THE LONG-TERM RESULTS OF SURGICAL TREATMENT OF PATIENTS WITH ISTHMIC SPONDYLOLISTHESIS USING ANTERIOR LUMBAR INTERBODY FUSION

The authors analyzed the long-term results of surgical treatment 47 patients with true spondylolisthesis. The follow up period ranged from 14 to 25 years. All patients underwent an isolated anterior interbody riving allograft fusion. The scales of VAS and ODI were used for subjective assessment of treatment outcomes; objective assessment was based on clinical and radiographic, CT and MRI outcomes. There were 42.6% (20 cases) patients with good, 31.9% (15 cases) with satisfactory and 25.5% (12 cases) unsatisfactory results in the long-term follow-up. The main reasons of poor outcome were: the continued high degree of displacement of the vertebral body (17.6%), instability (38.3%) and the disbalance of the lumbosacral spine (63.8%), persistent compression of neural structures (42.6%). Most patients had the combination of these factors that were existed against backdrop of progressive degenerative changes of the spine

Investigations of single crystal and polycrystalline metal mirrors under erosion conditions in TEXTOR

Metal mirrors are planned for optical diagnostic systems of ITER. However, erosion, deposition and particle implantation can change the performance of mirrors. Mirrors made from the single crystal (SC) materials are among the main candidates for use in ITER diagnostic systems operating under erosion-dominated conditions. Laboratory tests have confirmed good optical performance of SC mirrors under erosion, but the dedicated direct comparative test in tokamak environment was missing, Such a direct test was performed in TEXTOR. Single crystal molybdenum, tungsten and polycrystalline (PC) molybdenum mirrors were exposed under the same conditions in the SOL plasma of TEXTOR. Surface and optical properties of mirrors were characterized before and after exposure. Before exposure glow discharge cleaning in hydrogen restored the reflectivity of mirrors oxidized during storage on air. No significant changes in total reflectivity were observed for all mirrors after exposure. Drastic increase of diffuse reflectivity was measured for PC Mo mirror, no change for a SC one. Thus, specular reflectivity of single crystal is higher than of polycrystalline one. The most affected wavelength range is 250-1000 nm, no significant change of reflectivity was noticed in the range 1000-2000 nm. Negligible effect of the exposure on polarization characteristics was observed. (c) 2006 Elsevier B.V. All rights reserved