Posterior Transdural Discectomy for Thoracic Disc Herniation.

AIM: To evaluate the safety and efficacy of posterior transdural discectomy for thoracic disc herniation. MATERIAL AND METHODS: The medical records of seven patients who underwent posterior transdural discectomy for thoracic disc herniation were retrospectively evaluated. RESULTS: Between 2012 and 2020, seven patients (five men and two women) who were aged between 17 and 74 years underwent posterior transdural discectomy. Numbness is the most common presenting symptom, and two patients complained of urinary incontinence. T10-11 was the most affected level. All patients underwent at least 6 months of follow-up. There were no postoperative cerebrospinal fluid leaks and neurological complications postoperatively. All patients maintained their baseline neurological status or improved after surgery. No patient had secondary neurological deterioration or need for further surgical treatment. CONCLUSION: The posterior transdural approach is a safe procedure that should be considered in lateral and paracentral thoracic disc herniations providing a more direct surgical intervention.

Statistical Shape Analyses of Pediatric Patients with Scoliosis After Surgical Correction.

AIM: To investigate the preoperative and postoperative differences in the upper-body and spinal shapes of patients with scoliosis. MATERIAL AND METHODS: Digitized two-dimensional X-ray images were used to obtain the shapes of the upper-body and spine. The preoperative and postoperative mean shapes were compared by using a Generalized Procrustes analysis. The thin plate spline (TPS) method was used to evaluate the spinal shape deformation between the preoperative and postoperative periods. RESULTS: The pre- and postoperative upper-body and spinal shape differences were significant. The TPS graphics showed highlevel deformations between the pre- and postoperative periods. The left superior border of the L4 spinous process showed the highest deformation. CONCLUSION: The preoperative and postoperative upper-body and spinal shape differences and structural deformations that correlated with scoliosis were shown to be significant.

Diagnostic value of the CSF levels of D-Lactate and pro-inflammatory cytokines (TNF-alpha, IL-6, IL-8 and IL-17) in the patients with suspected nosocomial meningitis.

INTRODUCTION: This study aims to determine the diagnostic value of IL-6, IL-8, IL-17, TNF-α and D-lactate levels in the cerebrospinal fluid (CSF) in nosocomial meningitis. METHODS: CSF levels of cytokines and D-lactate were compared across 29 episodes who were diagnosed with nosocomial meningitis, 38 episodes with pleocytosis but without meningitis and 54 control subjects. RESULTS: CSF levels of IL-6, IL-8, and D-lactate were higher in the group with nosocomial meningitis compared to the control group and to the group with pleocytosis without meningitis (p<0.05). For the levels of IL-6, when the threshold was considered to be > 440 pg/mL, the sensitivity and specificity were 55.17% and 94.74%, respectively. For IL-8 levels, when the threshold was considered to be >1249 pg/mL, the sensitivity and specificity were 44.83% and 84.21%, respectively. In the patients with nosocomial meningitis, when the threshold of D-lactate levels was considered to be >1.05µmol/mL, the sensitivity and specificity were found to be 75.86% and 63.16%, respectively. In the pleocytosis without meningitis CSF samples and in the CSF samples diagnosed with nosocomial meningitis, the highest AUC was calculated for triple combination model of IL-6, IL-8, and D-lactate levels (AUC= 0.801, p<0.001), and double combination model IL-6 and IL-8 (AUC= 0.790) (p<0.001). CONCLUSION: In our study, we have concluded that IL-6, IL-8 and D-lactate levels could be diagnostic markers for nosocomial meningitis.

Leptomeningeal pneumocephalus and pneumorrhachis: Signs of pneumothorax in case of syringopleural shunting.

In this article, we present a case of leptomeningeal pneumocephalus and pneumorrhachis secondary to pneumothorax that occurred six years after syringopleural shunting.

Contribution of the xenograft bone plate-screw system in lumbar transpedicular stabilization: An in vivo study in dogs.

