Posterior Spinal Elements Research Articles

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.

Spinal Fractures during Touristic Motorboat Sea Cruises: An Underestimated and Avoidable Phenomenon

Each summer, many vacationers enjoy the Mediterranean Sea shores. Among the recreational nautical activities, motorboat cruise is a popular choice that leads to a significant number of thoracolumbar spine fractures at our clinic. This phenomenon seems to be underreported, and its injury mechanism remains unclear. Here, we aim to describe the fracture pattern and propose a possible mechanism of injury. We retrospectively reviewed the clinical, radiological, and contextual parameters of all motorboat-related spinal fracture cases during a 14-year period (2006-2020) in three French neurosurgical level I centers bordering the Mediterranean Sea. Fractures were classified according to the AOSpine thoracolumbar classification system. A total of 79 patients presented 90 fractures altogether. Women presented more commonly than men (61/18). Most of the lesions occurred at the thoracolumbar transition region between T10 and L2 (88.9% of the levels fractured). Compression A type fractures were seen in all cases (100%). Only one case of posterior spinal element injury was observed. The occurrence of neurological deficit was rare (7.6%). The most commonly encountered context was a patient sitting at the boat's bow, without anticipating the trauma, when the ship's bow suddenly elevated while crossing another wave, resulting in a "deck-slap" mechanism hitting and propelling the patient in the air. Thoracolumbar compression fractures are a frequent finding in nautical tourism. Passengers seated at the boat's bow are the typical victims. Some specific biomechanical patterns are involved with the boat's deck suddenly elevating across the waves. More data with biomechanical studies are necessary to understand the phenomenon. Prevention and safety recommendations should be given before motorboat use to fight against these avoidable fractures.

Prophylactic Radiation Therapy vs. Standard-of-Care for Patients with High-Risk, Asymptomatic Bone Metastases: A Multicenter, Randomized Phase II Trial

<h3>Purpose/Objective(s)</h3> External beam radiotherapy (RT) is standard-of-care (SOC) for pain relief of symptomatic bone metastases. We aimed to test whether radiation for asymptomatic bone metastases prevents skeletal-related events (SRE). <h3>Materials/Methods</h3> We conducted a multicenter, randomized phase 2 trial (NCT03523351) of prophylactic RT to high-risk, asymptomatic bone metastases vs SOC. Patients were eligible if they were at least 18 years old with a metastatic solid tumor malignancy and more than 5 metastatic lesions, including at least one asymptomatic high-risk bone lesion, defined as: bulky disease (≥2cm in longest diameter), junctional spine or posterior spinal element disease, disease involving hip or sacroiliac joint, or disease in long bone involving 1/3-2/3 cortical thickness. Patients were stratified by histology and planned SOC (systemic therapy or observation) and randomly assigned in a 1:1 ratio to RT to all enrolled high-risk bone metastases or SOC alone. The primary outcome of SRE (defined as fracture, cord compression, or intervention with surgery or radiation) was analyzed from randomization to death or 12 months. A sample size of 66 was deemed necessary to achieve 80% power to detect a difference of 30% (experimental arm) versus 60% (SOC arm) using a two-sample, one-sided proportion test with alpha<0.05. We used the log-rank test for time-to-event analyses and Wilcoxon rank sum test to compare hospitalizations, brief pain inventory and quality of life (using EQ-5D-5L) between arms. <h3>Results</h3> Between May 8, 2018 and August 9, 2021, 78 patients with 122 bone metastases were enrolled and randomized to prophylactic RT (n=39) or SOC (n=39). The most common primary cancer types were lung (27%), breast (24%), and prostate (22%). Seventy-one patients (91%) were evaluable for the primary endpoint. At one year, SRE occurred in 1 of 62 lesions (1.6%) in the RT arm and 14 of 49 lesions (29%) in the SOC arm (p<0.001). There was a significant difference in time-to-SRE by type of high-risk feature (p=0.016), with most events occurring in junctional spine and bulky disease. There were significantly fewer patients hospitalized for SRE in the RT arm compared to the SOC arm (4 vs 0, p=0.045). At a median follow-up of 2.4 years, overall survival was significantly longer in the RT arm (HR 0.50, 95% CI 0.28, 0.91; p=0.02). Median OS among 11 patients with an SRE was 1.1 years compared to 1.5 years among 67 patients without an SRE. Pain was reduced at 3 months in the RT arm (p<0.05) compared to the SOC arm. EQ-5D-5L was similar between the groups at all time points. <h3>Conclusion</h3> Radiation delivered prophylactically to asymptomatic, high-risk bone metastases reduced skeletal-related events, meeting the primary endpoint of the study. Importantly, we observed an improvement in overall survival, with potential mechanisms of palliation or debulking warranting further investigation in a phase 3 trial.

