Controlled release of biological factors for endogenous progenitor cell migration and intervertebral disc extracellular matrix remodelling

The recent description of resident stem/progenitor cells in degenerated intervertebral discs (IVDs) supports the notion that their regenerative capacities could be harnessed to stimulate endogenous repair of the nucleus pulposus (NP). In this study, we developed a delivery system based on pullulan microbeads (PMBs) for sequential release of the chemokine CCL-5 to recruit these disc stem/progenitor cells to the NP tissue, followed by the release of the growth factors TGF-β1 and GDF-5 to induce the synthesis of a collagen type II- and aggrecan-rich extracellular matrix (ECM). Bioactivity of released CCL5 on human adipose-derived stem cells (hASCs), selected to mimic disc stem/progenitors, was demonstrated using a Transwell® chemotaxis assay. The regenerative effects of loaded PMBs were investigated in ex vivo spontaneously degenerated ovine IVDs. Fluorescent hASCs were seeded on the top cartilaginous endplates (CEPs); the degenerated NPs were injected with PMBs loaded with CCL5, TGF-β1, and GDF-5; and the IVDs were then cultured for 3, 7, and 28 days to allow for cell migration and disc regeneration. The PMBs exhibited sustained release of biological factors for 21 days. Ex vivo migration of seeded hASCs from the CEP toward the NP was demonstrated, with the cells migrating a significantly greater distance when loaded PMBs were injected (5.8 ± 1.3 mm vs. 3.5 ± 1.8 mm with no injection of PMBs). In ovine IVDs, the overall NP cellularity, the collagen type II and the aggrecan staining intensities, and the Tie2+ progenitor cell density in the NP were increased at day 28 compared to the control groups. Considered together, PMBs loaded with CCL5/TGF-β1/GDF-5 constitute an innovative and promising strategy for controlled release of growth factors to promote cell recruitment and extracellular matrix remodelling.

In vitro and in vivo evaluation of an electrospun-aligned microfibrous implant for Annulus fibrosus repair

Annulus fibrosus (AF) impairment is associated with reherniation, discogenic pain, and disc degeneration after surgical partial discectomy. Due to a limited intrinsic healing capacity, defects in the AF persist over time and it is hence necessary to adopt an appropriate strategy to close and repair the damaged AF. In this study, a cell-free biodegradable scaffold made of polycaprolactone (PCL), electrospun, aligned microfibers exhibited high levels of cell colonization, alignment, and AF-like extracellular matrix deposition when evaluated in an explant culture model. The biomimetic multilayer fibrous scaffold was then assessed in an ovine model of AF impairment. After 4 weeks, no dislocation of the implants was detected, and only one sample out of six showed a partial delamination. Histological and immunohistochemical analyses revealed integration of the implant with the surrounding tissue as well as homogeneously aligned collagen fiber organization within each lamella compared to the disorganized and scarcer fibrous tissue in a randomly organized control fibrous scaffold. In conclusion, this biomimetic electrospun implant exhibited promising properties in terms of AF defect closure, with AF-like neotissue formation that fully integrated with the surrounding ovine tissue.

Natural course and prognosis of anaplastic gangliogliomas: a multicenter retrospective study of 43 cases from the French Brain Tumor Database

Background

Anaplastic gangliogliomas (GGGs) are rare tumors whose natural history is poorly documented. We aimed to define their clinical and imaging features and to identify prognostic factors.

Methods

Consecutive cases of anaplastic GGGs in adults prospectively entered into the French Brain Tumor Database between March 2004 and April 2014 were screened. After diagnosis was confirmed by pathological review, clinical, imaging, therapeutic, and outcome data were collected retrospectively.

