was 13.4 ± 1.6 years and the average LC was 28.5 ± 8.8 °s. The average GRC in the control group was − 0.1 ± 1.6, compared to + 4.4 ± 2.2 in the Schroth group. The correlation between LC and GRC was adequate (r = − 0.34, p < 0.05). The MID for the LC was 1.0 °. The area under the ROC was 0.69 (0.52–0.86), suggesting a 70% chance to properly classify a patient as perceiving No Improvement/Stable or Improvement based on the change in the LC. Patients undergoing Schroth treatment perceived improved status of their backs even if the Cobb angle did not improve beyond the conventionally accepted threshold of 5°. Standard of care aims to slow/stop progression while Schroth exercises aim to improve postural balance, signs and symptoms of scoliosis. Given the very small MID, perceived improvement in back status is likely due to something other than the Cobb angle. This study warrants investigating alternatives to the Cobb angle that might be more relevant to patients. ClinicalTrials.gov , NCT01610908 . Retrospectively registered on April 2, 2012 (first posted on June 4, 2012 - https://clinicaltrials.gov/ct2/keydates/NCT01610908 )

A Longitudinal Study of Trunk Muscle Properties and Severity of Thoracic Kyphosis in Women and Men: The Framingham Study.

Abstract: BACKGROUND Cross-sectional studies suggest that trunk muscle morphology in the lumbar spine is an important determinant of kyphosis severity in older adults. The contribution of age-related changes in muscle morphology in the thoracic and lumbar spine to progression of kyphosis is not known. Our objective was to determine cross-sectional and longitudinal associations of thoracic and lumbar muscle size and density with kyphosis. METHODS Participants were 1,087 women and men (mean age: 61 years) of the Framingham Heart Study who underwent baseline and follow-up quantitative computed tomography (QCT) scanning 6 years apart. We used QCT scans to measure trunk muscle cross-sectional area (CSA, cm2) and density (HU) at the thoracic and lumbar spine and Cobb angle (degrees) from T4 to T12. Linear regression models estimated the association between muscle morphology and kyphosis. RESULTS At baseline, smaller muscle CSA and lower density of thoracic (but not lumbar) spine muscles were associated with a larger (worse) Cobb angle in women and men. For example, each standard deviation decrease in baseline thoracic paraspinal muscle CSA was associated with a larger baseline Cobb angle in women (3.7 degrees, 95% CI: 2.9, 4.5) and men (2.5 degrees, 95% CI: 1.6, 3.3). Longitudinal analyses showed that loss of muscle CSA and density at the thoracic and lumbar spine was not associated with progression of kyphosis. CONCLUSIONS Our findings suggest that kyphosis severity is related to smaller and lower density trunk muscles at the thoracic spine. Future studies are needed to determine how strengthening mid-back musculature alters muscle properties and contributes to preventing kyphosis progression.

An Application of Artificial Intelligence to Diagnostic Imaging of Spine Disease: Estimating Spinal Alignment From Moiré Images.

Abstract: The use of artificial intelligence (AI) as a tool supporting the diagnosis and treatment of spinal diseases is eagerly anticipated. In the field of diagnostic imaging, the possible application of AI includes diagnostic support for diseases requiring highly specialized expertise, such as trauma in children, scoliosis, symptomatic diseases, and spinal cord tumors. Moire topography, which describes the 3-dimensional surface of the trunk with band patterns, has been used to screen students for scoliosis, but the interpretation of the band patterns can be ambiguous. Thus, we created a scoliosis screening system that estimates spinal alignment, the Cobb angle, and vertebral rotation from moire images. In our system, a convolutional neural network (CNN) estimates the positions of 12 thoracic and 5 lumbar vertebrae, 17 spinous processes, and the vertebral rotation angle of each vertebra. We used this information to estimate the Cobb angle. The mean absolute error (MAE) of the estimated vertebral positions was 3.6 pixels (~5.4 mm) per person. T1 and L5 had smaller MAEs than the other levels. The MAE per person between the Cobb angle measured by doctors and the estimated Cobb angle was 3.42°. The MAE was 4.38° in normal spines, 3.13° in spines with a slight deformity, and 2.74° in spines with a mild to severe deformity. The MAE of the angle of vertebral rotation was 2.9°±1.4°, and was smaller when the deformity was milder. The proposed method of estimating the Cobb angle and AVR from moire images using a CNN is expected to enhance the accuracy of scoliosis screening.

