Elevated nutrient availability enhances chondrocyte metabolism and biosynthesis in tissue-engineered cartilage

OBJECTIVE

Chondrocytes, which typically rely on anaerobic metabolism, exhibit upregulated biosynthetic activity when subjected to conditions that elicit mixed aerobic-anaerobic metabolism. Previously, we observed that increasing media volume resulted in the transition from anaerobic to mixed aerobic-anaerobic metabolism. Maximal extracellular matrix (ECM) accumulation occurred at this transition as a result of changes in hypoxia-inducible factor 1α signaling and associated hypoxic gene expression. This study aimed to explore the effect of further increases in media availability on ECM synthesis and chondrocyte metabolism.

METHODS

Primary bovine chondrocytes were grown in 3D high-density tissue culture under varying levels of media availability (4-16 mL/106 cells). Changes in ECM accumulation and metabolism were determined through biochemical assays and 13C-metabolic flux analysis (13C-MFA).

RESULTS

Increasing media volumes resulted in higher accumulation of cartilaginous ECM (collagen and proteoglycans) and cellularity. Extracellular metabolite measurements revealed that elevated media availability led to increased glucose and glutamine metabolism, along with increased anaerobic activity. 13C-MFA utilizing [U-13C] glucose demonstrated that increased media availability significantly impacted central carbon metabolism, upregulating all glucose-related metabolic pathways (glycolysis, lactate fermentation, the tricarboxylic acid (TCA) cycle, hexosamine biosynthetic pathway, and the malate-aspartate shuttle). Furthermore, 13C-MFA indicated that glutamine was donating carbons to the TCA cycle, and additional studies involving [U-13C] glutamine tracing supported this notion.

CONCLUSIONS

Elevated media availability upregulates ECM synthesis and leads to significant changes in metabolic phenotype. Glutamine plays an important role in chondrocyte metabolism and increases in glutamine metabolism correlate with increases in ECM accumulation.

13C Metabolic Flux Analysis in Chondrocytes Reveals a Novel Switch in Metabolic Phenotype

Chondrocytes are typically known for their anaerobic metabolism both in vivo and under culture conditions in vitro. However, chondrocytes have been shown to display greater biosynthetic activity when subjected to conditions that elicit aerobic metabolism. We have previously shown that tissue formation by chondrocytes can be upregulated by controlling nutrient availability and that this response arises from changes in glucose metabolism. The aim of the present study was to further characterize these changes through 13C-metabolic flux analysis (13C-MFA), as well as to determine the most optimal response. Primary bovine chondrocytes were grown in scaffold-free high-density tissue culture. [U-13C] glucose labeling experiments were combined with a tissue-specific metabolic network model to carry out 13C-MFA under varying levels of nutrient availability. 13C-MFA results demonstrated that when subjected to increasing nutrient availability, chondrocytes switch from a predominately anaerobic to a mixed aerobic-anaerobic phenotype. This metabolic switch was attributed to the saturation of the lactate fermentation pathway and metabolite overflow toward the tricarboxylic acid cycle. This effect appears to be similar to, but the inverse of, the Crabtree effect ("inverse Crabtree effect"). The relationships between metabolic flux and nutrient availability were then utilized to identify culture conditions that promote enhanced tissue formation. This novel metabolic effect presents a simple but effective approach for enhancing the biosynthetic response of chondrocytes-a key requirement to develop functional engineered cartilaginous tissue for joint resurfacing.

Effect of nutrient metabolism on cartilaginous tissue formation

A major shortcoming in cartilage tissue engineering is the low biosynthetic response of chondrocytes. While different strategies have been investigated, a novel approach may be to control nutrient metabolism. Although known for their anaerobic metabolism, chondrocytes are more synthetically active under conditions that elicit mixed aerobic-anaerobic metabolism. Here, we postulate this metabolic switch induces HIF-1α signaling resulting in improved growth. Transition to different metabolic states can result in the pooling of metabolites, several of which can stabilize HIF-1α by interfering with PHD2. Chondrocytes cultured under increased media availability accelerated tissue deposition with the greatest effect occurring at 2 ml/10⁶ cells. Under higher media availability, metabolism switched from anaerobic to mixed aerobic-anaerobic. Around this transition, maximal changes in PHD2 activity, HIF-1α expression, and HIF-1 target gene expression were observed. Loss-of-function studies using YC-1 confirmed the involvement of HIF-1. Lastly, targeted metabolomic studies revealed that intracellular lactate and succinate correlated with PHD2 activity. This study demonstrates that cartilaginous tissue formation can be regulated by nutrient metabolism and that this response is mediated through changes in HIF-1α signaling. By harnessing this newly identified metabolic switch, engineered cartilage implants may be developed without the need for sophisticated methods which could aid translation to the clinic.

Optimization of culture media to enhance the growth of tissue engineered cartilage

Tissue engineering is a promising option for cartilage repair. However, several hurdles still need to be overcome to develop functional tissue constructs suitable for implantation. One of the most common challenges is the general low capacity of chondrocytes to synthesize cartilage-specific extracellular matrix (ECM). While different approaches have been explored to improve the biosynthetic response of chondrocytes, several studies have demonstrated that the nutritional environment (e.g., glucose concentration and media volume) can have a profound effect on ECM synthesis. Thus, the purpose of this study was to optimize the formulation of cell culture media to upregulate the accumulation of cartilaginous ECM constituents (i.e., proteoglycans and collagen) by chondrocytes in 3D culture. Using response surface methodology, four different media factors (basal media, media volume, glucose, and glutamine) were first screened to determine optimal media formulations. Constructs were then cultured under candidate optimal media formulations for 4 weeks and analyzed for their biochemical and structural properties. Interestingly, the maximal accumulation of proteoglycans and collagen appeared to be elicited by different media formulations. Most notably, proteoglycan accumulation was favored by high volume, low glucose-containing DMEM/F12 (1:1) media whereas collagen accumulation was favored by high volume, high glucose-containing F12 media. While high glutamine-containing media elicited increased DNA content, glutamine concentration had no apparent effect on ECM accumulation. Therefore, optimizing the nutritional environment during chondrocyte culture appears to be a promising, straight-forward approach to improve cartilaginous tissue formation. Future work will investigate the combined effects of the nutritional environment and external stimuli.