An Externally Validated RPA-Based Pre-Treatment Decision-Making Tool Identifying Ideal Candidates for Spine SBRT

<h3>Purpose/Objective(s)</h3> We sought to develop and validate a novel decision-making tool predictive of overall survival (OS) for patients receiving stereotactic body radiation therapy (SBRT) for spinal metastases. <h3>Materials/Methods</h3> Treatments were performed at two institutions and most commonly involved one or three fractions of spine SBRT. Recursive partitioning analysis (RPA) was conducted using decision-tree analysis. Potential correlations between variables were assessed with a correlation heatmap. OS was analyzed using the Kaplan-Meier method. Exclusion criteria included: treatments with proton therapy, benign primary histologies, missing variables of interest, and patients with the first course of spine SBRT outside of the participating institutions. <h3>Results</h3> The initial dataset consisted of 424 patients with 522 treated lesions. Of these, 361 patients were used for the RPA and initial model development because not all components of the SINS score were available for 63 patients. After consideration of 9 candidate variables, the final model consisted of the following variables and corresponding scores: SINS ≥ 6 (1); time from primary diagnosis < 21 months (1); ECOG performance status = 1 and ECOG > 1 (1 and 2, respectively); and > 1 organ systems involved (1). Each variable was an independent predictor of OS (p<0.001), and each 1-point increase in score was associated with a hazard ratio of 2.01 (95% confidence interval (CI): 1.79-2.25, p<0.0001) (Table). The concordance value was 0.75 (95% CI: 0.71-0.78). The scores were then discretized into 3 groups: favorable (score: 0-1), intermediate (score: 2), and poor (score: 3-5) survival, with 2-year OS of 84% (95% CI: 79-90%), 46% (95% CI: 36-59%), and 21% (95% CI: 14-32%), respectively (p<0.0001 for each). In the external validation set (182 patients), the score was predictive of OS (p<0.0001). The favorable, intermediate, and poor survival groups each demonstrated statistical significance (p<0.002), with 2-year OS of 77%, 50%, and 36%. Increasing SINS score was predictive of decreased OS as a continuous variable, with a hazard ratio of 1.17 (95% CI: 1.12-1.23, p<0.0001). Of the 6 components of the SINS score, 4 demonstrated associations with OS: pain, type of bone lesion, vertebral body collapse, and posterior spinal element involvement. <h3>Conclusion</h3> We propose this novel score as a decision-making tool to help optimize patient selection for spine SBRT. The SINS score may be an independent predictor of OS.

POS1005 ACTIVE INFLAMMATORY LESIONS OF THE SPINE IN SACROILIAC JOINTS MRI (SIJs-MRI): AN OVERLOOKED FINDING BY RADIOLOGISTS.

