Platelet-rich plasma (PRP) can accelerate bone union in spinal fusion surgery with an autogenous bone graft. However, it is unclear whether bone union can be obtained by using artificial bone and PRP ...together in spinal interbody fusion surgery.
This study aimed to determine whether interbody fusion can be achieved by transplanting porous hydroxyapatite/collagen(HAp/Col) which is an artificial bone material frequently used in spinal fusion surgery, together with PRP in the intervertebral disc space in rats.
A controlled laboratory study.
A total of fourty 10-week old Sprague-Dawley rats were used in this study and assigned to three groups as follow: disc curettage only (control group, n=10), disc curettage + HAp/Col transplant (H group, n=10), and disc curettage + HAp/Col + PRP transplant (H+P group, n=10). The other 10 rats were sacrificed as blood donors for acquisition of PRP. Microcomputed tomography (μCT) examinations were performed to evaluate bone union, bone volume (BV), and bone mineral density (BMD) at 4, 8, and 12 weeks following surgery. Twelve weeks postoperatively, each group of three of L4–L5 spines was harvested to perform histological examination (hematoxylin & eosin stain) and the others were subjected to biomechanical testing (compression properties).
The platelet count in PRP was approximately 4.1 times greater than that in whole blood (260.6±26.2 × 104 mg/dL and 64.3±2.9 × 104 mg/dL in PRP and whole blood, respectively). All the L4–L5 lumbar discs were fused in the H+P group, whereas only one case was fused in the H group and none in the control group at 12 weeks after surgery. BV was significantly higher in the H+P group than in the H group or control groups (both p<.01), although BMD was not significantly different among the three groups. Upon histological analysis, mature bone formation was observed at the transplanted space in all cases in the H+P group, whereas fibrous tissue was observed at the location in the H and control groups. Regarding biomechanical properties, the ultimate load to failure was significantly higher in the H+P group than in the H group or control group (p=.021 and .013, respectively), although stiffness was not significantly different between the three groups.
The combination of porous HAp/Col and PRP at an appropriate concentration can promote bone union in the intervertebral disc space without using an autologous bone graft in the rat model. Bone tissue formation was histologically confirmed, and it was mechanically strong.
This preclinical study showed that porous HAp/Col, when combined with PRP at an appropriate concentration, can induce bone union without autologous bone grafts. The results may eliminate the need for autologous bone collection for spinal fusion surgery in the future.
Spondylosis deformans is a non-inflammatory osteophytic reaction that develops to re-establish the stability of weakened joints between intervertebral discs. However, assessing these changes using ...radiography is subjective and difficult. In human medicine, attempts have been made to use artificial intelligence to accurately diagnose difficult and ambiguous diseases in medical imaging. Deep learning, a form of artificial intelligence, is most commonly used in medical imaging data analysis. It is a technique that utilizes neural networks to self-learn and extract features from data to diagnose diseases. However, no deep learning model has been developed to detect vertebral diseases in canine thoracolumbar and lumbar lateral X-ray images. Therefore, this study aimed to establish a segmentation model that automatically recognizes the vertebral body and spondylosis deformans in the thoracolumbar and lumbar lateral radiographs of dogs.
A total of 265 thoracolumbar and lumbar lateral radiographic images from 162 dogs were used to develop and evaluate the deep learning model based on the attention U-Net algorithm to segment the vertebral body and detect spondylosis deformans.
When comparing the ability of the deep learning model and veterinary clinicians to recognize spondylosis deformans in the test dataset, the kappa value was 0.839, indicating an almost perfect agreement.
The deep learning model developed in this study is expected to automatically detect spondylosis deformans on thoracolumbar and lumbar lateral radiographs of dogs, helping to quickly and accurately identify unstable intervertebral disc space sites. Furthermore, the segmentation model developed in this study is expected to be useful for developing models that automatically recognize various vertebral and disc diseases.
Purpose
Knowledge of interlaminar space is important for undertaking percutaneous endoscopic discectomy via an interlaminar approach (PED-IL). However, dynamic changes in the lumbar interlaminar ...space and the spatial relationship between the interlaminar space and intervertebral disc space (IDS) are not clear. The aim of this study was to anatomically clarify the changes in interlaminar space height (ILH) and variation in distance between the two spaces during flexion–extension of the lumbar spine in vitro.
Methods
First, we used a validated custom-made loading equipment to obtain neutral, flexion, and extension 3D models of eight lumbar specimens through 3D reconstruction software. Changes in ILH (ILH, IL-yH, IL-zH) and distances between the horizontal plane passing through the lowest edge of the lamina of the superior lumbar vertebrae and the horizontal plane passing through the lowest position of the trailing edge of the same-level IDS (DpLID) at L3/4, L4/5 and L5/S1 were examined on 3D lumbar models.
