Vertebral Rotation Research Articles

3D prediction of curve progression in adolescent idiopathic scoliosis based on biplanar radiological reconstruction.

This systematic review aims to identify 3D predictors derived from biplanar reconstruction, and to describe current methods for improving curve prediction in patients with mild adolescent idiopathic scoliosis. A comprehensive search was conducted by three independent investigators on MEDLINE, PubMed, Web of Science, and Cochrane Library. Search terms included "adolescent idiopathic scoliosis","3D", and "progression". The inclusion and exclusion criteria were carefully defined to include clinical studies. Risk of bias was assessed with the Quality in Prognostic Studies tool (QUIPS) and Appraisal tool for Cross-Sectional Studies (AXIS), and level of evidence for each predictor was rated with the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. In all, 915 publications were identified, with 377 articles subjected to full-text screening; overall, 31 articles were included. Torsion index (TI) and apical vertebral rotation (AVR) were identified as accurate predictors of curve progression in early visits. Initial TI > 3.7° and AVR > 5.8° were predictive of curve progression. Thoracic hypokyphosis was inconsistently observed in progressive curves with weak evidence. While sagittal wedging was observed in mild curves, there is insufficient evidence for its correlation with curve progression. In curves with initial Cobb angle < 25°, Cobb angle was a poor predictor for future curve progression. Prediction accuracy was improved by incorporating serial reconstructions in stepwise layers. However, a lack of post-hoc analysis was identified in studies involving geometrical models. For patients with mild curves, TI and AVR were identified as predictors of curve progression, with TI > 3.7° and AVR > 5.8° found to be important thresholds. Cobb angle acts as a poor predictor in mild curves, and more investigations are required to assess thoracic kyphosis and wedging as predictors. Cumulative reconstruction of radiographs improves prediction accuracy. Comprehensive analysis between progressive and non-progressive curves is recommended to extract meaningful thresholds for clinical prognostication.

Direct vertebral rotation versus simple rod derotation techniques in correction of adolescent idiopathic scoliosis.

One method for treating adolescent idiopathic scoliosis (AIS), which is characterized by abnormal spinal alignment in the coronal, sagittal, and rotational planes, is surgical correction. The two surgical techniques most typically used to correct spine alignment are simple rod derotation (SRD) and direct vertebral derotation (DVR). The study's goal was to assess the effectiveness of two treatment methods for adolescent idiopathic scoliosis: simple rod derotation and direct vertebral rotation. A randomized controlled research involving 36 adolescents with idiopathic scoliosis was done. Patients were randomly split into one of two groups: 18 patients in group A had DVR treatment, while 18 patients in group B received SRD with a 2-year follow-up. Apical Vertebral Rotation measured from CT scans in DVR group was 24.4° ± 8.38° preoperatively and it decreased significantly postoperatively to 14.4° ± 4.61° with (42.22%) correction rate, while in SRD group, it was 25.03° ± 7.99° preoperatively and it also decreased significantly postoperatively to a mean value of 21.41° ± 7.01° with (14.65%) correction rate. There were statistically significant differences between both groups post-operative (P < 0.001). The apical vertebral rotation was greatly enhanced in both procedures, with direct vertebral rotation being better. Both Simple rod derotation and direct vertebral rotation reduce the rib hump, although the improvement is much greater with direct vertebral rotation.

The Mid-term Outcome of Intervertebral Disc Degeneration After Direct Vertebral Rotation in Adolescent Idiopathic Scoliosis: Magnetic Resonance Imaging-based Analysis for a Mean 11.6-year Follow-up.

A retrospective cohort study. To evaluate the mid-term effect of intervertebral disc degeneration (DD) in patients with adolescent idiopathic scoliosis (AIS) who underwent pedicle screw instrumentation (PSI) and rod derotation (RD) with direct vertebral rotation (DVR). Posterior spinal fusion is a mainstay of surgical treatment in AIS, and DVR is considered a main corrective maneuver for vertebral rotation. However, the mid-term effect of intervertebral DD after DVR is still unknown in AIS. A total of 336 vertebrae for 48 patients with AIS who underwent PSI and RD with DVR were retrospectively assessed for intervertebral DD. They were divided into two groups based upon intervertebral DD, defined as Pfirmann grade more than IV. The Pfirrmann grade and modic change were evaluated at the disc above the uppermost instrumented vertebra (UIV), the disc below the lowest instrumented vertebra (LIV), and the lumbar disc levels. With the 11.6 years of mean follow-up, 41.7% (20/48) of patients exhibited DD, while modic changes were observed in 4.2% (2/48) of the included patients. The discs below the LIV, L4-5, and L5-S1 were significantly shown to have an increasing trend of Pfirmann grade. The preoperative thoracic kyphosis was significantly lower in the DD group (22.0°) than in the non-DD group (31.4°) ( P = 0.025) and negatively correlated with DD ( r = -0.482, P = 0.018). The Pfirrmann grade of L5-S1 showed a high level of correlation with DD ( r = 0.604, P < 0.001). The degenerative change at the disc below the LIV, L4-5, and L5-S1 levels was observed following PSI and RD with DVR. Thoracic hypokyphosis may negatively influence intervertebral discs in patients with AIS required for deformity correction. Therefore, the restoration of thoracic kyphosis is important to prevent long-term DD in AIS.

