Treatment Of Spinal Diseases Research Articles

Medical Care Utilization Behavior for the Diagnosis and Treatment of Spine Disease: A Questionnaire-based Study of Orthopaedic Spine Center Outpatients at a Tertiary Educational Hospital

Medical Care Utilization Behavior for the Diagnosis and Treatment of Spine Disease: A Questionnaire-based Study of Orthopaedic Spine Center Outpatients at a Tertiary Educational Hospital

Medical Care Utilization Behavior for the Diagnosis and Treatment of Spine Disease: A Questionnaire-based Study of Orthopaedic Spine Center Outpatients at a Tertiary Educational Hospital

Medical Care Utilization Behavior for the Diagnosis and Treatment of Spine Disease: A Questionnaire-based Study of Orthopaedic Spine Center Outpatients at a Tertiary Educational Hospital

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

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. Moiré 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 moiré 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 moiré images using a CNN is expected to enhance the accuracy of scoliosis screening.

Internet of Things, Digital Biomarker, and Artificial Intelligence in Spine: Current and Future Perspectives.

Recent interest in medical artificial intelligence (AI) has increased with onset of the fourth industrial revolution. Real-time monitoring of patients is an important research area of medical AI. The medical AI is very closely related to the Internet of Things (IoT), a core element of the fourth industrial revolution. Attempts to diagnose and treat patients using IoT have been already applied to patients with chronic disease such as hypertension and arrhythmia. However, in the spine, research on IoT and digital biomarkers are still in the early stages. The digital biomarker obtained by IoT devices is objective and could represent real-time, real-world, and abundant data. Based on its characteristics, IoT and digital biomarkers can also be useful in the spine. Currently, research on real-time monitoring of physical activity or spinal posture is ongoing. Therefore, the authors introduce the basic concepts of IoT and digital biomarkers, their relationship to AI, and recent trends. Current and future perspectives of IoT and digital biomarker in spine are also discussed. In the future, it is expected that IoT, digital biomarkers, and AI will lead to a paradigm shift in the diagnosis and treatment of spinal diseases.

Research progress in the application status and development trend of artificial intelligence in the diagnosis and treatment of spinal disease

The cross-fusion research of artificial intelligence technology and spinal surgery represented by machine learning and neural network model is a new research direction and hot issue in the field of artificial intelligence in recent years. The anatomy and disease symptoms of the spine are complex, and the diagnosis and treatment of spinal surgery require rich clinical experience. However, the distribution of medical resources in China is seriously uneven. How to improve the ability of primary medical services so that the most extensive patient groups can benefitis still an urgent problem to be solved. Artificial intelligence is a technical science that researches and develops theories, methods, technologies, and application systems for simulating, extending and expanding human intelligence. With the advent of the era of big data medical technology, artificial intelligence technology may solve this problem by transforming experts sinking into tech sinking . At present, technologies such as confrontation learning, weakly supervised learning, intensive learning and graph neural networks have become research hotspots in the field of artificial intelligence, and have also played an important role in many fields of clinical medicine. Based on the advantages of deep learning and neural network in disease learning, many spine surgeons combine it with the diagnosis and treatment of cervical spondylosis, low back pain, lumbar degenerative diseases, spinal deformity, spinal tumors, and other spine-related diseases. The rapid location and accurate diagnosis of the disease not only makes it an effective tool for the comprehensive diagnosis of spinal diseases but also provides the basis for the most reasonable treatment options for spinal diseases. In the domestic application of artificial intelligence in the diagnosis and treatment of spinal surgery, it can also solve the problems of difficult diagnosis and complicated treatment of spinal diseases faced by primary doctors, reduce the rate of misdiagnosis and missed diagnosis, and effectively reduce the economic and social burden of spinal diseases. This paper reviews the research progress of artificial intelligence represented by deep learning in the field of diagnosis and treatment of spinal surgery at home and abroad, and the advantages and application prospects of artificial intelligence in the diagnosis and treatment of spinal surgery.

