Posterior Elements Research Articles

Diffusion-Weighted Imaging and Chemical Shift Imaging to Differentiate Benign and Malignant Vertebral Lesion: A Hospital-Based Cross-Sectional Study.

Objective The aim of this study was to evaluate the role of diffusion-weighted imaging (DWI) and chemical shift imaging (CSI) for the differentiation of benign and malignant vertebral lesions. Methods Patients with vertebral lesions underwent routine magnetic resonance imaging (MRI) along with DWI and CSI. Qualitative analysis of the morphological features was done by routine MRI. Quantitative analysis of apparent diffusion coefficient (ADC) from DWI and fat fraction (FF) from CSI was done and compared between benign and malignant vertebral lesions. Results Seventy-two patients were included. No significant difference was noted in signal intensities of benign and malignant lesions on conventional MRI sequences. Posterior element involvement, paravertebral soft-tissue lesion, and posterior vertebral bulge were common in malignant lesion, whereas epidural/paravertebral collection, absence of posterior vertebral bulge, and multiple compression fractures were common in benign vertebral lesion ( p < 0.001). The mean ADC value was 1.25 ± 0.27 mm 2 /s for benign lesions and 0.9 ± 0.19 mm 2 /s for malignant vertebral lesions ( p ≤ 0.001). The mean value of FF was 12.7 ± 7.49 for the benign group and 4.04 ± 2.6 for the malignant group ( p < 0.001). A receiver operating characteristic (ROC) curve analysis showed that an ADC cutoff of 1.05 × 10 -3 mm 2 /s and an FF cutoff of 6.9 can differentiate benign from malignant vertebral lesions, with the former having 86% sensitivity and 82.8% specificity and the latter having 93% sensitivity and 96.6% specificity. Conclusion The addition of DWI and CSI to routine MRI protocol in patients with vertebral lesions promises to be very helpful in differentiating benign from malignant vertebral lesions when difficulty in qualitative interpretation of conventional MR images arises.

Shape diversity in conodont elements, a quantitative study using 3D topography

The flourishment of conodont diversity through the Paleozoic is evidenced by the strong diversification of the shape of the elements composing their feeding apparatus. Among the different elements that compose the feeding apparatus, the platform elements (P1) are the most robust. However, the P1 elements also represent the most posterior dental elements of the apparatus, performing therefore the ultimate stage of food processing before ingestion of the food bowl. Thus, characterizing the shape of these elements across various species of conodonts could be relevant to decipher the diversity of feeding behavior among this group. Here we use topographic indices initially developed for the description of teeth relief (RFI, Slope), orientation (OPCr) and sharpness (ARC, DNE) to discriminate quantitatively P1 element shapes among conodont communities of the Late Famennian from the Montagne Noire Area (south France). We evidence methodological considerations such as voxel size impact on topographic indices that should be imperatively considered before conducing these methods on conodonts. Under several homogeneous conditions, this quantification of shape diversity, even on poorly damaged specimens, could bring new clues for the understanding of P1 elements kinematics and feeding strategies among conodonts.

24 Stereotactic Body Radiotherapy for Posterior Element Only Spinal Metastases: Outcomes and Validation of Recommended Clinical Target Volume Delineation Practice

24 Stereotactic Body Radiotherapy for Posterior Element Only Spinal Metastases: Outcomes and Validation of Recommended Clinical Target Volume Delineation Practice

An MRI-Based Radiomics Nomogram for Differentiation of Benign and Malignant Vertebral Compression Fracture

