Hakan Bozkus

Posterior fossa arachnoid cysts

Arachnoid cysts of the posterior fossa are rare lesions that are considered to be mostly congenital in origin. In this article, we retrospectively review 12 patients who underwent surgical treatment for their symptomatic posterior fossa arachnoid cysts. The most common presenting symptoms were gait disturbances and headache. The diagnosis was established on computed tomography or magnetic resonance imaging. Surgery consisted of cyst wall excision with fenestration in nine cases and shunting procedures in three cases. In all cases except one who-died, the postsurgical follow-up neuroradiological investigations showed that the cysts had decreased in size, the cerebellum had re-expanded, and if there was preoperative hydrocephalus, the ventricular size was decreased. The follow-up period ranged from 1 to 11 years. All surviving cases are free of symptoms and no arachnoid cysts recurred. The classification, pathophysiology, differential diagnosis and surgical treatment of infratentorial arachnoid cysts are discussed and the relevant literature is reviewed.

Dynamic lumbar pedicle screw-rod stabilization: in vitro biomechanical comparison with standard rigid pedicle screw-rod stabilization

OBJECT It is unclear how the biomechanics of dynamic posterior lumbar stabilization systems and traditional rigid pedicle screw-rod systems differ. This study examined the biomechanical response of a hinged-dynamic pedicle screw compared with a standard rigid screw used in a 1-level pedicle screw-rod construct. METHODS Unembalmed human cadaveric L3-S1 segments were tested intact, after L4-5 discectomy, after rigid pedicle screw-rod fixation, and after dynamic pedicle screw-rod fixation. Specimens were loaded using pure moments to induce flexion, extension, lateral bending, and axial rotation while recording motion optoelectronically. Specimens were then loaded in physiological flexion-extension while applying 400 N of compression. Moment and force across instrumentation were recorded from pairs of strain gauges mounted on the interconnecting rods. RESULTS The hinged-dynamic screws allowed an average of 160% greater range of motion during flexion, extension, lateral bending, and axial rotation than standard rigid screws (p < 0.03) but 30% less motion than normal. When using standard screws, bending moments and axial loads on the rods were greater than the bending moments and axial loads on the rods when using dynamic screws during most loading modes (p < 0.05). The axis of rotation shifted significantly posteriorly more than 10 mm from its normal position with both devices. CONCLUSIONS In a 1-level pedicle screw-rod construct, hinged-dynamic screws allowed a quantity of motion that was substantially closer to normal motion than that allowed by rigid pedicle screws. Both systems altered kinematics similarly. Less load was borne by the hinged screw construct, indicating that the hinged-dynamic screws allow less stress shielding than standard rigid screws.

Discal cysts of the lumbar spine: report of five cases and review of the literature

Discal cysts are rare causes of low back pain and radiculopathy. Only few reports in the literature describe these pathologies. In this article, the authors report five cases (3 males and 2 females) of lumbar discal cysts treated surgically by microdiscectomy. These patients were admitted with a history of back pain and/or sciatalgia. Magnetic resonance imaging of the lumbar spine of all patients revealed lumbar discal cysts, causing compression to the spinal dura and roots. All patients were treated by partial hemilaminectomy and microscopic cyst resection. Postoperatively, the complaints showed improvement, and the patients were discharged with no complications. The cases of lumbar discal cysts are described in the literature as individual case reports, therefore; the authors performed a wide systemic review of all these cases published in PubMed and MedLine, including the patients in the present report. The data of all patients were analyzed to obtain statistically based estimated information about the incidence, the epidemiology, the natural history and the optimum management of these lesions.

Nitric Oxide (NO) metabolism in the cerebrospinal fluid of patients with severe head injury: inflammation as a possible cause of elevated no metabolites