Results

Forty-three patients with anaplastic GGG (median age, 49.4 y) from 18 centers were included. Presenting symptoms were neurological deficit (37.2%), epileptic seizure (37.2%), or increased intracranial pressure (25.6%). Typical imaging findings were unifocal location (94.7%), contrast enhancement (88.1%), central necrosis (43.2%), and mass effect (47.6%). Therapeutic strategy included surgical resection (95.3%), adjuvant radiochemotherapy (48.8%), or radiotherapy alone (27.9%). Median progression-free survival (PFS) and overall survival (OS) were 8.0 and 24.7 months, respectively. Three- and 5-year tumor recurrence rates were 69% and 100%, respectively. The 5-year survival rate was 24.9%. Considering unadjusted significant prognostic factors, tumor midline crossing and frontal location were associated with shorter OS. Temporal and parietal locations were associated with longer and shorter PFS, respectively. None of these factors remained statistically significant in multivariate analysis.

Conclusions

We report a large series providing clinical, imaging, therapeutic, and prognostic features of adult patients treated for an intracerebral anaplastic GGG. Our results show that pathological diagnosis is difficult, that survivals are only slightly better than for glioblastomas, and that complete surgical resection followed with adjuvant chemoradiotherapy offers longer survival.

Non neurologic burst thoracolumbar fractures fixation: Case-control study

STUDY DESIGN

Burst fractures not associated with any neurological deficits are frequent but not therapeutic agreement on their management is available to date. This case-control study was conducted to try to help guide therapeutic decision in the treatment of such fractures.

MATERIALS AND METHODS

This case-control study includes consecutive retrospective evaluation of 25 case-patients treated by posterior short-segment fixation associated with kyphoplasty (SFK) in the treatment of A3 thoracolumbar unstable fractures, as compared to a control-group composed of 82 patients treated by long-segment (LF) pedicle screws.

RESULTS

SFK patients bled significantly less than the LF patients (p=0.04). Assessment of deformation progression, vertebral height restoration and reduction of the regional kyphotic angle in the SFK and LF groups revealed no statistically significant superiority of one approach on another. In contrast, the height of endplates was significantly increased in the SFK group (p=0.006). The patients' pain levels were significantly improved in the SFK group (p=0.002). However, patients from the SFK group stood earlier postoperatively (1.7 vs 3.7days, p=0.001).

CONCLUSION

We believe that SFK in vertebral fractures is as efficient as LF for bone consolidation and spine stabilization. In addition, SFK patients may use fewer analgesics.

Odontoid balloon kyphoplasty associated with screw fixation for Type II fracture in 2 elderly patients

Anterior screw fixation is a well-recognized technique that is used to stabilize Type IIB fractures of the odontoid process in the elderly. However, advanced age and osteoporosis are 2 risk factors for pseudarthrosis. Kyphoplasty has been described in the treatment of lytic lesions in C-2. The authors decided to combine these 2 techniques in the treatment of unstable fractures of the odontoid. Two approximately 90-year-old patients were treated for this type of fracture. Instability was demonstrated on dynamic radiography in one patient, and the fracture was seen on static radiography in the other. Clinical parameters, pain, range of motion, 36-Item Short Form Health Survey (SF-36) score (for the first patient), and radiological examinations (CT scans and dynamic radiographs) were studied both before and after surgery. After inflating the balloon both above and below the fracture line, the authors applied a high-viscosity polymethylmethacrylate cement. Some minor leakage of cement was noted in both cases but proved to be harmless. The screws were correctly positioned. The clinical result was excellent, both in terms of pain relief and in the fact that there was no reduction in the SF-36 score. The range of motion remained the same. A follow-up CT scan obtained 1 year later in one of the patients showed no evidence of change in the materials used, and the dynamic radiographs showed no instability. This combination of kyphoplasty and anterior screw fixation of the odontoid seems to be an interesting technique in osteoporotic Type IIB fractures of the odontoid process in the elderly, with good results both clinically and radiologically.