Effect of surgical factors on the augmentation of cement-injectable cannulated pedicle screw fixation by a novel calcium phosphate-based nanocomposite.

Bone cement-augmented pedicle screw system demonstrates great efficacy in spinal disease treatments. However, the intrinsic drawbacks associated with clinically used polymethylmethacrylate (PMMA) cement demands for new bone cement formulations. On the basis of our previous studies, a novel injectable and biodegradable calcium phosphate-based nanocomposite (CPN) for the augmentation of pedicle screw fixation was systematically evaluated for its surgical feasibility and biomechanical performance by simulated and animal osteoporotic bone models, and the results were compared with those of clinical PMMA cement. ASTM-standard solid foam and open-cell foam models and decalcified sheep vertebra models were employed to evaluate the augmentation effects of CPN on bone tissue and on the cement-injected cannulated pedicle screws (CICPs) placed in osteoporotic bone. Surgical factors in CICPs application, such as injection force, tapping technique, screw diameter, and pedicle screw loosening scenarios, were studied in comparison with those in PMMA. When directly injected to the solid foam model, CPN revealed an identical augmentation effect to that of PMMA, as shown by the similar compressive strengths (0.73 ± 0.04 MPa for CPN group vs. 0.79 ± 0.02 MPa for PMMA group). The average injection force of CPN at approximately 40-50 N was higher than that of PMMA at approximately 20 N. Although both values are acceptable to surgeons, CPN revealed a more consistent injection force pattern than did PMMA. The dispersing and anti-pullout ability of CPN were not affected by the surgical factors of tapping technique and screw diameter. The axial pullout strength of CPN evaluated by the decalcified sheep vertebra model revealed a similar augmentation level as that of PMMA (1351.6 ± 324.2 N for CPN vs. 1459.7 ± 304.4 N for PMMA). The promising results of CPN clearly suggest its potential for replacing PMMA in CICPs augmentation application and the benefits of further study and development for clinical uses.

Paraspinal Muscle Segmentation Based on Deep Neural Network.

The accurate segmentation of the paraspinal muscle in Magnetic Resonance (MR) images is a critical step in the automated analysis of lumbar diseases such as chronic low back pain, disc herniation and lumbar spinal stenosis. However, the automatic segmentation of multifidus and erector spinae has not yet been achieved due to three unusual challenges: (1) the muscle boundary is unclear; (2) the gray histogram distribution of the target overlaps with the background; (3) the intra- and inter-patient shape is variable. We propose to tackle the problem of the automatic segmentation of paravertebral muscles using a deformed U-net consisting of two main modules: the residual module and the feature pyramid attention (FPA) module. The residual module can directly return the gradient while preserving the details of the image to make the model easier to train. The FPA module fuses different scales of context information and provides useful salient features for high-level feature maps. In this paper, 120 cases were used for experiments, which were provided and labeled by the spine surgery department of Shengjing Hospital of China Medical University. The experimental results show that the model can achieve higher predictive capability. The dice coefficient of the multifidus is as high as 0.949, and the Hausdorff distance is 4.62 mm. The dice coefficient of the erector spinae is 0.913 and the Hausdorff distance is 7.89 mm. The work of this paper will contribute to the development of an automatic measurement system for paraspinal muscles, which is of great significance for the treatment of spinal diseases.