Results
We found that ILH was greater at L4/5 than at L3/4 and L5/S1 in the neutral position, but the difference was not significant. In the flexion position, ILH was significantly more than that in neutral and extension positions at L3/4, L4/5, and L5/S1. There were significantly more DpLID changes from neutral to flexion than that from neutral to extension at all levels (L3/4, L4/5, L5/S1).
Conclusion
These findings demonstrated level-specific changes in ILH and DpLID during flexion–extension. The data may provide a better understanding of the spatial relationship between lumbar interlaminar space and IDS, and aid the development of segment-specific treatment for PED-IL.
To visualize widening of the intervertebral discspace (IDS), X-rays areirradiated tangentially on the articular surface. However, accurately estimatingthe deflection angle of the x-ray tube is ...difficult. Therefore, we classifiedthe standing lateral lumbar spine images into 5 types by a Deep ConvolutionalNeural Network, determined the deflection angle of the X-ray tube for moreefficient visualization of the extension of the IDS in the standing frontallumbar spine images. In the lumbar lateral images of 500 patients, the x-raytube deflection angle was measured manually for each intervertebral space, and 1723 regions cut out into 256×256 regions per vertebra wereused．Data augmentation increased the data to 3795 regions. The accuracy, precision and recall were 83.0 %, 84.1% and 83%, respectively, and the f-value was 83.3%, resulting in a relatively highclassification accuracy. Many patientsare already having lower back pain, requiring them to shift from the lateral tofrontal body positions swiftly. For this reason, using deep learning wouldenable taking the IDS measurement in a short time, thereby reducing burden onthe patient and improving the imaging flow.
The objective of this study was to provide a morphometric description of the caudal cervical intervertebral disc (IVD) spaces of small-breed dogs and cats. Specimens consisting of C4 through C7 from ...five small-breed dogs and six cats were positioned in neutral, flexion, extension, and lateral bending positions; and CT images were acquired. Height and width of the cranial and caudal vertebral endplates (VEPs), angle between the VEPs (IVD wedge angle), and craniocaudal distance (IVD width) between VEPs for the four loading positions were measured and compared for three segments (C4-C5, C5-C6, and C6-C7). VEP size normalized to body weight from medium-sized dogs was retrieved from a previous study and compared with data from small dogs and cats. A linear mixed model was used to compare outcome measures. Significance was set to
< 0.05. VEP size normalized to body weight was the largest in small dogs compared with cats (
= 0.0422) and medium-sized dogs (
= 0.0064). Cats and medium-sized dogs were similar (
= 0.2763) in this regard. Flexion and extension induced a reduction of IVD width in the ventral portion of the IVD and the area of the nucleus. The dorsal part of the IVD remained unchanged throughout loading conditions. Unique morphometric characteristics of the caudal cervical IVD space of small dogs and cats were detected that are different from those described in sizes of dogs (medium-sized) typically affected by caudal cervical spondylomyelopathy (CSM). These findings may help to understand the different pathomechanisms in cervical spinal disease between small- and medium-sized dogs, including caudal CSM.
Background
It is known that sagittal compensating mechanisms are created for counteracting sagittal imbalance problems; however, they can sometimes be associated with incidents which affect the plan ...of management.
Purpose
The purpose of this study was to report a case of the occurrence of common iliac vessel displacement into the intervertebral disc space following one of the spinal compensatory mechanisms.
Material and methods
The authors demonstrated this case by showing the patient history, physical examination, imaging studies, and treatment strategy as well as by reviewing some related literature.
Results
An 81-year-old woman presented with a long history of low back pain with claudication. An upright plain radiograph and flexion–extension study demonstrated a progressive local thoracolumbar kyphosis and losing of lumbar lordosis with significant widening of the intervertebral disc space of L4–L5. An MRI scan and 3D volume rendering spiral computed tomography (3D-CT) revealed an abnormal content which was depicted as common iliac vessels inside the disc space of L4–L5. Consequently, a rare case of the occurrence of common iliac vessel displacement into the intervertebral disc space following one of the spinal compensatory mechanisms was reported.
Conclusion
The occurrence of vascular displacement into the intervertebral disc space related to lumbar hyperextension, as a compensating mechanism, is a rare incident but can occur. Consequently, when this mechanism presents with abnormal widening of the intervertebral disc space, especially at the low lumbar level, it should raise surgeon’s concern about the probability of vascular injury when performing a disc procedure. Thorough investigation with imaging studies and selecting the optimum surgical treatment are warranted.