Symptomatic vertebral hemangiomas during pregnancy

Symptomatic vertebral hemangiomas during pregnancy are rare, as only 27 cases have been reported in the literature since 1948. However, symptomatic vertebral hemangiomas can be responsible for spinal cord compression, in which case they constitute a medical emergency, which raises management difficulties in the context of pregnancy. Pregnancy is a known factor responsible for deterioration of these vascular tumors. In this paper, the authors report 2 clinical cases of symptomatic vertebral hemangiomas during pregnancy, including 1 case of spontaneous fracture that has never been previously reported in the literature. The authors then present a brief review of the literature to discuss emergency management of this condition. The first case was a 28-year-old woman at 35 weeks of gestation, who presented with paraparesis. Spinal cord MRI demonstrated a vertebral hemangioma invading the body and posterior arch of T-3 with posterior epidural extension. Laminectomy and vertebroplasty were performed after cesarean section, allowing neurological recovery. The second case involved a 35-year-old woman who presented with spontaneous fracture of T-7 at 36 weeks of gestation, revealing a vertebral hemangioma with no neurological deficit, but it was responsible for pain and local instability. Treatment consisted of postpartum posterior interbody fusion. With a clinical and radiological follow-up of 2 years, no complications and no modification of the hemangiomas were observed. A review of the literature reveals discordant management of these rare cases, which is why the treatment course must be decided by a multidisciplinary team as a function of fetal gestational age and maternal neurological features.

A case of atypical chronic subdural hematoma: a spontaneous rupture of dural lymphoma nodule

In forensic medicine, a chronic subdural hematoma (SDH) usually results from trauma, sometimes minimal for elderly people. The case reported here is a forensic medical description of an atypical chronic subdural hematoma. A woman aged of 40-year-old died following a coma. The autopsy and histological analyses revealed the hemorrhagic disintegration of a lymphoid nodule, a metastasis from generalized lymphoma. The combination of chronic symptomatic SDH and a tumor of the dura mater have been described, but are very rare. The possibility of trauma, even minimal, has never been excluded in these cases. In fact, the clinical picture of these patients suggested a significant movement of the brain within the cranial cavity due to the physiological decrease in brain volume. In the reported case, this particular process was excluded since the spontaneous hemorrhagic effusion produced by the meningeal lymphoid nodule was the cause of the chronic SDH. This pathophysiological explanation was possible because the entire brain and meninges were removed for histological analysis. Trauma, even minimal trauma, is not always involved in the formation of a chronic SDH.

Ethmoid Adenocarcinoma: Systematic Associated Skull Base Resection Improves Disease-Free Survival

Objectives:

Ethmoid adenocarcinoma is an occupational tumor affecting woodworkers with prognosis correlated to the local control of the disease. Since 1998, we have developed a technique of skull base resection with reconstruction by exclusive transfacial approach. This method allows a resection of the cribriform plate and dura mater associated with the removal of the tumor with simplified postoperative features compared with mixed approach.

Methods:

We performed a retrospective analysis of 89 patients presenting with ethmoid adenocarcinoma from 1998 to 2010 (144 months). All patients treated with surgical removal and postoperative adjuvant radiotherapy were included. Postoperative features and oncologic outcomes were analyzed.

Results:

89 patients were treated by surgical removal of the ethmoid tumor associated or not with skull base resection by a transfacial approach. The median age was 67.6 years, and 91% were occupational woodworkers. Among these 89 patients, 71 benefited from skull base resection by transfacial approach. Disease free survival was significantly better in the skull base removal group ( P = 0.009) and decreased for T4 stages ( P = 0.008). Overall survival was not influenced by the surgical technique. This method provided less morbidity than mixed approach and good results of 5-years specific survival (85 %).

Conclusions:

Prognosis of ethmoid adenocarcinomas is related to local control. In our experience the transfacial approach for systematic skull base resection associated with tumor removal and reconstruction is safe, efficient, and improves local control with a low morbidity, allowing a curative treatment for a larger number of patients.