BackgroundEstablishing a diagnosis for axial spondylarthritis (axSpA) is based on the combined presence of several clinical and laboratory features in association with imaging: the presence of active inflammatory lesions (bone marrow edema, BME) in sacroiliac joints (SIJs), also associated with structural lesions, is the main element in favor of a diagnosis of axSpA and SIJ MRI is currently the main recommended technique for detecting inflammation, enabling early diagnosis in patients with normal radiographic findings. MRI of the spine is generally not recommended for axSpA diagnosis, since spine involvement is considered less sensitive and specific. Several studies explored the incremental value of spine MRI for diagnosing patients with axSpA, especially when the findings of SI are equivocal, and “predicting” clinical disease activity.ObjectivesTo evaluate the effectiveness of the MRI study dedicated to SIJs to identify the inflammatory involvement of the lumbar spine in patients with active sacroiliitis and clinical diagnosis of axSpA.MethodsMRI of 96 patients (26 M, 70 F, mean age 48 years) with SIJs-MRI positive for inflammatory involvement according to ASAS criteria, were evaluated retrospectively. The presence of signs of inflammation of posterior spinal elements and vertebral bodies included in the field of vision (FOV) was therefore researchedResultsOf 96 patients with active sacroiliitis, 88 had concomitant inflammatory lesions of the lumbar spine. Facet capsulitis (87.6 %) and posterior enthesitis (42.2 %) were the most common lesions and these lesions frequently coexisted (39.3%). Twelve patients with facet capsulitis presented also facet arthritis. Only 20 out of 96 patients (22%) had vertebral bodies inflammatory lesions: 15 corner inflammatory lesions and 5 aseptical spondylodiscitis.ConclusionOn the basis of current working consensus MRI examination of the spine is not recommended for axSpA diagnosis, because it is considered less sensitive and specific. However the high prevalence (91.7%) of spinal inflammatory changes in patients with active sacroiliitis suggests that these features can be used as an additional element in favor of diagnosis, especially in doubtful cases. This evaluation takes little reporting time, without any increase in MRI execution time.

Posterior Lumbar Interbody Fusion with Preservation of Posterior Structures for Management of Lumbar Spondylolisthesis

Introduction: Successful posterior lumbar interbody fusion requires excessive removal of posterior spinal elements and distraction of neural structures. It also requires a large amount of bone graft. The authors have developed this technique to assess results of treatment of degenerative spondylolisthesis by posterior lumbar interbody fusion with preservation of posterior spinal elements and also to examine the safety and efficacy of the recapping T-saw laminoplasty technique for the management of degenerative lumbar spondylolisthesis using posterior lumbar interbody fusion by interbody cages with preservation of posterior elements.&#x0D; Methodology: Twenty-five patients with degenerative spondylolisthesis underwent recapping T-saw laminoplasty in the lumbar spine for posterior lumbar interbody fusion with interbody cage. The T-saw was used for the division of the posterior elements. After discectomy and insertion of cages, the excised lamina was replaced exactly in situ to their original anatomic position. Patients were followed neurologically and radiologically.&#x0D; Result: Only one lamina was excised and replaced again. Primary bone healing was obtained in all patients by four to six months post surgery. No complications such as postoperative spinal canal stenosis, facet arthrosis, or kyphosis were observed.&#x0D; Conclusion: This technique of posterior lumbar interbody fusion through recapping laminoplasty provide wide space for easier insertion of cages and allow anatomic reconstruction of the vertebral arch preserving its important mechanical roles.

MRI-based early diagnosis: a diabetic Charcot spine case report

BackgroundSpinal neuroarthropathy (SNA), also known as Charcot spine, is an uncommon aggressive arthropathy, secondary to loss of proprioceptive and nociceptive feedback from the spine. A diagnosis of SNA is frequently delayed due to the scarcity of symptoms in its early stages, leading to significant neurological deterioration. Therefore, prompt suspicion of the disease is critical to providing better outcomes. This case assembles two rare characteristics of SNA: diabetic aetiology and a precocious time of diagnosis, and aims to highlight the magnetic resonance imaging (MRI) findings that allowed for the diagnosis.Case presentationA 44-year-old woman, with long-term type 1 diabetes, presented with a two-month history of progressive lumbar pain, difficulty in maintaining an upright position, and discrete trunk forward-leaning. Diabetes-related vasculopathy and nephropathy were already known, and laboratory test results did not show any new abnormalities. A lumbar MRI revealed extensive signal intensity changes of the L2 and L3 vertebral bodies associated with marginal areas of enhancement and the involvement of regions adjacent to interapophyseal articulations and spinous processes from L2–L3 to L5–S1, in association with degenerative changes of the thoracolumbar spine. These findings were identified by the radiologist as suggestive of SNA. To rule out neoplastic and infectious disease, a bone biopsy at the L2–L3 level was executed. The pathology report revealed intervertebral disc material and fragments of fibrous tissue, with a complete absence of inflammatory cells. It was decided to perform a six-month MRI follow-up, which showed stability of the findings, confirming the hypothesis of Charcot spine. The patient was under clinical and radiological follow-up and did not require surgical fixation at the moment of diagnosis. After 2.5 years from the initial diagnosis, a new MRI revealed progression of the lesions with oedema and enlarged paravertebral soft tissues; these findings are compatible with the patient’s latest complaints of lumbar pain recurrence.ConclusionTo the best of our knowledge, this is the first case report of an MRI-based early diagnosis of diabetic SNA, a rare disease with nonspecific symptoms in its initial stages and a wide spectrum of differential diagnoses. The MRI findings, distinctly the involvement of both anterior and posterior spinal elements, were the key to allowing for the proper diagnosis. A precocious diagnosis, although challenging, is fundamental to providing early intervention and to preventing further neurological impairment.

