The addition of chondroitin sulphate (CS) to bone cements with calcium phosphate has lead to an enhancement of bone remodeling and an increase in new bone formation in small animals. The goal of this study was to verify the effect of CS in bone cements in a large animal model simulating a clinically relevant situation of a segmental cortical defect of a critical size on bone-implant interaction and bone remodeling. The influence of adding CS to hydroxyapatite/collagen (HA/Col) composites on host response was assessed in a standard sheep tibia model. A midshaft defect of 3 cm was created in the tibiae of 14 adult female sheep. The defect was filled with a HA/Col cement cylinder in seven animals and with a CS-modified hydroxyapatite/collagen (HA/Col/CS) cement cylinder in seven animals. In all cases the tibia was stabilized with an interlocked universal tibial nail. The animals in each group were analyzed with X-rays, CT scans, histology, immunohistochemistry, and enzymehistochemistry, as well as histomorphometric measurements. The X-ray investigation showed a significantly earlier callus reaction around the HA/Col/CS implants compared to HA/Col alone. The amount of newly formed bone at the end point of the experiment was significantly larger around HA/Col/CS cylinders both in the CT scan and in the histomorphometric analysis. There were still TRAP-positive osteoclasts around the HA/Col implants after 3 months. The number of osteopontin-positive osteoblasts and the direct bone contact were significantly higher around HA/Col/CS implants. We conclude that addition of CS enhances bone remodeling and new bone formation around HA/Col composites. The addition of components of the extracellular matrix to hydroxyapatite cements containing type I collagen (HA/Col) has proved effective in stimulating bone cell activity and increasing the osteoconductive properties of HA/Col composites. 1,2 However, the application of full components (such as proteins of the extracellular matrix) is limited by the availability and quality of species-specific proteins, the sparse information about the necessary concentration of proteins and also by the high costs of a large amount of proteins. 3,4 Therefore, some investigators have added only the functional component of proteins of the extracellular matrix to HA/Col, obtaining similar enhanced bone remodeling, and increased bone cell activity around these composites. [3][4][5][6] Particularly, the addition of chondroitin sulphate seems to have a prominent role compared to other functional components such as rgd peptide, phosphoserin, or sodium-citrate. [3][4][5] Chondroitin sulphate (CS) is an important glycosaminoglycane found in the extracellular matrix of bone, 7 predominantly as a part of large proteoglycans like decorin and aggrecan. CS consists of repeating disaccharide units of D-glucuronic acid linked to N-acetylgalactosamine. The galactosamine residues are sulphated in position 4 or 6. The active functional groups like sulphate and carboxyl groups are believed to interact w...
RESUMO -A vertebroplastia percutânea (VP) é procedimento minimamente invasivo que visa tratar a dor local decorrente de fratura do tipo compressão da coluna vertebral. A VP está indicada para o alívio da dor grave e incapacitante da coluna vertebral, em pacientes com fraturas vertebrais decorrentes de osteoporose, metástases (osteolíticas), mieloma e hemangioma agressivo. Analisamos os resultados da VP realizadas em 18 vértebras de 11 pacientes. Houve melhora acentuada da dor em 90,9% dos casos. O retorno às atividades habituais ocorreu em 77,8% até o primeiro mês. De acordo com os dados da literatura e em nossa casuística, a VP se mostrou opção terapêutica promissora nos casos selecionados.PALAVRAS-CHAVE: vertebroplastia percutânea, fratura vertebral osteoporótica, metástase vertebral. Percutaneous vertebroplasty: option of treatment for osteoporotic vertebral fractureABSTRACT -Percutaneous vertebroplasty (PV) is a minimally invasive procedure used to treat focal pain from compressive vertebral fracture. The PV is indicated for the treatment of debilitating vertebral pain from osteoporotic vertebral fractures, metastatic disease (osteolytic), myeloma and hemagioma. We analyzed the results of PV at 18 vertebrae of 11 patients. In 90.9% there war significant pain relief. The return to their usual activities at the first month occurred at 77.8% of the patients. According to the literature review and our study, PV is a promising therapy for selected cases.KEY WORDS: percutaneous vertebroplasty, osteoporotic vertebral fracture, spinal metastases.
Considering the error margin for CT analysis, correction within 5 to 10 degrees seems practical.
Meningeal melanocytoma is a rare type of benign pigmented tumor of the central nervous system that derives from leptomeningeal melanocytes, which originate from the neural crest. These tumors are commonly focal, but there are descriptions of multifocal forms in the literature, and reports of malignant transformation, with leptomeningeal dissemination. In this paper, a case of meningeal melanocytoma with leptomeningeal dissemination is reported and, based on a review of the literature, comments on the diagnostic and therapeutic difficulties relating to this disease are made.
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