Age-related Changes in Cervical Sagittal Alignment: A Radiographic Analysis.

Abstract: Study design Retrospective cohort study. Objective To identify age-related changes in cervical sagittal parameters using standard radiographs. Summary of background data Cervical sagittal balance is important for the maintenance of neutral head posture and horizontal gaze. Degenerative changes in the cervical spine that occur with aging may alter cervical sagittal balance, which can lead to chronic neck pain and predispose to various cervical spine pathologies. Methods We performed a retrospective cohort study of 151 patients with lateral cervical spine radiographs taken at our institution between December 2017 and June 2018. Cervical sagittal parameters were measured, including C1 inclination, C2 slope, C2-C7 Cobb angle, cervical sagittal vertical axis (cSVA), cervical tilt, upper and lower C7 slopes, T1 slope, and T1 slope minus cervical lordosis (TS-CL). The association between age and cervical sagittal parameters was assessed using the Pearson correlation coefficient and a linear regression analysis. An analysis of variance (ANOVA) with Tukey adjustments was then performed to identify differences in cervical sagittal parameters among patients aged 18 to 39 years, 40 to 64 years, and >64 years of age. Results There were positive correlations between age and C2-C7 Cobb angle (r = 0.231, P = 0.004), upper C7 slope (r = 0.280, P 64 years old had significantly higher C2-C7 Cobb angle, upper C7 slope, lower C7 slope, and T1 slope. Conclusion Changes in cervical sagittal alignment with age are characterized by increased cervical lordosis and increased thoracic kyphosis. Level of evidence 3.

Review of scoliosis-specific exercise methods used to correct adolescent idiopathic scoliosis

Abstract: Adolescent idiopathic scoliosis (AIS) refers to a spinal curvature of an unknown origin diagnosed in otherwise healthy children. A conservative treatment approach includes physiotherapy scoliosis-specific exercises (PSSE) with or without corrective bracing in preventing further spinal column deviation. However, several PSSE types have been developed to facilitate a positive patient outcome and/or preclude surgical remediation. Based on other reviews, there has been insufficient evidence published on the efficacy of PSSEs. In addition, the superiority of PSSE over no intervention or compared to other exercise modes has yet to be determined. A comprehensive search of AIS literature, inception through February 2018, was conducted to reveal relevant PSSE articles. Only studies using commonly reported PSSEs were included. Examined databases included PubMed, Scopus, CINAHL Complete, and Physiotherapy Evidence Database (PEDro). Google Scholar search engine was also examined. Article types included randomized or clinical control trials. All articles were published in English or were of English translation. Search parameters were collectively defined by the reviewers and subsequently used to determine included studies. Individual PSSE study methodology quality was determined by the PEDro scale. Effect sizes (Hedge’s g) and their 95% confidence intervals were calculated for Cobb angle between group changes. Of the initial 24 articles recovered only eight (33%) met the established search criteria. Patient ages from these sources ranged from 11.4–16.2 including both males and females. Examined papers included two Schroth method and six specifying the Scientific Exercise Approach to Scoliosis (SEAS) method. All articles demonstrated positive between group effect sizes for PSSEs. There were no studies that compared one PSSE to another. Determined PEDro scores indicated an overall moderate quality of these studies. There is insufficient evidence to suggest that both Schroth and SEAS methods can effectively improve Cobb angles in patients with AIS compared to no intervention. There is limited evidence that the SEAS method is more effective at reducing Cobb angles compared to traditional exercises in treating AIS. Overall, this review revealed a noticeable lack of contemporary studies that could be used in answering our questions. Evidence-based medicine (EBM) supplies clinicians with verifiable results from well-designed and managed research studies. Consequently, more and varied studies of higher quality are needed before any definitive determination can be made as to the effectiveness of any PSSE let alone the one offering better patient outcomes.

Brace treatment of Idiopathic Scoliosis is effective for a curve over 40 degrees, but is the evaluation of Cobb angle the only parameter for the indication of treatment?