Functional and Radiological Outcomes of All-Posterior Surgical Correction of Dystrophic Curves in Patients with Neurofibromatosis Type 1.

A retrospective cohort study. To determine outcomes following all-posterior surgery using computed tomography navigation, hybrid stabilization, and multiple anchor point techniques in patients with neurofibromatosis type 1 (NF-1) and dystrophic scoliosis. Previous studies favored antero-posterior fusion as the most reliable method; however, approaching the spine anteriorly was fraught with significant complications. With the advent of computer assisted navigation and multiple anchor point method, posterior only approach is reporting successful outcomes. This study included patients who underwent all-posterior surgical deformity correction for dystrophic NF-1 curves. Coronal and sagittal Cobbs angles, apical rotation, and the presence of dystrophic features were evaluated before surgery. Postoperatively, sagittal, coronal, and axial correction, implant position, and implant densities were evaluated. The decline in curve correction and implant-related complications were evaluated at follow-up. Clinical outcomes were evaluated using the Scoliosis Research Society-22 revised index. This study involved 50 patients with a mean age of 13.6 years and a mean follow-up duration of 5.52 years. With a mean coronal flexibility of 18.7%, the mean apical vertebral rotation (AVR), preoperative coronal Cobb angle, and sagittal kyphosis were 27.4°, 64.01°, and 47.70°, respectively. The postoperative mean coronal Cobb angle was 30.17° (p <0.05), and the sagittal kyphosis angle was 25.4° (p <0.05). The average AVR correction rate was 41.3%. The correction remained significant at the final mean follow-up, with a coronal Cobb angle of 34.14° and sagittal kyphosis of 25.02° (p <0.05). The average implant density was 1.41, with 46% of patients having a high implant density (HID). The HID had a markedly higher mean curve correction (29.30° vs. 38.05°, p <0.05) and a lower mean loss of correction (5.7° vs. 3.8°, p <0.05). Utilizing computer-assisted navigation, hybrid instrumentation, and multiple anchor point technique and attaining high implant densities, this study demonstrates successful outcomes following posterior-only surgical correction of dystrophic scoliosis in patients with NF-1.

Elasticity and cross-sectional thickness of paraspinal muscles in progressive adolescent idiopathic scoliosis.

(1) Compare the cross-sectional thickness (CST) and shear wave speed (SWS) of paraspinal muscles (PSM) in adolescent idiopathic scoliosis (AIS) with and without curve progression; (2) investigate the relationship between CST/SWS and radiographic characteristics in AIS with curve progression; (3) compare the CST/SWS between AIS and non-scoliosis controls. This cross-sectional study analyzed the CST and SWS of PSM in 48 AIS with mild to moderate curvature and 24 non-scoliosis participants. Participants with scoliosis greater than 45° of Cobb angles were excluded. The Change of Cobb angles within the last 6-months was retrieved to allocate AIS into progression and non-progression groups. The SWS and CST of multifidus; longissimus and iliocostalis of the major curve were measured using B-mode ultrasound image with an elastography mode. Discrepancies of the SWS (SWS-ratio: SWS on the convex side divided by SWS on the concave side) and CST (CST-ratio: CST on the convex side divided by CST on the concave side) at the upper/lower end and apical vertebrae were studied. A higher SWS at the apical vertebrae on the concave side of the major curve (multifidus: 3.9 ± 1.0 m/s vs. 3.1 ± 0.6 m/s; p < 0.01, longissimus: 3.3 ± 1.0 m/s vs. 3.0 ± 0.9 m/s; p < 0.01, iliocostalis: 2.8 ± 1.0 m/s vs. 2.5 ± 0.8 m/s; p < 0.01) was observed in AIS with curve progression. A lower SWS-ratio at apical vertebrae was detected with a greater vertebral rotation in participants with curve progression (multifidus [grade II]: 0.7 ± 0.1 vs. grade I: 0.9 ± 0.2; p = 0.03, longissimus [grade II]: 0.8 ± 0.2 vs. grade I: 1.1 ± 0.2; p < 0.01). CST was not different among the progressive, non-progressive AIS and non-scoliosis controls. Increased SWS of PSM without change of CST was observed on the concave side of the major curve in participants with progressive AIS.