BACKGROUND This article investigates nitric oxide (NO) metabolism following severe head injury (SHI). We wished to clarify the alterations of NO metabolism end products that is associated with SHI, and to delineate the role of inflammation in this process. METHODS In a prospective study, we simultaneously measured the concentrations of NO metabolites and interleukin-8 (IL-8) in the ventricular cerebrospinal fluid (CSF) of 11 patients who had suffered SHI. The CSF concentrations of nitrite (NO(-)(2)) and nitrate (NO(-)(3)) combined, and of IL-8 were measured during the following four time periods post-trauma: 6 to 10, 20 to 28, 40 to 56, and 64 to 74 hours. Levels were measured using the corresponding kits. RESULTS Compared to the ventricular CSF control values, all of our SHI patients had significantly elevated CSF levels of NO(-)(2) plus NO(-)(3) (NO(-)(2) + NO(-)(3)) and IL-8 during all periods tested. CSF NO(-)(2) + NO(-)(3) and IL-8 concentrations reached their maximums simultaneously at 20 to 28 hours following trauma (Spearmans rank correlation = 0.609, p < 0.05), and NO(-)(2) + NO(-)(3) levels were significantly higher than those measured at 6 to 10, 40 to 56, and 64 to 74 hours. [Nitrite-nitrate concentrations: 6-10 hours: 19.22 +/- 6.75, 20-28 hours: 25 +/- 6.2 micromol/l, 40-56 hours: 19.82 +/- 4.47, and 64-74 hours: 19.72 +/- 4.61 micromol/l, (p < 0.05). IL-8 concentrations: 6-10 hours: 3,232 +/- 2,976.2, 20-28 hours: 3,458.45 +/- 3,048 pg/mL, 40-56 hours: 2,616.41 +/- 2,539.21, 64-74 hours: 1,388.88 +/- 1,216.7 pg/mL, (p < 0.001).]. This simultaneous surge in NO(-)(2) + NO(-)(3) and IL-8 in the initial 24 hours post-traumatic indicated that inflammation secondary to SHI increased the rate of NO metabolism, resulting in higher levels of metabolites in the CSF. CONCLUSION In patients with SHI, CSF concentrations of the dominant metabolites of NO are elevated in the first 3 days after trauma. A similar concurrent spike in the CSF level of IL-8, a marker of acute inflammatory response, can also be demonstrated. These data indicate that the predominant cause of the higher CSF NO(-)(2) + NO(-)(3) concentrations observed in SHI is most likely inflammation.

Dynamic lumbar pedicle screw-rod stabilization: two-year follow-up and comparison with fusion.

Background: A lumbar pedicular dynamic stabilization system (LPDSS) is an alternative to fusion for treatment of degenerative disc disease (DDD). In this study, clinical and radiological results of one LPDSS (Saphinaz, Medikon AS, Turkey) were compared with results of rigid fixation after two-year follow-up. Methods: All patients had anteroposterior and lateral standing x-rays of the lumbar spine preoperatively and at 3 months, 12 months and 24 months after surgery. Lordosis of the lumbar spine, segmental lordosis and ratio of the height of the intervertebral disc spaces (IVS) measured preoperatively and at 3 months, 12 months and 24 months after surgery. All patients underwent MRI and/or CT preoperatively, 3months, 12 months and 24 months postoperatively. The ratio of intervertebral disc space to vertebral body height (IVS) and segmental and lumbar lordosis were evaluated preoperatively and postoperatively. Pain scores were evaluated via Visual Analog Scale (VAS) and Oswestry Disability Index (ODI) preoperatively and postoperatively. Results: In both groups, the VAS and ODI scores decreased significantly from preoperatively to postoperatively. There was no difference in the scores between groups except that a lower VAS and ODI scores were observed after 3 months in the LPDSS group. In both groups, the IVS ratio remained unchanged between preoperative and postoperative conditions. The lumbar and segmental lordotic angles decreased insignificantly to preoperative levels in the months following surgery. Conclusions: Patients with LPDSS had equivalent relief of pain and maintenance of sagittal balance to patients with standard rigid screw-rod fixation. LPDSS appears to be a good alternative to rigid fixation.

Bilateral traumatic abducens nerve paralysis with cervical spine flexion injury

Bilateral traumatic abducens nerve palsy is a rare condition. We report a case associated with cervical spine flexion injury. This may be the first such case report, as no similar case was found in our review of the literature. The mechanisms of injury in this case are relevant to theories that explain hyperextension injuries.

The Results of ??-tricalcium Phosphate Coated Hydroxyapatite (??-TCP/HA) Grafts for Interbody Fusion After Anterior Cervical Discectomy

Study Design The efficacy of tricalcium phosphate and hydroxyapatite (β-TCP/HA) grafts was studied after anterior cervical discectomy (ACD). Objective This study presents our observations about the efficacy of β-TCP/HA grafts after ACD. Summary of Background Data Especially in the last 2 decades, fusion materials such as autograft and allograft, as well as different kind of cages were used to maintain fusion after ACD. Methods β-TCP/HA grafts after ACD were used in 17 patients. The cervical and radicular pain was evaluated via visual analog scale (VAS) score preoperatively, at postoperative third week, and after 20 months (range: 18 to 24 mo) after the operation. The radiologic evaluations were done preoperatively, at postoperative first day and at the latest follow-up. The VAS, intervertebral space ratio, height of intervertebral disc space and neural foramen, and cervical and segmental lordosis angles were recorded preoperatively and during the postoperative follow-up period. The presence of fusion was controlled in computed tomography scans taken at the latest follow-up. Results Both clinical and radiologic evaluations yielded satisfactory results. VAS scores decreased significantly in all patients. The intervertebral space and neural foramen and intervertebral disc heights increased at postoperative day 1 but were found to be decreased at the latest follow-up (P<0.05). On the contrary the cervical and segmental lordosis angles decreased at postoperative day 1 but were found to be increased at the latest follow-up (P<0.05). There was a solid fusion in 16 out of 17 patients (94.11%). Conclusions Although there was a loss of the initially obtained neural foraminal and disc height, the application of β-TCP/HA graft after ACD resulted in a high rate of fusion and patient satisfaction. Additionally, the cervical and segmental lordosis was preserved. We concluded that it is a good alternative to current methods to maintain cervical alignment and fusion after ACD.