Delayed surgery in neurologically intact patients affected by thoraco-lumbar junction burst fractures: to reduce pain and improve quality of life

Background

This is a retrospective study on 18 patients affected by thoraco-lumbar junction burst fractures (TLJBF) A3 or A4 at computed tomography (CT) scan who referred to our hospital. To assess the surgical results in terms of pain and quality of life in a series of neurologically intact patients affected by TLJBF who underwent surgery after 3-4 months from the injury. In literature there is controversy if pain could be an indication for surgery in TLJBF and series of patients conservatively managed with success have been reported.

Methods

A retrospective study on 18 patients is reported. Patients included in this series were neurologically intact and affected by a TLJBF A3 or A4 at CT scan, the height of the burst vertebral body was >50%, spinal canal invasion was <30% and kyphosis deformity <30 degrees. Pain and quality of life were evaluated using graphic rating scale (GRS) and EuroQol (EQ-5D) scores on admission, at the clinical follow-up and in post-surgical period.

Results

Comparing pre- and post-operative EQ-5D, the scores had a statistically significant decrease after the operation (P<0.001) [pre-surgery EQ-5D was 2.60 (SD =0.67), post-surgery EQ-5D was 1.37 (SD =0.41)]. Also analyzing the EQ5D-VAS scores, the t-test revealed that surgery (P<0.01) improved the quality of life with statistically significance (EQ5D-VAS pre =43.89, SD =12.43 and EQ5D-VAS post =73.33, SD =10.84). Analyzing pre- and post-surgical GRS scores, the pain decreased significantly with the maximum mean difference among the 2nd and 3rd month before surgery and at 12 months after surgery (respectively D =5.444, P<0.001 and D =5.167, P<0.001).

Conclusions

Conservatively managed patients affected by TLJBF require a strict clinical follow-up since pain sometimes is present in the following months and it affects the quality of life. Surgery should be considered for these cases.

Lumbar ganglion cyst: Nosology, surgical management and proposal of a new classification based on 34 personal cases and literature review

AIM

To analyze different terms used in literature to identify lumbar extradural cysts and propose a common scientific terminology; to elaborate a new morphological classification of this pathology, useful for clinical and surgical purposes; and to describe the best surgical approach to remove these cysts, in order to avoid iatrogenic instability or treat the pre-existing one.

METHODS

We retrospectively reviewed 34 patients with symptomatic lumbar ganglion cysts treated with spinal canal decompression with or without spinal fixation. Microsurgical approach was the main procedure and spinal instrumentation was required only in case of evident pre-operative segmental instability.

RESULTS

The complete cystectomy with histological examination was performed in all cases. All patients presented an improvement of clinical conditions, evaluated by Visual Analogic Scale and Japanese Orthopaedic Association scoring.

CONCLUSION

Spinal ganglion cysts are generally found in the lumbar spine. The treatment of choice is the microsurgical cystectomy, which generally does not require stabilization. The need for fusion must be carefully evaluated: Pre-operative spondylolisthesis or a wide joint resection, during the operation, are the main indications for spinal instrumentation. We propose the terms “ganglion cyst” to finally identify this spinal pathology and for the first time its morphological classification, clinically useful for all specialists.

C5 palsy after insertion of a winged expandable cervical cage: a case report and literature review

C5 nerve root palsy is a well-known complication after anterior or posterior cervical decompression. Many theories have been proposed but the etiology is still unclear. The use of a winged expandable cage after single or multiple corpectomy is among the used techniques in reconstructing the cervical spine. Herein we report a case of C5 palsy after a three-level corpectomy and reconstruction using this device for the treatment of cervical spondylosis. In our case the preexisting foraminal stenosis, wide anterior decompression and partial improvement of cervical alignment were factors supposed contributing to the palsy.

A case of cervical tuberculosis with severe kyphosis treated with a winged expandable cage after double corpectomy

In this case report, we demonstrate that the use of a winged expandable cage was able to obtain good clinical and radiological results in a case of cervical tuberculosis with severe kyphosis. However, case series will be necessary to affirm its validity as a stand-alone device for similar cases with high risk of instability.

Static and dynamic cervical MRI: two useful exams in cervical myelopathy

BACKGROUND

Cervical magnetic resonance imaging (MRI) is the gold standard exam in the assessment of patients affected by cervical myelopathy and is very useful in planning the operation. Herein we present a series of patients affected by long tract symptoms who underwent dynamic MRI in addition to the static exam.

METHODS

In the period between March 2010 and March 2012, three-hundred-ten patients referred to our department since affected by neck/arm pain or symptoms related to cervical myelopathy. Thirty-eight patients complained "long-tract symptoms" related to cervical myelopathy. This series of patients was enrolled in the study. All patients underwent clinical and neurological exam. In all the cases, a static and dynamic cervical MRI was executed using a 3.0-T superconducting MR unit (Intera, Philips, Eindhoven, Netherlands). The dynamic exam was performed with as much neck flexion and extension the patient could achieve alone. On T2-weigthed MRI each level was assessed independently by two neuroradiologists and Muhle scale was applied.

RESULTS

According to Muhle's classification of spinal cord compressions, static MRI demonstrated 156 findings: 96 (61.54%) anterior and 60 (38.46%) posterior. Dynamic MRI showed 186 spinal cord compressions: 81 (43.5%) anterior and 105 (56.5%) posterior. The anterior compressions were: grade 1 in 23 cases (28.4%), grade 2 in 52 cases (64.2%), grade 3 in 6 cases (7.4%). The posterior compressions were: 32 (30.48%) of grade 1, 60 (57.14%) of grade 2, 13 (12.38%) of grade 3.

CONCLUSIONS

The dynamic MRI demonstrated a major number of findings and spinal cord compressions compared to the static exam. Finally, we consider the dynamic exam able to provide useful information in these patients, but we suggest a careful evaluation of the findings in the extension exam since they are probably over-expressed.

Decompression versus decompression and fusion for degenerative lumbar stenosis: analysis of the factors influencing the outcome of back pain and disability

BACKGROUND

The objective of this study is to evaluate the factors influencing the outcome of back pain and disability in patients operated for lumbar stenosis without instability and deformity using two classical surgical techniques: decompression alone and decompression plus fusion.

