World Neurosurg
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In vertebrae with low bone mineral densities pull out strength is often poor, thus various substances have been used to fill screw holes before screw placement for corrective spine surgery. We performed biomechanical cadaveric studies to compare nonaugmented pedicle screws versus hydroxyapatite, calcium phosphate, or polymethylmethacrylate augmented pedicle screws for screw tightening torques and pull out strengths in spine procedures requiring bone screw insertion. ⋯ Hydroxyapatite and calcium phosphate augmentation in osteoporotic vertebrae showed a trend toward increased pedicle screw pull out strength versus controls. Pedicle screw pull out force of polymethylmethacrylate in the insertion stage was higher than that of hydroxyapatite. However, hydroxyapatite is likely a better clinical alternative to polymethylmethacrylate, as hydroxyapatite augmentation, unlike polymethylmethacrylate augmentation, stimulates bone growth and can be revised.
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Atypical and anaplastic meningiomas (World Health Organization classification grade II and III) represent a small and heterogeneous subgroup of meningiomas that has a more aggressive biological nature and higher frequency of recurrence. The atypical form accounts for 4.7%-7.2%, whereas the anaplastic type accounts for 1%-2.8% of all meningiomas. The aim of this study is to evaluate the role of postoperative radiotherapy on overall survival and progression-free survival in patients operated for atypical and anaplastic meningiomas. ⋯ The addition of adjuvant radiotherapy to surgery for atypical and anaplastic meningiomas resulted in a clinically meaningful and statistically significant survival benefit.
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Case Reports
Acute Traumatic Cervical Cord Injury in Pediatric Patients with os Odontoideum: A Series of 6 Patients.
Os odontoideum can lead to instability of the atlantoaxial joint and places the spinal cord at significant risk for acute traumatic catastrophic events or chronic neurologic change. The purpose of this study was to retrospectively review acute cervical cord injury after minor trauma in 6 pediatric patients with os odontoideum. ⋯ Pediatric patients with asymptomatic or myelopathic atlantoaxial instability secondary to os odontoideum are at risk for acute spinal cord injury even after minor traumatic injury. Sufficient fixation and fusion should be undertaken as prophylactic treatment of developing myelopathy and to improve neurologic symptoms with acute traumatic cervical cord injury in pediatric patients with os odontoideum.
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Surgical trapping or endovascular deconstruction commonly is used for the treatment of giant or complex intracranial aneurysms. Preoperative balloon test occlusion and cerebral blood flow studies and intraoperative neurophysiologic monitoring can indicate whether sufficient collateralization exists or whether revascularization is needed. Hemodynamic insufficiency can occur, however, despite passing these tests, necessitating posttreatment revascularization. ⋯ Ischemic complications must always be anticipated in the treatment of giant or complex intracranial aneurysms, even if pre- and intraoperative blood flow studies indicate sufficient collateralization. Here we show that extracranial-to-intracranial bypass is an effective option to rescue unanticipated hemodynamic insufficiency after parent vessel occlusion. This study emphasizes the need for cerebrovascular surgeons to maintain proficiency in complex bypass techniques.