BIOMECHANICAL STUDY OF PEDICLE SCREW FIXATION STRENGTH: ASSOCIATION OF SCREW MALPOSITION AND SCREW INSERTION TORQUE

Pedicle screws have been widely used for the treatment of spinal diseases, but improper screw placement is not uncommon and may lead to neurovascular injuries and reduced screw fixation strength. This study aimed to investigate the feasibility of using real-time screw insertion torque monitoring to prevent screw penetration. Commercially available synthetic L4 vertebrae were divided in to seven test groups based on different screw placements. Screw insertion torque and maximal pullout strength were compared among groups. The results indicated that the insertion torque gradually increased when the screw tip was within vertebral cancellous bone without penetration. However, an instantaneous decrease of torque value was observed once the screw tip penetrated the cortex wall. When compared to the control group, higher pullout strength was found for the groups with medial cortex penetration. However, vertebrae with medial cortex penetration may lead to the concern of neurovascular damage. Meanwhile, lower pullout strength was found for the groups with lateral cortex penetration and end-plate penetration, which may lead to the concern of screw loosening. We concluded that pedicle screw penetration can be judged using real-time screw insertion torque monitoring during surgery, which may aid surgeons in avoiding neurovascular injury and reduction of screw fixation strength.

Effect of needle type on intravascular injection in transforaminal epidural injection: a meta-analysis.

BackgroundLumbosacral transforaminal epidural injection (TFEI) is an effective treatment for spinal disease. However, TFEI may have several types of complications, some of which can be attributed to intravascular injection. We reviewed studies to compare the intravascular injection rate among different needle types.MethodsWe searched the literature for articles on the intravascular injection rate among different needle types used in TFEI. The search was performed using PubMed, MEDLINE, the Cochrane Library, EMBASE, and Web of Science.ResultsA total of six studies comprising 2359 patients were identified. Compared with the Quincke needle, the Whitacre needle reduced the intravascular injection rate (OR = 0.57, 95% CI = [0.44–0.73], P < 0.001). However, compared with the Quincke needle, the Chiba needle did not reduce the intravascular injection rate (OR = 0.80, 95% CI = [0.44–1.45], P = 0.46). In one study, the intravascular injection rate using a blunt-tip needle was lower than that using a sharp needle. In another study, the Whitacre and the blunt-tip needle have similar intravascular injection rates, while, the catheter-extension needle showed a reduced intravascular injection rate.ConclusionsThis meta-analysis showed that the Whitacre needle reduced the intravascular injection rate as compared with the Quincke needle, but failed to establish that the Chiba needle can decrease the intravascular injection rate in TFEI. Moreover, the blunt-tip needle can reduce the intravascular injection rate compared with the Quincke needle, and the catheter-extension needle can reduce the intravascular injection rate compared with the Whitacre and the blunt-tip needle.

Use of intraoperative neurophysiological monitoring in surgical treatment of spinal diseases

Intraoperative neurophysiological monitoring (IONM) is a method, which uses different kinds of electrophysiological methods for monitoring and mapping of neural structures during surgical procedures with the aim to preserve them. If we know how important the function of the spine, spinal cord, nerve roots, and all other structures are, it is obvious how important it is to preserve them in surgical procedures where these structures are under risk. Although the frequency of neurological complications is not high, it is considered that these deficits are devastating complications of spinal surgery, which can have serious consequences on the quality of life and can increase health care costs. Because of that, the accent is on intraoperative neurophysiological methods development, which provide optimal monitoring of the spinal cord function during routine and complex spinal procedures and has high efficacy detecting possible neurological deficits. The concept of multimodal neuromonitoring, which is used today, relies on advantages of each modality separately and then in combination of these modalities it achieves a more reliable estimation of functional integrity. Today IONM is routinely used worldwide, but in Serbia, its use is still limited even though its advantages are well known.