METHODS

This is a retrospective cohort study of patients who underwent lumbar surgery with standard posterior decompression or standard posterior decompression plus pedicle screw fixation for degenerative lumbar stenosis without deformity, spondylolisthesis or instability at our department from June 2010 to January 2014. They were divided into two groups: decompression group (D) and decompression-fusion group (F). We analyzed the following factors: age, gender, levels of stenosis, pre-surgical "micro-instability", and post-surgical "micro-instability".

RESULTS

A total of 174 patients were enrolled in the study. Both Graphic Rating Scale (GRS) and Oswestry Disability Index (ODI) scores were significantly decreased after surgery (P<0.001). Female patients appeared to have lesser improvements from surgery, for both D and F groups. An analysis of variance using the decrease of pain (GRS pre-post) as dependent variable and type of surgery, age, gender and their interaction as factors showed that the main effects of type of surgery and gender were significant. The analysis of variance for the decrease of pain (GRS) and disability (ODI) according to the levels of stenosis showed a significant interaction for GRS scores. Female patients that underwent fixation surgery reported the least improvement in disability. A significant interaction was found on the one-way analysis of variance for the D group without pre-surgical micro-instability using post-surgical micro-instability as factor.

CONCLUSIONS

Our study supports posterior decompression alone as the gold standard option as treatment for lumbar stenosis without instability and deformity. Additional fusion should be considered only to prevent post-surgical instability. The "micro-instability" is a radiological finding that has its clinical surrogate but is not able to guide the choice of the type of surgery. Moreover the significance of "micro-instability" is still unclear. We suggest a prospective study following patients with asymptomatic micro-instability to definitively understand the clinical history.

Surgery for vertebral involvement in multiple myeloma

BACKGROUND

To evaluate the results of surgery for vertebral involvement in multiple myeloma (MM) following the introduction of the new chemotherapy in 2006.

METHODS

Retrospective cohort study evaluating the patients with MM vertebral lesions from January 2006 to January 2014. Outcomes were based upon participation in ODI and EQ-5D. Statistical interpretation of the data was performed with SPSS version 19 software (SPSS Inc, Chicago, IL, USA).

RESULTS

One hundred twenty patients affected by MM were potentially eligible for recruitment. About 1/3 patients needed an operation for vertebral involvement. The disability was mainly related to the number of vertebrae affected by MM. No difference in disability and quality of life was observed between operated and non-operated patients, according to age, levels, and follow-up. The operated patients with a Thoracic location reported lower disability and higher quality of life than non-operated patients. Non-operated patients with one or two vertebrae affected reported lower levels of quality of life.

CONCLUSIONS

When a spinal column involvement occurs, the probability of undergoing surgery is about 40%. Operated patients show a moderate disability and the increased tendency is related to the number of vertebrae involved. The quality of life is middle in average and middle-high in patients operated for thoracic lesions. Nowadays the spinal surgeon must have a perspective view about MM vertebral lesions, evaluating the stability of the spine, the presence of deformity, the risk of vertebral fractures and the presence of drug resistant pain, that deteriorate the disability and the quality of life related to the underlying disease.

Thoracic Spondylodiscitis Caused by Methicillin-resistant Staphylococcus aureus as a Superinfection of Pulmonary Tuberculous Granuloma in an Immunocompetent Patient: A Case Report

Study Design Case report. Objective To describe a very rare case of an immunocompetent man who underwent surgery for thoracic spondylodiscitis caused by methicillin-resistant Staphylococcus aureus (MRSA) that developed as a superinfection of a pulmonary tuberculous granuloma. Methods Posterior decompression and pedicle screw vertebral fixation were followed by T5-T6 anterior somatotomy with implant of an expandable mesh and lateral plating as symptoms worsened. During the anterior approach, an atypical resection of the left lower lobe was also performed. Results A tuberculous granuloma was detected on histology. Ziehl-Neelsen stain confirmed the diagnosis. Culture also detected MRSA. Conclusions Early medical management is the first choice for spondylodiscitis to eradicate the infection and alleviate pain. Immobilization of the affected spine segments can protect the patient from vertebral collapse and from the appearance of neurologic deficits. Surgery is suggested if there are compressive effects on the spinal cord, spinal epidural abscess, vertebral collapse, and deformity. We decided to remove the abscess and to restore the anterior column using an anterior approach. Moreover, in this case, an anterior approach allowed us to identify the etiology of the lesion and to determine the best chemotherapy regimen.

Surgery in extensive vertebral hemangioma: case report, literature review and a new algorithm proposal

Hemangiomas are benign dysplasias or vascular tumors consisting of vascular spaces lined with endothelium. Nowadays, radiotherapy for vertebral hemangiomas (VHs) is widely accepted as primary treatment for painful lesions. Nevertheless, the role of surgery is still unclear. The purpose of this study is to propose a novel algorithm of treatment about VHs. This is a case report of an extensive VH and a review of the literature. A case of vertebral fracture during radiotherapy at a total dose of 30 Gy given in 10 fractions (treatment time 2 weeks) using a linear accelerator at 15 MV high-energy photons for extensive VH is reported. Using PubMed database, a review of the literature is done. The authors have no study funding sources. The authors have no conflicting financial interests. In the literature, good results in terms of pain and neurological deficits are reported. No cases of vertebral fractures are described. However, there is no consensus regarding the treatment for VHs. Radiotherapy is widely utilized in VHs determining pain. Surgery for VHs determining neurological deficit is also widely accepted. Perhaps, regarding the width of the lesion, no indications are given. We consider it important to make an evaluation before initiating the treatment for the risk of pathologic vertebral fracture, since in radiotherapy, there is no convention regarding structural changes determined in VHs. We propose a new algorithm of treatment. We recommend radiotherapy only for small lesions in which vertebral stability is not concerned. Kyphoplasty can be proposed for asymptomatic patients in which VHs are small and in patients affected by VHs determining pain without spinal canal invasion in which the VH is small. In patients affected by pain without spinal canal invasion but in which the VH is wide or presented with spinal canal invasion and in patients affected by neurological deficits, we propose surgery.