Microwave Ablation as a Minimally Invasive Surgical Option for the Posterior Spinal Elements Osteoid Osteoma: A Case Report

We report a 24-year-old male who was presented with constant intensive low back pain on the right side for 3 years. Large doses of NSAIDs were ineffective and resulted in gastric ulcer. Magnetic resonance tomography and computed tomography imaging revealed osteoid osteoma of L3 pars interarticularis and a needle biopsy confirmed it. An innovative approach for spinal osteoid osteoma was chosen after many considerations. The patient underwent microwave ablation of the lesion in the spine.

Intraoperative image guidance for lateral position surgery.

Recent advances in minimally invasive spine surgery techniques have precipitated the popularity of lateral position spine surgery, such as lateral lumbar interbody fusion (LLIF) and oblique lumbar interbody fusion (OLIF). Lateral position surgery offers a unique, minimally invasive approach to the lumbar spine that allows for preservation of anterior and posterior spinal elements. Traditionally, surgeons have relied upon fluoroscopy for triangulation and implant placement. Over the last decade, intraoperative 3-dimensional navigation (ION) has risen to the forefront of innovation in LLIF and OLIF. This technology utilizes intra-operative advanced imaging, such as comminuted tomography (CT), to map the patient’s 3D anatomy and allows the surgeon to accurately visualize instruments and implants in spatial relationship to the patient’s anatomy in real time. ION has the potential to improve accuracy during instrumentation, decrease operating room times, lower radiation exposure to the surgeon and staff, and increase feasibility of single-position surgery during which the spine is instrumented both laterally and posteriorly while the patient remains in the lateral decubitus position. Despite the advantages of ION, the intra-operative radiation exposure risk to patients is controversial. Future directions include continued innovation in ultra low radiation imaging (ULRI) techniques and image enhancement technology and in uses of robot-assisted navigation in single-position spine surgery.

Magnetic resonance imaging evaluation of posterior spinal tuberculosis: a cross-sectional study.

Isolated posterior spinal (element) tuberculosis (TB) is uncommon compared to classical anterior spinal or para-discal TB. Here, we report magnetic resonance imaging (MRI) findings of posterior spinal TB in 19 patients without involvement of the vertebral body and intervertebral disc. To evaluate the MRI findings in isolated posterior spinal (element) TB. Clinical and MRI data of 19 patients of isolated posterior spinal TB were retrospectively evaluated. Of the 19 patients, group A comprised 4 (21%) patients with rapid onset lower limb weakness and pyramidal signs while group B comprised 15 (79%) patients without any neurological deficit. Lumbar vertebrae commonly affected 9 (47.4%) patients followed by dorsal vertebrae in 8 (42.1%) patients and cervical vertebrae in 2 (10.5%) patients. The pedicle was most commonly involved in 12 (63.2%) patients followed by the lamina in 11 (58%) patients, and spinous process and facet joint in 6 (31.6%) patients each. Extra-spinal inflammation/pyomyositis/paraspinal abscess was found in 13 (68.4%) patients followed by epidural abscess 3 (15.8%) patients and both extra spinal inflammation and epidural abscess in 3 (15.8%) patients (15.8%). Compressive cord myelopathy was observed in 4 (21%) patients, where three patients underwent emergency decompression laminectomy and the remaining 16 patients were treated conservatively with anti-tubercular therapy. Initial diagnosis of isolated posterior element TB is challenging and requires a high index of suspicion. Early diagnosis of isolated posterior spinal TB is important as early treatment may be beneficial and decreases patient morbidity.