Correlation of transverse rotation of the spine using surface topography and 3D reconstructive radiography in children with idiopathic scoliosis.

The relationship between axial surface rotation (ASR) measured by surface topography (ST) and axial vertebral rotation (AVR) measured by radiography in the transverse plane is not well defined. This study aimed to: (1) quantify ASR and AVR patterns and their magnitudes from T1 to L5; (2) determine the correlation or agreement between the ASR and AVR; and (3) investigate the relationship between axial rotation differences (ASR-AVR) and major Cobb angle. This is a retrospective study evaluating patients (age 8-18) with IS or spinal asymmetry with both radiographic and ST measurements. Demographics, descriptive analysis, and correlations and agreements between ASR and AVR were evaluated. A piecewise linear regression model was further created to relate rotational differences to Cobb angle. Fifty-two subjects met inclusion criteria. Mean age was 14.1 ± 1.7 and 39 (75%) were female. Looking at patterns, AVR had maximal rotation at T8, while ASR had maximal rotation at T11 (r = 0.35, P = .006). Cobb angle was 24.1° ± 13.3° with AVR of - 1° ± 4.6° and scoliotic angle was 20.9° ± 11.5° with ASR of -2.3° ± 6.6°. (ASR-AVR) vs Cobb angle was found to be very weakly correlated with a curve of less than 38.8° (r = 0.15, P = .001). Our preliminary findings support that ASR measured by ST has a weak correlation with estimation of AVR by 3D radiographic reconstruction. This correlation may further help us to understand the application of transverse rotation in some clinical scenarios such as specific casting manipulation, padding mechanism in brace, and surgical correction of rib deformity.

Does the addition of convex uniplanar screws in hybrid constructs improve 3D surgical correction in thoracic adolescent idiopathic scoliosis posterior fusion?

Hybrid techniques using thoracic sublaminar bands have proved their efficacy in adolescent idiopathic scoliosis posterior fusion, but clinical axial correction sometimes remained disappointing. One solution found was "the frame technique" and the second alternative was the replacement of the convex sublaminar bands by periapical uniplanar screws. The goal of this study was to compare clinical and radiological outcomes of both techniques in a consecutive cohort of adolescent idiopathic scoliosis patients. All patients undergoing primary posterior fusion for thoracic adolescent idiopathic scoliosis between January 2017 and March 2020 were included. Two groups were compared: Group 1 with thoracic sublaminar bands only and Group 2 with periapical uniplanar screws. All patients underwent standing stereoradiographs. The main frontal, sagittal, and axial (apical vertebra rotation) radiological parameters of interest were analyzed. Functional outcomes were assessed using the Scoliosis Research Society 30 score. A total of 147 adolescents were included (Group 1, n = 73 and Group 2, n = 74 patients). In the frontal plane, a greater reduction index was observed in Group 2 (68% versus 62%, p < 0.001) as well as a better apical axial correction (67.8% versus 46.6%, p = 0.03). The number of thoracoplasty performed was reduced (6.7% versus 20.5%, p = 0.02) in Group 2, with a significant decrease in the rate of mechanical complication. No significant loss of correction was observed during follow-up in any of the group. The adjunction of convex uniplanar screws at the periapical levels improved the three-dimensional surgical correction of thoracic adolescent idiopathic scoliosis treated with hybrid constructs. level III, retrospective comparative study.

3D analysis of the preoperative deformity in AIS can be used to guide surgical treatment decisions for selective thoracic fusion.

To identify 3D measures of scoliosis from preoperative imaging that are associated with optimal radiographic outcomes after selective thoracic fusion (STF) for adolescent idiopathic scoliosis (AIS). Subjects with primary thoracic curves (Lenke 1-4, B or C modifiers) fused selectively (L1 or above) who had preoperative 3D reconstructions and minimum 2 years of follow-up were included. An optimal outcome at 2 years was defined as having 4 of 5 parameters previously defined in the literature: (1) lumbar curve < 26º, (2) deformity flexibility quotient < 4, (3) C7-CSVL < 2cm, (4) lumbar prominence < 5º and (5) trunk shift < 1.5cm. Univariate and CART analyses were performed to identify preoperative variables associated with achieving an optimal outcome 2 years postoperatively. Ninety-nine (88F, 11M) patients met inclusion. Mean age was 15 ± 2years. Fifty-one subjects (52%) had an optimal outcome. Seven preoperative deformity measures representing smaller thoracolumbar/lumbar deformity in the optimal group were found to be significant on univariate analysis. CART analysis identified the following variables associated with optimal outcomes: difference in apical rotation > 30° = 27% optimal outcomes, difference in apical rotation ≤ 30° and coronal vertebral wedging of lumbar apex > 3° = 46% optimal outcomes, and difference in apical rotation ≤ 30° and coronal vertebral wedging of lumbar apex ≤ 3° = 80% optimal outcomes (p < 0.05). Optimal outcomes after STF were associated with a preoperative difference in apical vertebral rotation in the axial plane less than 30° between thoracic and lumbar curves as well as coronal plane vertebral wedging of the lumbar apical vertebra less than 3°.