Penetrating gunshot wound to the head: transotic approach to remove the bullet and masseteric-facial nerve anastomosis for early facial reanimation

INTRODUCTION

Gunshot wounds to the head (GSWH) account for the majority of penetrating brain injuries, and are the most lethal. Since they are rare in Europe, the number of neurosurgeons who have experienced this type of traumatic injury is decreasing, and fewer cases are reported in the literature.

CASE

We describe a case of gunshot to the temporal bone in which the bullet penetrated the skull resulting in the facial nerve paralysis. It was excised with the transotic approach. Microsurgical anastomosis among the masseteric nerve and the facial nerve was performed.

CONCLUSION

GSWH are often devastating. The in-hospital mortality for civilians with penetrating craniocerebral injury is very high. Survivors often have high rate of complications. When facial paralysis is present, masseteric-facial direct neurorraphy represent a good treatment.

Post laminoplasty cervical kyphosis-Case report

INTRODUCTION

Cervical kyphosis is a progressive cervical sagittal plane deformity that may cause a reduction in the ability to look horizontally, breathing and swallowing difficulties, sense of thoracic oppression and social isolation. Moreover, cervical kyphosis can cause myelopathy due to a direct compression by osteo-articular structures on the spinal cord or to a transitory ischaemic injury. The treatment of choice is surgery. The goals of surgery are: nervous structures decompression, cervical and global sagittal balance correction and vertebral stabilization and fusion.

PRESENTATION OF CASE

In October 2008 a 35 years old woman underwent surgical removal of a cervical-bulbar ependymoma with C1-C5 laminectomy and a C2-C5 laminoplasty. Five months after surgery, the patient developed a kyphotic posture, with intense neck and scapular girdle pain. The patients had a flexible cervical kyphosis. Therefore, we decided to perform an anterior surgical approach. We performed a corpectomy C4-C5 in order to achieve the anterior decompression; we placed a titanium expansion mesh.

DISCUSSION

Cervical kyphosis can be flexible or fixed. Some authors have reported the use of anterior surgery only for flexible cervical kyphosis as discectomy and corpectomy. This approach is useful for anterior column load sharing however it is not required for deformity correction.

CONCLUSION

The anterior approach is a good surgical option in flexible cervical kyphosis. It is of primary importance the sagittal alignment of the cervical spine in order to decompress the nervous structures and to guarantee a long-term stability.

Posterolateral arthrodesis in lumbar spine surgery using autologous platelet-rich plasma and cancellous bone substitute: an osteoinductive and osteoconductive effect

Study Design Prospective cohort study. Objectives To analyze the effectiveness and practicality of using cancellous bone substitute with platelet-rich plasma (PRP) in posterolateral arthrodesis. Methods Twenty consecutive patients underwent posterolateral arthrodesis with implantation of cancellous bone substitute soaked with PRP obtained directly in the operating theater on the right hemifield and cancellous bone substitute soaked with saline solution on the right. Results Computed tomography scans at 6 and 12 months after surgery were performed in all patients. Bone density was investigated by comparative analysis of region of interest. The data were analyzed with repeated-measures variance analyses with value of density after 6 months and value of density after 12 months, using age, levels of arthrodesis, and platelet count as covariates. The data demonstrated increased bone density using PRP and heterologous cancellous block resulting in an enhanced fusion rate during the first 6 months after surgery. Conclusions PRP used with cancellous bone substitute increases the rate of fusion and bone density joining osteoinductive and osteoconductive effect.

Surgery of Intradural Extramedullary Tumors

BACKGROUND:

Intradural extramedullary tumors (IDEMTs) are uncommon lesions that cause pain and neurological deficits.

OBJECTIVE:

To evaluate the effects of surgery for IDEMTs.

METHODS:

This cohort study recruited all patients operated on for IDEMTs at the Department of Neurology and Psychiatry of Sapienza University of Rome from January 2003 to January 2013. The analysis was conducted on clinical records evaluation over a 1-year follow-up. The Graphic Rating Scale was used to assess pain. Neurological deficits were detected through neurological examination. Quality of life was evaluated with the EuroQol (EQ-5D). Statistical interpretation of the data was performed with SPSS version 19 software.

RESULTS:

One hundred seven patients were recruited. Three were lost to follow-up. Patients reported lower level of pain 1 year after surgery (before surgery, 6.05; after surgery, 3.65). Mean comparison showed a significant decrease of −2.400 (P &lt; .001). Ninety-two patients (88.5%) were neurologically asymptomatic 1 year after surgery. Only 12 patients (11.5%) presented with a deficit, with a global decrease of 39% (χ2 = 27.6; P &lt; .005). The quality of life in patients was middle to high (mean rating of EQ-5D visual analog score, 61.78%). The lowest levels of quality of life were found in patients with sphincter dysfunctions (mean, 33.4).

CONCLUSION:

Surgery for IDEMTs has a good outcome. Patients reported lower levels of pain and a drastic reduction in neurological symptoms 1 year after surgery. The quality of life is middle to high. It is influenced mainly by the neurological outcome.

360° fusion for realignment of high grade cervical kyphosis by one step surgery: Case report

Surgical treatment for cervical kyphotic deformity is still controversial. Circumferential approach has been well described in the literature but long terms outcomes are not well reported. Important to decide the correct treatment option is the preoperative radiological exams to value the type of deformity (flexible or fixed). We report the case of a 67-year-old woman affected by a severe cervical kyphotic deformity who underwent combined anterior/posterior surgical approach, getting a good reduction of the deformity and an optimal stability in a long term follow up.

Multilevel oblique corpectomies as an effective surgical option to treat cervical chordoma in a young girl

Chordomas are malignant tumors arising from notochordal remnants. They are the most frequent tumors of the spine after plasmacytomas. Only 6% of chordomas are localized to the cervical level. In young patients, chordomas are rare and unpredictable. Despite this, the treatment of choice remains the total resection, as much as possible, followed by proton beam radiation. This case was managed using a precarotid and retrocarotid approach at the same time. The tumor was completely resected with the edges free from disease. The cervical spine was stabilized with an anterior plating C2-C4. Eighteen months after surgery the patient is still free from illness. Multilevel oblique corpectomies are an available and safe option for the treatment of upper cervical chordomas.

