Local adjuvants in surgical management of bone metastases.

Curettage is one of the most common method for surgical treatment of bone metastasis. Local adjuvant improve most commonly used for improving the effect of curettage in local cancer surgery may exerted their effects either chemically either physically; in Orthopedic Oncology the most common are phenol, liquid nitrogen, laser, and cement. This article reviewed the main characteristics of the most common chemical and physical agents used in bone oncology, emphasizing the toxic effects of some of them, especially phenol and liquid nitrogen.

Zirconia toughened alumina (ZTA) powders: ultrastructural and histological analysis.

Ceramic materials, as Alumina and Zirconia, has made an improvement in the choice of new biomaterials for the load bearing application in dental and orthopaedic implants. These materials has shown mechanical resistance to high stress related to weight bearing and low debris in time. For this reason they are indicated on young patients implant, with high demanding activities and long life expectance. In literature however the risk of chronic inflammation due to chronic wear debris release and the possibility of carcinogenesis, is still to be definitively investigated. Another point to investigate is the acute reaction of the tissue in case of acute release of powders of these materials. The aim of this study was to investigate the possible local and systemic acute effects of ceramic precursors in form of powders of different size when released into articular joint. Powders of ZTA were implanted in the knee joint of twenty-four New Zealand white adult rabbits, that were sacrificed at 1,3,6, and 12 months. Radiographic, histological and immunoistochemestry analysis were conducted on periprosthetic tissue and peripheral organs, to verifying local host response and systemic toxic effects.

Histological and ultrastructural reaction to different materials for orthopaedic application.

Prosthetic joints loosening in absence of infection is the most common reason for revision surgery and is known as aseptic loosening. A significant role in the pathogenesis of implant failure undoubtedly played by the generation of wear debris, mainly from the load bearing joint surfaces, and the cellular reaction through the formation of tissue membrane around implants. This article analyzes histologic, immunohistochemical ad ultrastructural aspects of periprosthetic tissue membrane collected at time of surgical revision, paying attention on cell host response to different materials: metals, polyethylene and ceramics. Dimension of particles seems to be crucial in the activation of different cell population to wear debris.

An original method for the evaluation of in vivo controlled release of the ceramic materials.

In recent years, the use of ceramic materials in orthopaedics and dentistry is becoming increasingly popular. However, it is important to know their biological and mechanical properties to optimize their use. The aim of this study is to describe a specific method to assess in vivo the effects of chronic release of ceramic materials implanted, in relation also to the type of material, pellets or powders. This was achieved by implanting ceramic powders and pellets, formed by low cohesion grains, in the patellar tendon of 48 New Zealand adult rabbits (24 with powders and 24 with pellets). The motion of the joint allowed easily and progressively the release of grains, detached from surface of the pellets and released to the joint space. Animals were sacrificed at different intervals (1, 3, 6, 12 months). Retrieved knee joints underwent X-Ray, histological and ultrastructural analysis.