Posterior Cortex Of Vertebral Body Research Articles

Cortical step sign in spinal clearance on trauma computed tomography – Indicator of acute thoracolumbar compression fracture

Introduction Differentiating an acute from chronic compression fracture of the thoracolumbar (TL) spine can pose a dilemma for radiologists interpreting spinal imaging following trauma. Mild wedging of the vertebrae can be due to spondylosis or osteoporosis, whilst acute simple compression fractures may not always be associated with loss of body height. In this observational study, we hypothesize that the presence of a vertebral body cortical step is a reliable sign of an acute compression fracture on Computed Tomography (CT) scans. Methods In a retrospective review of thoracolumbar CT scans following trauma, two observers analysed for the presence of a cortical step at the anterior or posterior vertebral body cortex, fracture morphology and associated injuries. A ‘cortical step’ is defined as a break of hyperdense cortex on CT scans, intervening non-sclerosed trabecular bone, and sharp overlap of the underlying cortex. MRI of the spine was used as gold standard. Results 187 consecutive CT scans over 2 years were assessed. Sensitivity, specificity and accuracy of cortical step sign were 100%, 90.2% and 97% in diagnosing an acute thoracolumbar compression fracture, respectively. The interobserver reliability was high (kappa = 0.97). False positive cortical step was seen in Kummel’s disease and large Schmorl’s nodule. Conclusion Our results demonstrate high sensitivity and specificity of ‘cortical step sign’ in diagnosing acute vertebral body compression fractures of TL spine on CT scans in patients with trauma. This sign can be useful to radiologists for safe clearance of the thoracolumbar spine following trauma, helping distinguish acute trauma from chronic causes of vertebral body height loss.

Surgical technique modification of circumferential decompression for thoracic spinal stenosis and clinical outcome

Progressive thoracic myelopathy caused by ossification of posterior longitudinal ligament (OPLL) responds poorly to conservative therapy. The most direct decompression is extirpation of ossified posterior longitudinal ligament (PLL). Surgical outcomes of posterior approaches to remove ossified PLL are not always satisfactory because of the risk of neurological deterioration. In this study, we modified the conventional anterior decompression technique via a posterior approach for thoracic OPLL. From an anterior approach, the posterior cortex of vertebral body was exposed and the ossified PLL was removed. Then kyphosis correction was done via posterior instrumentation to reduce cord compression between dura under tension and the anterior canal wall. From the back, the distal end of the ossified PLL was displaced anteriorly to create a gap between ossified PLL and dura, remaining adhesions were divided and the ossified PLL was manipulated through this gap under direct vision. The surgical technique was applied in 20 patients with thoracic myelopathy caused by OPLL. One case of postoperative neurological deterioration was encountered but this recovered fully. Our outcomes were relatively favorable.

Change in the cross-sectional area of the thecal sac following balloon kyphoplasty for pathological vertebral compression fractures prior to spine stereotactic radiosurgery.

OBJECTIVEPercutaneous vertebral augmentation procedures such as vertebroplasty and kyphoplasty are often performed in cancer patients to relieve mechanical axial-load pain due to pathological collapse deformities. The collapsed vertebrae in these patients can be associated with varying degrees of spinal canal compromise that can be worsened by kyphoplasty. In this study the authors evaluated changes to the spinal canal, in particular the cross-sectional area of the thecal sac, following balloon kyphoplasty (BKP) prior to stereotactic radiosurgery (SRS).METHODSThe authors retrospectively reviewed the records of all patients with symptomatic vertebral compression fractures caused by metastatic disease who underwent kyphoplasty prior to single-fraction SRS. The pre-BKP cross-sectional image, usually MRI, was compared to the post-BKP CT myelogram required for radiation treatment planning. The cross-sectional area of the thecal sac was calculated pre- and postkyphoplasty, and intraprocedural CT imaging was reviewed for epidural displacement of bone fragments, tumor, or polymethylmethacrylate (PMMA) extravasation. The postkyphoplasty imaging was also evaluated for evidence of fracture progression or fracture reduction.RESULTSAmong 30 consecutive patients, 41 vertebral levels were treated with kyphoplasty, and 24% (10/41) of the augmented levels showed a decreased cross-sectional area of the thecal sac. All 10 of these vertebral levels had preexisting epidural disease and destruction of the posterior vertebral body cortex. No bone fragments were displaced posteriorly. Minor epidural PMMA extravasation occurred in 20% (8/41) of the augmented levels but was present in only 1 of the 10 vertebral segments that showed a decreased cross-sectional area of the thecal sac postkyphoplasty.CONCLUSIONSIn patients with preexisting epidural disease and destruction of the posterior vertebral body cortex who are undergoing BKP for pathological fractures, there is an increased risk of further mass effect upon the thecal sac and the potential to alter the SRS treatment planning.

Evaluation of vertebral body fractures using susceptibility-weighted magnetic resonance imaging.

To test thediagnostic performance of susceptibility-weighted MRI (sMRI) for the evaluation of vertebral body fractures versus standard MRI-sequences, using CT as reference standard. In this prospective study 88 vertebral fractures (45 healed, 43 non-healed) were detected in 39 patients who underwent T1/T2/TIRM MRI-sequences and sMRI. All fractures were evaluated with CT as reference standard. In all modalities/sequences, displacement and height of the posterior vertebral body cortex and visibility of fracture lines and cortical breaks were assessed. Sensitivity, specificity and inter-reader agreement between MRI and CT were calculated. sMRI demonstrated highest diagnostic accuracy for detection of posterior vertebral body cortex involvement (sensitivity: 98 %/specificity: 100 %), fracture lines (86 %/99 %) and cortical breaks (93 %/100 %) versus T1/T2/TIRM sequences. Regarding evaluation of posterior vertebral body cortex displacement and height, sMRI demonstrated the closest intermodality agreement (R2=0.96; 95 % CI -0.92-0.89/R2=0.97; 95 % CI -1.67-1.23) with CT and the closest interobserver agreement (R2=0.97; 95 % CI -0.71-1.01). sMRI allows reliable evaluation of vertebral body fractures with regard to posterior vertebral body cortex displacement and height, cortical breaks and fracture lines with higher accuracy versus standard MRI, especially in patients with non-healed vertebral body fractures. • sMRI allows a reliable evaluation of vertebral body fractures. • sMRI has higher accuracy than standard-MRI for evaluation of vertebral body fractures. • sMRI is especially useful in patients with non-healed vertebral body fractures.

