Total Hip Articulation Options
The History 
McKee of Norwich, England
began designing metal-on-metal hip repiacements
as early as 1940, but it was not until his
collaboration with Watson-Farrar and their
use of methyl methacrylate to attach the
components to bone that a successful component
was developed. The clinical results varied, mainly because of the less than optimal manufacturing possbilities. Roundness of the femoral head, clearance between cup and head, surface roughness and implant stability were amongst parameters that wer at that time in the infant stage of the manufacturing processes.
Metal-on-Plastic 
Sir John Charnley began the development of various types of total hip replacement
arthroplasties between 1958 and 1963. His
initial results using Teflon were disastrous;
however, once he began to use high-density
polyethylene for the acetabular component,
results improved markedly. His development
of the low friction arthroplasty led to dramatic improvements in the function and
durability of total hip replacement
Ceramics 
onventional THA in terms of pain relief and improved mobility are generally considered to be good in elderly people (>65 years) and may last as long as 20 years. However, there are problems associated with this procedure when used in younger, more active adults. They include short device survival, device dislocation, and loosening in 3-4% of cases. The technique is invasive, associated with bone loss and weakening the existing bone and may only last 10 years before the patient needs a revision. In this population of young patients, 25-30% need revision within 15 years, compared to less than 5% at 10 years for older patients. Young, active patients with secondary OA may experience a revision rate of 50%. Revision hip replacements are more difficult to perform and generally have poorer outcomes than the primary replacement .
Resurfacing Hip
A relative new solution for the arthritic hip is hip resurfacing. It has the advantage that it does not require the insertion of a large stem inside the femur and this is appealing to many patients. The procedure aims to preserve femoral bone, maintain normal femoral loading and stresses, not to compromise future Total Hip Arthroplasty and to leave more options for future revisions. s the resurfaced head is more similar in size to the normal femoral head, the stability is increased andthe risk for dislocation is decreased in comparison with Total Hip replacement. .Because of low wear rates of the metal-on-metal bearing, the implant may not be subject to dislocation and loosening and the procedure may be more durable than 
conventional THR in comparable patient groups, thus reducing the need for revisions. In addition, this design reduces the risk of osteolysis (caused by polythylene wear debris) associated with conventional THA. However the wear that is generated by the metal-on-metal articulation is still a reason for concern. Please read the chapters "Wear Debris" and "Metal Ion Release"
In contrary to a total hip replacement that can be offered to virtually any patient, the resurfacing hip replacement may not be suited for everyone who is condidate for hip joint replacement .For instance, there has to be sufficient strong bone to support the femoral component and the femoral neck should not bee too short, to prevent impingement. Please read our patient information pagest or download the design rationale