Abdominal aortic rupture and spondylodiscitis: emergent EVAR and staged spinal fixation

Concomitant aortic aneurismal pathology and vertebral erosion are seldom reported in literature. The differential diagnosis between a primary vertebral disease affecting the aortic wall and a primary aortic pathology causing a vertebral disruption is quite difficult. We report on a patient presenting with increasing lumbar pain and neurologic lower limbs deficit due to a vertebral erosion accompanied by aortic rupture treated by emergent endovascular aortic repair procedure and then staged vertebral fixation. Microbiological tests on intraoperative periaortic fluid collection samples showed no clear sign of infection and clinical conditions progressively improved. At 12-month follow-up, the patient is in good clinical condition, with a small residual walking impairment and no clinical, laboratory, or imaging sign of aortic endograft infection.

Anterior surgical approaches to the cervicothoracic junction: when to use the manubriotomy?

BACKGROUND CONTEXT

The cervicothoracic junction (CTJ) is always a difficult area for anterior approaches. Among them, low anterior cervical approach alone or combined with manubriotomy is the most frequently used.

PURPOSE

To study the need of manubriotomy.

STUDY DESIGN/SETTING

Comparison of last guidelines proposed in literature.

PATIENT SAMPLE

Seven patients treated between March 2010 and March 2011.

METHODS

All the patients were scanned on with computed tomography and magnetic resonance of the spinal column before surgery. Measurements by Teng and Karikari were applied in all the cases. An illustrative case is showed.

RESULTS

The anterior approaches to the CTJ are reviewed. The most recent guidelines by Teng and Karikari are easy to apply and careful. The results obtained were the same in all the cases with good outcome.

CONCLUSIONS

Manubriotomy permits a good exposure of the CTJ area with a low rate of complications. Either Teng and Karikari's guidelines can be used to estabilish the need of manubriotomy.

Trans-sacral screw fixation in the treatment of high dyplastic developmental spondylolisthesis

We describe the case of a 67-year-old woman with L5-S1 ontogenetic spondylolisthesis treated with pedicle fixation associated with interbody arthrodesis performed with S1-L5 trans-sacral screwing according to the technique of Bartolozzi. The procedure was followed by a wide decompressive laminectomy. The patient had a progressive improvement of the symptoms which gradually disappeared in 12 mo. The radiograph at 6 and 12 mo showed complete fusion system. The choice of treatment in L5-S1 ontogenetic spondylolithesis is related to a correct clinical and diagnostic planning (X-ray, computer tomography magnetic resonance imaging, Measurement). In particular, the severity index and the square of unstable zone, and the standard measurements already described in the literature, are important to understand and to plane the correct surgical strategy, that require, in most of the times, fusion and interbody artrodesis.

Pott's disease: medical and surgical treatment

OBJECTIVES

To evaluate the best treatment of Pott's disease.

MATERIALS AND METHODS

7 cases of Pott's disease were treated in the department of Neurosurgery of Sapienza University of Rome (Italy) between 2004 to 2011.

RESULTS

All patients underwent surgical drainage of abscess and vertebral stabilization. In all cases culture exam showed positivity after 40 days of incubation. After surgery for a period of one year chemotherapy was administered. In all cases MRI scan with gd of the spinal column were performed 12 months after surgery and no recurrence of disease has been shown.

DISCUSSION

Pott's disease is defined as vertebral involvement of extrapulmonary Tubercolosis (TB), involving mainly toraco-lumbar tract of the spine. MRI with gd represents the gold standard for the diagnosis. Treatment can be medical, surgical or usually both. The slippery course of the disease often causes a delay in getting to a diagnosis that is not made prior to rising signs, such as large abscess, neurological impairment or vertebral fractures. In these cases medical treatment alone did not show effective results, because no specific antibiotic drug can permeate the abscess's capsule, and an effective concentration is not achieved in the infection's site. Therefore, surgical treatment is necessary to abscess draining and setting the correct medical treatment to mycobacterial eradication.

Alterations in the intracranial venous sinuses in spontaneous nontraumatic chronic subdural hematomas

Occlusion of the cerebral venous system is frequently associated with intraparenchymal or subarachnoid hemorrhage. There are few reports of cerebral venous thrombosis associated with nontraumatic chronic subdural hematoma (CSH). We aimed to evaluate the intracranial venous system in patients with spontaneous nontraumatic CSH and to identify alterations in their venous sinuses. In this study, eight patients with spontaneous, nontraumatic CSH were followed for a 7-year period (mean: 2.2 years, range: 1-7 years). Neuroradiological images were taken at the onset of symptoms and during follow-up. Venous angiography or magnetic resonance venography was used to evaluate the cerebral venous system of patients. In all patients, medical or surgical treatments were based on clinical symptoms. In seven of the eight patients, the CSH was in the left hemisphere, whereas one patient had bilateral CSH. In one of the eight patients, thrombosis of the transverse sinus and sigmoid sinus was found, but recanalization was observed at follow-up. In a further three patients, the superior sagittal sinus, the straight sinus, and the vein of Galen were markedly reduced in diameter compared to normal or were not visible at presentation, but normal flow was observed at follow-up. In the remaining four patients, the transverse sinus was not observed at symptom onset or during long-term follow-up. A nontraumatic CSH can occur secondary to a venous thrombosis or it can be associated with the inability to image some of the venous sinuses. Venous flow was restored at long-term follow-up. Increased intravenous pressure is thought to be the pathogenic factor that causes a nontraumatic CSH.

Microsurgical excision without fusion as a safe option for resection of synovial cyst of the lumbar spine: long-term follow-up in mono-institutional experience

Spinal synovial cysts are cystic dilatations of the synovial membrane that may arise at all levels of the spine. We describe our experience, paying attention to diagnosis, surgical treatment, and long-term follow-up. Between 1995 and 2007, 18 patients were surgically treated. Of these, three patients were excluded from the study because they presented spinal instability at pre-operative assessment. All patients were evaluated pre-operatively with CT, MRI, and dynamic X-rays, and underwent surgery for removal of the cyst by hemilaminectomy and partial arthrectomy. All patients were evaluated with early MRI and had a minimum 2-year follow-up by dynamic X-rays. None of the patients required instrumented fusion due to the absence of radiological signs of instability on the pre-operative dynamic tests. In all patients, there was an immediate resolution of the symptoms, with evidence of complete removal of the cysts on post-operative MRI. At 2-year follow-up, all patients underwent dynamic X-rays and responded to a questionnaire for evaluation of outcome. None of them showed signs of relapse. The gold standard for treatment is surgery, even though other conservative treatment regimens have been proposed. Correct surgical strategy relies on pre-operative assessment of biomechanical stability for deciding whether patients need instrumented fusion during cyst removal. Patients with no instability signs are suitable for hemilaminectomy with partial arthrectomy, preserving 2/3 of the medial portion of the articular facet, because this represents a valid option of treatment with a low risk of complications and a low rate of relapse.