Comparison of the effect of navigation template assisted spinal pedicle fixation and traditional pedicle screw fixation:a Meta-analysis

To systematically evaluate the efficacy of rapid prototyping drill navigation template-assisted pedicle screw fixation and traditional anatomic landmark-based fixation in the treatment of spinal disease by accessing and searching some relevant literatures home and abroad. Randomized Controlled Trials (RCTs) and prospective case-control studies or retrospective case-control studies about rapid prototyping drill templates-assisted pedicle screw fixation and traditional anatomic landmark-based fixation for the treatment of spinal disease were searched electronically in PubMed, The Cochrane Library(Issue 5, 2017), Clinical Trial, Google Scholar, Web of Science, CNKI, Wanfang database and VIP database before June 2017. According to the inclusion and exclusion criteria, two researchers independently screened the literatures, and extracted the data. The methodological quality of randomized controlled trials were evaluated by the Cochrane Handbook, and prospective case-control studies and retrospective case-control studies were evaluated by the NOS scale. The outcomes were analyzed using RevMan 5.3 software provided by the Cochrane information management system. A total of 7 articles were included, including 2 RCTs, 1 prospective case-control study and 4 retrospective case-control studies. A total of 237 patients were implanted with 1 688 pedicle screws, including 898 screws in the navigation template group, 790 screws in the conventional method group. Meta-analysis results showed that there was significant difference in the excellent rate of screw implantation between navigation template group and conventional method group [OR=5.05, 95% CI(3.13, 8.16), P<0.000 01], there was significant difference in operative time, intraoperative blood loss for thoracolumbar surgery [WMD=-27.19, 95% CI(-38.21, -16.17), P<0.000 01; WMD=-100.82, 95% CI(-182.26, -19.37), P=0.02]. Compared with traditional pedicle screw fixation, navigation template spine pedicle screw fixation has better clinical effect, which can improve the excellent rate of screw placement, reduce the operation time and intraoperative bleeding.

Short-term effects of combined pedicle/facet screw fixation plus interbody fusion through the channel-assisted muscle-splitting approach for the treatment of degenerative lumbar spine diseases in the elderly

Objective To examine the feasibility and early effects of unilateral pedicle screw fixation in combination with contralateral translaminar facet screw fixation plus interbody fusion through the channel-assisted muscle-splitting approach for the treatment of degenerative lumbar spine diseases in elderly patients. Methods A total of 82 elderly patients with degenerative lumbar spine diseases received treatment between January 2015 and June 2016.Of these patients, 25 had lumbar spinal stenosis, 42 had degenerative lumbar instability, 13 had giant lumbar disc herniation, and two had recurrent lumbar disc herniation; There were 69 cases of single segment and 13 cases of double segment lesions.Perioperative evaluation, imaging evaluation, and clinical evaluation were performed, and surgical complications were analyzed. Results The average length of incision was (2.6±0.4) cm in cases of single segment lesions and (4.4±0.5) cm in cases of two segment lesions.The mean operation time was (98.3±19.6) minutes and peri-operation blood loss was (232.2±25.8) ml.The post-operation height of the intervertebral disc space significantly increased at the last follow-up(P<0.05); the height of the intervertebral disc space was restored and well maintained with internal fixation showing no loosening, breakage or Cage shift.The post-operation lumbar coronal Cobb angle decreased(P<0.05)while the sagittal Cobb angle increased(P<0.05)at the last follow-up.There was no significant difference in the area and grade of the multifidus muscle on MRI 12 months after operation.Seventy-two patients were followed up for 12-18 months(mean=16.8 months), and there were 67 cases of intervertebral fusion(93.1%). The last follow-up showed a Japanese Orthopaedic Association(JOA)score of (25.8±1.7), which was significantly higher than the pre-operation score(10.6±1.3), with an excellence rate of 88.9%.The Oswestry Disability Index score was significantly reduced, from (50.9±21.6) at pre-operation to (9.6±4.8) at the last follow-up.There were 78 patients with primary wound healing, three cases of superficial wound necrosis, one case of dural tear, and one case of nerve root injury.No cardiovascular or cerebrovascular incident was observed during or after operation. Conclusions Combined pedicle/facet screw fixation plus interbody fusion through the channel-assisted muscle-splitting approach shows satisfactory short-term effects when used for the treatment of degenerative lumbar spine diseases in the elderly and possesses advantages such as minimal invasiveness, limited bleeding, quick recovery, high fusion rates and significantly improved clinical outcomes.However, further clinical studies are required to assess its medium-and long-term efficacy. Key words: Spinal fusion; Surgical procedures minimally invasive; Arthritis, degenerative

Epidemiological trends in spine surgery over 10years in a multicenter database.