Deletion of a conserved genomic region associated with adolescent idiopathic scoliosis leads to vertebral rotation in mice.

Adolescent idiopathic scoliosis (AIS) is the most common form of scoliosis, in which spinal curvature develops in adolescence, and 90% of patients are female. Scoliosis is a debilitating disease that often requires bracing or surgery in severe cases. AIS affects 2%-5.2% of the population; however, the biological origin of the disease remains poorly understood. In this study, we aimed to determine the function of a highly conserved genomic region previously linked to AIS using a mouse model generated by CRISPR-CAS9 gene editing to knockout this area of the genome to understand better its contribution to AIS, which we named AIS_CRMΔ. We also investigated the upstream factors that regulate the activity of this enhancer in vivo, whether the spatial expression of the LBX1 protein would change with the loss of AIS-CRM function, and whether any phenotype would arise after deletion of this region. We found a significant increase in mRNA expression in the developing neural tube at E10.5, and E12.5, for not only Lbx1 but also other neighboring genes. Adult knockout mice showed vertebral rotation and proprioceptive deficits, also observed in human AIS patients. In conclusion, our study sheds light on the elusive biological origins of AIS, by targeting and investigating a highly conserved genomic region linked to AIS in humans. These findings provide valuable insights into the function of the investigated region and contribute to our understanding of the underlying causes of this debilitating disease.

Intraobserver and Interobserver Reliability of Pelvic Obliquity Measurement Methods in Patients With Idiopathic Scoliosis.

Despite the importance of the assessment of pelvic obliquity, especially in the planning of surgery, there is no consensus on the pelvic obliquity measurements. The purpose of this study is to assess the intraobserver and interobserver reliability of 4 different pelvic obliquity measuring methods in patients with idiopathic scoliosis (IS): the Osebold, O'Brien, Maloney, and Allen&Ferguson methods. A retrospective cohort of 85 posteroanterior full-spine radiographs in the standing position of patients with IS involving the pelvic obliquity was evaluated by a team of 3 raters. The same researcher recorded the curve magnitude, apical vertebral rotation, Risser grade, curve pattern, and femoral head height difference. The pelvic obliquity angle was measured using the Osebold, O'Brien, Maloney, and Allen&Ferguson methods. The same graders were asked to regrade the same radiographs after at least 1 month. The Osebold method showed the highest interobserver reliability with an ICC of 0.994 and 0.983. The Allen&Ferguson method had the lowest reliability with an ICC of 0.911 and 0.934, but all of the methods were considered having excellent reliability. The Osebold method also showed the highest intraobserver reliability, ranging from 0.909 to 0.997. The Allen&Ferguson method had the lowest intraobserver reliability, with a range of 0.741 to 0.960. Also, all observers preferred the Osebold Method. The observers reported that the Allen&Ferguson method was considered the most time-consuming method, while the least time-consuming method was specified as the Osebold method. To the best of our knowledge, this study is the first to evaluate the intraobserver and interobserver reliability of pelvic obliquity among common measurement methods in patients with idiopathic scoliosis. All methods were evaluated as having excellent to good reliability in this study, but the Osebold method is the most reliable method of measuring pelvic obliquity on a frontal view radiograph in idiopathic scoliosis. The Osebold method is easier to use as it requires only the iliac crests to be visualized. Level III-Retrospective cohort study.

Automatic Vertebral Rotation Angle Measurement of 3D Vertebrae Based on an Improved Transformer Network.