This study aimed to develop and validate a magnetic resonance imaging (MRI)-based radiomics nomogram combining radiomics signatures and clinical factors to differentiate between benign and malignant vertebral compression fractures (VCFs). A total of 189 patients with benign VCFs (n=112) or malignant VCFs (n=77) were divided into training (n=133) and validation (n=56) cohorts. Radiomics features were extracted from MRI T1-weighted images and short-TI inversion recovery images to develop the radiomics signature, and the Rad score was constructed using least absolute shrinkage and selection operator regression. Demographic and MRI morphological characteristics were assessed to build a clinical factor model using multivariate logistic regression analysis. A radiomics nomogram was constructed based on the Rad score and independent clinical factors. Finally, the diagnostic performance of the radiomics nomogram, clinical model, and radiomics signature was validated using receiver operating characteristic and decision curve analysis (DCA). Six features were used to build a combined radiomics model (combined-RS). Pedicle or posterior element involvement, paraspinal mass, and fluid sign were identified as the most important morphological factors for building the clinical factor model. The radiomics signature was superior to the clinical model in terms of the area under the curve (AUC), accuracy, and specificity. The radiomics nomogram integrating the combined-RS, pedicle or posterior element involvement, paraspinal mass, and fluid sign achieved favorable predictive efficacy, generating AUCs of 0.92 and 0.90 in the training and validation cohorts, respectively. The DCA indicated good clinical usefulness of the radiomics nomogram. The MRI-based radiomics nomogram, combining the radiomics signature and clinical factors, showed favorable predictive efficacy for differentiating benign from malignant VCFs.

Minimally Invasive Bilateral Decompressive Lumbar Laminectomy with Unilateral Approach Among Obese versus Nonobese Patients

Decompressive lumbar laminectomy (DLL) is a common procedure for lumbar stenosis. A unilateral approach, unlike the traditional open approach, spares the posterior elements to mitigate the risk of iatrogenic instability associated with a DLL. Various minimally invasive techniques have been described but little attention has been aimed toward this specific microsurgical approach, particularly regarding obese patients. We aimed to compare operative details, perioperative outcomes, and complication profiles between obese and nonobese patients. One hundred and ninety-four patients who underwent bilateral laminectomy with a unilateral approach by the study surgeon from July 2013 to June 2018 were included. Of these patients, 105 were classified as obese, with body mass index (BMI) ≥30.0 kg/m2, and 89 were nonobese, with BMI <30.0 kg/m2. The obese and nonobese groups were compared; operative time, blood loss, and complications were assessed. Operative time was nonsignificantly increased in the obese group (177 vs. 166 minutes; P= 0.21) and estimated blood loss was nonsignificantly lower (91 mL vs. 97 mL; P= 1.00) in the obese group. Durotomy rates (3 [2.9%] obese vs. 2 [2.2%] nonobese; P= 0.789) and postoperative wound drainage rates (4 [3.8%] obese vs. 2 [3.8%] nonobese; P= 0.92) did not significantly differ between the 2 groups. Length of stay was significantly longer in the obese group (1.5 vs. 1.0 days; P= 0.0005). Compared with the nonobese group, the obese group had significantly longer length of hospitalization, as well as nonsignificantly increased length of operation and decreased blood loss. The 2 groups had similar perioperative complication rates.

Minimally Invasive Surgery Strategies to Prevent Proximal Junctional Kyphosis.

Proximal junctional kyphosis (PJK) is a common complication following long-segment thoracolumbar fusions for patients with adult spinal deformities. PJK is described as a progressive kyphosis at the upper instrumented vertebra or 1 or 2 segments adjacent to the instrumented vertebra. This condition can lead to proximal junction failure, which results in vertebral body fractures, screw pullouts, and neurological deficits. Revision surgery is necessary to address symptomatic PJK. Research efforts have been dedicated to elucidating risk factors and prevention strategies. It has been postulated that minimally invasive surgery (MIS) techniques may help prevent PJK because these techniques aim to preserve the soft tissue integrity at the top of the construct and maintain posterior element support. In this article, the authors define PJK, describe MIS strategies to prevent PJK, and compare PJK rates after MIS with PJK rates after open approaches for long-segment thoracolumbar fusion.

A FIRST REPORT ON OUTCOMES OF STEREOTACTIC BODY RADIOTHERAPY FOR POSTERIOR ELEMENT ONLY SPINAL METASTASES AND VALIDATION OF RECOMMENDED CLINICAL TARGET VOLUME DELINEATION PRACTICE