Laser-treated Nucleus pulposus as an innovative model of intervertebral disc degeneration

This study describes an innovative experimentally induced model of intervertebral disc degeneration. This innovative approach is based on the induction of extracellular matrix disorders in the intervertebral disc (IVD) using a diode laser. For this study, 15 one-year-old and five 30-month-old New Zealand White rabbits were used. Two procedures were tested to trigger IVD degeneration: needle aspiration (reference technique) and a laser approach. The IVD degeneration process was assessed 20, 40, 60, 90 and 120 days after surgery by X-ray radiography (IVD height), magnetic resonance imaging (MRI) (T2 intensity of IVD signal) and histological analysis using modified Boos' scoring. Our data indicate that a marked IVD degeneration was found compared with sham-operated animals regardless of the procedure tested. A significant decrease in disc height on X-ray radiographs was first demonstrated. In addition, MRI disc signals were significantly reduced in both groups. Finally, a statistically significant increase in Boos' scoring was found in both laser and aspiration-induced IVD degeneration. Interestingly, IVD degeneration induced by laser treatment was more progressive compared with aspiration. Moreover, the histological results indicated that laser-induced disc degeneration was quite similar to that obtained during the natural aging process as observed in 30-month-old rabbits. Our study describes the consistency of this innovative experimentally-induced animal model of IVD degeneration. The radiological, MRI and histological data confirm its relevance. The histological examination indicates that IVD degeneration induced by laser treatment is comparable to the degenerative process observed during the onset of spontaneous IVD degeneration. This model could be a useful tool to help us validate biomaterial-assisted, cell-based, regenerative medicine strategies for the prevention and treatment of IVD degeneration.

Leptomeningeal carcinomatosis from ethmoid sinus adenocarcinoma

INTRODUCTION

Adenocarcinoma of the ethmoid is an aggressive tumor, with potential extension to surrounding structures. Leptomeningeal extension is a rarely reported entity.

CASE REPORT

A carpenter, aged 55, developed multifocal cranial nerve-related symptoms 1 week after resection of adenocarcinoma of the ethmoid, evolving towards deteriorated general health status and death 10 weeks later. Brain MRI showed diffuse contrast enhancement of the cranial nerves, and repeated cerebrospinal fluid (CSF) examination found increased protein concentration associated with decreased glucose concentration, without malignant cells. The diagnosis of carcinomatous meningitis was based on the association of clinical, CSF and brain MRI data.

DISCUSSION/CONCLUSION

Leptomeningeal dissemination of adenocarcinoma of the ethmoid is rare; diagnosis is guided by clinical signs. MRI reveals neurological spread, but the presence of malignant cells in the CSF is sufficient for diagnosis. Due to poor prognosis, the only currently available treatments are palliative.

Identification of phenotypic discriminating markers for intervertebral disc cells and articular chondrocytes

OBJECTIVE

The present study was conducted to improve our knowledge of intervertebral disc (IVD) cell biology by comparing the phenotype of nucleus pulposus (NP) and annulus fibrosus (AF) cells with that of articular chondrocytes (ACs).

METHODS

Rabbit cells from NP and AF were isolated and their phenotype was compared with that of AC by real-time PCR analysis of type I (COL1A1), II (COL2A1) and V (COL5A1) collagens, aggrecan transcript (AGC1), matrix Gla protein (MGP) and Htra serine peptidase 1 (Htra1).

RESULTS

Transcript analysis indicated that despite certain similarities, IVD cells exhibit distinct COL2A1/COL1A1 and COL2A1/AGC1 ratios as compared with AC. The expression pattern of COL5A1, MGP and Htra1 makes it possible to define a phenotypic signature for NP and AF cells.

CONCLUSIONS

Our study shows that NP and AF cells exhibit a clearly distinguishable phenotype from that of AC. Type V collagen, MGP and HtrA1 could greatly help to discriminate among NP, AF and AC cells.