Abstract Gradual degeneration of intervertebral discs of the lumbar spine is one of the most common causes of low back pain. Although conservative treatment for low back pain may provide relief to ...most individuals, surgical intervention may be required for individuals with significant continuing symptoms, which is usually performed by replacing the degenerated intervertebral disc with an artificial implant. For designing implants with good bone contact and continuous force distribution, the morphology of the intervertebral disc space and vertebral body endplates is of considerable importance. In this study, we propose a method for parametric modeling of the intervertebral disc space in three dimensions (3D) and show its application to computed tomography (CT) images of the lumbar spine. The initial 3D model of the intervertebral disc space is generated according to the superquadric approach and therefore represented by a truncated elliptical cone, which is initialized by parameters obtained from 3D models of adjacent vertebral bodies. In an optimization procedure, the 3D model of the intervertebral disc space is incrementally deformed by adding parameters that provide a more detailed morphometric description of the observed shape, and aligned to the observed intervertebral disc space in the 3D image. By applying the proposed method to CT images of 20 lumbar spines, the shape and pose of each of the 100 intervertebral disc spaces were represented by a 3D parametric model. The resulting mean (±standard deviation) accuracy of modeling was 1.06 ± 0.98 mm in terms of radial Euclidean distance against manually defined ground truth points, with the corresponding success rate of 93% (i.e. 93 out of 100 intervertebral disc spaces were modeled successfully). As the resulting 3D models provide a description of the shape of intervertebral disc spaces in a complete parametric form, morphometric analysis was straightforwardly enabled and allowed the computation of the corresponding heights, widths and volumes, as well as of other geometric features that in detail describe the shape of intervertebral disc spaces.
Objectives
To evaluate the biomechanical effect of the X-Stop device on the intervertebral foramen (IVF) and segmental spinal canal length (SSCL), as well as the intervertebral disc space at the ...implanted and the adjacent segments in patients with lumbar spinal stenosis (LSS).
Materials and methods
Eight elderly patients with LSS, scheduled for X-stop implantation, were CT or MRI scanned to construct 3D vertebral models (L2–S1). Before and after the surgery, each patient was also imaged using a dual-fluoroscopic image system during weight-bearing standing and maximum extension–flexion. The positions of the vertebrae were then determined using an established 2D–3D model matching method.
Results
The data revealed that the postoperative IVF area was significantly increased by 32.9% (or 32 mm
2
) (
p
< 0.05) and the IVF width was increased by 24.4% (or 1.1 mm,
p
= 0.06) during extension, but with minimal change in standing and flexion. The IVF heights were significantly (
p
< 0.05) increased at standing by 1.2 mm and extension by 1.8 mm, but not at flexion. The SSCL were significantly (
p
< 0.05) increased at extension by 1.2 mm, but not at standing and flexion. Anterior disc space of the implanted level was significantly decreased from 8.0 to 6.6 mm during standing.
Conclusion
The X-Stop implantation efficiently enlarged the IVF area in the elderly patients with LSS at the operated level with little biomechanical effect immediately on the superior and inferior adjacent levels. However, it reduced the anterior disc space at the implanted level.
The insufficient investigations on the changes of spinal structures during traction prevent further exploring the possible therapeutic mechanism of cervical traction. A blind randomized ...crossover-design study was conducted to quantitatively compare the intervertebral disc spaces between axial and anterior lean cervical traction in sitting position. A total of 96 radiographic images from the baseline measurements, axial and anterior lean tractions in 32 asymptomatic subjects were digitized for further analysis. The intra- and inter-examiner reliabilities for measuring the intervertebral disc spaces were in good ranges (ICCs = 0.928–0.942). With the application of anterior lean traction, the statistical increases were detected both in anterior and in posterior disc spaces compared to the baseline (0.29 mm and 0.24 mm; both
P
< 0.01) and axial traction (0.16 mm and 0.35 mm; both
P
< 0.01). The greater intervertebral disc spaces obtained during anterior lean traction might be associated with the more even distribution of traction forces over the anterior and posterior neck structures. The neck extension moment through mandible that generally occurred in the axial traction could be counteracted by the downward force of head weight during anterior lean traction. This study quantitatively demonstrated that anterior lean traction in sitting position provided more intervertebral disc space enlargements in both anterior and posterior aspects than axial traction did. These findings may serve as a therapeutic reference when cervical traction is suggested.
PDF
