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Two-level anterior cervical discectomy and cage-assisted fusion without plates.
No full textOBJECT: Anterior cervical discectomy (ACD) is an effective and safe treatment for nerve root or spinal cord compression caused by disc herniation or spondylosis. Cervical interbody fusion allows preservation of the physiological lordosis and stability of the cervical spine. Based on data reported in the literature, fusion rates decrease significantly when more than one level undergoes surgery, and some authors recommend the addition of a plate system to improve results. At the authors' institution cervical carbon fiber cages (CFCs) are routinely used after ACD. They describe their experience in the treatment of 24 patients with two-level disease treated with CFCs alone. METHODS: Twenty-one patients with cervical radiculopathy and three with radiculomyelopathy underwent ACD. Surgery was performed at C5-6 and C6-7 in 18, at C4-5 and C5-6 in four, and at C3-4 and C5-6 in two patients. All the patients underwent magnetic resonance imaging and 15 also underwent computerized tomography (CT) to assess the results of surgery. Radiculopathy improved after surgery in all the cases, whereas myelopathy resolved in only one patient. At 1 year fusion was achieved in 96% of the surgically treated discs; this was verified on cervical spine x-ray films in all patients and on CT scans in three patients. Cervical lordosis was restored in eight of the nine patients in whom it was lost preoperatively. No complications related to cage extrusion and no cases of symptomatic pseudarthrosis were observed. CONCLUSIONS: Interbody fusion cages have a load-sharing function and stabilize the spine to increase segmental stiffness, thus achieving fusion rates similar to those associated with bone grafts, even in multilevel disease
Cellular-localization of Glucocorticoid Receptor Messenger-rnas In Human Cns Tumors By Insitu Hybridization
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Cervical spine biomechanics following implantation of a disc prosthesis
No full textThis study presents a finite element model of the C4-C7 segment in healthy conditions and after implantation of a disc prosthesis at a single level, in order to investigate of the influence of disc arthroplasty on the biomechanics of the cervical spine. A nonlinear finite element model of the C4-C7 segment in intact conditions was developed and run in flexion and extension. A detailed model of the Bryan disc prosthesis, including contacts between the different components of the device, was built and positioned at C5-C6. The calculated segmental motion resulted preserved after disc arthroplasty, with respect to the model of the intact spine, in both flexion and extension. A general preservation of the forces transmitted through the facet joints was obtained; a minor force increase at the implanted level was detected. The analysis of the instantaneous centers of rotation (ICR) in flexion-extension showed the preservation of a physiological kinematics. The mechanical behaviour showed an asymmetry between flexion and extension, probably due to the removal of the anterior longitudinal ligament and the anterior part of the annulus fibrosus, and the preservation of the posterior structures. In general, the disc prosthesis showed to be able to reproduce a nearly physiological motion. However, other important mechanical aspects, such as the possible micromotion at the bone-implant interface and the possible degenerative conditions of the spine, need to be evaluated before drawing a conclusion about total disc arthroplasty from an engineering point of view
Cell-kinetic characteristics of human brain tumors.
No full textThe proliferative potential of human brain tumors was investigated, in vivo, using bromodeoxyuridine (BUDR) incorporation and flow cytometry (FCM). Patients with a variety of human brain tumors were preoperatively injected with 250 mg of BUDR intravenously. The cell cycle parameters of most of the specimen were measured within 24 h of sampling. The results show that this method is very practical, fast, and feasible for determining the cell-kinetic parameters of human brain tumors. In this study important kinetic parameters such as the duration of S-phase and the potential doubling time of each tumor were calculated in some samples. Our results show a significant difference in labelling index between meningiomas and gliomas. No difference between benign and anaplastic meningiomas was demonstrated in this limited number of cases. The correlation between the labelling index and the clinical and radiological follow-up of each patient should make the assessment of the prognostic significance of the kinetic evaluation, possible. This method could be a useful aid in the selection of new treatment schedule
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