Abstract: BACKGROUND The recent literature showed positive results for bracing of patients with idiopathic scoliosis above 45° who refused surgery. However, no one has investigated whether other parameters can affect the results. AIM The aim of this study was to evaluate the effectiveness of bracing in idiopathic scoliosis with curves above 40° and to verify the mechanical and biological parameters which go beyond the simple bend value expressed in Cobb degrees. DESIGN This is an observational controlled cohort study nested in a prospective clinical on-going database including 1,238 patients with idiopathic scoliosis. SETTING Inpatients and outpatients in Rome. POPULATION The study enrolled 160 patients with idiopathic scoliosis with curves above 40°. METHODS This is a prospective study based on an ongoing database including 1,238 patients with idiopathic scoliosis. The patients studied had idiopathic scoliosis with curves of 40° or more, Risser grade 0-4, and had refused any surgical treatment. 160 patients met the inclusion criteria. Of these, 104 patients had a definite outcome, 28 abandoned treatment and 28 are currently under treatment. The minimum duration of follow-up was 24 months. X-rays were used to obtain Cobb degrees and torsion of the apical vertebrae (Perdriolle's method). Three outcomes were distinguished according to SRS-SOSORT criteria: correction, stabilization and progression. To achieve the second aim, we divided the sample into subgroups according to Cobb degrees (<45°; ≥45°), Risser (0-2; 3-4) and rotation (<20; ≥20). Furthermore, logistic regression was applied by Stepwise Regression. RESULTS The results of our study showed that in 104 patients with a definite outcome the Cobb mean value was initially 47±5.25 SD and 34.19 ±8.45 SD at follow-up. Perdriolle was initially 20.04±5.53 SD and 16.76±7.04 at follow-up. Overall, 81 patients (78%) obtained a curve correction, and stabilization was achieved in 14 cases (13%). Nine patients experienced curve progression (9%), 16 patients were recommended for surgery because the curve at follow up was over 45°. The analysis of subgroups shows that with Cobb <45° at baseline, the average reduction was 11.46° Cobb, while in cases with Cobb ≥45 at baseline, the mean correction was 13.74° Cobb. In subgroups with Perdriolle <20° at baseline, the average reduction was 16.02° Cobb, while in cases with Perdriolle ≥20° at baseline, the mean correction was 8.4° Cobb. In subgroups with Risser 0-2 at baseline, the average reduction was 14.7° Cobb, while in cases with Risser 3-4 at baseline, the mean correction was 6.7° Cobb. The logistic regression model shows significance for the initial value of Perdriolle and Risser. CONCLUSIONS Our results indicate that an adequate conservative treatment must definitely be considered for patients with scoliotic curves who refuse surgery; the results will be better particularly if the rotation is lower than 20 and Risser is between 0-2. CLINICAL REHABILITATION IMPACT With the simultaneous evaluation of the Cobb angle, the vertebral rotation and the potential vertebral growth, it was possible to predict the final results at the start of treatment.

Unilateral and Bilateral Percutaneous Kyphoplasty for Thoracolumbar Osteoporotic Compression Fractures.

Abstract: OBJECTIVE To compare the efficacies of unilateral and bilateral percutaneous kyphoplasty (PKP) in the treatment of thoracolumbar osteoporotic compression fractures. STUDY DESIGN Experimental study. PLACE AND DURATION OF STUDY Department of Orthopedics, Hubei 672 Orthopedics Hospital of Integrated Chinese and Western Medicine, China, from November 2014 to January 2017. METHODOLOGY One hundred and seventy-eight patients with single-level thoracolumbar osteoporotic compression fractures included in this study. These patients were randomly assigned to unilateral (n=83) and bilateral (n=95) PKP groups. The operation time, bone cement volume, number of X-ray views, preoperative and postoperative pain visual analogue scale scores (VAS), Oswestry Dysfunction Index (ODI), Cobb angle, and vertebral height in both groups were recorded. RESULTS Operation time, bone cement volume and intraoperative number of X-ray views were significantly different between unilateral and bilateral PKP groups (29.8 ±2.7 vs. 31.5 ±3.9 minutes; 9.3 ±2.6 vs. 11.2 ±3.7 times; 3.1 ±0.7 vs. 3.5 ±1.2 ml, respectively, p <0.05). VAS scores and ODI in both groups were significantly different before and 24 hours, 3 months and 6 months after surgery. The heights of anterior and middle borders of vertebral body and Cobb angle in the two groups were significantly different before and after surgery (p <0.05). CONCLUSION The short-term efficacy was identical between unilateral and bilateral PKP. The unilateral PKP is characterized by short operation time, low hospital cost, less number of X-ray views and less bone cement volume. The unilateral PKP shows a higher risk of re-fracture of adjacent vertebral body compared with the bilateral PKP.