The measurement of vertebral rotation angles serves as a crucial parameter in spinal assessments, particularly in understanding conditions such as idiopathic scoliosis. Historically, these angles were calculated from 2D CT images. However, such 2D techniques fail to comprehensively capture the intricate three-dimensional deformities inherent in spinal curvatures. To overcome the limitations of manual measurements and 2D imaging, we introduce an entirely automated approach for quantifying vertebral rotation angles using a three-dimensional vertebral model. Our method involves refining a point cloud segmentation network based on a transformer architecture. This enhanced network segments the three-dimensional vertebral point cloud, allowing for accurate measurement of vertebral rotation angles. In contrast to conventional network methodologies, our approach exhibits notable improvements in segmenting vertebral datasets. To validate our approach, we compare our automated measurements with angles derived from prevalent manual labeling techniques. The analysis, conducted through Bland-Altman plots and the corresponding intraclass correlation coefficient results, indicates significant agreement between our automated measurement method and manual measurements. The observed high intraclass correlation coefficients (ranging from 0.980 to 0.993) further underscore the reliability of our automated measurement process. Consequently, our proposed method demonstrates substantial potential for clinical applications, showcasing its capacity to provide accurate and efficient vertebral rotation angle measurements.

The Comparison of Posterior Intervertebral Release Combined with Posterior Column Osteotomy and Posterior Column Osteotomy Alone for the Treatment of Moderate-to-Severe Rigid Scoliosis: A Prospective Controlled Study.

There is no consensus on the treatment of moderate-to-severe rigid scoliosis. Anterior release and three-column osteotomy are excessively traumatic, whereas posterior column osteotomy (PCO) alone results in poor outcomes. An emerging surgical technique, posterior intervertebral release (PR), can release the rigid spine from the posterior approach. This study was performed to compare the multi-segment apical convex PR combined with PCO and PCO alone in patients with moderate-to-severe rigid scoliosis. From June 2021 to June 2022, this prospective study of moderate-to-severe (Cobb: 70-90°) rigid scoliosis (flexibility of main curve <25%) involved two groups defined by surgical procedure: the PR group, the patients undergoing PR combined with PCO; and the PCO group, the patients undergoing PCO alone. Follow-up was at least 12 months. Radiographic results mainly included main curve Cobb, correction of per PR/PCO segment, apical vertebra rotation (AVR) and apical vertebra translation (AVT). Demographics, surgical data, complications were also recorded. Student's independent samples t test and Pearson's chi-square test were used to compare the differences between groups. Forty patients with an average age of 16.65 years were included (PR group, n = 20; PCO group, n = 20). The main curves averaged 77.56° ± 5.86° versus 78.02° ± 5.72° preoperatively and 20.07° ± 6.73° versus 33.58° ± 5.76° (p < 0.001) at the last follow-up in the PR and PCO groups, respectively. The mean correction rates were 74.30% and 56.84%, respectively (p < 0.001). The average coronal curve correction was 13.49° per release segment, which was significantly higher than the PCO correction of 6.20° (p < 0.001). The correction of apical vertebra rotation and translation in the main thoracic curve was significantly better in the PR group than in the PCO group (p < 0.05). Several minor complications in the two groups improved after conservative treatment. The multi-segment apical convex PR combined with PCO offers more advantages than PCO alone in the treatment of patients with moderate-to-severe rigid scoliosis. Owing to its excellent corrective effect and few complications, this is a high benefit-risk ratio surgical strategy for rigid scoliosis.

Ab. No. 36 Integrated Effect of 3d Schroth Method and Cellular Rhythm Therapy on 4-D Postural Analysis in an Individual With Idiopathic Structural Scoliosis- Single Case Study

Introduction: The study attempts to widen the horizons of physiotherapy profession by promoting insights towards the advanced non-invasive treatment approaches for the management of Idiopathic Structural Scoliosis and aims to investigate the combined effect of 3D Schroth Method (spinal corrective exercise program) and Cellular Rhythm Therapy on 4D Postural Analysis in an individual with Idiopathic Structural Scoliosis Methods: An 18-year-old male diagnosed with idiopathic scoliosis for 4 years. He had thoracic levoscoliosis and lumbar dextroscoliosis with a baseline Cobb’s angle of 35º. Physical findings were uneven shoulder heights, slight right scapular winging, prominent left hip, and increased space between left elbow and trunk due to trunk deviation towards the right side. The patient intervened with Cellular Rhythm Therapy for 20 minutes followed by 3D Schroth Method exercises for 20 minutes. The treatment was given for a total of 30 days (5 sessions per week). Pre and Post interventional objective assessment was done using 4D postural analysis and subjective assessment was done using the Italian Spine-Related Quality of Life (ISYQOL) questionnaire at day 0 and day 30. Result: Significant change was found in lumbar lordosis angle (46º -31º), sagittal imbalance (6º - 2º), pelvic torsion (4º- 2º), vertebral rotation (17º -13º), apical deviation (49º - 21º), lumbar lordosis depth (32º- 30º) and in Cobb’s angle from 35º to 29º, along with difference in Italian Spine-Related Quality of Life (ISYQOL) questionnaire from 37% to 39%. Conclusion: According to the study’s findings, 3D Schroth Method and Cellular Rhythm Therapy can be an effective treatment for patients with Scoliosis. Implications: This combinational approach anticipates a useful reference guide for future management of Idiopathic Structural scoliosis.