Is an Intact Posterior Vertebral Body Cortex Protective for Percutaneous Ablation?

After the lung and liver, bone is the most common site for metastatic disease and the spine is the most common site of bony metastases.[1][1] Roughly 70% of patients with cancer will develop metastatic disease. Of these, 40% develop spinal metastatic disease and 10%–20% of these will develop

Surgical Anatomy of the Uncinate Process and Transverse Foramen Determined by Computed Tomography.

Study Design Computed tomography–based cohort study. Objective Although there are publications concerning the relationship between the vertebral artery and uncinate process, there is no practical guide detailing the dimensions of this region to use during decompression of the intervertebral foramen. The purpose of this study is to determine the anatomic parameters that can be used as a guide for thorough decompression of the intervertebral foramen. Methods Fifty-one patients with three-dimensional computed tomography scans of the cervical spine from 2003 to 2012 were included. On axial views, we measured the distance from the midline to the medial and lateral cortices of the pedicle bilaterally from C3 to C7. On coronal reconstructed views, we measured the minimum height of the uncinate process from the cranial cortex of the pedicle adjacent to the posterior cortex of vertebral body and the maximal height of the uncinate process from the cranial cortex of the pedicle at the midportion of the vertebral body bilaterally from C3 to C7. Results The mean distances from midline to the medial and lateral cortices of the pedicle were 10.1 ± 1.3 mm and 13.9 ± 1.5 mm, respectively. The mean minimum height of the uncinate process from the cranial cortex of the pedicle was 4.6 ± 1.6 mm and the mean maximal height was 6.1 ± 1.7 mm. Conclusions Our results suggest that in most cases, one can thoroughly decompress the intervertebral foramen by removing the uncinate out to 13 mm laterally from the midline and 4 mm above the pedicle without violating the transverse foramen.

Is Vertebral Augmentation the Right Choice for Cancer Patients With Painful Vertebral Compression Fractures?

Cancer-related fractures of the spine are different from osteoporotic ones, not only in pathogenesis but also in natural history and treatment. Higher class evidence now supports offering balloon kyphoplasty to a patient with cancer, provided that the pain is significant in intensity, has a positional character, and correlates to the area of the fractured vertebrae. Absence of clinical spinal cord compression and overt instability are paramount. Because of the frequent disruption of the posterior vertebral body cortex in these patients, the procedure should be performed by experienced operators who could also quickly perform an open decompression if cement extravasation occurs. Patients will benefit from vertebral augmentation, even in chronic malignant fractures. A biopsy should be routinely performed and a combination with radiation treatment would be beneficial in most cases.

Experts' agreement on therapy for bone metastases

Experts' agreement on therapy for bone metastases

High-Resolution Imaging of the Spine Using Multidetector-Row Computed Tomography

The purpose of this study was to investigate the ability of high-resolution computed tomography (CT) images to distinguish between benign and malignant vertebral compression fractures. Computed tomography images of 45 benign compression fractures in 40 patients and 33 malignant compression fractures in 33 patients were evaluated. A 16-slice multidetector-row CT scanner was used for data acquisition, and axial images with a slice thickness of 1 mm and sagittal and coronal multiplanar reconstruction images with a slice thickness of 0.7 to 1 mm were used for interpretation. The following findings were significantly more frequent in malignant fractures: destruction of the anterolateral and/or posterior cortex of the vertebral body, destruction of the cancellous bone of the vertebral body, destruction of the end plate, destruction of the pedicle, a paraspinal soft tissue mass, and an epidural mass. The extremely reliable signs of malignancy were destruction of the anterolateral and/or posterior cortex of vertebral body (100% accuracy) and destruction of the cancellous bone of the vertebral body (97.4% accuracy). High-resolution CT can provide many useful signs for differentiating between benign and malignant vertebral compression fractures, and its diagnostic ability is sufficient for clinical use.

Pull-out strength of Caspar cervical screws.

Anterior cervical instrumentation as an adjunct to bone fusion has an important role in cervical spine surgery. Posterior vertebral body cortex purchase is strongly recommended in the use of the Caspar system, although few biomechanical data exist to validate this requirement. In this study, Caspar screws were placed in 43 human cadaveric cervical vertebral bodies, either putting them into the posterior vertebral cortex as identified radiographically or penetrating it by 2 mm as recommended in the literature. Pull-out tests were conducted with tension applied to a connected plate at 0.25 mm/s, and force-deformation data were obtained. Failure typically occurred with clean pull-out; in most instances, cancellous bone remained attached to screw threads. Mean load without posterior cortical purchase was 375 +/- 53 N; with penetration it was 411 +/- 70 N. These differences were nonsignificant. Average deformation to failure was 1.41 +/- 0.10 mm in the group without posterior cortical penetration. In the posterior penetration group, mean deformation was 1.56 +/- 0.16 mm. Again, differences were not significant. Posterior cortical penetration does not improve the pull-out strength of Caspar screws in an isolated vertebral body model, but other biomechanical studies need to be done before insertion methods are altered.