Laminotomy in adults: technique and results

The objective of this study was to describe step by step our surgical technique of laminotomy and analyze our series with regard to spinal deformities (risk and predisposing factors), postoperative pain and rate of postoperative contusions. Data regarding patients who underwent our technique of laminotomy (N = 40, mean follow-up: 52 ms) (N = 40) between 2002 and 2006 were retrospectively evaluated. The technique used is illustrated in depth. Chronic pain was present in 30% with a mean score of 3/10 cm (Graphic Rating Scale). Postoperative kyphoses occurred in three patients, all below 35 years of age and with laminotomies which involved C2 and/or C7. None of these deformities required further surgical treatment because they were self-limiting or asymptomatic at a mean follow-up of 52 months. Based on the results, our technique proved to be safe and effective in terms of late deformities, blood loss, early and chronic postoperative pain and protection from postoperative accidents over the surgical site.

The use of platelet gel in postero-lateral fusion: preliminary results in a series of 14 cases

Over the last few years, some hemocomponents have been used advantageously in clinical neurosurgical practice, not systemically via transfusion but topically as a sealant (fibrin glue). This has diverted the attention of many authors to the role of platelets in the healing process. The combination of hyper-concentrated platelets and fibrin glue (fibrinogen, XIII factor, fibronectin) with activated thrombin produces a platelet gel that can be easily applied to "difficult" wounds. This topical use of hemocomponents has gained an important role in regenerative medicine. The authors have considered the possibility of using a preparation with a high autologous platelet concentration applied in addition to autologous bone during vertebral postero-lateral fusion. The aim of the procedure is to induce a higher rate of vertebral fusion. Between November 2007 and November 2008, 14 patients (9 men and 5 women, mean age 58.9) underwent laminectomy, vertebral stabilization and postero-lateral fusion. The number of vertebral levels involved in stabilization was: 1 in 2 patients, 2 in 5 patients, 3 in 5 patients, 4 in 1 patient and 5 in 1 patient. Platelet gel was obtained by taking 16 ml of peripheral venous blood from the patient. For this procedure two patented test tubes were used for each patient, with a capacity of 8 m each. These make up the REGEN-THT(®) (Thrombocyte Harvesting Tube) system that makes it possible to obtain 8 ml of autologous platelet gel in 40-45 min. The addition of Ca gluconate and ethanol at 95% makes it possible to obtain a preparation of plasma rich in platelets and activated thrombin with a platelet concentration five times superior to the haematic one. The platelet gel is combined with fragments of autologous bone and synthetic bone during surgical operation. To allow a comparative assessment of the degree of fusion achieved with and without application of the platelet preparation in each patient, it was arbitrarily decided to use it in only one half of the operative field. All patients underwent serial CT scans 3 and 6 months after surgery as well as plain X-rays to evaluate bone fusion. The reconstructed CT images, especially in sagittal and axial planes, permitted an evaluation of the degree of vertebral fusion and "bone growth". The fusion rate was calculated measuring the increment of bone density on CT images, by means of an evaluation of the ROI (HU) in the newly formed bone, and comparing bone density within the bone callus formed by autologous and synthetic bone alone in the one to which the platelet preparation had been added. A good rate of fusion was observed in all patients. Furthermore, a comparative analysis of ROI at 3 and 6 months after surgery demonstrated a high increase in the fusion rate during the first 3 months after surgery. After 6 months the differences in ROI between the two sides had balanced out. However, at 6-month follow-up examination, bone density in the half of the surgical field in which platelet gel had been added to autologous-heterologous bone was higher in comparison to the contralateral one. Bony neoformation after posterior-lateral arthrodesis is well-evident 3 months after surgery and usually continues gradually for the following 18-24 months. The autologous platelet preparation used seems to accelerate bony deposition and to promote tissue healing, increasing bone density at the level of posterior-lateral arthrodesis. Moreover, this preparation has low production costs and is easy to apply.

Five-year outcome of stand-alone fusion using carbon cages in cervical disc arthrosis

From January 1, 2001 to December 31, 2003, in the Neurosurgery Department of Rome University o "Sapienza," 167 patients underwent anterior surgery for cervical spondylodiscoarthrosis. The levels treated by the anterior stand-alone technique were: C3-C4 (11%), C4-C5 (19%), C5-C6 (40%), and C6-C7 (30%). All patients underwent left anterior presternocleidomastoid-precarotid approach, microdiscectomy, and interbody fusion using a carbon fiber cage filled with hydroxyapatite. All patients were discharged within 48 h after surgery with cervical orthosis. In one case, a hematoma of the surgical site occurred within 12 h of surgery; for this reason the patient underwent surgical revision and was discharged 4 days later. All patients have worn cervical orthosis for a mean period of 7 weeks and underwent radiological follow-up with cervical RX at 1 and 3 months after surgery. All patients underwent follow-up from 54 to 90 months after surgery, and all of them underwent cervical RX, cervical CT scans for the estimate of fusion, and evaluation of neurological status using VAS and NDI. Of 167 patients, 132 were cooperative for this study, 18 were non-cooperative, and 17 died. The estimation of fusion made by cervical CT scans with sagittal reconstruction showed complete osteointegration of the cage in 115 patients (87.1%), while it showed pseudoarthrosis in 17 patients (12.9%). In 24 patients, we observed adjacent segment degeneration, and 13 of these underwent new surgical procedures in this institute or in another hospital. Clinical evaluation with VAS and NDI showed a good outcome, with poorest benefit in patients over 60 years. The clinical analysis showed a good fusion rate in according with literature, 13% of non-fusion rate without clinical evidence and 20% of ASDegeneration but only 10% had required new surgery. We also observed that patients over 60 years of age had less satisfactory outcome, probably related with the evolution of pathophysiological degeneration of the cervical spine. In the opinion, pseudoarthrosis is caused by malpositioning of the carbon fiber cage.

