Saturday, 1 October 2016

An Overview of Orthopedic Implants

Bone defects occur due to accidents, diseases, trauma or abnormal development require a skeletal reconstruction such as grafts of natural and synthetic materials to replace lost bonor to enhance new bone formation. Biomaterials are used to make devices to replace a part or a function of the body in a reliable, safe, physiologically acceptable and economic manner to improve the quality of life, increasing mobility and reducing pain. It covers a broad range of materials from metals, ceramics and polymers, to composites.There are several requirements of metals depend on the specific implant applications. Stents and stent grafts are implanted to open stenotic blood vessels; therefore, they require plasticity for expansion and rigidity for maintaining dilatation. In orthopaedic implant applications, metals are required to have excellent toughness, elasticity, rigidity,strength and resistance to fracture. Additionally, for total joint replacement metals are needed to be wear resistance to avoid debris formation from friction. Dental restoration requires strong and rigid metals and even the shape memory effect for better results.

Orthopedic implants are the medical devices manufactured to support a damaged bone or to replace a missing joint or bone. These orthopedic implants are mainly fabricated using metallic alloys such as stainless steel, cobalt-chromium and titanium alloys (as a permanent implants) for their superior mechanical properties (hardness, stiffness, etc.), and lined with plastic to act as artificial cartilage.Used for implants composed of 18wt% Cr and 8wt% Ni made it more resistant to corrosion and stronger than steel. The addition of Mo further improves its corrosion resistance, known as type 316 stainless steel.

These are generally known for their excellent wear resistance where they have been in use in dentistry and in making artificial joints. Is featured by its light weight compared to other alloys. The most known Ti alloys, Ti-6Al-4V, are considered as having excellent tensile strength and pitting corrosion resistance.In particular cases, metallic implants are needed only temporary and are expected to support the healing process and to thereafter degrade. These degradable bio Mg is biocompatible, vital for metabolic processes, and the alloys show higher strength. Metallic Implants are used for Two Primary Purposes Used as prostheses serve to replace a portion of the body and include devices such as total joint   replacements.

The surgical procedure for each implant involves removal of the damaged joint and an artificial prosthesis replacement. Osteoarthritis is the primary reason for orthopaedic implants, which also called degenerative joint disease. Orthopaedic implants are available for the hip,knee, shoulder and elbow. Internal fixation is an operation in orthopaedics that involves the surgical implementation of implants for the purpose of repairing a bone. Though a broken bone, being a living tissue, has a tendency to heal itself provided the broken bone to withhold in the correct position. In the cases where broken bones have to be fixed in the correct and appropriate position, nails, wires, pins, staples and other orthopaedic implants play important role by holding the broken bone.

No comments:

Post a Comment