Application of the Six-Minute Walk Test in Assessment of the Cardiopulmonary Function of Children With Idiopathic Scoliosis.

A retrospective observational study. To assess whether the six-minute walk test (6MWT) can predict cardiopulmonary function in children with idiopathic scoliosis (IS) as an alternative to the cardiopulmonary exercise test (CPET). Cardiopulmonary functional impairment in the setting of IS is a common health problem. A simple and convenient assessment method is needed. We recruited 65 children (eight male, 57 female) aged 10.70 to 14.84 years old with IS. Radiographic characteristics of the cohort were measured, including Risser's sign and Cobb angle. We measured cardiopulmonary exercise tolerance using both the 6MWT and CPET and their corresponding indicators, including six-minute walking distance (6MWD) and peak oxygen uptake (peak VO 2 ), respectively. Pearson correlation analysis was used to determine the relationship between 6MWT indicators and IS parameters. Linear regression models were used to explore the relationship between 6MWT and CPET response indicators. Over a third of the cohort (35.4%) had a Risser's sign grade of 0, with 21.5% in grade 2 and 3, respectively. The cohort's mean Cobb angle was 26.02°. 6MWD was significantly positively correlated with Risser's sign ( R =0.258; P =0.038) and change in respiratory rate positively correlated with vertebral rotation ( R =0.264; P =0.034). 6MWD positively correlated with peak VO 2 , peak VO 2 /heart rate (HR), and metabolic equivalents, and negatively correlated with the ventilation equivalent of the carbon dioxide slope (VE/VCO 2 slope) ( P <0.05). These four CPET indicators were found to be predicted from 6MWD in the linear regression model ( P <0.05). CPET response indicators, especially peak VO 2 , can be predicted using 6MWD, among other factors. The 6MWT can therefore be used to rapidly and efficiently predict the cardiorespiratory tolerance of children with IS. 3.

Inter-Specimen Analysis of Diverse Finite Element Models of the Lumbar Spine.

Over the past few decades, there has been a growing popularity in utilizing finite element analysis to study the spine. However, most current studies tend to use one specimen for their models. This research aimed to validate multiple finite element models by comparing them with data from in vivo experiments and other existing finite element studies. Additionally, this study sought to analyze the data based on the gender and age of the specimens. For this study, eight lumbar spine (L2-L5) finite element models were developed. These models were then subjected to finite element analysis to simulate the six fundamental motions. CT scans were obtained from a total of eight individuals, four males and four females, ranging in age from forty-four (44) to seventy-three (73) years old. The CT scans were preprocessed and used to construct finite element models that accurately emulated the motions of flexion, extension, lateral bending, and axial rotation. Preloads and moments were applied to the models to replicate physiological loading conditions. This study focused on analyzing various parameters such as vertebral rotation, facet forces, and intradiscal pressure in all loading directions. The obtained data were then compared with the results of other finite element analyses and in vivo experimental measurements found in the existing literature to ensure their validity. This study successfully validated the intervertebral rotation, intradiscal pressure, and facet force results by comparing them with previous research findings. Notably, this study concluded that gender did not have a significant impact on the results. However, the results did highlight the importance of age as a critical variable when modeling the lumbar spine.

A finite element method study of the effect of vibration on the dynamic biomechanical response of the lumbar spine

BackgroundStudies focusing on lumbar spine biomechanics are very limited, and the mechanism of the effect of vibration on lumbar spine biodynamics is unclear. To provide guidance and reference for lumbar spine biodynamics research and vibration safety assessment, this study aims to investigate the effects of different vibrations on lumbar spine biodynamics. MethodsA validated finite element model of the lumbosacral spine was utilized. The model incorporated a 40 kg mass on the upper side and a 400 N follower preload. As a comparison, another model without a coupled mass was also employed. A sinusoidal acceleration with an amplitude of 1 m/s2 and a frequency of 5 Hz was applied to the upper and lower sides of the model respectively. FindingsWhen the coupled mass point is not introduced: in the case of upper-side excitation, the lumbar spine shows a significantly larger response in the x-direction than in the z-direction, while in the case of lower-side excitation, the lumbar spine experiences rigid body displacement in the z-direction without any movement, deformation, rotation, or stress changes in the x-direction. When the coupled mass point is introduced: both upper and lower-side excitations result in significant differences in z-directional displacement, with relatively small differences in vertebral rotation angle, disc deformation, and stress. Under upper excitation, low-frequency oscillations occur in the x-direction. In both types of excitations, the anterior-posterior deformation of the L2-L3 and L4-L5 intervertebral discs is greater than the vertical deformation. The peak (maximum) disc stress exceeds the average stress and stress amplitude across the entire disc. Regardless of the excitation type, the stress distribution within the disc at the moment of peak displacement remains nearly identical, with the maximum stress consistently localized on the anterior side of the L4-L5 disc. InterpretationAccurately simulating lumbar spine biodynamics requires the inclusion of the upper body mass in the lumbosacral spine model. The physiological curvature of the lumbar spine could escalate the risk of lumbar spine vibration injuries. It is more instructive to apply local high stress in the disc as a lumbar spine vibration safety evaluation parameter.