Abstract Spine stereotactic body radiotherapy (SBRT) improves local control and pain response compared to conventional external beam radiotherapy. Consensus stipulates MRI-based delineation of the clinical target volume (CTV) and is based on spine segment sector involvement. The applicability to metastases limited to the posterior elements remains to be validated. We aimed to determine the patterns of failure and safety of treating posterior element metastases when the vertebral body (VB) was intentionally excluded from the CTV. METHODS AND MATERIALS: A retrospective review of a prospectively maintained database of 605 patients and 1412 spine segments treated with spine SBRT was performed. Only treated segments involving the posterior elements alone were included. The primary outcome was local failure and secondary outcomes included patterns of failure, toxicities. RESULTS: 24/605 patients and 31/1412 segments were treated to the posterior elements only. Local failure occurred in 11/31 segments. The cumulative rate of local recurrence was 9.7% at 12 months and 30.8% at 24 months. Amongst local failures, the most common histologies were renal cell carcinoma (36.4%) and non-small cell lung cancer (36.4%) and 73% had baseline paraspinal disease extension. 6/11 (54.5%) failed exclusively within treated CTV sectors and 5/11 (45.5%) with both treated and adjacent untreated sectors. 4/5 cases had recurrent disease extending into the VB, but no failure was observed exclusively within the VB. CONCLUSIONS: Posterior element alone metastases are rare. Our analyses support SBRT consensus contouring guidelines such that the VB can be excluded from CTV in spinal metastases confined to the posterior elements.

Modification to the placement of the navigation reference frame in posterior corrective fusion of spinal deformity with myelomeningocele: a series of 6 cases.

To show a modified placement of the navigation reference frame in posterior corrective fusion of spinal deformity with myelomeningocele. This was a retrospective, single-surgeon case series, and IRB-approved study. Six consecutive patients (one male and five females) who were diagnosed with spinal deformity with myelomeningocele underwent posterior corrective fusion surgery from the upper thoracic spine to the pelvis with preoperative computed tomography navigation (pCTN). At the level of the spina bifida, where posterior elements such as the spinous process were missing, the reference frame of the pCTN was placed on the flipped lamina or pedicles, and a pedicle screw (PS) or iliac screw (IS) was inserted. Screw deviation was investigated by using postoperative CT. A total of 55 screws were placed at the spina bifida level and pelvis. Of these, 12 ISs were placed on each side in each case. The screws placed using the pCTN were not reinserted or removed intraoperatively or postoperatively. However, only one PS was found to have perforated the spinal canal on postoperative CT but was left in place because it caused no neurological problem. By modifying the placement of the reference frame, such as placing it on the flipped lamina or pedicles, pCTN could be used even at the levels of the spina bifida, where the posterior elements are missing, to accurately place PSs and various types of ISs.

Computer navigation-guided transpedicular excision of L4 vertebral body osteoblastoma

Abstract Osteoblastoma is a benign bone tumor that accounts for 10% of all spinal tumors and mostly arises from the posterior spinal elements. Isolated vertebral body osteoblastoma is relatively rare and generally requires extensive surgery. We report a rare case of L4 vertebral body osteoblastoma, which was managed successfully by computer navigation-guided transpedicular excision. A 22-year-old female presented with progressive lower back pain for the past six months. Radiological investigation revealed a sclerotic lesion involving the anterior cortex with a prominent central nidus in the anterior part of the L4 vertebral body. Based on the lesion size, a diagnosis of benign osteoblastoma (Enneking stage 2) was made, and she underwent computer navigation-assisted intralesional excision of the lesion by the bilateral transpedicular route. Histopathological examination confirmed the diagnosis of osteoblastoma. In the immediate postoperative period, the patient was completely relieved of symptoms, and the final follow-up magnetic resonance imaging showed no evidence of recurrence at the end of seven years. The intraoperative 3D navigation technology allowed a transpedicular minimal access approach to excise an osteoblastoma of the L4 vertebral body while preserving intervertebral stability and decreasing morbidity.

