Total Hip Prostheses consists of three components a) Femoral Head with tapered fixation hole in one side b) metallic stem of different designs made out of Stainless Steel (SS 316L) or Ti-6Al-4V Alloys and c) Accetabular Cup of suitable size to be used as articulat ing counterface with Femoral Head ball. State of the art Hip Joint Prostheses which have already taken lions market share are made of Ceramic Femoral head and Ti-V-Al Alloy based stems.
 Ceramic Femoral Head manufactured as per know how of CGCRI is made of medical grade Alumina Powder which has been tested for bio compatibility, chemical inertness and non-toxicity. Unlike conventional metallic head, which give rise to local infection occasionally, prone to chemical corosion in body fluid, needs replacement after regular interval of 5 to 7 years, Ceramic head offer better wear resistance and therefore longer service life. Average life of Ceramic head is over 20-25 years.
Following are the Advantages of Alumina based Femoral Head, multi centered clinical trials whereof have also been done with satisfactory results.
Low wear - On polyethylene acetabular cups show a more than 50% wear reduction compared with metal to polyethylene acetabular cups
Minimal wear - Clinical experience and stimulated trials confirm that ceramic on ceramic bearing reduces wear to less than two micrometeres per year. This is due to unusual hardness of ceramics
Beneficial wettability - Artificial Hip Joints are spherical, ball and socket bearing surfaces. Synovial fluid builds a film between the spherical head and inner cup. Beneficial wettability of ceramic surfaces allows excellent joint librication and therefore reduces friction at the joint.
Scratch resistant - Surface of a ceramic head or inlay withstands damage from surgical instruments or intra-articular foreign bodies. So called three body wear resulting from bone cement or bone particles is eliminated. Only adiamond can damage the ceramic surface. Even a damaged ceramic surface avoid expelling particles, unlike metal or polythene.
Bio compatibility - Aluminium Oxide ceramic is bio inert. Strong affinity between aluminium and oxygen makes it extremely corrosion resistant. High purity of material rules out chance of any chemical reaction. |
Hip Joint Prostheses are the most widely used orthopaedic implants, which are commonly used to replace ailing hip joints of patients who are suffering from Osteo-arthrititis, trauma due to accidents, bone deformity or any other degenerative bone diseases. Most of Femoral head prostheses being used are either made of Stainless Steel (SS 316L) or Co-Cr Alloys or Ti-V-All Alloys, which wear out quickly and generally have average life of 10 to 15 years.