The biomechanical effect of single-level laminectomy and posterior instrumentation on spinal stability in degenerative lumbar scoliosis: a human cadaveric study.

Abstract: OBJECTIVEDegenerative lumbar scoliosis, or de novo degenerative lumbar scoliosis, can result in spinal canal stenosis, which is often accompanied by disabling symptoms. When surgically treated, a single-level laminectomy is performed and short-segment posterior instrumentation is placed to restore stability. However, the effects of laminectomy on spinal stability and the necessity of placing posterior instrumentation are unknown. Therefore, the aim of this study was to assess the stability of lumbar spines with degenerative scoliosis, characterized by the range of motion (ROM) and neutral zone (NZ) stiffness, after laminectomy and placement of posterior instrumentation.METHODSTen lumbar cadaveric spines (T12-L5) with a Cobb angle ≥ 10° and an apex on L3 were included. Three loading cycles were applied per direction, from -4 Nm to 4 Nm in flexion/extension (FE), lateral bending (LB), and axial rotation (AR). Biomechanical evaluation was performed on the native spines and after subsequent L3 laminectomy and the placement of posterior L2-4 titanium rods and pedicle screws. Nonparametric and parametric tests were used to analyze the effects of laminectomy and posterior instrumentation on NZ stiffness and ROM, respectively, both on an individual segment's motion and on the entire spine section. Spearman's rank correlation coefficient was used to study the correlation between disc degeneration and spinal stability.RESULTSThe laminectomy increased ROM by 9.5% in FE (p = 0.04) and 4.6% in LB (p = 0.01). For NZ stiffness, the laminectomy produced no significant effects. Posterior instrumentation resulted in a decrease in ROM in all loading directions (-22.2%, -24.4%, and -17.6% for FE, LB, and AR, respectively; all p < 0.05) and an increase in NZ stiffness (+44.7%, +51.7%, and +35.2% for FE, LB, and AR, respectively; all p < 0.05). The same changes were seen in the individual segments around the apex, while the adjacent, untreated segments were mostly unaffected. Intervertebral disc degeneration was found to be positively correlated to decreased ROM and increased NZ stiffness.CONCLUSIONSLaminectomy in lumbar spines with degenerative scoliosis did not result in severe spinal instability, whereas posterior instrumentation resulted in a rigid construct. Also, prior to surgery, the spines already had lower ROM and higher NZ stiffness in comparison to values shown in earlier studies on nonscoliotic spines of the same age. Hence, the authors question the clinical need for posterior instrumentation to avoid instability.

A Semi-Automatic Algorithm for Estimating Cobb Angle.

Abstract: Background: Scoliosis is the most common type of spinal deformity. A universal and standard method for evaluating scoliosis is Cobb angle measurement, but several studies have shown that there is intra- and inter- observer variation in measuring cobb angle manually. Objective: Develop a computer- assisted system to decrease operator-dependent errors in Cobb angle measurement. Methods: The spinal cord in the given x-ray image of the spine is highlighted using contract-stretching technique. The overall structural curvature of the spine is determined by a semi-automatic algorithm aided by the operator. Once the morphologic curve of the spine is determined, in the last step the cobb-angle is estimated by calculating the angle between two normal lines to the spinal curve at the inflection points of the curve. Results: Evaluation results of the developed algorithms using 14 radiographs of patients ( 4 - 40 years old) with cobb angle ranges from 34 - 82 degrees, revealed that the developed algorithm accurately estimated cobb angle. Statistical analysis showed that average angle values estimated using the developed method and that provided by experts are statistically equal. The correlation coefficient between the angle values estimated using the developed algorithm and those provided by the expert is 0.81. Conclusion: Compared with previous algorithms, the developed system is easy to use, less operator-dependent, accurate, and reliable. The obtained results are promising and show that the developed computer-based system could be used to quantify scoliosis by measuring Cobb angle.