Sex-based differences in clinical and radiological presentation of patients with degenerative lumbar scoliosis: a cross-sectional study

BackgroundTo evaluate the sex-based differences in clinical and radiological presentation of patients with degenerative lumbar scoliosis (DLS) and to explore whether the difference is helpful in investigating the etiology and progression of DLS.MethodA retrospective review of 199 patients (41 males, 158 females) with DLS was included. Patient demographics including age, gender, bone mineral density were collected. Back and leg pain was assessed by visual analog scale, and general physical condition was assessed by Oswestry Disability Index. Cobb’s angle was measured, and direction of scoliosis, position of the superior, inferior and apex vertebrae, number of vertebrae included in the scoliosis, rotation of apex vertebrae (Nash-Mo index), translation of apex vertebrae were recorded. Sagittal longitudinal axis, thoracolumbar kyphosis, lumbar lordosis (LL), pelvic incidence angle (PI), sacral slope, apex of lumbar lordosis and coronal balance distance were measured by whole spine lateral radiographs, and type of coronal imbalance was evaluated in all patients. Fat infiltration rate (FIR) of the paraspinal muscles at the vertebral apex was measured by MRI.ResultCompared to female patients, male patients showed more back and leg pain on clinical presentation and smaller Cobb angle, less parietal rotation, larger LL, smaller PI-LL and lower paravertebral muscle FIR on radiologic features.ConclusionGender differences do exist in DLS patients with regard to clinical and radiological presentation, low back pain was more pronounced in male patients, and scoliosis was more severe in female patients based on this cross-sectional study.

Dual Growing Rods and the Apical Control Technique for Treating Congenital Early-Onset Scoliosis: Lessons Learned.

Congenital early-onset scoliosis (CEOS) is characterized by a spectrum of vertebral anomalies, including formation failures and segmentation failures at the apex segment, which makes CEOS different from other etiologies of early-onset scoliosis. To date, studies on patients who have graduated from CEOS treatment using traditional dual growing rods (TDGR) have been scarce, and the preliminary results of TDGR with or without the apical control technique (ACT) have varied. We therefore compared the final outcomes of patients with CEOS who graduated from TDGR with or without the ACT. A retrospective study of patients with CEOS who had graduated from TDGR treatment performed from 2007 to 2020 was conducted. Graduation included final fusion or observation after reaching skeletal maturity. Patients were divided into the ACT-TDGR group (apical vertebrectomy and/or hemivertebrectomy with short fusion and TDGR) and the TDGR-only group. Demographic characteristics, radiographic data, patient-reported clinical outcomes, pulmonary function, and complications were analyzed. A total of 41 patients with CEOS were enrolled: 13 in the ACT-TDGR group and 28 in the TDGR-only group. The lengthening intervals were longer in the ACT-TDGR group (mean [and standard deviation], 1.26 ± 0.66 years) than in the TDGR-only group (0.80 ± 0.27 years). The preoperative main curve was larger in the ACT-TDGR group (80.53° ± 19.50°) than in the TDGR-only group (64.11° ± 17.50°). The residual curve was comparable between groups (26.31° ± 12.82° in the ACT-TDGR group compared with 27.76° ± 15.0° in the TDGR group) at the latest follow-up. The changes in apical vertebral rotation and thoracic rotation were significantly larger in the ACT-TDGR group. Patients had comparable T1-12 and T1-S1 heights, pulmonary function, and 22-item Scoliosis Research Society (SRS-22) scores at the latest follow-up. The mean number of mechanical-related complications per patient was lower in the ACT-TDGR group (0.77 ± 0.73) than in the TDGR-only group (1.54 ± 1.43). Seventeen patients underwent final fusion. In this small-scale study, we observed that both ACT-TDGR and TDGR-only could correct the deformity while allowing for spinal growth in patients with CEOS. ACT-TDGR yielded better correction in severe cases and did not have a deleterious effect on spinal height. A large number of cases will be needed to validate the clinical value of the ACT. Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Ultrasound-assisted lumbar puncture with a horizontal and perpendicular paramedian approach based on positioning in patients with abnormal spinal anatomy: a case report and technical description

