RESUMEN
INTRODUCTION: To circumvent the risk to the vertebral artery with C2 pars or pedicle screws, C2 laminar screws were considered as a method for rigid fixation of the axis. Although considered to be a relatively safe method, ventral spinal canal violations have been reported. Three-dimensional (3D) fluoroscopy-based image guidance may enhance the accuracy and safety of the technique. There is only one previous report in the literature on its use in the placement of C2 laminar screws. The purpose of this study was to assess the accuracy of C2 translaminar screws inserted using 3D fluoroscopy-based navigation. METHODS: Data from a single centre was gathered retrospectively and then analysed. 3D fluoroscopy-based navigation was used to insert five translaminar screws in four patients (two male, two female). Their mean age was 45.3 years and the average follow-up period was 13.8 months. The accuracy of screw placement and fusion was ascertained using postoperative computed tomography imaging. RESULTS: There were no complications in this series. No breach in the dorsal or ventral laminar wall was noted for any of the translaminar screws inserted. The average time required to set up the navigation platform and screen was 18 minutes. Successful fusion was observed in all four patients at six months follow-up. CONCLUSIONS: Although considered a relatively safe technique, laminar cortical violations have been reported with C2 translaminar screws. 3D fluoroscopy-based image guidance can greatly enhance the accuracy of C2 translaminar screw insertion, as this technology provides real-time images during screw insertion and permits accurate screw sizing.
Asunto(s)
Tornillos Óseos , Fluoroscopía/métodos , Fijadores Internos , Fusión Vertebral/métodos , Adulto , Articulación Atlantoaxoidea/diagnóstico por imagen , Articulación Atlantoaxoidea/patología , Femenino , Estudios de Seguimiento , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Ortopedia/métodos , Estudios Retrospectivos , Programas InformáticosRESUMEN
INTRODUCTION: The aim of this research was to study the effect of the tibial tunnel position in anterior cruciate ligament (ACL) reconstruction using bone-patellar tendon-bone (BPTB) grafts in ensuring optimal knee functioning. METHODS: A prospective study was conducted on 41 patients who underwent arthroscopically assisted ACL reconstruction using a BPTB graft and who were followed up for a minimum period of two years. The radiographic position of the tibial tunnel was compared with the clinical outcome using the International Knee Documentation Committee (IKDC) and modified Lysholm knee scores at two years after surgery. RESULTS: Six out of eight patients with a fair outcome based on the modified Lysholm score and five out of eight patients with an abnormal outcome based on the IKDC score had their tibial tunnel within the 10 percent to 25 percent anteroposterior width of the tibial plateau. The tibial tunnel of patients with a fair Lysholm outcome (mean 22.2 percent) was significantly anterior compared to that of those with an excellent (mean 38.1 percent) and good (mean 34.1 percent) outcome (p is less than 0.01). The analysis using the IKDC score showed a similar trend. CONCLUSION: Placing the tibial tunnel in the anterior 25 percent of the tibial plateau is associated with a poor knee outcome. More predictable results can be achieved through 35 percent to 46 percent anteroposterior placement of the tibial tunnel.
Asunto(s)
Ligamento Cruzado Anterior/cirugía , Artroscopía/métodos , Plastía con Hueso-Tendón Rotuliano-Hueso/métodos , Traumatismos de la Rodilla/cirugía , Procedimientos de Cirugía Plástica/métodos , Tibia/diagnóstico por imagen , Análisis de Varianza , Ligamento Cruzado Anterior/diagnóstico por imagen , Lesiones del Ligamento Cruzado Anterior , Plastía con Hueso-Tendón Rotuliano-Hueso/instrumentación , Humanos , Traumatismos de la Rodilla/diagnóstico por imagen , Análisis Multivariante , Estudios Prospectivos , Radiografía , Tibia/cirugía , Resultado del TratamientoRESUMEN
Cervical laminectomy has been known to cause postlaminectomy kyphosis and instability, often necessitating extensive anterior and posterior procedures with instrumentation for the stabilisation and correction of the deformity. We report a case of spontaneous stabilisation of postlaminectomy cervical kyphosis by anterior longitudinal ossification in the absence of an ossified posterior longitudinal ligament, thus circumventing the need for surgical intervention.
Asunto(s)
Cifosis/cirugía , Laminectomía/efectos adversos , Ligamentos Longitudinales/cirugía , Compresión de la Médula Espinal/cirugía , Adulto , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/cirugía , Descompresión Quirúrgica/efectos adversos , Descompresión Quirúrgica/métodos , Humanos , Masculino , Complicaciones Posoperatorias/cirugía , Radiografía , Resultado del TratamientoRESUMEN
Down-regulation of retroviral vector expression occurs in a number of cell types after transplantation. Although a number of vector elements have been shown to affect expression in specific experimental situations, the results can vary depending on the specific cDNA being expressed, the individual retroviral elements included in vectors, the promoter, or the inclusion of selectable markers. In previous experiments with the lysosomal enzyme beta-glucuronidase, silencing has occurred in more than 95% of transduced cells regardless of the position of the expression unit within the vector, whether a eukaryotic or viral promoter was used, whether a bacterial selectable marker gene was present or not, the target cell type, or the species of the host. It has been a consistent finding that a small number of continuously expressing cells persist for long periods after transplantation. In this study we found that deletion of all the transcriptional regulatory elements from the vector LTR, inclusion of a permissive primer binding site sequence, and use of a eukaryotic housekeeping promoter could greatly increase the number of expressing cells in fibroblast grafts in subcutaneous neo-organs and in the brain. Furthermore, the level of enzyme expression was increased five-fold on a per positive cell basis, indicating that the deleted regulatory elements were exerting a negative effect on expression in the few cells that were positive before modification of the vector. This resulted in more than a 50-fold increase in total activity compared with the previous highest expressing vector.
Asunto(s)
Fibroblastos/enzimología , Silenciador del Gen , Vectores Genéticos/genética , Glucuronidasa/genética , Virus de la Leucemia Murina de Moloney/genética , Animales , Sitios de Unión/genética , Ingeniería Genética , Ratones , Ratones Endogámicos C57BL , Transducción Genética/métodos , Transfección/métodosRESUMEN
The p53 gene family, comprising p53, p63, and p73, has overlapping and distinctive functional roles. These members share structural similarities allowing for dynamic interplay in the activation of genes that are important in development and key cellular functions, such as the induction of apoptosis. Whereas p53 is a classical tumor suppressor gene, p63 and p73 do not share this feature in cancer formation and progression. The compensation in the expression level of these members in a background that is deficient for one of them has not been examined previously. Given the importance of p63 in the development and differentiation of oral-esophageal stratified squamous epithelia and the absence of oral-esophageal tumors in p53-null mice, we postulated and describe herein that p63 expression is associated with the loss of p53 in a p53-deficient background. Both full-length and amino-truncated forms of p63 are expressed and increased in oral-esophageal epithelia of p53-null mice when compared with wild-type mice, and the induction of p21 may potentially be preserved through the increase of p63.