Bracing in Adolescent Idiopathic Scoliosis Trial (BrAIST): Development and Validation of a Prognostic Model in Untreated Adolescent Idiopathic Scoliosis Using the Simplified Skeletal Maturity System.

Abstract: Study Design Prognostic study and validation using prospective clinical trial data. Objective To derive and validate a model predicting curve progression to ≥45° before skeletal maturity in untreated patients with adolescent idiopathic scoliosis (AIS). Summary of Background Data Studies have linked the natural history of AIS with characteristics such as sex, skeletal maturity, curve magnitude, and pattern. The Simplified Skeletal Maturity Scoring System may be of particular prognostic utility for the study of curve progression. The reliability of the system has been addressed; however, its value as a prognostic marker for the outcomes of AIS has not. The BrAIST trial followed a sample of untreated AIS patients from enrollment to skeletal maturity, providing a rare source of prospective data for prognostic modeling. Methods The development sample included 115 untreated BrAIST participants. Logistic regression was used to predict curve progression to ≥45° (or surgery) before skeletal maturity. Predictors included the Cobb angle, age, sex, curve type, triradiate cartilage, and skeletal maturity stage (SMS). Internal and external validity was evaluated using jackknifed samples of the BrAIST data set and an independent cohort (n = 152). Indices of discrimination and calibration were estimated. A risk classification was created and the accuracy evaluated via the positive (PPV) and negative predictive values (NPV). Results The final model included the SMS, Cobb angle, and curve type. The model demonstrated strong discrimination (c-statistics 0.89–0.91) and calibration in all data sets. The classification system resulted in PPVs of 0.71–0.72 and NPVs of 0.85–0.93. Conclusions This study provides the first rigorously validated model predicting a short-term outcome of untreated AIS. The resultant estimates can serve two important functions: 1) setting benchmarks for comparative effectiveness studies and 2) most importantly, providing clinicians and families with individual risk estimates to guide treatment decisions. Level of Evidence Level 1, prognostic.

The Effect of Schroth Therapy on Thoracic Kyphotic Curve and Quality of Life in Scheuermann’s Patients: A Randomized Controlled Trial

Abstract: Study design Randomized controlled single-blinded clinical trial. Purpose To evaluate the efficacy of Schroth therapy on thoracic curve angle, pain, and self-perceived body image (SPBI) of the back in Scheuermann's patients in comparison with the efficacy of classic anti-gravitation exercises. Overview of literature Scheuermann disease is the most common cause of hyperkyphosis of the thoracic and thoracolumbar spine during adolescence. However, very few studies evaluated the effect of exercises on the progression of kyphosis in Scheuermann patients. Schroth three-dimensional exercise therapy was found in several studies to be effective in the treatment of adolescent scoliosis, however, we found no randomized controlled trials that evaluated the efficacy of this method in Scheuermann patients. Methods A total of 50 young adults (males and females) with Scheuermann's disease were randomly divided into either the experimental group (Schroth therapy treatment, n=25) or the control group (classic anti-gravitation exercises, n=25). Participants in both the groups were provided a course of individual treatment sessions during few weeks, with one appointment per week. They were required to perform the exercises daily throughout the study period (12 months) and fill their performance in a research log. We evaluated the thoracic Cobb angle (main outcome measure), pain, SPBI, flexion of the shoulder (supine), flexion of the shoulder (standing), kyphotic deformity measured using inclinometer, and L5 kyphosis apex line (L5-KAL) as well as administered the Scoliosis Research Society-22 Questionnaire for the participants before the treatment, after 6 months, and 1 year postoperatively. These results were then compared. Results In the mixed analysis of variance, the main effect of time was significant in the thoracic kyphosis (F [1]=5.72, p=0.02), and in the L5-KAL (F [1]=5.76, p=0.02). The main effect of time on the kyphotic deformity, measured using an inclinometer, did not reach the significance level; however, it showed the tendency (F [1]=2.80, p=0.07). In the group-by-time interaction, a significant difference was found in the thoracic kyphosis (F [1]=4.91, p=0.03) and in the kyphotic deformity, measured using an inclinometer (F [1]=4.05, p=0.02). Thus, the Schroth therapy group showed significantly greater improvement than the classic anti-gravitation exercises group. Conclusions The present findings indicate that back exercises in general, and Schroth therapy in particular, is an effective treatment for preventing and significantly improving the thoracic Cobb angle and symptomatic representation in Scheuermann's patients.