SHORT- TO MIDTERM RADIOGRAPHIC AND CLINICAL OUTCOMES OF ANTERIOR OPENING OSTEOTOMY WITH LAMINA SPARING IN POST-TRAUMATIC KYPHOSIS: A CASE SERIES

Purpose: Most spinal osteotomy procedures applied for spinal deformity and concomitant malalignment cases are associated with varied complications. This study evaluates the short- to midterm clinical and radiographic efficacy of the transpedicular anterior opening osteotomy technique. Methods: We retrospectively enrolled six patients who underwent transpedicular anterior opening osteotomy due to symptomatic rigid kyphotic deformity from May 2005 to 2016. During surgery, we created a new fracture line at the collapsed anterior vertebral body through bilateral pedicles, filled spaces with compacted bone grafts while preserving posterior elements, including lamina, and secured structure using posterior instrumentation. The kyphotic Cobb angle, Visual Analog Scale (VAS), and Oswestry Disability Index (ODI) before and after surgery were measured and analyzed. Results: The mean preoperative kyphotic Cobb angle was 31.41 ± 4.77[Formula: see text] while the postoperative value was 15.75 ± 1.66[Formula: see text]. The mean correction angle was 15.55 ± 6.66[Formula: see text]. The mean follow-up duration was 50.17 ± 44.16 months. During the final follow-up, the mean kyphotic angle was not statistically different from the postoperative values. All patients with documented VAS Back and ODI had improved values postoperatively. Conclusions: Transpedicular anterior opening osteotomy with posterior element preservation improves clinical outcomes and is safe and effective in correcting regional, fixed kyphotic deformities.

Tofacitinib Reduces Spinal Inflammation in Vertebral Bodies and Posterolateral Elements in Ankylosing Spondylitis: Results from a Phase 2 Trial.

This post hoc analysis of phase 2 trial data assessed the efficacy of tofacitinib on magnetic resonance imaging (MRI) outcomes with the detailed anatomy-based Canada-Denmark (CANDEN) MRI scoring system and evaluated tofacitinib suppression of spinal inflammation in patients with active ankylosing spondylitis (AS). Patients with active AS (per modified New York criteria) were randomized 1:1:1:1 to receive tofacitinib 2, 5, or 10mg twice daily (BID), or placebo, in a 16-week, phase 2, double-blind clinical trial. Spine MRI assessments were performed at baseline and week 12. For post hoc analysis, MRI images from patients receiving tofacitinib 5 or 10mg BID, or placebo, were re-evaluated by two readers blinded to time point/treatment and assessed by the CANDEN MRI scoring system. Least squares mean changes from baseline to week 12 were reported for CANDEN-specific MRI outcomes, with analysis of covariance used for comparisons of pooled tofacitinib and tofacitinib 5 or 10mg BID versus placebo. p values without multiplicity adjustment were reported. MRI data from 137 patients were analyzed. At week 12, CANDEN spine inflammation score and vertebral body, posterior elements, corner, non-corner, facet joint, and posterolateral inflammation subscores were significantly reduced with pooled tofacitinib versus placebo (p < 0.0001; except non-corner subscore, p < 0.05). Total spine fat score was numerically increased with pooled tofacitinib versus placebo. In patients with AS, tofacitinib treatment was associated with significant reductions in MRI scores of spinal inflammation versus placebo, as assessed by the CANDEN MRI scoring system. Tofacitinib reduced inflammation in posterolateral elements of the spine and facet joints, which has not been described previously. ClinicalTrials.gov registry (NCT01786668).

Minimally invasive LLIF surgery to decrease the occurrence of adjacent-segment disease compared to conventional open TLIF.