Anterior approach to the thoracic spine

An anterior approach affords the spine surgeon excellent visualization and access to the anterior thoracic spine, the vertebral bodies, intervertebral disks, spinal canal, and nerve roots. This approach is currently used in the surgical treatment of thoracic disk disease, vertebral osteomyelitis or discitis, fractures and tumors of the vertebral bodies, allowing for proper decompression of neural elements and spine stabilization. Over a 10-year period in a single institution, a total of 142 patients with a mean age of 49.6 years underwent anterior thoracic exposure of the spine. The indication for surgery was trauma fracture in 20 patients, malignancy in 35, degenerative disease in 29 and correction of scoliosis in 58. Surgical approaches were determined based on the location and length of spinal involvement, including cervico-thoracic approach (15) thoracotomic approach (85) video-assisted thoracoscopy (10) and thoracolumbar exposure (32). Mean operative time was 334 min (range from 256 to 410 min). There was no perioperative mortality. Thirty-one patients (21.8%) developed postoperative complications. The anterior approach to the thoracic spine is safe and effective and even the presence of complications can be appropriately managed. An adequate preoperative evaluation stratifying the risk and instituting measures to reduce it, accurate surgical planning and careful surgical technique are key to yielding a good outcome and to reduce the risk of complications.

Intramedullary non-specific inflammatory lesion of thoracic spine: a case report

Background

There are several non-neoplastic lesions which mimick intramedullary spinal cord neoplasm in their radiographic and clinical presentation. These can be classified as either infectious (TB, fungal, bacterial, parasytic, syphilis, CMV, HSV) and non-infectious (sarcoid, MS, myelitis, ADEM, SLE) inflammatory lesions, idiopathic necrotizing myelopathy, unusual vascular lesions and radiation myelopathy. Although biopsy may be indicated in many cases, an erroneous diagnosis of intramedullary neoplasm can often be eliminated pre-operatively.

Case description

the authors report a very rare case of intramedullary non-specific inflammatory lesion of unknown origin, without signs of infection or demyelinization, in a woman who showed no other evidence of systemic disease.

Conclusions

Intramedullary lesions that mimick a tumor can be various and difficult to interpret. Preoperative MRI does not allow a certain diagnosis because these lesions have a very similar signal intensity pattern. Specific tests for infective pathologies are useful for diagnosis, but histological examination is essential for establishing a certain diagnosis. In our case the final histological examination and the specific tests that we performed have not cleared our doubts regarding the nature of the lesion that remains controversial.

Paraganglioma of the filum terminale: case report

Background

Paragangliomas affecting the filum terminale are extremely rare, benign tumors. The literature yielded thirty-two cases of paraganglioma in this site.

Case presentation

A 49 year-old-man, whose presenting symptoms were low back pain and left leg weakness, was diagnosed as having a paraganglioma of the filum terminale. The clinical, histological and radiological characteristics of this case, that brings the total number of cases described to 33, are discussed in the light of published data.

Conclusions

This extremely rare pathology can usually be successfully treated by total surgical resection, which represents the gold standard. In the event of incomplete removal, assiduous long-term follow-up is mandatory.

Multiple disc herniations in a type II diabetic patient: case report and review of the literature

Disc herniation is a common pathology associated with physical trauma or degenerative diseases. The authors present the case of a patient with 8 disc herniations without known risk factors or other associated pathologies except for a long story of type II diabetes. Basing on studies reported in literature, it can be assumed that diabetes may be the reason of multiple disc herniations in this case.

Tc-99m Exametazime-Labeled Leukocyte Scans in the Study of Infections in Skull Neurosurgery

Diagnosis and follow-up of skull infections are usually performed by neurologic examination, laboratory tests and instrumental diagnostic methods such as computed tomography (CT) and magnetic resonance imaging (MRI). These have, however, shown some limitations for specificity. The aim of the current study was to evaluate the overall contribution of Tc-99m exametazime-labeled leukocyte imaging scan Tc-99m hexamethylpropyleneamine (HMPAO) labeled white blood cells (WBC) in the diagnosis and management of infections in skull neurosurgery. Thirty-four patients were subdivided into 4 groups on the basis of the suspected pathology: intracerebral lesions on CT or MRI (group A, n = 20), suspected postsurgical infections (group B, n = 6), suspected deep infection of the surgical wound (group C, n = 4), and suspected infection of the ventriculoperitoneal shunt (group D, n = 4). All patients underwent CT, MRI, and Tc-99m HMPAO WBC imaging. Patients in group C also underwent bacteriologic and culture examinations of wound secretions if present. In positive cases in group A, Tc-99m HMPAO WBC imaging was repeated. The scintigraphic results were compared with histologic findings in patients who underwent surgery and with the results of a 12-month clinical follow-up in the remaining patients. Tc-99m HMPAO WBC scans correctly detected the infections in all groups. Furthermore, such imaging proved to be able to document recovery from the disease in all of the assessed cerebral abscesses. This study may have an important role both in the diagnosis and in the management of infections in skull neurosurgery, which, it is hoped, will be confirmed in the future.

Evaluation of CZ-resin vials for packaging protein-based parenteral formulations

Due to the fact that some proteins have a tendency to bind to glass surfaces, plastic CZ-resin vials were evaluated as an alternative material to glass vials for packaging protein-based parenteral formulations. Physico-chemical tests including protein binding, extractable evaluation, oxygen permeation, light transmission and moisture loss were performed. Data show that two proteins (A and B) were found to bind to USP type I glass but not to CZ-resin. The CZ-resin vials passed all USP test specifications for extractables (organic extractable, non-volatile residue and residue on ignition). The oxygen permeation rate (79.06 cm(3)mm/m(2)24 h atm) was consistent with that reported by the vendor (67 cm(3)mm/m(2)24 h atm). The value obtained for light transmission, which was also found to be consistent with that reported by the vendor, shows that these vials offer no protection from light. The average moisture loss from 2 cm(3) vials filled with water was gravimetrically determined to be 0.04 mg/day/vial when the vials were stored at 40 degrees C/75% relative humidity (RH). Assuming a 1cm(3) product fill, this corresponds to approximately a 3% loss over a 2-year period. However, moisture loss was found to be negligible at the typical storage condition of 5 degrees C for protein formulations. The physico-chemical tests indicate that CZ-resin vial is a suitable candidate for packaging parenteral formulations since it shows low moisture loss at typical storage condition of 5 degrees C, and does not leach out extractables. However, it should not be used for light-sensitive and oxygen-sensitive parenteral formulations. For proteins A and B, the CZ-resin vial is a viable alternate to the use of glass vials since it offered significantly less protein binding. Protein binding in general, should be evaluated on a case by case basis, since it may vary for different proteins and under different formulation conditions.