OBJECTIVES: Xenograft bone plate-screws (XBPSs) can be alternative tools in lumbar transpedicular stabilization (TS). The aim of this study was to show biomechanical and histopathological contribution of the XBPSs system in lumbar TS. MATERIALS AND METHODS: Fifteen (n = 15) hybrid dog and ten (n = 10) L2-4 cadaveric specimens were included in the study. The dogs were separated according to surgical techniques: L3 laminectomy and bilateral facetectomy (LBF) in Group I (experimental group [EG I] (n = 5), L3 LBF plus TS with metal plate-screws (MPSs) in Group II (EG II) (n = 5), and L3 LBF plus TS with XBPSs in Group III (EG III) (n = 5). The cadaveric specimens were separated to L2-4 intact in Group I (CG I), (n = 5), and L3 LBF in Group II (CG II), (n = 5). The dogs were sacrificed at the end of 3rd month, and their L2-4 spinal segments were en bloc removed and prepared as in control groups. Flexion, extension, left-right bending, rotation, and compression tests were applied to all segments. Stiffness values were calculated and analyzed statistically. All dog segments were evaluated histopathologically. RESULTS: XBPS system showed a higher average stiffness values for left bending, extension, flexion, and compression compared to MPS, but these differences were not statistically meaningful. XBPS system had superiority to the fusion formation, as well. CONCLUSIONS: XBPSs provide stability and help the fusion formation, but this system does not have a biomechanical advantage over MPS system in TS.

Rod Migration to the Thoracic Subarachnoid Space after C1-2 Instrumentation: A Case Report and Literature Review.

Posterior instrumented fusion of the cervical spine is a common surgical procedure in the treatment of cervical subluxation, fractures, and stenosis. Although malpositions are commonly seen, it is rare to observe the malposition of the rod or interconnection because of hardware failure. A 62-year-old woman with spastic tetraparesis as a sequel to pediatric meningitis with C1 -C2 cervical subluxation and myelomalacia had undergone laminectomy of C1 and C1 lateral mass and C2 bilateral pedicular screw fixation. Three years after the stabilization, she presented with complaints of headache, neck pain, and difficulty walking. There was no history of trauma during that period. A previously unrecorded and unusual migration of a rod through the thoracic subarachnoid space was detected. In this study, we report a case of atlantoaxial stabilization using the screw-rod technique that was followed by rod migration to the thoracic subarachnoid space, and outline the subsequent management of the case. Failure of bony fusion can result in micromotion and subsequent migration of fixation device components. Routine radiographic follow-up could be used to identify migration events.

Effects of Systemic and Local Interferon Beta-1a on Epidural Fibrosis.

STUDY DESIGN: Level 1 randomized controlled study. PURPOSE: To investigate the effects of systemic and local interferon-beta-1a (IFN-ß-1a) on prevention of epidural fibrosis using histopathological parameters. OVERVIEW OF LITERATURE: Epidural fibrosis involves fibroblastic invasion of nerve roots into the epidural space. Formation of dense fibrous tissue causes lumbar and radicular pain. Many surgical techniques and several materials have been proposed in the literature, but no study has assessed the effect of IFN-ß-1a on prevention of epidural fibrosis. METHODS: Forty-eight adult female Sprague-Dawley rats were divided into six groups of eight: sham group, control group, systemic 44 µg IFN-ß-1a group and 22 µg IFN-ß-1a group (after laminectomy and discectomy, 0.28 mL and 0.14 mL IFN-ß-1a applied subcutaneously three times for a week, respectively), local 44 µg IFN-ß-1a group (laminectomy and discectomy, followed by 0.28 mL IFN-ß-1a on the surgical area), and local 22 µg IFN-ß-1a group (laminectomy and discectomy, followed by 0.14 mL IFN-ß-1a on the surgical area). All rats were sacrificed after 4 weeks and groups were evaluated histopathologically. RESULTS: Compared with sham and control groups, significantly less epidural fibrosis, dural adhesion, and fibroblast cell density were observed in the local and systemic 44 µg IFN-ß-1a groups. No other differences were evident between the local and systemic groups. CONCLUSIONS: IFN-ß-1a is effective in preventing epidural fibrosis with systemic and local application.

Effects of cross-linked high-molecular-weight hyaluronic acid on epidural fibrosis: experimental study.