Lateral lumbar interbody fusion with percutaneous pedicle screw fixation (Mis-LLIF) can establish indirect decompression by lifting the vertebra with a large intervertebral cage, which causes less damage to the posterior elements. Thus, Mis-LLIF is expected to reduce the incidence of adjacent segment disease (ASD). The aim of the study was to compare the occurrence of ASD between Mis-LLIF and conventional open transforaminal interbody fusion (TLIF). A total of 156 patients (TLIF group = 88, Mis-LLIF group = 68) who underwent single-level lumbar interbody fusion (L2/3, L3/4, or L4/5) at a single institution between 2003 and 2018 with minimum 2-year follow-up were retrospectively reviewed. The incidence of symptomatic ASD requiring reoperation (S-ASD) and radiological adjacent segment degeneration (R-ASD) 2years postoperatively were investigated between 51 paired patients from both groups who were propensity score (PS) matched by demographic and baseline clinical data. The effect of characteristics arising from differences in surgical methods between Mis-LLIF and TLIF, such as the amount of distraction of the index fused level (∆H), on S-ASD and R-ASD was also examined. There were no significant differences in the incidence of S-ASD between the Mis-LLIF and TLIF groups (adjusted OR 1.3; 95% CI 0.41-3.9). There was no significant difference in the incidence of R-ASD between the Mis-LLIF and TLIF groups both at the cranial (adjusted OR 1.0; 95% CI 0.22-4.5) and caudal level (adjusted OR 1.5; 95% CI 0.44-5.3). On the other hand, ∆H was significantly higher in the Mis-LLIF group than in the TLIF group (3.6mm vs. 1.7mm, respectively, P < 0.0001), and was extracted as a significant independent risk factor for S-ASD (adjusted HR 2.7; 95% CI 1.1-6.3) and R-ASD at the cranial side (adjusted HR 6.4; 95% CI 1.7-24) in multivariable analysis with PS adjustment. The incidence of R-ASD or S-ASD was not significantly reduced in the Mis-LLIF group compared to the TLIF group, with greater ∆H potentially being a contributing factor. Using a thin cage in both TLIF and Mis-LLIF may decrease the occurrence of ASD.

Astaxanthin suppresses oxidative stress and calcification in vertebral cartilage endplate via activating Nrf-2/HO-1 signaling pathway.

Cartilage endplate (CEP) degeneration is an important initiating factor leading to intervertebral disc degeneration (IVDD). Astaxanthin (Ast) is a natural lipid-soluble and red-orange carotenoid which possesses various biological activities, including antioxidant, anti-inflammatory, and anti-aging effects in multiple organisms. However, the effects and mechanism of Ast on endplate chondrocytes remain largely unknown. The objective of the current study was to investigate the effects and of Ast on CEP degeneration and its underlying molecular mechanisms. Tert-butyl hydroperoxide (TBHP) was used to mimic the IVDD pathological environment. We investigated the effects of Ast on the Nrf2 signaling pathway and damage-associated events. The IVDD model was constructed by surgical resection of L4 posterior elements to explore the role of Ast in vivo. We found that the activation of the Nrf-2/HO-1 signaling pathway was enhanced by Ast, thus promoted mitophagy process, inhibited oxidative stress and CEP chondrocytes ferroptosis, eventually ameliorated extracellular matrix (ECM) degradation, CEP calcification and endplate chondrocytes apoptosis. Knockdown of Nrf-2 using siRNA inhibited Ast induced mitophagy process and its protective effect. Moreover, Ast inhibited oxidative stimulation-induced NF-κB activity and could ameliorate the inflammation response. The results also were confirmed by experiments in vivo, Ast alleviated IVDD development and CEP calcification. Ast could protect vertebral cartilage endplate against oxidative stress and degeneration via activating Nrf-2/HO-1 pathway. Our results imply that Ast may serve as a potential therapeutic agent for IVDD progression and treatment.

MRI features of spinal chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis in children.

Spinal lesions in pediatric chronic recurrent multifocal osteomyelitis/chronic non-bacterial osteomyelitis (CRMO/CNO) can cause permanent sequelae; thus, early recognition of these is vital for management. To characterize the MR imaging features and patterns of pediatric spinal CRMO/CNO. This cross-section study received IRB approval. The first available MRI with documented spine involvement in children with CRMO/CNO was reviewed by a pediatric radiologist. Descriptive statistics were used to describe the characteristics of vertebral lesions, disc involvement, and soft tissue abnormality. Forty-two patients were included (F:M, 30:12); median age was 10years (range 4-17). At diagnosis, 34/42 (81%) had spine involvement. Kyphosis in 9/42 (21%) and scoliosis in 4/42 (9.5%) patients were present at the time of spinal disease recognition. Vertebral involvement was multifocal in 25/42 (59.5%). Disc involvement was found in 11/42 (26%) patients, commonly in the thoracic spine and often with adjacent vertebrae height loss. Posterior element abnormalities were present in 18/42 patients (43%) and soft tissue involvement in 7/42 (17%). One hundred nineteen vertebrae were affected, commonly the thoracic vertebrae (69/119; 58%). Vertebral body edema was focal in 77/119 (65%) and frequently superior (42/77; 54%). Sclerosis and endplate abnormality were present in 15/119 (13%) and 31/119 (26%) vertebrae, respectively. Height loss was present in 41/119 (34%). Chronic non-bacterial osteomyelitis of spine is usually thoracic. Vertebral body edema is often focal at the superior vertebral body. Kyphosis and scoliosis occur in a quarter and vertebral height loss in a third of children at spinal disease recognition.

