Comparison of Cobb Angles Measured Manually,Calculated from 3-D Spinal Reconstruction,and Estimated from Torso Asymmetry

While scoliotic spinal deformity is traditionally measured by the Cobb angle, we seek to estimate scoliosis severity from the torso surface without X-ray radiation. Here, we measured the Cobb angle in three ways: by protractor from postero-anterior X-ray, by computer from a 3-D digitized model of the vertebral body line, and by neural-network estimation from indices of torso surface asymmetry. The estimates of the Cobb angle by computer and by neural network were equally accurate in 153 records from 52 patients (standard deviation of 6° from the Cobb angle, r =0.93 ), showing that torso asymmetry reliably predicted spinal deformity. Further improvements in predictive accuracy may require estimation of other 3-D indices of spinal deformity besides the Cobb angle with its wide measurement variability.     

Reconstruction of Laser-scanned 3D Torso Topography and Stereoradiographical Spine and Rib-cage Geometry in Scoliosis

Assessments of scoliosis are routinely done by means of clinical examination and full spinal x-rays. Multiple exposure to ionization radiation, however, can be hazardous to the child and is costly. Here, we explain the use of a noninvasive imaging technique, based on laser optical scanning, for quantifying the three-dimensional (3D) trunk surface topography that can be used to estimate parameters of 3D deformity of the spine. The laser optical scanning system consisted of four BIRIS laser cameras mounted on a ring moving along a vertical axis, producing a topographical mapping of the entire torso. In conjunction with the laser scans, an accurate 3D reconstruction of the spine and rib cage were developed from the digitized x-ray images. Results from 14 scoliotic patients are reported. The digitized surfaces provided the foundation data to start studying concordance of trunk surface asymmetry and spinal shape in idiopathic scoliosis.     

Accelerated intervertebral disc degeneration in scoliosis versus physiological ageing develops against a background of enhanced anabolic gene expression

Molecular consequences of long-term deformation and altered mechanical loading of intervertebral disc (IVD) tissue in scoliosis have yet to be elucidated. We hypothesized that histological disc degeneration is faster in scoliosis than in normal ageing and that this is reflected by an altered gene expression profile. A semiquantitative histodegeneration score (HDS) revealed significantly enhanced degeneration in scoliosis (HDS 5.3) versus age-matched control IVDs (HDS 2.25; p = 0.001). Gene expression analysis by cDNA array and RT-PCR demonstrated higher mRNA levels for extracellular-matrix molecules like aggrecan, biglycan, decorin, lumican, chondromodulin, and COL2A1 in scoliotic discs versus normal discs of identical degeneration score. No differences were evident for catabolic molecules like MMP3, MMP13, MMP17, and TIMP1. In sum, morphologic disc degeneration was accelerated by about 2 decades in scoliosis versus physiological ageing and developed against a background of stronger anabolic matrix metabolism at younger age or in response to the altered mechanical environment of the tissue.     

Intra-Operative Analysis of Scoliosis Surgery in 3-D

Scoliosis is a three-dimensional deformity characterized by coronal, sagittal and axial rotation of the spine. Surgical fusion of the spine is required in severe cases. Assessment of the surgical procedure requires enough accuracy and flexibility to allow planning of individual interventions or implant designs. Conventional 2-D radiography and even 3-D CT scanning have limitations for in-depth analysis of scoliosis that limit the ability to see the three-dimensional deformity and expose the patient to considerable doses of radiation, respectively. Our stereophotogrammetric analysis is able to provide accurate, intraoperative measurement of vertebral movement during surgical manuevres. Stereophoto pairs taken at each stage of the operation and robust statistical techniques can be used to determine rotation, translation, goodness of fit, and overall spinal contour before, during, and after the surgical instrumentation. A demonstration of data available from this system is included.     

sEMG activity of masticatory, neck, and trunk muscles during the treatment of scoliosis with functional braces. A longitudinal controlled study

Background

Studies on the relationship between occlusal problems and the spine are of increasing interest. In this study, we monitored the sEMG activity of masticatory, neck, and trunk muscles during the treatment of scoliosis in young patients, and compared the data with a control of untreated group.

Subjects and methods

Twelve white Caucasian patients (nine males and three females; mean age of 8.0 ± 1.5 years) with scoliosis and Class I occlusion (without crowding) were included in this study (study group). Fifteen healthy subjects (nine males and six females; mean age of 9.5 ± 0.8 years) were recruited as control group. The subjects were visited before they underwent the treatment of scoliosis, as well as after 3 (T1) and 6 months (T2) of their treatment for scoliosis. The patients were instructed to wear the device during sleep and during the day, according to the protocol given by their orthopedic.

Results

The treated group showed statistically significant changes in the sEMG activity of masticatory, neck, and trunk muscles, both at rest and during MVC of the mandible with respect to T0. The masseter and the anterior temporalis showed a significant improvement in the asymmetry index from T0 to T2. On the other hand, subjects in the control group did not register much change.

Conclusion

Our findings suggest that the use of a functional device for the treatment of scoliosis induces a significant reduction in the asymmetry index of the trunk muscles, as well as a significant increase in the contractility of masticatory muscles.     

Personalised Mechanical Properties of Scoliotic Vertebrae Determined In Vivo Using Tomodensitometry

This in vivo study investigated the mechanical properties of apical scoliotic vertebrae using computed tomography (CT) and finite element (FE) meshing. CT examination was performed on seven scoliotic girls. FE meshing of each vertebral body allowed automatic mapping of the CT scan and the visualisation of the bone density distribution. Centroids and mass centres were compared to analyse the mechanical properties distribution. Compared to the centroid, the mass centre migrated into the concavity of the curvature. The three vertebrae of a same patient had the same body migration behaviour because they were located at the curvature apex. This observation was verified in the coronal plane, but not in the sagittal plane. These results represent new data over few geometrical analyses of scoliotic vertebrae. Same in vivo personalisation of mechanical properties should be performed on intervertebral discs or ligaments to personalise stiffness properties of the spine for the biomechanical modelling of human torso. Moreover, do this mechanical deformation of scoliotic vertebrae, that appears before the vertebral wedging, could be a predictive tool in scoliosis treatment?     