Reconstruction of suboccipital craniectomy with autologous bone chips

BACKGROUND

In patients submitted to suboccipital craniectomy in whom the bone is not repositioned, there may be a significant aesthetic defect due to lack of bone tissue, sometimes accompanied by paresthaesia and painful symptoms.

METHOD

In 15 patients submitted to suboccipital craniectomy, the bone chips were repositioned during wound closure.

FINDINGS

At a mean follow up of 19 months (from 6 to 36 months), 2 patients (13%) complained of mild wound discomfort or occasional local pain. Twelve patients underwent control CT-scan. In three cases (25%) the bone fragments had been partly reabsorbed whereas in the other 9 (75%) they either formed a thin (4 patients) or consistent (5 patients) bony wall, with variable degree of adaptation to the contour of the contralateral occipital bone. The best cosmetic and functional results were obtained in young patients in whom the cerebellar parenchyma was well-preserved, as opposed to those in whom a CSF collection had replaced areas of cerebellar tissue.

INTERPRETATION

In the majority of cases in whom an osteoplastic suboccipital craniotomy is not possible, repositioning of the bone chips from suboccipital craniectomy is able to restore a bone table, thus allowing morphological and functional recovery of the occipital region.

Occipitocervical pseudomalignant osseous tumor of the soft tissue (Fasciitis ossificans). Case report

The authors describe the case of a 12-year-old girl in whom a pseudomalignant osseous tumor of the soft tissue was diagnosed. The lesion was resected, and at 3-year postresection follow-up examination, neuroradiological studies demonstrated no recurrence of the tumor.

Chronic subdural haematomas in patients aged under 50

The clinical findings in 31 patients with chronic subdural haematoma (CSH), aged between 20 and 50, are described. Aetiopathogenetic factors responsible for the formation of CSH match those of patients aged over 50 with CSH. A history of cranial trauma was present in 77% of the cases. In the remaining patients, a defect of haemostatic mechanisms was responsible for the subdural blood collection. On the computed tomography (CT) the haematoma generally appears as a thin subdural layer. The reliability of magnetic resonance imaging for detection of CSH makes it the most desirable investigation in such patients. Prognosis is influenced by preoperative clinical status and by the disease responsible for the formation of CSH.

Supratentorial hemangioblastoma in a patient with breast cancer. A case report

Patients with breast cancer may develop cerebral metastasis. Radio- and chemotherapy are advocated as an alternative to surgery in such patients. A woman operated on for breast cancer 2 years earlier developed a cerebral lesion. A definite preoperative diagnosis of the lesion was not possible on the basis of CT and MRI findings. The lesion proved to be a supratentorial hemangioblastoma. Neurosurgical treatment is recommended for patients with breast cancer who present a cerebral lesion, since a correct diagnosis may only be possible in the operating theater.

Gunshot wound of the atlas in a youth

The case of a bullet retained, without causing neurological symptoms, in the anterior arch of a youth's atlas after a gun had been fired a short distance from his mouth is reported. The patient was managed with external stabilization.

Chronic subdural haematoma: a possible relationship with tamoxifen

Five patients operated on between 6 months and 7 years earlier for breast cancer were surgically treated for chronic subdural haematoma. This unusual association may be explained on the basis of known factors such as coagulative impairment subsequent to chemotherapy, a degree of cerebral atrophy or mild trauma. On the other hand, since four of the patients were taking antioestrogen therapy to control the disease, it is speculated that the oestrogenic properties of tamoxifen may have contributed to subdural bleeding.

Primary benign tumors of the orbital cavity: comparative data in a series of patients with optic nerve glioma, sheath meningioma, or neurinoma

BACKGROUND

Patients operated on for the most common benign pathologies of the orbital cavity-optic nerve glioma, sheath meningioma and neurinoma-should be surgically treated. However, postoperative visual impairment is frequently inevitable. A wait-and-see policy due to a slow rate of growth of these lesions is criticized.

METHODS

Collecting data from three series of patients operated, we compare the surgical procedures and long-term results.

RESULTS

"En bloc" removal in patients with optic nerve glioma led to complete visual deficit but ensures excellent long-term prognosis. Because optic nerve meningiomas are typically circumferential to the optic nerve and adhere tightly to the perineural pial microvascular structures, it is impossible to avoid trauma to the optic nerve and recurrences. Patients with neurinoma of the orbital cavity have the most favourable prognosis both in terms of visual function as well as long-term quality of life. Due to its slow rate of growth, a wait-and-see policy can be adopted for optic nerve glioma before deciding on surgical removal, whereas surgical treatment of meningioma may be postponed if symptoms are slight and steady. Removal of orbital cavity neurinoma should not be postponed since surgical outcome is excellent.

Solitary plasmacytoma of the spine: relationship of IGM to tumour progression and recurrence

The authors report a retrospective study of 15 patients with solitary vertebral plasmacytoma. 15 patients were considered in this study on the basis of the following characteristics: 1) histologically confirmed plasmacytoma following surgical removal; 2) existence of a single vertebral lesion, documented by skeletal and MRI scan; 3) no signs, at diagnosis of disseminated disease by blood laboratory test, urine analysis, sternal puncture, iliac bone marrow biopsy, a total-body CT scan. The clinical course of the patients has been analysed on the basis of the following factors: age, sex, length of clinical history before diagnosis, site, presence/absence of the M component. The M component is an electrophoretically homogeneous immunoglobin. The most significant factors for predicting development of multiple myeloma proved to be the presence /absence of the M component at diagnosis and, to a lesser degree, the age of the patient. In the light of other reports too, it would seem that the presence of the M component at diagnosis is a reflection of aggressive biological and clinical tumour behaviour.