Spontaneous pyogenic spinal epidural abscess.

AIM Spontaneous pyogenic spinal epidural abscess (SEA) is a rare condition but might be devastating and fatal. Traditional treatment is surgical decompression and antibiotics. A retrospective study was designed to assess the eff ect of clinical findings and treatment methods on the outcome. MATERIAL AND METHODS 14 patients were reviewed (10 male, 4 female, mean age 59.14). Six dorsal, seven ventral and one dorsal with ventral SEA were observed. SEA found in thoracal (5), lumbar (4), cervical (3) regions. One patient showed both cervical and thoracal and one patient showed cervical, thoracal and lumbar involvement. All patients received minimum 3 weeks of I.V., followed by minimum 3 weeks of oral antibiotics. All patients complained of spinal pain. Ten patients presented with fever. Neurological deficit was observed in 9 cases. RESULTS A total of 22 interventions was performed. Instrumentation was applied in 5 cases. Full recovery was achieved in 7 patients, significant improvement was observed in 5 patients. The neurological findings did not change in one patient. One mortality and one morbidity were observed. CONCLUSION Spontaneous SEA is a rare disease but might result in catastrophic neurological deficits and fatal even with prompt treatment. Therefore, one should always keep SEA in mind if a patient presents with fever, vague and spinal pain.

Unilateral dynamic stabilization for unilateral lumbar spinal pathologies; a new surgical concept.

AIM Minimally invasive surgical techniques for spine surgery have gained popularity over the last decade. In this study, the authors describe a unilateral dynamic stabilization for unilateral spinal pathologies. MATERIAL AND METHODS A total of 7 patients with an average age of 46.1 years (range 21-80 years) were included in this study. They are represented various spinal pathologies (degenerative disorders, various tumor pathologies) and having undergone a unilateral facetectomy (or facetectomies) with or without a hemilaminectomy procedure were analyzed in this study. The surgical stabilization was achieved with unilateral dynamic stabilization. RESULTS The new surgical concept is described here, and the comparative early results of the Oswestry disability index (ODI) and the visual analog scale (VAS) are presented as well. The preoperative average ODI was 73.14 (range 62-94), and the average VAS was 8.14 (range 7-10). Twelve months after the surgery, ODI was 10.6 (range 0-16), and the average VAS was 1 (range 0-2) (p < 0.01). CONCLUSION Although the limited number of cases analyzed reflects data of only early patient outcome, the procedure is safe, feasible, and cost effective. The unilateral dynamic pedicle screw stabilization without fusion is as a technical option to avoid possible segmental instability after unilateral total facetectomy procedure.

Which is better Stainless Steel or Titanium alloy

AIM To investigate immunologic reactions after implantation of stainless steel (SS) alloy and titanium (Ti) alloy in a rat model. Macrophage and cytokine responses have been reported after the in vivo and in vitro application of different biomaterials. MATERIAL AND METHODS Wistar albino rats after an exploration of the thoracolumbar paravertebral muscle tissue of the subjects, group I underwent a sham surgery, and groups II and III were implanted Ti alloy and SS alloy rods respectively. The CD4, CD8, CD25 (IL-2R) (lymphocyte and CD4 gate), CD4+CD8+ and CD4+CD25+Foxp3+ (Tregs), IL-4, IL-10, IL-6, IL-17A, TGF-β, TNF-α in the blood were analyzed. RESULTS CD4, CD25 (IL-2R), CD4+CD8+ and Tregs levels were lower in the Group III compared to the sham and Group IIs. IL-6, IL-17A, TGF-β and TNF-α levels in the G III showed a significant increase on all days in comparison with the sham and Group II. IL-4 and IL-10 levels, were lower in the Group III than those in the Group II; and a significant decrease was observed in the IL-10 level. While there was a reduction in IL-6 and IL-17A levels in the Group II as opposed to the sham group. CONCLUSION As opposed to SS alloy, Ti alloy suppresses the development of inflammations by inhibiting proinflammatory response; strengthens the humoral immune system by intensifying the antibody-dependent immune response; triggers the development of immune tolerance by regulating the immune response; and activates the mechanism that prevents immune response-related damage from occurring.