Onur Yaman

Subarachnoid, subdural and interdural spaces at the clival region: an anatomical study.

AIM We aimed to show the significance of the anterior pontine membrane as a determining structure between the subdural and subarachnoid space in the clival region. MATERIAL AND METHODS Five adult cadaver heads and five cerebral hemispheres were used. The skull vault and hemipheres were removed by sectioning through the pontomesencephalic junction. Five other heads hemispheres were removed but the arachnoid membrane was protected and the cerebral side of the clival dura mater was dissected. In another specimen, the dural porus of the abducens nerve was sectioned for histological evaluation. Three cases of hematoma at the clivus were presented to support our findings. RESULTS The anterior pontine membrane is the arachnoid membrane forming the anterior wall of the prepontine cistern with its lateral extension at the skull base. This membrane forms the subdural and subarachnoid spaces by forming a barrier between the clival dura mater and neurovascular structures of the brainstem. There were rigid fibrous trabeculations between both cerebral and periosteal dural layers forming the basilar plexus as the interdural space in the clivus. CONCLUSION The anterior pontine membrane separates the subdural and subarachnoid spaces at the clival region. The hematomas of the clival region require to be evaluated with consideration given to the existance of the subdural space.

The Comparison of Pullout Strengths of Various Pedicle Screw Designs on Synthetic Foams and Ovine Vertebrae.

AIM One of the most common problems with transpedicular screws is screw pullout. This study was conducted to measure the pullout strengths of newly designed transpedicular screws. MATERIAL AND METHODS The design of the three group screws were conical cored standard pedicle screw (Type A), dual threaded pedicle screw (Type B), dual core and dual threaded pedicle screw (Type C), respectively. Polyurethane (PU) blocks in 25 mm and 50 mm thickness were used to investigate the effect of just the pedicle on pullout strength and both distal (vertebral body) and proximal (pedicle) parts of the screw. The screws were also tested in ovine lumbar vertebrae. RESULTS Type C screw exhibited 5.9% and 12.9% higher pullout strength than Type A and Type B, and 15.4% and 8.6% higher pullout strength than Type A and Type B, respectively on 25 mm and 50 mm thick PU foam block. Type C also exhibited 74.5% and 22.5% higher pullout strength than Type A and Type B, respectively on the ovine vertebrae. CONCLUSION Transpedicular screws redesigned with modified helical angles exhibit higher pullout strength compared to the classical transpedicular screws and can be inserted more rapidly with the same number of screwing rounds result with doubled insertion depth.

Surgical treatment in sacral fractures and traumatic spinopelvic instabilities.

AIM Sacral fractures are generally seen together with pelvic ring fractures. They can also develop in isolated form rarely. Instability is observed in these fractures in rates reaching 30%. MATERIAL AND METHODS Spinopelvic stabilization was applied to 10 cases with pelvic fractures together with sacral fractures and spinopelvic instability. Two cases were treated with adductive screws extending from the iliac wing to the sacrum, 5 cases with standard lumboiliac instruments and 3 cases were treated with iliac wing plates that are our own design. The cases were evaluated according demographic data, VAS, ASIA and Oswestry scores and the types of the trauma and fracture. RESULTS Six cases had unilateral sacroiliac instability while the instability was bilateral in 4 cases. Follow-up periods range between 6 and 91 months. Preoperative VAS was 8.4, Oswestry mean value was 91.2, postoperative late VAS was 2.2, and Oswestry was 24.4. CONCLUSION Serious spinopelvic instability can be talked of in sacral fractures accompanied by pelvic fractures, particularly when the anterior and posterior integrity of the pelvic ring is interrupted together. An aggressive stabilization and fixation must be performed without delay.

The contribution of cervical dynamic magnetic resonance imaging to the surgical treatment of cervical spondylotic myelopathy.

AIM Cervical spine is the most kinetic segment of the whole vertebrae. The radiologic imaging methods concern with the morphologic changes but give no functional data. At flexion, spinal cord strains, anterior osteophytic compression increases. At extension, spinal canal gets narrower, cord shortens and gets thicker, compression of posterior ligament gets abberant and cord compression increases. MATERIAL AND METHODS 258 cervical spondylotic myelopathy (CSM) cases were scanned by conventional magnetic resonance imaging (MRI) and additionally dynamic MRI. Contributions of dynamic cervical MRI to the surgical plans and results were evaluated. RESULTS We had sagittal and axial T2W MR scans at flexion and extension, in addition to the neutral cervical MR imaging. We found that the AP diameter of spinal canal is increased 14.9 % in flexion and decreased 13.4 % in extension relative to the neutral MR imaging. CONCLUSION The changes of the cord compression and the transvers area of cord which is the most important prognostic indicator in spinal diseases and also the area of spinal cord and subarachnoid space can be detected via dynamic axial sections of MRI. Dynamic MR images may be helpfull in the decision making for the surgical treatment of CSM.

Supraclavicular surgical approach for thoracic outlet syndrome: 10 years of experience.

AIM Symptoms of thoracic outlet syndrome (TOS) may be vascular, neurological or combined symptoms involving both. Treatment of TOS is generally conservative. Surgical treatment is required when radiological results indicate anatomical abnormality. This study aims to present the surgical outcomes of TOS patients treated with supraclavicular approach via microsurgery. MATERIAL AND METHODS 41 patients with thoracic outlet syndrome were rewieved retrospectively. The pain was determined using both on visual analogue scale (VAS) and Oswestry score both in the preoperative and postoperative period. All patients underwent electromyography including brachial plexus, ulnar and median nerves. Computed Tomography (CT) angiographic examination was applied dynamically with required manoeuvres. RESULTS Post-op VAS scores were recorded as 0.8 for the arm, 0.6 for the shoulder and 0.5 for the neck, while pre-op VAS scores were 6.3 for the arm, 6.0 for the shoulder and 5.2 for the neck. Post-op Oswestry disability index (ODI) average was found as 14,2, while this figure was 67,4 during the pre-operative period. CONCLUSION Accurate patient selection is imperative for increasing the success of TOS surgery. Microscopic TOS surgery yields satisfactory results with smaller incision, safer surgery and a lower rate of complication.