Computer-based Cobb angle measurement using deflection points in adolescence idiopathic scoliosis from radiographic images

Abstract: Idiopathic scoliosis treatment depends on the accurate assessment of the Cobb angle, which is usually performed manually. Manual measurements, however, can lead to observer variations, which depend on the correct selection of the curvature superior and inferior vertebrae in order to draw the needed lines for Cobb angle measurements. In this paper, we are proposing an algorithm to measure the Cobb angle semi-automatically. The algorithm is based on two processing phases in which each column in the raw X-ray image is reduced to two points representing the end points of the spine and containing its general structure and outline. These points are then used to fit a fifth-order polynomial. We hypothesize that the deflection points of the fitted curve represent the superior and inferior vertebrae of the scoliosis curvature. The deflection points were used to calculate the Cobb angle. The algorithm was tested on X-ray images from 28 subjects (14 females and 14 males, average age of 15.6 ± 1.3 years) diagnosed with adolescence idiopathic scoliosis. Three manual measurements were obtained, with manually measured Cobb angles ranging from of 10° to 98°. The mean of the standard deviation of the manual readings and the algorithm results was 5.28° and 2.64°, respectively, with mean abs error of 6.6° and R value of 0.81. Excluding the cervical and rib cage touching scoliosis cases, the mean of the standard deviation of the manual readings and the algorithm results was 4.73° and 2.35°, respectively, with mean abs error of 3.78° and R value of 0.94. From the results, we can conclude that our proposed algorithm can minimize and simplify user intervention, thus allowing easier and more accurate Cobb angles measurements and resulting in a shorter diagnosis time and requiring no special skills from the user.

Minimum 5-Year Follow-up of Mehta Casting to Treat Idiopathic Early-Onset Scoliosis.

Abstract: Background With the exception of Mehta's 2005 report on her experience treating early-onset scoliosis with serial casting, all subsequent studies have had limited follow-up. This current study sought to assess the results of serial casting at a minimum 5-year follow-up and to identify the predictors of the sustained resolution of scoliosis. Methods This study is a retrospective review of children treated for idiopathic early-onset scoliosis with serial casting at a children's hospital between 2001 and 2013 with a minimum 5-year follow-up. A Cobb angle of ≤15° and a decrease in the Cobb angle of >20° at the most recent follow-up were separately assessed. The differences between groups based on these criteria were tested with Student t tests with alpha = 0.05. Results Fifty-four children were treated during the study period; of these, 38 had at least 5 years of follow-up and comprised the study sample. The mean follow-up (and standard deviation) was 8 ± 2 years (range, 5 to 13 years). The mean patient age at the time of the first cast was 24 ± 15.1 months (range, 9 to 63 months), with a mean Cobb angle of 56.2° ± 20.1° (range, 22° to 109°). Forty-nine percent of children had scoliosis of ≤15° at the time of the most recent follow-up, and 73% of children were improved by at least 20°. Children with ≤15° scoliosis, compared with children with >15° scoliosis, had significantly lower initial Cobb angle (48.2° compared with 63.7°; p = 0.016), supine traction Cobb angle (22.5° compared with 33.2°; p = 0.048), first-in-cast Cobb angle (24.1° compared with 37.6°; p = 0.01), and first-in-cast rib-vertebral angle difference (12.8° compared with 26.2°; p 0.05) between the groups. Three children who initially achieved scoliosis of ≤15° after casting substantially relapsed. Conclusions At a minimum follow-up of 5 years, the initial Cobb angle, first-cast Cobb angle, rib-vertebral angle difference, and traction Cobb angle were all predictive of sustained scoliosis of ≤15°. However, with continued growth, relapse of scoliosis was seen in 3 patients. Level of evidence Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Abnormal lacuno-canalicular network and negative correlation between serum osteocalcin and Cobb angle indicate abnormal osteocyte function in adolescent idiopathic scoliosis.