OBJECT: Epidural fibrosis is nonphysiological scar formation, usually at the site of neurosurgical access into the spinal canal, in the intimate vicinity of and around the origin of the radicular sheath. The formation of dense fibrous tissue causes lumbar and radicular pain. In addition to radicular symptoms, the formation of scar tissue may cause problems during reoperation. The authors aimed to investigate the effects of cross-linked high-molecular-weight hyaluronic acid (HA), an HA derivative known as HA gel, on the prevention of epidural fibrosis by using histopathological and biochemical parameters. METHODS: Fifty-six adult female Sprague-Dawley rats were evaluated. The rats were divided into 4 groups. Rats in the sham group (n = 14) underwent laminectomy and discectomy and received no treatment; rats in the control group (n = 14) underwent laminectomy and discectomy and received 0.9% NaCl treatment in the surgical area; rats in the HA group (n = 14) received HA treatment at the surgical area after laminectomy and discectomy; and rats in the HA gel group (n = 14) underwent laminectomy and discectomy in addition to receiving treatment with cross-linked high-molecular-weight HA in the surgical area. All rats were decapitated after 4 weeks, and the specimens were evaluated histopathologically and biochemically. The results were statistically compared using the Mann-Whitney U-test. RESULTS: Compared with the sham and control groups, the HA and HA gel groups showed significantly lower fibroblast cell density and tissue hydroxyproline concentrations (p < 0.05). There was statistically significant lower dural adhesion and foreign-body reaction between the control and HA gel groups (p < 0.05). Granulation tissue and epidural fibrosis were significantly lower in the HA and HA gel groups compared with the sham group (p < 0.05). There were no significant differences in any histopathological parameters or biochemical values between Groups 3 and 4 (p > 0.05). CONCLUSIONS: Cross-linked high-molecular-weight HA had positive effects on the prevention of epidural fibrosis and the reduction of fibrotic tissue density. The efficacy of this agent should also be verified in further experimental and clinical studies.

Biomechanical contribution of the rib cage to thoracic stability.

STUDY DESIGN: In vitro assessment of rib cage biomechanics in the region of true ribs with the ribs intact then sequentially resected in 5 steps. OBJECTIVE: To determine the contribution of the rib cage to thoracic spine stability and kinematics. SUMMARY OF BACKGROUND DATA: Previous in vitro studies of rib cage biomechanics have used animal spines or human cadaveric spines with ribs left unsecured, limiting the ability of the ribs to contribute to stability. METHODS: Eight upper thoracic specimens that included 4 ribs and sternum were tested in special fixtures that disallowed relative movement of the distal ribs and their vertebrae. While applying 7.5 Nm pure moments in 3 planes, angular motion at the middle motion segment was studied in intact specimens and then (1) after splitting the sternum, (2) after removing the sternum, (3) after removing 50% of ribs, (4) after removing 75% of ribs, and (5) after disarticulating and completely removing ribs. RESULTS: During flexion/extension, the sternum and anterior rib cage most contributed to stability. During lateral bending, the posterior rib cage most contributed to stability. During axial rotation, stability was directly related to the proportion of ribs remaining intact. On average, intact ribs accounted for 78% of thoracic stability. An intact rib cage shifted the axis of rotation unpredictably, but its position remained consistent after partial resection of the ribs. During lateral bending, coupled axial rotation was mild and unaffected by ribs. CONCLUSION: Because of testing methodology, the rib cage accounted for a greater percentage of thoracic stability than previously estimated. Different rib cage structures resisted motion in different loading planes.

Pediatric multilevel spine injuries: an institutional experience.