One-stage posterior surgery with intraoperative ultrasound assistance for thoracic myelopathy with simultaneous ossification of the posterior longitudinal ligament and ligamentum flavum at the same segment: a minimum 5-year follow-up study

BACKGROUND CONTEXTOssification of the posterior longitudinal ligament (OPLL) and ligamentum flavum (OLF) are not uncommon independent causes of thoracic myelopathy (TM); however, concomitant OPLL and OLF at the same segment is rare. The ideal surgical strategy remains controversial, and it is difficult for surgeons to balance sufficient neural decompression while simultaneously reducing the occurrence of postoperative neurological defect after circumferential decompression (CD). Aiming to solve this dilemma, we investigated a CD-based surgery using intraoperative ultrasound (IOU) assistance to evaluate spinal decompression sufficiency. PURPOSEThe aims of this study are to evaluate the surgical outcomes and identify prognostic factors of one-stage posterior surgery with IOU assistance in patients with concomitant OPLL and OLF. STUDY DESIGN/SETTINGRetrospective study of a single-center TM database with long-term follow-up. PATIENT SAMPLETwenty-four patients with TM and concomitant OPLL and OLF. OUTCOME MEASURESJapanese Orthopaedic Association (JOA) score system for TM, recovery rate (RR), complication rate. METHODSTwenty-four patients’ data were retrospectively reviewed. All patients initially underwent en bloc excisions of posterior spinal canal elements, and IOU was then used to evaluate spinal decompression sufficiency. If any compression of OPLL was confirmed in IOU, further CD procedure was performed. The JOA score was used to evaluate health-related quality of life. RR was calculated using the Hirabayashi formula. A RR ≥50% was considered favorable, and a RR <50% was considered unfavorable. The paired t test was performed to statistically compare the preoperative and postoperative JOA scores. The chi-squared test, rank sum test, and logistic regression analyses were performed to find variants associated with unfavorable surgical outcomes The prognostic factors were analyzed by Spearman correlation and Pearson correlation analyses. RESULTSThe invasive CD procedure were avoided in 9 of 28 segments were avoided, with a mean blood loss of 1,458 mL. Seventeen patients experienced cerebrospinal fluid leakage, and 5 experienced immediate postoperative paralysis. The mean JOA score improved from 4.25±2.2 (preoperative) to 8.16±1.9 (final follow-up). The mean RR was 57.7%±29.4%. There was a significant difference (p<.01) between the preoperative and final follow-up JOA score. A comparison between the favorable and the unfavorable groups showed no significant differences in the evaluated factors, but the considerable blood loss was a significant risk factor for poor RR (p=.036, b=−0.43). CONCLUSIONSOne-stage CD-based surgery via a posterior approach with IOU assistance for the treatment of concomitant OPLL and OLF led to significant functional improvement in the majority of patients. Under the premise of sufficient decompression, the postoperative paralysis rate reduced compared to that in previous studies. However, there were still high cerebral spinal fluid leakage rates. Considerable blood loss is a risk factor for poor RR.

Stereotactic Body Radiotherapy for Spinal Metastases at the Extreme Ends of the Spine: Imaging-Based Outcomes for Cervical and Sacral Metastases.