Abstract: Adolescent idiopathic scoliosis (AIS) is a prevalent spinal deformity occurring during peripubertal growth period that affects 1-4% of adolescents globally without clear etiopathogenetic mechanism. Low bone mineral density is an independent and significant prognostic factor for curve progression. Currently, the cause underlying low bone mass in AIS remains elusive. Osteocytes play an important role in bone metabolism and mineral homeostasis, but its role in AIS has not been studied. In the present study, iliac bone tissues were harvested from 21 patients with AIS (mean age of 14.3 ± 2.20 yr old) with a mean Cobb angle of 55.6 ± 10.61° and 13 non-AIS controls (mean age of 16.5 ± 4.79 yr old) intraoperatively. Acid-etched scanning electron microscopy (SEM) images of AIS demonstrated abnormal osteocytes that were more rounded and cobblestone-like in shape and were aligned in irregular clusters with shorter and disorganized canaliculi. Further quantitative analysis with FITC-Imaris technique showed a significant reduction in the canalicular number and length as well as an increase in lacunar volume and area in AIS. SEM with energy-dispersive X-ray spectroscopy analysis demonstrated a lower calcium-to-phosphorus ratio at the perilacunar/canalicular region. Moreover, microindentaion results revealed lower values of Vickers hardness and elastic modulus in AIS when compared with controls. In addition, in the parallel study of 99 AIS (27 with severe Cobb angle of 65.8 ± 14.1° and 72 with mild Cobb angle of 26.6 ± 9.1°) with different curve severity, the serum osteocalcin level was found to be significantly and negatively associated with the Cobb angle. In summary, the findings in this series of studies demonstrated the potential link of abnormal osteocyte lacuno-canalicular network structure and function to the observed abnormal bone mineralization in AIS, which may shed light on etiopathogenesis of AIS.-Chen, H., Zhang, J., Wang, Y., Cheuk, K.-Y., Hung, A. L. H., Lam, T.-P., Qiu, Y., Feng, J. Q., Lee, W. Y. W., Cheng, J. C. Y. Abnormal lacuno-canalicular network and negative correlation between serum osteocalcin and Cobb angle indicate abnormal osteocyte function in adolescent idiopathic scoliosis.

New sagittal classification of AIS: validation by 3D characterization.

Abstract: In order to improve surgical planning of sagittal correction in AIS, we proposed a new sagittal classification—Abelin-Genevois et al. Eur Spine J (27(9):2192–2202, 2018. https://doi.org/10.1007/s00586-018-5613-1 ). The main criticism is related to the fact that 2D lateral view results from the projection of the 3D deformity. The aim of this study is to show that the new sagittal classification system is a reliable system to describe the different sagittal scenarios that AIS could create both in 2D and 3D. We performed retrospective radiograph analysis of prospectively collected data from 93 consecutive AIS patients who underwent an examination of the whole spine using the EOS® imaging system. 2D (Keops®) and 3D analyses (sterEOS®) provided frontal and sagittal spinal and spinopelvic parameters. In addition, 3D analysis provided apical vertebra rotation (AVR). Comparing 2D and 3D measurements for the general cohort, excellent correlation can be found for all parameters, but only fairly good for T10L2 and L1S1 angles. The highest variability was observed for T10L2, differences between 2D and 3D measurements being greater when the Cobb angle increased. AVR did not influence concordance between 2D and 3D measurements. Eighty-two percent were similarly classified in 2D and 3D according to the new classification. Misclassified patients were all AIS sagittal type 3 in 3D analysis, thoracolumbar junction (TLJ) lordosis being underestimated on 2D view. In conclusion, for the majority of cases (82%), 2D analysis may provide enough information for decision making when using a semi-automated 2D measurement system. However, in severe cases, especially when Cobb angle exceeds 55°, 3D analysis should be used to get a more accurate view on the thoracolumbar junction behavior. These slides can be retrieved under Electronic Supplementary Material.