OBJECT: Spinal column trauma is relatively uncommon in the pediatric population, representing 1-2% of all pediatric fractures. However, pediatric spinal injury at more than one level is not uncommon. The purpose of this study was to evaluate the mechanisms and patterns of the injury and factors affecting management and outcomes of pediatric multilevel spine injuries. PATIENTS AND METHODS: Patients with pediatric spine injury (183) were retrospectively reviewed. Patients (28 boys, 20 girls; mean age 12.8 years; range 3 to 16 years) identified with multilevel spinal injuries were 48 (26.2%): 7 patients (14.5%) were between 3 and 9 years of age, and 41 patients (85.5%) were between 9 and 16 years of age. Of the 48 patients, 30 (62.5%) were at contiguous levels and 18 (37.5%) were at noncontiguous. A total of 126 injured vertebrae were diagnosed. The cervical region alone was most frequently (31.2%) involved, and the thoracic region alone was the least frequently involved (12.5%). Overall, 73% of patients were neurologically intact, 4.1% had incomplete spinal cord injury (SCI), and 8.3% had complete SCI. Treatment was conservative in 36 (75%) patients. Surgical treatments were done in 12 patients (25%). Postoperatively, one patient (16.6%) with initial neurologic deficit improved. The overall mortality rate was 6.2%. CONCLUSIONS: Multilevel spine injuries are most common in children between 9 and 16 years of age and are mainly located in the cervical region. The rostral injury was most often responsible for the neurologic deficit. The treatment of multilevel spine injuries should follow the same principles as single level injury, stability and neurologic symptoms indicate the appropriate treatment.

In vitro biomechanical analysis of a new lumbar low-profile locking screw-plate construct versus a standard top-loading cantilevered pedicle screw-rod construct: technical report.

OBJECTIVE: A standard top-loading lumbar pedicle screw-rod system is compared with a pedicle screw-plate system with smaller-diameter screws, more medial entry, and lower profile to assess the relative stability, strength, and resistance to fatigue of the 2 systems. METHODS: Seven human cadaveric specimens were studied with each surgical construct. Nondestructive, nonconstraining pure moments were applied to specimens to induce flexion, extension, lateral bending, and axial rotation while recording L5-S1 motion optoelectronically. After initial tests, specimens were fatigued for 10,000 cycles and retested to assess early postoperative loosening. Specimens were then loaded to failure in hyperextension. RESULTS: The standard screw-rod construct reduced range of motion to a mean of 20% of normal, whereas the screw-plate construct reduced range of motion to 13% of normal. Differences between systems were not significant in any loading mode (P > 0.06). The 14% loosening of the screw-rod system with fatigue was not significantly different from the 10% loosening observed with the screw-plate system (P > 0.15). Mean failure loads of 30 Nm for screw-rod and 37 Nm for screw-plate were also not significantly different (P = 0.38). CONCLUSION: Posterior fixation at L5-S1 using the low-profile screw-plate system offers stability, resistance to fatigue, and resistance to failure equivalent to fixation using a standard cantilevered pedicle screw-rod system.

Trajectory analysis and pullout strength of self-centering lumbar pedicle screws.

OBJECT: An experiment was performed to study the limits of the ability of screws designed to center themselves in the pedicle during insertion, and to study whether straight-ahead versus inward screw insertion trajectories differ in their resistance to pullout. METHODS: Forty-nine human cadaveric lumbar vertebrae were studied. Pedicle screws were inserted in trajectories starting 0 degrees, 10 degrees, 20 degrees, or 30 degrees from the optimal trajectory, either medially or laterally misdirected. The surgeon then inserted the screw with forward thrust but without resisting the screw's tendency to reorient its own trajectory during insertion. On the opposite pedicle, a control screw was inserted with the more standard inward-angled anatomical trajectory and insertion point. Cortical wall violation during insertion was recorded. Screws were then pulled out at a constant displacement rate while ultimate strength was recorded. RESULTS: Lateral misdirection as small as 10 degrees was likely to lead to cortical wall violation (3 of 7 violations). Conversely, medial misdirection usually resulted in safe screw insertion (1 of 21 violations for 10 degrees, 20 degrees, or 30 degrees medial misdirection). The resistance to pullout of screws inserted in a straight-ahead trajectory did not differ significantly from that of screws inserted along an inward trajectory (p = 0.68). CONCLUSIONS: Self-tapping, self-drilling pedicle screws can redirect themselves to a much greater extent during medial than during lateral misdirection. The cortical wall is more likely to be violated laterally than medially. The strength of straight-ahead and inward trajectories was equivalent.

