the early designs 
In the past many attempts have been made to make an implant that would only replace the part where the pathology occurs: the cartilage. Many designs were attempted but failed because of the limitation of the materials used (glass, ivory, gold leave)
. The first design that showed reasonable clinical results was the Smith Petersom implant that was made of the first Chromium-Cobalt Allloy
The second generation
With the development of the total hip components in the 1960-1970's again attempts were made to make an resurfaciong implant. The amount of material that can be resected each site of the articulation (the acetabulum and the femur) is 3-4 mm . This means that resurfacing is only possible when thin materials are used, Polyethylene was used in these early designs and it showed that such thin polyethylene is not able to withstand the normal load for a long time: massive wear occurred and the wear particles caused a reaction leading to osteolysis and subsequent loosening of the components. And the idea wass left again
the third generation 
Mr. Derrick McMinn, orthopaedic surgeon from the Birmingham University (UK) reintroduced Hip Resurfacing in the early 90's of last century and since then it has become a popular and promising alternative for a Total Hip Arthroplasty. Hip Resurfacing has the advantage that it does not require the insertion of a large stem inside the femur and this is appealing to many patients. In case a revision is needed there is still sufficient bone stock to perform the standard Total Hip Arthroplasty. Although Hip Resurfacing may not be suited for all patients, (the patient must have sufficient bone to make this type of joint replacement possible) in some countries the percentage of surface replacements is close to 10 % of the total number of hip replacements
the fourth generation 
All major manufacturer have developed their resurfacing system. Why do they call it th e fourth generation?. These systems have a microfinished surfaces. have thinner shells and more accurate clearances (the room between the two components)Alll of these implants have in coommon that they are manufacture from a Chromium Cobalt alloy, all have a cemented femoral component and a cemented acetabular component and they are all of the metal-on-metal type.
the fith generation 
The Accis Resurfacing Hip was developed to reduce the possible negative aspected of metal-on-metal articlation. The sufracing engineering with a Titanium-Niobium-Nitride ceramics not only reduces the generation of wear particles, but also prevents the release of excess metal ions
Many esteemed surgeons have been involved in the development of the products and its instrumentation and contributed to the clinical investigations