There are few epidemiological studies of spinal surgery in Asia and none in Japan. The goal of this study was to review spine surgeries performed in our group between 2004 and 2015 in a cross-sectional study, with a focus on the effects of the superaging society on the characteristics and trends of spinal surgeries. A retrospective review was performed for all 45,831 spinal surgeries conducted between 2004 and 2015 and recorded in our prospective multicenter database. During the study period, there was a significant increase in annual spine surgeries (p<0.05). The proportion of elderly patients (aged≥70) also increased, and the mean age at the time of surgery significantly increased from 54.6years in 2004 to 63.7years in 2015 (p<0.05). Regarding the etiology, there were significant increases in degenerative disease (p<0.01) and osteoporotic vertebral fracture, and a significant decrease in rheumatic spondylosis from 2004 to 2015 (p<0.01). Instrumentation surgery increased over time, with the performance of MIS, BKP and LLIF as new procedures in recent years (p<0.01). The mean reoperation rate was 2.0% and this rate did not change significantly over time, although the rate of reoperation due to surgical site infection significantly increased from 0.9 to 1.5% (p<0.05). Our data showed marked increases in the number of spine surgeries, the age of patients, and the number of surgeries for degenerative diseases. This large-scale study provides indicators for planning the future development of spine surgery and for treatment of spinal diseases in daily practice. These slides can be retrieved under Electronic Supplementary Material.

Clinical comparison of unilateral biportal endoscopic technique versus open microdiscectomy for single-level lumbar discectomy: a multicenter, retrospective analysis

BackgroundThe unilateral biportal endoscopic (UBE) technique is a minimally invasive procedure for spinal surgery, while open microscopic discectomy is the most common surgical treatment for ruptured or herniated discs of the lumbar spine. A new endoscopic technique that uses a UBE approach has been applied to conventional arthroscopic systems for the treatment of spinal disease. In this study, we aimed to compare and evaluate the perioperative parameters and clinical outcomes, including recovery from surgery, pain and life quality modification, patient’s satisfaction, and complications, between UBE and open lumbar microdiscectomy (OLM) for single-level discectomy procedures.MethodsThis study included 141 patients with degenerative disc disease requiring discectomy at a single level from L2–L3 to L5–S1. A total of 60 and 81 patients underwent UBE and OLM, respectively. Analysis was based on comparison of perioperative metrics, operation time (OT); estimated blood loss (EBL); length of hospital stay (HS); clinical outcomes, including assessment using the Visual Analogue Scale (VAS) and Oswestry Disability Index (ODI); patient satisfaction (the MacNab score); and the incidence of reoperation and complications.ResultsThe study cohort was 56.7% women, and the mean patient age was 50.98 ± 18.23 years. The mean VAS (the back and leg), MacNab score, and ODI improved significantly from the preoperative period to the last follow-up (12.92 ± 3.92) in both groups (p < 0.001). One week after operation, the back VAS score in the UBE group showed significantly more improvement than that in the OLM group. However, the 1-week, 3-month, and 12-month VAS (the back and leg), ODI improvement, modified MacNab score, and OT were not significantly different between the two groups. In the UBE group, EBL (34.67 ± 16.92) was smaller and HS (2.77 ± 1.2) was shorter than that of the OLM group (140.05 ± 57.8, 6.37 ± 1.39). However, OT (70.15 ± 22.0) was longer in the UBE group than in the OLM group (60.38 ± 15.5), and the difference was statistically significant. Meanwhile, the differences in the rate of surgical conversion and complications between the two groups were not statistically significant.ConclusionsThe UBE for single-level discectomy yielded similar clinical outcomes to OLM, including pain control, functional disability, and patient satisfaction, but incurred minimal EBL, HS, and postoperative back pain.Trial registrationNot applicable.