P272 ROLE OF 3D TRANSESOPHAGEAL ECHOCARDIOGRAPHY IN DIANOSIS OF DYSFUNCTION OF MECHANICAL PROSTHESES

Abstract Infections with endocardial vegetation or the exuberant growth of neoendothelialization tissue (cloth –tissue overgrowth) in heart valve prostheses lead, among other complications, to the malfunction of the prostheses themselves due to obstruction. Among the diagnostic methods available to us, to achieve the diagnosis of prosthetic dysfunction, in recent years three–dimensional transesophageal echocardiography (3D TTE) has become increasingly imposed. We present two clinical cases of patients admitted to our Cardiology department Case 1: Patient of 62 years old, hospitalized for established congestive heart failure. In 2006 he underwent ascending aorta replacement with Dacron 28 prosthesis and aortic valve replacement with mechanical prosthesis (Sorin 25) for aortic bicuspid and ascending aortic aneurysm. During the last follow–up was observed a slight increase in the value of intraprosthetic gradients, as well as a variability in INR values. Physical examination showed signs of heart failure (NT–ProBNP &amp;gt;1000 pg/ml); normal inflammation indices (PCR &amp;lt;2.9 mg/l); ECG: sinus rhythm at 85 bpm with left ventricular overload; trans–thoracic echocardiography showed severe intraprosthetic aortic gradient (Gmax 132mmHg–Gmed 72mmHg), doubtful for cloth adhered to prosthetic discs; 3D TTE shoved hyperechoreflective image adhered to the posterior mobile element (5x9mm) which was fixed in semi–closure. Subsequently, the patient underwent prosthetic replacement surgery with biological prosthesis. Case 2: Patient of 67 years old, heavy smoker, hypertensive, with aortic mechanical prosthesis, a few weeks before hospitalized for Corynebacterium Jeikeium infection. Hospitalized again for fever with increased inflammation indices (CRP 202mg/l). A first TTE concluded for suspected endocarditis of the prosthesis; this doubt was also dissolved by 3D TTE which showed a soft protruding image of the posterior mobile element, preventing the opening and determining severe stenosis (Gmax 160mmHg–Gmed of 80 mmHg), so this patients was transferred to the cardiac surgery department. Conclusions 3D TTE is a method of rapid and safe execution that can be exploited not only pre– or intraoperatively but also to settle diagnostic suspicions not clarified by traditional 2d methods, even managing to distinguish cloth deposits from vegetation / abscesses.

Primary bone diffuse B cell lymphoma of the thoracic spine: a rare entity

Primary bone lymphoma is a rare entity, accounting for approximately 3-7% of malignant bone tumors, 5% of extra-nodal lymphomas and &amp;lt;1% of all non-Hodgkin lymphomas. Primary spine localized lymphoma is 1.7% of all primary bone lymphomas. A 73 year-old female presented with a two month history of severe backache. T1W and T2W MRI showed a hypointense soft tissue component extending from the left posterior elements to Th7 corpus. The patient underwent Th6-7-8 total laminectomy. Th7-8 extradural mass was totally resected. Excisional biopsy was performed through Th7 left pedicle and vertebroplasty was applied. Significant reduction in pain was seen postoperatively. The patient was diagnosed with diffuse large B cell lymphoma. R-CHOP chemotherapy and local radiotherapy were applied. Any other lesions were not detected after the examinations following 6 months period and it was accepted as primary bone lymphoma.