The unique anatomy and biomechanical features of the cervical spine and sacrum may impact treatment outcomes following spine stereotactic body radiotherapy (SBRT). Current data for spine metastases are not specific for these locations. To report imaging-based SBRT outcomes to cervical and sacral metastases. We retrospectively reviewed our prospective spine SBRT database for cervical and sacral metastases. Patients were followed at 2- to 3-mo intervals with a clinical visit and full spine magnetic resonance imaging (MRI) and we report overall survival (OS), vertebral compression fracture (VCF), and MR imaging-based local control (LC) rates. Fifty-two patients and 93 treated spinal segments were identified. Fifty-six segments were within the cervical spine and 37 within the sacrum, the median follow-up was 14.4 and 19.5 mo, and the median total dose/number of fractions was 24 Gy/2, respectively. Cumulative LC at 1 and 2 yr were 94.5% and 92.7% for the cervical cohort, and 86.5% and 78.7% in the sacral cohort, respectively. Lack of posterior spinal element involvement in the cervical spine (P<.0001) and absence of epidural disease (hazard ratio 0.275, 95% confidence interval 0.076-0.989, P=.048) in the sacral cohort predicted LC. Median OS was 16.3 and 28.5 mo in the cervical spine and sacrum cohorts, respectively. Two cases of sacral VCF, 1 brachial plexopathy, and 1 lumbar-sacral plexopathy were observed. Although high rates of LC were observed, strategies specific to the sacrum may require further optimization.

Kyphectomy in Myelomeningocele for Severe Early-Onset Kyphosis Using Distal Intravertebral Fixation and Thoracic Growing Rods

Background:Most kyphectomy techniques require distal dissection of the bifid posterior spinal elements for implants placement in the thoracolumbar/pelvic regions, traversing the scarred tissue associated with previous MMC closure, thereby theoretically increasing the risk of wound complications. The Halifax kyphectomy technique avoids the MMC scar but does not reliably facilitate thoracic growth for early-onset kyphosis. This study aims to report the technique and outcomes of a combined Halifax kyphectomy (resection of the apical vertebrae with distal anterior multilevel vertebral body fixation) and thoracic growing rod construct used to treat early-onset symptomatic gibbus in a patient with myelomeningocele (MMC).Methods:A 3-year-old girl with a thoracic MMC presented with symptomatic gibbus requiring surgical intervention. Correction by the Halifax kyphectomy technique combined with spine-based growing rods was performed.Results:After the correction, the skin was closed primarily without the need for any flap for coverage. No wound complications or infection occurred post-operatively. The intraoperative blood loss was 200 mL, and the surgical time was 419 minutes. No pulmonary complications occurred postoperatively. At the final follow-up at 3 years 11 months postoperatively, the child had no recurrence of the deformity.Conclusions:The combination of distal anterior multilevel vertebral body fixation with spine-based thoracic growing rods can successfully achieve kyphosis correction in MMC, with the potential to reduce complication rates and facilitate thoracic growth. Further investigation is necessary to prove whether the outcomes and the complication rates are superior to other established techniques.

Indication for anterior spinal cord decompression via a posterolateral approach for the treatment of ossification of the posterior longitudinal ligament in the thoracic spine: a prospective cohort study.

For ossification of the posterior longitudinal ligament (OPLL) in the thoracic spine, anterior decompression is the most effective method for relieving spinal cord compression. The purpose of this study was to prospectively analyze the surgical outcomes based on our strategy in the treatment of thoracic OPLL. This study included 23 patients who underwent surgery for thoracic OPLL based on the following strategy between 2011 and 2017. For patients with a beak-type OPLL in the kyphotic curve with a ≥ 50% canal occupying ratio, circumferential decompression via a posterolateral approach and fusion (CDF) was indicated. For other types of OPLL, posterior decompression and fusion (PDF) was commonly indicated. Posterior fusion without decompression (PF) was applied when the spinal cord was separated from the posterior spinal elements. Clinical and radiological outcomes were compared among the CDF, PDF, and PF groups with a minimum of 20-month follow-up. Ten, eleven, and two patients underwent CDF, PDF, and PF, respectively. The preoperative Japanese Orthopedic Association (JOA) score in the CDF group was significantly lower than that in the PDF group. The average recovery rate, according to JOA score, was 63%, 56%, and 25% in the CDF, PDF, and PF groups, respectively. The result in the CDF group was better than that in the PF group. Anterior decompression was appropriate for patients with localized spinal cord compression by a large OPLL in the kyphotic curve, and CDF via a posterolateral approach appears to be safe and effective. These slides can be retrieved under Electronic Supplementary Material.

