May "Dubel" be a solution for pullout problem of the pedicle screws at osteoporotic spine?

AIM: To improve the strength of stabilization systems currently used in osteoporotic spinal fractures, essentially by increasing the fixation force of pedicle screws. MATERIAL AND METHODS: Six human cadaveric vertebrae were used. Bone mineral densities of the specimens were measured with Dual Energy X-ray Absorptiometry in order to assess the osteoporosis. All vertebrae were found to be severely osteoporotic. Standard pedicle screws were applied to left pedicles of vertebrae. Pedicle screws reinforced by fixing plugs "Dubel" were applied to right pedicles of vertebrae. Afterwards the vertebrae were embedded in acrylic casts to prevent possible fracture of the osteoporotic vertebrae and to obtain a correct vertical pull-out vector. The biomechanical pullout tests were performed with biomechanical testing machine. Pullout forces in each group were recorded and compared with Mann-Whitney U test. RESULTS: The pedicle screws strengthened by "Dubel" were found to be four times stronger than the standard pedicle screws, in the osteoporotic human cadaveric vertebrae. CONCLUSION: "Dubel"-augmented pedicle screws may contribute to developing better stabilization systems for osteoporotic thoracolumbar fractures needing surgery and in the revision of the previous fusion surgeries of the spine.

Massive congenital intracranial immature teratoma of the lateral ventricle with retro-orbital extension: a case report and review of the literature.

Germ cell tumors comprise 0.4-3.1% of all intracranial tumors, and teratoma constitutes 9-30% of them. Congenital intracranial tumors are very rare and only account for 0.5-1.5% of all childhood brain tumors. The most common type of these tumors present at birth is teratomas, which represent 0.5% of all intracranial tumors. Most teratomas are midline tumors located predominantly in the sellar and pineal regions. In this study, we report a neonatal intracranial immature teratoma at the lateral ventricle because of its rare location. A 5-day-old female neonate presented with a history of irritability and left eye protrusion since birth. A head computed tomographic (CT) scan and magnetic resonance imaging (MRI) disclosed a large tumor filling the left lateral ventricle and extending into the ipsilateral retro-orbital space. With left frontotemporoparietal craniotomy, a large grayish-white lobulated vascular mass was encountered, and total removal of tumor was performed. Histological examination revealed the diagnosis of immature teratoma. The prognosis of congenital intracranial immature teratoma is usually poor because the lesions are extensive when they are identified. Prenatal ultrasonography is necessary for the prenatal diagnosis. Fetal MRI should be made for the evaluation of intracranial tumor. If the tumor is detected before the 24th week of gestation, termination of the pregnancy should be considered.