Sylvian cistern dermoid cyst presenting with dysgeusia.

It is rare for a patient with a dermoid cyst (DC) to present with taste dysfunction. A 58-year-old man presented with an altered sense of taste. Magnetic resonance imaging of the brain showed a mass lesion in the right insula with compression effect. The tumour was resected and was found to be a DC. The postoperative course was uneventful, and the patient resumed his usual taste sensation within the early postoperative period. To the best of our knowledge, this is the first report of a sylvian cistern DC that presented with dysgeusia.

Primary thoracolumbar Ewing's sarcoma presenting as isolated epidural mass.

BACKGROUND CONTEXT: Ewing's sarcoma is the most common childhood malignancy of bone, but it rarely occurs as a primary extraosseous epidural tumor. PURPOSE: To heighten awareness and treatment options of this rare (epidural) presentation of Ewing's sarcoma. STUDY DESIGN: Case report. METHODS: Retrospective review. RESULTS: We present a 13-year-old boy with progressive low back and bilateral lower extremity pain and normal neurologic examination. Magnetic resonance imaging showed an extradural tumor in the dorsal epidural space from T11 to L1. He underwent a posterior laminoplasty and gross total resection of tumor; histopathological diagnosis was consistent with Ewing's sarcoma. After surgery, the patient underwent adjuvant chemotherapy and irradiation. At 10 months follow-up, the patient is neurologically intact without evidence of residual disease. CONCLUSIONS: Ewing's sarcoma of the epidural space should be considered in the differential diagnosis of epidural mass lesions. Because wide surgical margins cannot be obtained, close follow-up with a low threshold for reoperation is mandatory.

Biomechanical consequences of cervical spondylectomy versus corpectomy.

OBJECTIVE: To evaluate the differences in spinal stability and stabilizing potential of instrumentation after cervical corpectomy and spondylectomy. METHODS: Seven human cadaveric specimens were tested: 1) intact; 2) after grafted C5 corpectomy and anterior C4-C6 plate; 3) after adding posterior C4-C6 screws/rods; 4) after extending posteriorly to C3-C7; 5) after grafted C5 spondylectomy, anterior C4-C6 plate, and posterior C4-C6 screws/rods; and 6) after extending posteriorly to C3-C7. Pure moments induced flexion, extension, lateral bending, and axial rotation; angular motion was recorded optically. RESULTS: After corpectomy, anterior plating alone reduced the angular range of motion to a mean of 30% of normal, whereas added posterior short- or long-segment hardware reduced range of motion significantly more (P < 0.003), to less than 5% of normal. Constructs with posterior rods spanning C3-C7 were stiffer than constructs with posterior rods spanning C4-C6 during flexion, extension, and lateral bending (P < 0.05), but not during axial rotation (P > 0.07). Combined anterior and C4-C6 posterior fixation exhibited greater stiffness after corpectomy than after spondylectomy during lateral bending (P = 0.019) and axial rotation (P = 0.001). Combined anterior and C3-C7 posterior fixation exhibited greater stiffness after corpectomy than after spondylectomy during extension (P = 0.030) and axial rotation (P = 0.0001). CONCLUSION: Circumferential fixation provides more stability than anterior instrumentation alone after cervical corpectomy. After corpectomy or spondylectomy, long circumferential instrumentation provides better stability than short circumferential fixation except during axial rotation. Circumferential fixation more effectively prevents axial rotation after corpectomy than after spondylectomy.

Stab injury of the thoracic spinal cord: case report.

Stab injuries of the spinal cord are rare. We report a case of a 22-year-old male who was hospitalized because of a spinal cord injury resulting from a stab wound in the posterior thoracolumbar area. On admission, the patient had 2/5 muscle strength of the right leg (monoparesis) and hypoesthesia below the L1 level. Radiological investigation revealed the retained tip of a knife that penetrated the spinal canal at the T12 level. An urgent right T12 hemilaminotomy was performed and retained knife fragment was removed. Six months after operation, the motor deficit had completely improved although hypoesthesia was still present. Surgery should be considered as the first-line treatment in cases of incomplete injuries of the spinal cord with retained metallic object.