BackgroundThe use of ultrasound has been reported to be beneficial in challenging neuraxial procedures. The angled probe is responsible for the main limitations of previous ultrasound-assisted techniques. We developed a novel technique for challenging lumbar puncture, aiming to locate the needle entry point which allowed for a horizontal and perpendicular needle trajectory and thereby addressed the drawbacks of earlier ultrasound-assisted techniques.Case presentationPatient 1 was an adult patient with severe scoliosis who underwent a series of intrathecal injections of nusinersen. The preprocedural ultrasound scan revealed a cephalad probe’s angulation (relative to the edge of the bed) in the paramedian sagittal oblique view, and then the probe was rotated 90° into a transverse plane and we noted that a rocking maneuver was required to obtain normalized views. Then the shoulders were moved forward to eliminate the need for cephalad angulation of the probe. The degree of rocking was translated to a lateral offset from the midline of the spine through an imaginary lumbar puncture’s triangle model, and a needle entry point was marked. The spinal needle was advanced through this marking-point without craniocaudal and lateromedial angulation, and first-pass success was achieved in all eight lumbar punctures. Patient 2 was an elderly patient with ankylosing spondylitis who underwent spinal anesthesia for transurethral resection of the prostate. The patient was positioned anteriorly obliquely to create a vertebral rotation that eliminated medial angulation in the paramedian approach. The procedure succeeded on the first pass.ConclusionsThis ultrasound-assisted paramedian approach with a horizontal and perpendicular needle trajectory may be a promising technique that can help circumvent challenging anatomy. Larger case series and prospective studies are warranted to define its superiority to alternative approaches of lumbar puncture for patients with difficulties.

A Novel Multiple Screw Distraction Reducer System in the Treatment of Scoliosis with a Severe Rib Hump.

The treatment of scoliosis with a severe rib hump remains a major challenge. Traditional vertebral rotation techniques are not satisfactory, and thoracoplasty has many pulmonary complications that limit its application. A novel surgical device, the multiple screw distraction reducer (MSDR) system, provides longitudinal distraction during the corrective operation while at the same time providing lateral translation and axial derotation, which may facilitate the correction of a rib hump. This study was performed to investigate the effectiveness of the MSDR system for adolescent idiopathic scoliosis (AIS) with a severe rib hump. This was a case-matched study of patients with retrospectively collected data from our hospital between January 2017 and December 2021. Sixty-eight patients who underwent one-stage posterior pedicle screw-instrumented spinal fusion were matched by the Cobb angle of the main curve and rib hump. All patients underwent a minimum of 2 years of follow-up. The patients were divided into two groups: the MSDR group (using the MSDR system, n = 34) and the DVR group (using direct vertebral derotation, n = 34). The patients were evaluated for the height of the rib hump, deformity correction, complications, and SRS-30 scores. The unpaired Student's t-test and Pearson's χ2 -test were used to compare the outcome measures between the two groups. Multiple linear regression analysis was used to examine the variables that affected the correction of a rib hump. The rib hump was 30.21 ± 6.21 mm versus 29.35 ± 6.52 mm (p = 0.583) preoperatively and 9.18 ± 4.06 mm versus 13.82 ± 5.54 mm (p < 0.001) at the last follow-up in the MSDR and DVR groups, respectively. The correction rates were 70.83% and 53.56%, respectively (p < 0.001). Preoperatively, the main thoracic curve was 58.43° ± 7.97° and 57.84° ± 6.32° (p = 0.736) and was corrected to 10.92° ± 5.47° and 19.14° ± 5.32° (p < 0.001) at last follow-up in the MSDR and DVR group, respectively. Thoracic kyphosis was restored from 18.24° ± 5.19° and 17.98° ± 5.28° (p = 0.836) in the MSDR and DVR group to 24.59° ± 4.41° and 19.32° ± 4.96° (p < 0.001), respectively. Correction of apical vertebra rotation and translation in the main thoracic curve were significantly better in the MSDR group than in the DVR group (p < 0.05). There was no significant difference in the Lenke type, implant density, estimated blood loss, or follow-up duration between the two groups, whereas the operation time in the DVR group was significantly less than that in the MSDR group. There were only two minor pulmonary complications in the MSDR group. At the last follow-up, the MSDR group scored higher in terms of appearance and satisfaction (p < 0.05). The MSDR system, enabling better coronal alignment, thoracic kyphosis, and axial derotation, could be a safe and effective technique for severe rib hump correction in AIS.