Aneurysmal bone cyst of the pelvis and extremities: Contemporary management

Aneurysmal bone cysts are tumors of bone occurring predominantly in the metaphyses of long bones and posterior elements of spine in adolescents and young adults. Radiographically, on x-rays they appear as eccentric metaphyseal expansile lytic lesions containing “fluid-fluid” levels. Computed tomographic scan and magnetic resonance imaging clearly define the cysts and fluid-fluid levels; the former delineates cortical expansion and the latter the fibrovascular component clearly. Magnetic resonance imaging is particularly useful in differentiating aneurysmal bone cysts from malignant lesions. Histologically, these cysts are characterized by fibrovascular tissue, multinucleated giant cells, inflammatory cells, fiber-osteoid, “blue bone,” and blood filled lacunae. Chromosomal translocation has been found, implying a neoplastic basis for the development of aneurysmal bone cysts. Malignant transformation has been reported where radiation therapy was used, and in cysts associated with sarcomas. A high ratio of cellular component as compared with osteoid, and a high mitotic index have been reported to be associated with higher recurrence after treatment. Management is aimed at addressing patients’ symptoms and preventing/treating fracture, and can broadly be divided into nonoperative management (drug and radiation therapy), minimally invasive strategies (angiographic embolization, percutaneous injections), and operative management (curettage and bone grafting, en bloc excision). To reduce chances of recurrence, adjuvants such as electrocautery, high speed burr, phenol, cryotherapy, and argon beam laser have been used with variable degrees of success. With contemporary management, a cure rate of 70%–90% is expected.

Microneurosurgical Removal of a Cervical Intramedullary Tumor Via Hemilaminoplasty: 3-Dimensional Operative Video.

Intramedullary tumors of the spinal cord are rare and account for 2% to 8.5% of all central nervous system tumors. In adults, ependymomas are the most common intramedullary tumors. The primary choice of treatment should be radical surgical removal, as this is curative for most tumors. Adequate tumor exposure is crucial and mostly achieved through standard laminectomy followed by midline myelotomy. However, extensive removal of posterior spinal elements may lead to worsening kyphotic deformities. After obtaining patient consent, this 3-dimensional video publication was prepared to present microneurosurgical removal of a C3-C6 cervical intramedullary tumor using right-sided hemilaminoplasty. C3-C6 hemilaminae were lifted en bloc. After dural and arachnoid incision, midline myelotomy was performed. Using microneurosurgical technique, the tumor was removed totally. After the dural closure, C3-C6 hemilaminae were placed into the previous position and reconstructed with mini-plates and screws. Preserving contralateral paraspinal muscles, spinous processes, midline spinal ligaments and bilateral facet joints helped maintaining the alignment of the spinal column. Comparing to laminectomy, hemilaminoplasty, decreases the postoperative pain and the total blood loss as only one side muscle dissection is enough. In the presented case, postoperative MRI showed total removal of the tumor. The final histopathology report indicated an ependymoma (WHO-Grade 2). Successful bone healing was demonstrated by postoperative cervical radiographs and CT scans. The patient has no postoperative neurological deficit. In conclusion, hemilaminoplasty is an effective and a less-invasive method in removal of intradural-intramedullary tumors with its advantages such as preventing the instability and reduction of blood loss and postoperative pain.

Role of Magnetic Resonance Image in Children with Lumbosacral and Perineal Hemangiomas: Case Reports and Review of the Literature

Cutaneous hemangiomas are the most frequent benign tumors in children. When they affect the lumbar and perineal area some cases can be associated with an occult spinal dysraphism. The management of these hemangiomas lack consensus. We report 3 cases of children with lumbosacral and perineal hemangiomas with magnetic resonance image abnormalities and we review the literature to find out the type and timing of tests that should be performed to complete the study in these patients. Ultrasound is typically requested as young as possible, as this imaging technique is not possible 11the posterior spinal elements have ossified. MRI is the gold standard for diagnosing occult spinal dysraphism. According to the literature, the mean age for MRI screening should be around 6 months, when the fat formation in the filum terminale is expanded. In our opinion, an MRI scan should be performed at 6 months of age in every children with lumbar or perineal hemangioma regardless the lesion size, neurological symptoms or the ultrasound results.