Comparison of prognostic scores and surgical approaches to treat spinal metastatic tumors: a review of 57 cases.

Surgical treatment of metastatic spinal cord compression with or without neural deficit is controversial. Karnofsky and Tokuhashi scores have been proposed for prognosis of spinal metastasis. Here, we conducted a retrospective analysis of Karnofsky and modified Tokuhashi scores in 57 consecutive patients undergoing surgery for secondary spinal metastases to evaluate the value of these scores in aiding decision making for surgery. Comparison of preoperative Karnofsky and modified Tokuhashi scores with the type of the surgical approach for each patient revealed that both scores not only reliably estimate life expectancy, but also objectively improved surgical decisions. When the general status of the patient is poor (i.e., Karnofsky score less than 40% or modified Tokuhashi score of 5 or greater), palliative treatments and radiotherapy, rather than surgery, should be considered.

MR imaging in the detection of diffuse axonal injury with mild traumatic brain injury.

PURPOSE: To evaluate the occurrence and distribution of mild traumatic brain injury (MTBI) caused by diffuse axonal injury (DAI) using magnetic resonance (MR) imaging and to attempt to correlate MR findings with post-concussion symptoms (PCS). PATIENTS AND METHODS: Forty MTBI patients (mean age: 32.5 years) with normal cranial computed tomography (CT) findings were examined with standard MR protocol including T(1)-weighted, T(2)-weighted, fluid attenuated inversion recovery (FLAIR), gradient echo (GRE) and diffusion-weighted (DW) sequences. MR imaging was performed within 24 hours of injury. The lesions were classified as DAI based on their location and morphologic appearance. RESULTS: In MR imaging of five (12.5%) of the patients, the lesions compatible with DAI were observed. Four patients (10%) had the foci of low signal intensity compatible with hemorrhagic shear injury on the GRE sequence, and five (12.5%) patients had high signal intensity on FLAIR and DW sequence. CONCLUSION: MR imaging can be helpful in revealing DAI lesions in patients with normal CT scan findings after MTBI. FLAIR, GRE and DW sequences are superior to conventional spin-echo images in detecting DAI lesions.

Contribution of the xenograft bone plate-screw system in lumbar transpedicular stabilization of dogs: an in-vitro study.

We performed biomechanical comparison of a xenograft bone plate-screw (XBPS) system for achieving cadaveric lumbar transpedicular stabilization (TS) in dogs. Twenty dogs' cadaveric L(2-4) lumbar specimens were harvested and their muscles were removed, but the discs and ligaments were left intact. These specimens were separated to four groups: the L(2-4) intact group as control (group I, n = 5), the L(3) laminectomy and bilateral facetectomy group (LBF) (group II, n = 5), the LBF plus TS with metal plate-screw group (group III, n = 5) and the LBF plus TS with XBPS group (group IV, n = 5). Five kinds of biomechanical tests were applied to the specimens: flexion, extension, left-right bending and rotation. The averages of the 16 stiffness values were calculated and then these were statistically analyzed. The statistical results show that the XBPS system contributes spinal stability and this system can be a good choice for achieving TS.

Pituitary apoplexy as a cause of internal carotid artery occlusion.

Occlusion of intracranial arteries by pituitary apoplexy with resulting infarction is a rare occurrence. A 50-year-old man who presented with a history of sudden onset of frontal headache and visual impairment was admitted to another medical centre and MRI revealed a non-enhancing sellar lesion with suprasellar and infrasellar extension. Thereafter, the patient's consciousness deteriorated progressively and he showed signs of herniation; he was then referred to our centre for further evaluation. CT scanning revealed infarction of the left internal carotid artery territory. Transcranial resection of the tumour followed by a large decompressive craniotomy restored the blood flow in the internal carotid artery. Histological examination revealed the tumour to be a pituitary adenoma that contained formed blood elements. The patient's neurological status did not improve and he died on the ninth postoperative day despite vigorous treatment for controlling intracranial pressure. This case study documents a rare presentation of pituitary apoplexy that caused signs of raised intracranial pressure due to mechanical obstruction of an internal carotid artery with resulting infarction.