Extraosseous, Epidural Cavernous Hemangioma with Back Pain

Summary Background Cavernous malformations are characterized by enlarged vascular structures located in benign neural tissues within the cerebellum and spinal cord of the central nervous system. Cavernous hemangiomas (CHs) account for 5% to 12% of all spinal vascular malformations. Case Report We removed a hemorrhagic thoracic mass in a 40-year-old male patient who presented with progressive neurological deficits. Conclusions We found it appropriate to present this case due to its rarity.

A Retrospective Study of 39 Patients Treated With Anterior Approach of Thoracic and Lumbar Spondylodiscitis: Clinical Manifestations, Anterior Surgical Treatment, and Outcome.

AbstractThe aim of this study is to report our 39 patients treated with anterior debridement and autologous iliac bone grafting with or without anterior instrumentation, which is the presumed treatment of choice for thoracic or lumbar spondylodiscitis.Our patients underwent surgical treatment of spondylodiscitis using anterior debridement and autologous iliac bone grafting with or without anterior instrumentation and were analyzed with a mean follow-up of 8 years (range, 2–11 years). Kaneda 2-rod system instrumentation was used in 12 patients, in total. Clinical outcomes were assessed by the Frankel grade. Radiographic fusion was characterized based on 3-dimensional computed tomography.Of the whole group, 20 patients suffered from tuberculous spondylodiscitis and 19 suffered from hematogenous spondylodiscitis. Pathogens responsible for pyogenic infection included Staphylococcus aureus (4 patients), Pseudomonas aeruginosa (3 patients), and Brucella melitensis (1 patient). Fifteen patients had thoracic involvement, 20 had lumbar involvement, and 4 had thoracolumbar junction involvement. Preoperative neurological deficits were noted in 13 of the 39 patients. In terms of Frankel grade, 8 patients have improved, 4 have remained the same, and 1 patient has worsened during the follow-up period. Imaging-documented fusion was achieved in 23 of 27 patients in the graft group (85% fusion rate) and 11 of 12 patients in the graft + Kaneda instrumentation group (91% fusion rate).There was no instrumentation failure, loosening, or graft-related complication such as slippage or fracture of the graft. This approach demonstrated a good recovery rate of neurological functions and a high fusion rate.

Thoracolumbar Fractures: A Review of Classifications and Surgical Methods

Thoracolumbar fractures are an important topic in spinal surgery. In this article, the instability of the thoracolumbar fracture classifications and surgical treatments are discussed, with a particular focus on treatment concepts that are based on the modern classification systems.

A Comparison of Bilateral Decompression via Unilateral Approach and Classic Laminectomy in Patients with Lumbar Spinal Stenosis: A retrospective Clinical Study.

AIM Bilateral decompression via unilateral approach is one of the minimally invasive methods used for degenerative spinal stenosis. The aim of this retrospective study was to observe the clinical and radiological results of classic laminectomy and bilateral decompression via unilateral approach applied for lumbar stenosis. MATERIAL AND METHODS The data of 40 patients who underwent surgical treatment for lumbar spinal stenosis with different techniques was reviewed retrospectively. The patients were divided into 2 groups according to the surgical technique. In the first group, patients underwent classic laminectomy, while in the second group patients underwent bilateral decompression via unilateral approach. Preoperative and postoperative computed tomography section areas of both groups were examined. Visual analogue scale (VAS) was used to evaluate low back and leg pain in preoperative and postoperative 1, 6, and 12 months. The two groups were compared in respect of surgery time and bleeding. RESULTS In both groups, postoperative low back and leg pain VAS scores declined compared to the preoperative condition. Low back pain VAS scores were lower at postoperartive 1, 6, and 12 months. The bleeding was higher in the 1st group, whereas the surgery time was higher in the 2nd group. CONCLUSION Bilateral decompression through unilateral approach is an effective method without instability effect, which provides sufficient decompression in the degenerative stenosis and increases patient comfort in the postoperative period.

A new technique in the surgical treatment of Hangman's fractures: Neurospinal Academy (NSA) technique.

Context: Treatment of Hangmans fractures is still controversial. Hangmans fractures Type II and IIA are usually treated with surgical procedures. Aim: This study aims at describing the Neurospinal Academy (NSA) technique as an attempt to achieve an approximation of the fracture line to the axis body, which may be used for Type II and IIA patients with severe displacement and angulation. Settings and Design: NSA technique both pars or pedicle screws are placed bicortically to ensure that anterior surface of C2 vertebral body will be crossed 1-2 mm. A rod is prepared in suitable length and curve to connect the two screws. For placing the rod, sufficient amount of bone is resected from the C2 spinous process. C2 vertebral body is pulled back by means of the screws that crossed the anterior surface of C2 vertebral body. Materials and Methods: Hangman II and IIA patient are treated with NSA technique. Result: Angulated and tilted C2 vertebral body was pulled back and approximated to posterior elements. Conclusions: In Hangmans fractures Type II and IIA with severe vertebral body and pedicle displacement, NSA technique is an effective and reliable treatment alternative for the approximation of posterior elements to the C2 vertebral body, which is tilted, angulated, and dislocated.