ABSTRACT
The toxicity of alloying elements in magnesium alloys used for biomedical purposes is an interesting and innovative subject, due to the great technological advances that would result from their application in medical devices (MDs) in traumatology. Recently promising results have been published regarding the rates of degradation and mechanical integrity that can support Mg alloys; this has led to an interest in understanding the toxicological features of these emerging biomaterials. The growing interest of different segments of the MD market has increased the determination of different research groups to clarify the behavior of alloying elements in vivo. This review covers the influence of the alloying elements on the body, the toxicity of the elements in Mg-Zn-Ca, as well as the mechanical properties, degradation, processes of obtaining the alloy, medical approaches and future perspectives on the use of the Mg in the manufacture of MDs for various medical applications.
Subject(s)
Alloys , Biocompatible Materials/chemistry , Calcium/chemistry , Magnesium/chemistry , Zinc/chemistry , Absorbable Implants , Animals , Corrosion , Elastic Modulus , Humans , Materials Testing , Metals/chemistry , Mice , Powders , Rats , Stress, MechanicalABSTRACT
BACKGROUND: Currently, the metatarsophalangeal joint replacement through a restorative arthroplasty, where implants are used, is a viable invasive surgical medical procedure in the treatment of severe cases of osteoarthritis in this joint, better known as hallux rigidus. However, few things are known about the postoperative complications that implants can cause on the joint, like Swanson and Tornier implants.Research in this field can provide a valuable information that would help the specialist surgeon in the decision-making during the selection of the more suitable joint implant in each patient, as well as the redesign of the devices, to make them more efficient, durable and biocompatible with the human body. METHODS: The aim of this work is to perform a structural biomechanical analysis of a restorative arthroplasty of the first metatarsophalangeal joint, and to analyze the interaction between bone and medical grade silicone implants. For that, a simulation of a foot with Swanson and Tornier joint implants were performed to evaluate the stress/strain distribution during a critical stage (toe-off). RESULTS AND CONCLUSIONS: Principal stresses obtained for the first metatarsal with both implants suggest that failure is induced in this bone because, values exceed (up to 136.84% for Swanson model) the tensile strength reported for phalange trabecular bone, which may be related to osteolysis. Stress and strain values obtained in this work suggest that arthroplasty surgery with Swanson implant is more likely to cause postoperative complications versus Tornier implant.