The construction of the scoliosis 3D finite element model and the biomechanical analysis of PVCR orthopaedy

ObjectiveThe objective is to investigate the biomechanical conditions of the Posterior Vertebral Column Resection (PVCR) of the constructed scoliosis 3D finite element model.MethodsA patient with scoliosis was selected; before the PVCR orthopaedy, the patient was submitted to the radiography of normal and lateral full-length vertebral column scans and the total magnetic resonance imaging (MRI) scans; then, the idiopathic scoliosis model was constructed by the 3D finite element method, and the 3D finite element software utilized in the process of model construction included Mimics software, Geomagic Studio 12 software, and Unigraphic 8.0 (UG 8.0) software; in addition, PVCR orthopaedy was utilized to correct the scoliosis of the patient, and the biomechanical parameters, such as orthodontic force, vertebral body displacement, orthopedic rod stress, stress on the pin-bone interface of the vertebral body surface, and the stress on the intervertebral disc, were studied.ResultsThe 3D effective finite element model of scoliosis was successfully constructed by the Mimics software, the Geomagic Studio 12 software, and the UG 8.0 software, and the effectiveness was tested. PVCR orthopaedy could effectively solve the problem of scoliosis. The magnitude of the orthodontic force that a patient needed depended on the physical conditions and the personal orthodontic requirements of the patient. The maximum vertebral body displacement on the X-axis was the vertebral body L1, the maximum displacement on the Y-axis was the vertebral body T3, the maximum displacement on the Z-axis was the vertebral body T1, and the rang of orthopedic rod stress was 0.0050214e⁷ MPa to 0.045217e⁷ MPa, in which the maximum stress of 2 vertebral bodies in, above, and below the osteotomy area reached 0.045217e⁷ MPa, the stress on the pin-bone interface of the T10 vertebral body surface reached 11.83 MPa, and the stress of T8/T9 intervertebral disc reached 13.84 MPa.ConclusionThe 3D finite element model based on 3D finite element software was highly efficient, and its numerical simulation was accurate, which was important for the subsequent biomechanical analysis of PVCR orthopaedy. In addition, the vertebral stress of PVCR orthopaedy was different in each body part, which was mainly affected by the applied orthodontic force and the sites of the orthodontic area.     

DR全脊柱成像技术应用探讨

目的探讨DR全脊柱成像技术在脊柱侧弯畸形诊断及测量中的价值,研究不同检查方法对成像质量及测量精度的影响。方法利用PHIIAPS公司Digital Diagnost DR系统和具有全脊柱拼接功能的SUN后处理工作站,对分次所摄的脊柱正位、侧位、左、右侧屈位影像进行拼接处理后作必要的测量,并打印成像。结果经上述处理后的全脊柱正位、侧位及左、右侧屈位均能将颈、胸、腰、骶椎完整联接,显示在1张14＋17的X光片上,其测量的数据真实可靠。结论DR全脊柱成像技术克服了以往颈、胸、腰、骶椎单独成像后测量上的误差,为临床手术提供了更精确的数据。     

DR全脊柱摄影技术在脊柱侧弯中的应用与优势

目的:探讨数字化X线摄影(DR)全脊柱摄像技术在脊柱侧弯中的应用和优势。方法:收集2012年2月至2013年6月于本院进行治疗的脊柱侧弯病例88例,应用数字化X线摄影(DR)技术对脊柱由上至下进行正位和侧位的扫描,均进行3次曝光,每两次曝光间隔均为9秒,曝光后通过图像拼接技术将患者脊柱图像进行拼接和重叠,形成全景图像,对全部患者的图像质量进行观察和评估。结果:所有入选病例中有84例患者图像清晰显示了脊柱侧弯的方向和角度、椎体和椎间隙、对称的椎弓根、根间距及对脏器的影响程度。其中1例因运动不合作出现伪影,3例曝光不足。全脊柱图像质量正位优秀率为92.43%,侧位优秀率为85.92%;全脊柱图像拼接正位优秀率为83.44%,侧位优秀率为86.58%。结论:数字化X线摄影(DR)技术应用上方便快捷,患者配合时间较短,图像质量较好,能够满足临床医生进行诊断和治疗,有助于患者预后康复情况的评估,值得在临床诊断中推广应用。     

脊柱侧弯患者下颌骨的三维形态分析

目的:通过锥形束CT对脊柱侧弯患者下颌骨三维重建模型进行测量,分析下颌骨对称性,为进一步揭示脊柱侧弯与错牙合畸形的相互关系提供参考依据。方法:对73例脊柱侧弯患者(其中特发性38例,先天性35例)及40例身体姿势无异常志愿者拍摄锥形束CT并经三维重建后,对下颌骨左右侧结构进行测量分析,对比不对称指数。结果:(1)先天性脊柱侧弯患者脊柱畸形及身体姿势失平衡程度较特发性脊柱侧弯患者严重。(2)脊柱侧弯患者下颌骨体长度、下颌升支长度、下颌骨总长度不对称指数均较对照组无明显差异(P0.05)。(3)脊柱侧弯组中下颌角点成角不对称指数均较对照组高(P0.05),先天性脊柱侧弯组髁突顶点成角也明显高于对照组(P0.05)。结论:脊柱侧弯患者下颌骨结构偏斜,提示脊柱形态及身体姿势对下颌骨发育可能存在一定影响。