[Dialysis-associated spondyloarthropathy. Case report and literature review]

Hemodialysis has considerably prolonged the life of patients suffering from terminal renal failure. However, long-term hemodialysis leads to new bone complications and spinal disorders such as destructive spondyloarthropathy (DSA). At the present time DSA is reported in 8% to 18% of the dialysed patients. Diagnosis is based on severe narrowing of the intervertebral disk, erosions and geodes of the adjacent vertebral plates simulating infectious spondylitis. Lesions progressively involve posterior joints and may lead to severe destruction of the spine. The pathogenesis of this syndrome is still unknown. Several factors have been implicated, including microcrystal deposition, amyloidosis, inflammatory and foreign body reactions and suggest that the pathogenesis of erosive spondyloarthropathies of hemodialysed patients is multifactorial. Spinal instability inducing myelopathy and radiculopathy were observed in 8% of the cases. Treatment must be accorded to the natural disease course and to the quality of the bone. We report the case of a chronic dialysed patient with destructive spondyloarthropathy involving the cervical and thoracic spine. Pathogenesis, radiological datas and therapeutic approach are discussed.

Le neurochirurgien face aux algies périnéales

The investigation of patients suffering from perineal pain when sitting led us to perform an anatomical study of the pudendal nerve. We dissected 50 cadavers and found areas of conflict for the nerve fibers. The nerve trunk can become entrapped at the level of the ischiatic spine, in the Alcock's canal and when it crosses the falciform process. Considering the clinical and neurophysiological data, this type of chronic pain may arise from compression of the nerve between the sacro-tuberal and the sacro-spinal ligaments, and/or in the fascia of the internal obturator muscle. Much like treatment of entrapment of the median nerve in the wrist, we decided to treat chronic perineal pain by nerve blocks, and later by surgery. We describe here the clinical symptoms, the neurophysiological data, and the technique of the nerve blocks. For patients with persistent pain, we propose a posterior surgical approach which has provided successful pain relief in two third of patients.

[Chronic lower back pain: a new therapeutic approach]

Lower back pain is a common complaint of patients seen in our consultations. Despite progress, surgical procedures are still often unsuccessful in relieving pain. Blocks performed in the epidural spaces or more often in the articular facets have provided poor relief of chronic lower back pain. The pain has vegetative components. Considering anatomic findings, we describe the innervation of the peridiscal tIssues which suffer during degenarative conditions. We analyze the course of the autogenic nerves mediating lumbar pain, and select the site of the blocks necessary to obtain optimal selective pain relief. A well-defined block at the level of the communicating rami is described.

Arachnoiditis ossificans of the cauda equina

✓ The authors describe a case of arachnoiditis ossificans (AO) of the cauda equina. The lesion is a rare pathological entity usually confined to the thoracic and high lumbar regions that can cause progressive spinal cord and cauda equina compression, inducing severe neurological deterioration. The authors analyze the clinical symptoms, radiological features, histological data, and treatment options relating to this case and 13 others described in the literature; additionally, they consider the possible mechanisms responsible for ossification of the leptomeninges. Although clustered arachnoidal cells are usually implicated in its pathogenesis, an environment induced by arachnoiditis and disturbed cerebrospinal fluid flow appears to be a more important factor. A therapeutic strategy is proposed for AO for which no effective treatment currently exists.

Inverted-hook occipital clamp system in occipitocervical fixation. Technical note

The authors describe an occipitocervical fixation procedure in which they use inverted occipital hooks inserted through a burr hole drilled in the squamous part of the occipital bone. Fifteen patients with unstable lesions of the occipitocervical junction underwent occipitocervical internal fixation. The mean follow-up period was 21 months (range 2-63 months). No implant failed, and postoperative immobilization was not required. The placement of a posterior occipitocervical graft (for which fusion is uncertain) can be avoided in certain conditions.

Occipitocervical fixation with a single occipital clamp using inverted hooks

A simple occipitocervical osteosynthesis technique using cervical CCD (compact Cotrel-Dubousset) material is described in a clinical case. The originality of this technique consists in the occipital fastening used, involving the simultaneous insertion of two hooks into a single burr-hole. This greatly facilitated the positioning of the osteosynthesis rods, reduced surgical time, and provided immediate stability. These criteria are of considerable importance since this difficult surgical procedure is often performed in patients in a frail condition.