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Over the last few years, alternate bearing surfaces have been developed to increase the longevity of total hip replacement.  The conventional articulating surface and the gold standard has been the cobalt-chromium femoral head articulating with a highly cross-linked polyethylene.

With increasing patient population and functional demands on the hip joint, pulyethylene wear and osteolysis have emerged as majpr problems and the no. 1 reason for revision surgery after 10 years.

The newer bearing surfaces inclufe the metal on metal, ceramic on ceramic, ceramic on polyethylene and the 3rd generation highly cross-linked polyethylene with a cobalt-chromium or a ceramic head.  Ceramic heads can either be biolox delta or biolox forte depending on the composition of alumina and zirconia. 

All these baring surfaces have their plus and minuses. Metal on metal articulation have a problem of serum ions and the long term effect of these on kidney function and carcinogenic potential is not known. Ceramic have historically been kbown to fracture and the incidence with latest ceramics is around 1 in 5000.  The newer polyethylene are not as resistant to fatigue failure as were the conventional polyethylene.

Only long term follow up and time will tell the best articulating surface amongd these.

• hip
• replacement
• THR