Stereotactic Body Radiation Therapy for Posterior Element-Only Spinal Metastases: A First Report on Outcomes and Validation of Recommended Clinical Target Volume Delineation Practice

Spine stereotactic body radiotherapy (SBRT) results in improved local control and pain response compared to conventional external beam radiotherapy. Consensus exists stipulating that MRI-based delineation of the clinical target volume (CTV) is critical and based on spine segment sector involvement. The applicability of contouring guidelines to metastases involving the posterior elements alone remains to be validated, and the purpose of this report was to determine the patterns of failure and safety of treating posterior element metastases when the vertebral body (VB) was intentionally excluded from the CTV. A retrospective review of a prospectively maintained database of 605 patients and 1412 spine segments treated with spine SBRT was performed. Only treated segments involving the posterior elements alone were included for the analyses. The primary outcome was local failure, as per SPINO recommendations, and secondary outcomes included patterns of failure, toxicities. 24/605 patients and 31/1412 segments were treated to the posterior elements only. Local failure occurred in 11/31 segments. The cumulative rate of local recurrence was 9.7% at 12 months and 30.8% at 24 months. Amongst local failures, the most common histologies were renal cell carcinoma (36.4%) and non-small cell lung cancer (36.4%) and 73% had baseline paraspinal disease extension. 6/11 (54.5%) failed exclusively within treated CTV sectors and 5/11 (45.5%) with both treated and adjacent untreated sectors. Four of these 5 cases had recurrent disease extending into the VB, but no failure was observed exclusively within the VB. Posterior element alone metastases are rare. Our analyses support SBRT consensus contouring guidelines such that the VB can be excluded from CTV in spinal metastases confined to the posterior elements.

Aneurysmal bone cyst: a review.

Aneurysmal bone cyst (ABC) is a benign locally destructive bone neoplasm composed of multi-loculated blood-filled cystic spaces. The most common sites of involvement are the meta-diaphysis of the long bones and posterior elements of the vertebrae. Secondary, ABC-like changes can complicate a variety of other benign and malignant primary bone neoplasms, including giant cell tumor, fibrous dysplasia, and osteosarcoma. About two-third of primary ABCs have a rearrangement of the USP6 gene, which is not present in the ABC-like changes that occur secondary to other primary bone tumors (i.e., secondary ABC). Primary ABC of bone carries a variable but generally high rate of local recurrence. This paper provides an overview of the pathophysiology, clinical presentation, radiographic and pathologic findings, treatment, and prognosis of ABC.

Differentiating tubercular from pyogenic causes of spine involvement on Magnetic Resonance Imaging.

Based on clinical parameters alone, it is difficult to differentiate between tubercular (TB) and pyogenic spondylodiscitis. Therefore, this study aimed to identify imaging features that can help to differentiate these two entities. This retrospective observational study included microbiologically confirmed cases of TB and pyogenic spondylitis over three years. Magnetic resonance imaging of included cases was reviewed for a predefined set of imaging findings. A multivariable logistic regression analysis was done to compare the radiological features of both groups. A scoring system was created using the features that were significant in univariate and multivariable analysis. Of the 90 included cases, 44 were TB and 46 were pyogenic. Involvement of the thoracic vertebra, paravertebral abscess, epidural abscess, posterior element involvement, loss of height, spine deformity, nerve compression, destruction of the disc and larger abscess size were more common in patients with TB. Involvement of the thoracic spine, posterior element involvement and spine deformity were independent predictors of diagnosing TB spine. At a score of 7 (out of 11) or above, the scoring system had a sensitivity and specificity of 86% and 94%, respectively, in diagnosing the TB spine. In the presence of relevant clinical findings, specific MRI findings can help to differentiate TB from pyogenic spondylitis.

Tumors of the Posterior Elements of the Spine in Children-an Overview.

In this narrative review, we aim to describe the clinical features, diagnosis, and management of common primary osseous tumors affecting the posterior elements of the spine in children. We searched PubMed, Mendeley, and Google Scholar using the terms primary osseous tumors of the spine in children, tumors of the posterior elements of the spine, and names of individual tumors. The clinical features, investigations, and treatment modalities were analyzed, and a narrative review of the topic was prepared. We have included 54 studies published in the last 20years. The majority are isolated reports or case series. Tumors of the posterior elements of the spine are rare. They are common in children and the majority of them are benign. Pain and deformity are common presentations. It is better to perform thorough investigations of children complaining of back pain to rule out primary tumors of the posterior elements of the spine.