Impaired Annulus Fibrosus Development and Vertebral Fusion Cause Severe Scoliosis in Mice with Deficiency of c-Jun NH2-Terminal Kinases 1 and 2

Mitogen-activated protein kinases, including c-Jun NH2-terminal kinase (JNK), play an important role in the development and function of a large variety of tissues. The skeletal phenotype of JNK1 and JNK2 double-knockout (dKO) mice (JNK1fl/flCol2-Cre/JNK2-/-) and control genotypes were analyzed at different embryonic and postnatal stages. JNK1/2 dKO mice displayed a severe scoliotic phenotype beginning during development that was grossly apparent around weaning age. Alcian blue staining at embryonic day 17.5 showed abnormal fusion of the posterior spinal elements. In adult mice, fusion of vertebral bodies and of spinous and transverse processes was noted by micro-computed tomography, Alcian blue/Alizarin red staining, and histology. The long bones developed normally, and histologic sections of growth plate and articular cartilage revealed no significant abnormalities. Histologic sections of the vertebral column at embryonic days 15.5 and 17.5 revealed an abnormal organization of the annulus fibrosus in the dKOs, with chondrocyte-like cells and fusion of dorsal processes. Spinal sections in 10-week-old dKO mice showed replacement of intervertebral disk structures (annulus fibrosus and nucleus pulposus) by cartilage and bone tissues, with cells staining for markers of hypertrophic chondrocytes, including collagen X and runt-related transcription factor 2. These findings demonstrate a requirement for both JNK1 and JNK2 in the normal development of the axial skeleton. Loss of JNK signaling results in abnormal endochondral bone formation and subsequent severe scoliosis.

Papel de la resonancia magnética en niños con hemangiomas lumbosacros y perineales: informe de 3 casos clínicos y revisión de la literatura

Cutaneous hemangiomas are the most frequent benign tumors in children. When they affect the lumbar and perineal area some cases can be associated with an occult spinal dysraphism. The management of these hemangiomas lack consensus. We report 3 cases of children with lumbosacral and perineal hemangiomas with magnetic resonance image abnormalities and we review the literature to find out the type and timing of tests that should be performed to complete the study in these patients. Ultrasound is typically requested as young as possible, as this imaging technique is not possible 11the posterior spinal elements have ossified. MRI is the gold standard for diagnosing occult spinal dysraphism. According to the literature, the mean age for MRI screening should be around 6 months, when the fat formation in the filum terminale is expanded. In our opinion, an MRI scan should be performed at 6 months of age in every children with lumbar or perineal hemangioma regardless the lesion size, neurological symptoms or the ultrasound results.

The Four Fixation Points of the Axis: Technique and Case Report.

Instrumentation of the axis can be accomplished through a variety of techniques including transarticular screw fixation, pars and pedicle screw fixation, translaminar screw fixation, and posterior wiring. We report on the evolution of the axial 4-screw technique. Retrospective case review. After exposure of posterior spinal elements, the medial and superior walls of the C2 pedicle were identified from within the spinal canal. A high-speed drill was then advanced under lateral fluoroscopy, which guided craniocaudal angulation. Medial angulation was based on anatomic landmarks and preoperative imaging. This was followed by placement of translaminar screws according to the technique described by Wright. When extending the construct into the subaxial spine or the occiput, lateral connectors are placed in translaminar screws, which are usually more offset. The rod is directly connected to the pedicle screws, which are usually more in alignment with the subaxial/occipital instrumentation. Two male patients ages 56 and 58 underwent posterior instrumentation of the axis employing a combination of pedicle and laminar polyaxial screws. Indications included multilevel spinal cord compression and deformity in a patient with Down syndrome and cervical meningioma, respectively. Follow-up was 1 year and 5 years, respectively. Medical complications (N = 2) occurred in the patient with Down syndrome resulting in prolonged intubation with tracheostomy placement. Reduction was maintained in both patients at last follow-up. There were no neurologic, vascular, or instrumentation related complications. The axis serves as a versatile anchor point and offers 4 potential points of fixation. Lateral connectors play a crucial role and allow for incorporation of the C2 screws with the rest of the construct. Local anatomy will dictate the necessity and ability to place instrumentation and detailed preoperative planning is of paramount importance.