Radiographic, Pulmonary, and Clinical Outcomes With Halo Gravity Traction

Abstract: Study Design Single-center retrospective chart review. Objectives and Summary Halo gravity traction (HGT) is a safe and effective intervention to improve spinal deformity prior to corrective instrumentation. Our study aimed to report on a large series of patients undergoing HGT, demonstrate the correlation between thoracic height achieved and pulmonary function, and evaluate the efficacy of nutritional assessment and intervention while in HGT for these often malnourished or nutritionally compromised patients. Methods 107 patients underwent HGT for severe spinal deformity. Major coronal and sagittal Cobb angles, T1–T12 ht, and T1–S1 ht were collected pre-HGT, during HGT, postoperation, and 2 years postoperation. Pulmonary function tests (PFTs) recorded forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1). Nutritional interventions such as formal nutrition consult, resulting nutritional supplementation, or interventions were recorded. Results Patients were in HGT for mean of 82.1 days and mean maximum percentage body weight in traction was 49.5%. Mean major coronal Cobb angle prior to HGT was 92.6°, improving to 65.8° in maximal traction and to 47° after surgical intervention. Traction accounted for 78% of T1–T12 height and 79% of T1–S1 length gains from pre- to postoperation. We showed a positive correlation between gain in T1–T12 height and percentage predicted changes in FVC and FEV1. Weight Z score for the entire cohort of patients improved from −2.8 pretraction to −2.4 in traction and then to −2.3 postoperative. Conclusions Our study again demonstrated that HGT achieves radiographic improvement safely and effectively in severe spinal deformity. We demonstrated a positive correlation between improvement in PFTs and increase in thoracic height seen with HGT. Additionally, improvement in weight Z score was seen in the entire population and the most at risk patients for malnutrition, results that have not been shown before. Level of Evidence Level IV.

Less invasive spinal deformity surgery: the impact of the learning curve at tertiary spine care centers

Abstract: Objective The past decade has seen major advances in techniques for treating more complex spinal disorders using minimally invasive surgery (MIS). While appealing from the standpoint of patient perioperative outcomes, a major impediment to adoption has been the significant learning curve in utilizing MIS techniques. Methods Data were retrospectively analyzed from a multicenter series of adult spinal deformity surgeries treated at eight tertiary spine care centers in the period from 2008 to 2015. All patients had undergone a less invasive or hybrid approach for a deformity correction satisfying the following inclusion criteria at baseline: coronal Cobb angle ≥ 20°, sagittal vertical axis (SVA) > 5 cm, or pelvic tilt > 20°. Analyzed data included baseline demographic details, severity of deformity, surgical metrics, clinical outcomes (numeric rating scale [NRS] score and Oswestry Disability Index [ODI]), radiographic outcomes, and complications. A minimum follow-up of 2 years was required for study inclusion. Results Across the 8-year study period, among 222 patients, there was a trend toward treating increasingly morbid patients, with the mean age increasing from 50.7 to 62.4 years (p = 0.013) and the BMI increasing from 25.5 to 31.4 kg/m2 (p = 0.12). There was no statistical difference in the severity of coronal and sagittal deformity treated over the study period. With regard to radiographic changes following surgery, there was an increasing emphasis on sagittal correction and, conversely, less coronal correction. There was no statistically significant difference in clinical outcomes over the 8-year period, and meaningful improvements were seen in all years (ODI range of improvement: 15.0-26.9). Neither were there statistically significant differences in major complications; however, minor complications were seen less often as the surgeons gained experience (p = 0.064). Operative time was decreased on average by 47% over the 8-year period.Trends in surgical practice were seen as well. Total fusion construct length was unchanged until the last year when there was a marked decrease in conjunction with a decrease in interbody levels treated (p = 0.004) while obtaining a higher degree of sagittal correction, suggesting more selective but powerful interbody reduction methods as reflected by an increase in the lateral and anterior column resection techniques being utilized. Conclusions The use of minimally invasive methods for adult spinal deformity surgery has evolved over the past decade. Experienced surgeons are treating older and more morbid patients with similar outcomes. A reliance on selective, more powerful interbody approaches is increasing as well.