Reliability of the EOS Imaging System for Assessment of the Spinal and Pelvic Alignment in the Sagittal Plane.

BackgroundThe sagittal alignment of the spine and pelvis is not only closely related to the overall posture of the body but also to the evaluation and treatment of spine disease. In the last few years, the EOS imaging system, a new low-dose radiation X-ray device, became available for sagittal alignment assessment. However, there has been little research on the reliability of EOS. The purpose of this study was to evaluate the intrarater and interrater reliability of EOS for the sagittal alignment assessment of the spine and pelvis.MethodsRecords of 46 patients were selected from the EOS recording system between November 2016 and April 2017. The exclusion criteria were congenital spinal anomaly and deformity, and previous history of spine and pelvis operation. Sagittal parameters of the spine and pelvis were measured by three examiners three times each using both manual and EOS methods. Means comparison t-test, Pearson bivariate correlation analysis, and reliability analysis by intraclass correlation coefficients (ICCs) for intrarater and interrater reliability were performed using R package “irr.”ResultsWe found excellent intrarater and interrater reliability of EOS measurements. For intrarater reliability, the ICC ranged from 0.898 to 0.982. For interrater reliability, the ICC ranged from 0.794 to 0.837. We used a paired t-test to compare the values measured by manual and EOS methods: there was no statistically significant difference between the two methods. Correlation analysis also showed a statistically significant positive correlation.ConclusionsEOS showed excellent reliability for assessment of the sagittal alignment of the spine and pelvis.

Effect of epidural corticosteroid injection on magnetic resonance imaging findings.

BackgroundMagnetic resonance imaging (MRI) of the spine is the preferred diagnostic tool for pathologic conditions affecting the spine. However, in patients receiving epidural corticosteroid injection (ESI) for treatment of spinal diseases, there is a possibility of misreading of MR images because of air or fluid in the epidural space after the injection. Therefore, we defined the characteristics of abnormal changes in MRI findings following an ESI in patients with low back pain.MethodsWe reviewed the medical records of 133 patients who underwent MRI of the lumbar spine within 7 days after ESI between 2006 and 2015.All patients were administered an ESI using a 22-gauge Tuohy needle at the lumbar spine through the interlaminar approach. The epidural space was identified by the loss of resistance technique with air.ResultsThe incidences of abnormal changes in MRI findings because of ESI were 54%, 31%, and 25% in patients who underwent MRI at approximately 24 h, and 2 and 3 days after ESI, respectively. Abnormal MRI findings included epidural air or fluid, needle tracks, and soft tissue changes. Epidural air, the most frequent abnormal finding (82%), was observed in 41% of patients who underwent MRI within 3 days after injection. Abnormal findings due to an ESI were not observed in MR images acquired 4 days after ESI or later.ConclusionsPain physicians should consider the possibility of abnormal findings in MR images acquired after epidural injection using the interlaminar approach and the loss of resistance technique with air at the lumbar spine.

Neurospinal Surgery Innovations

Over the past few decades, majority of neurosurgeons only specialize in spinal cord diseases. However, with the advances in spine surgery, more and more neurosurgeons focus on spine diseases. Precision minimally invasive technique in surgery of spine and spinal cord is an important branch of neurosurgery. As traditional surgery has been gradually replaced by precision surgery, open surgery has been gradually replaced by minimally invasive surgery (MIS), the diagnosis and treatment of spine diseases has been benefiting from minimally invasive techniques. With minimal surgical trauma, precise localization, MIS has become the inevitable trend of new neurosurgery. The model of multidisciplinary team is gradually becoming universal in the world in order to make the best treatment plan for the patient with spine diseases on the basis of the comprehensive disciplinary opinion.

A study on a pedicle-screw-based reduction method for artificially reduced artifacts

The purpose of this study is a quantitative analysis of the degree of the reduction of the artifacts that are induced by pedicle screws through the application of the recently developed iterative metallic artifact reduction (I MAR) software. Screw-type implants that are composed of 4.5 g/cm3 titanium (Ti) with an approximate average computed tomography (CT) value of 6500 Hounsfield units (HUs) that are used for the treatment of spinal diseases were placed in paraffin, a tissueequivalent material, and then dried. After the insertion, the scanning conditions were fixed as 120 kVp and 250 mA using multidetector computed tomography (MDCT) (Enlarge, Siemens, Germany). The slice thickness and the increment were set at the fields of view (FOVs) of 3 mm and 120 mm, respectively; the pitch is 0.8; the rotation time is 1 s; and the I MAR software was applied to the raw data of the acquired images to compare the CT-value changes of the posterior images. When the I MAR software was applied to animal vertebrae, it was possible to reduce the 65.7% image loss of the black-hole-effect image through the application of the I MAR software. When the I MAR image loss (%) was compared with the white-streak-effect image, the high-intensity image type with the white-streak effect could be reduced by 91.34% through the application of the I MAR software. In conclusion, a metal artifact that is due to a high-density material can be reduced more effectively when the I MAR algorithm is applied compared with that from the application of the conventional MAR algorithm. The I MAR can provide information on the various tissues that form around the artifact and the reduced metal structures, which can be helpful for radiologists and clinicians in their determination of an accurate diagnosis.

Study and Analysis of Mechanical Behavior between Rigid and Dynamic Fixation Systems Analyzed by the Finite Element Method

Orthopedic fixation devices are widely used in treatment of spinal diseases. It is expected that application of dynamic stabilization confers valuable movement possibility besides its main role of load bearing. Comparative investigation between pedicle screw model rigid fixation and (B Dyne, Elaspine, Bioflex, Coflexe rivet) models dynamic fixation systems may elucidate the efficacy of each design. The goal of the present study is to evaluate the efficacy of five fixation systems mounted on L4-L5 motion segment. In this numerical study, a 3D precious model of L4, L5 and their intervertebral disc has been employed based on CT images. five fixation devices have been also implanted internally to the motion segment. Finite element method was used to evaluate stress distribution in the disc and determine the overall displacement of the segment as a measure of movement possibility. The results show that The Coflex rivet implantation can provide stability in all motions and reduce disc annulus stress at the surgical segment (L4-L5), on the other hand, Maximum stress in the disc has been observed in dynamic systems but within the safe range. The greater movement of the motion segment has been also appeared in dynamic fixations. Existence of the fixation systems reduced the stress on the intervertebral disc which might be exerted in intact cases. Use of the fixation devices can considerably reduce the load on the discs and prepare conditions for healing of the injured ones. Furthermore, dynamic modes of fixation confer possibility of movement to the motion segments in order to facilitate the spinal activities.

An Anesthesia, Surgery, and Harvest Method for the Evaluation of Transpedicular Screws Using an In Vivo Porcine Lumbar Spine Model.

Pedicle screw fixation is the gold standard for the treatment of spinal diseases. However, many studies have reported the issue of loosening pedicle screws after spinal surgery, which is a serious concern. To address this problem, diverse types of pedicle screws have been examined to identify those with good fixation strength and osseointegration in spine bone. The porcine spine is a good alternative for the human spine in the evaluation of pedicle screws due to the anatomical size, mechanical characteristics, and cost. Although several studies have reported that pedicle screws are efficient in the porcine model, no study has described detailed protocols for the evaluation of a pedicle screw using the porcine model. Here, we describe a detailed method for evaluating transpedicular screws using an in vivo porcine lumbar spine model. The technical details for anesthesia, spine surgery, and harvest provided here will facilitate with the evaluation of the transpedicular screw fixation model.