The Charnley prosthesis had by far the best and most comprehensive evidence base with better than 90 % implant survival after about 10 years .
Some uncemented stems have shown promising medium-term outcome , but no combination of uncemented cup and stem fulfilled the benchmark criterion of > or = 90 % implant survival at 10 years , which we propose as a minimum requirement for unrestricted clinical use for prostheses used in primary THR .
We have conducted a systematic review of the scientific literature concerning outcome and clinical effectiveness of  prostheses used for primary total hip replacement ( THR ) in Norway .
Poor eight-year survival of cemented zirconia-polyethylene total hip replacements.
Between January 1988 and January 1991 we performed 100 consecutive cemented total hip replacements using a zirconia head , a titanium alloy stem and a polyethylene cup .  We review ed 78 of these hips in 61 patients in detail at a mean of 5.8 years ( 1 to 9 ) . Aseptic loosening was seen in 11 hips ( 14 % ) . Eight needed revision . In total , 37 cups ( 47.5 % ) showed radiolucent lines , all at the cement-bone interface , with 18 ( 23 % ) involving all the interface . Of the 78 femoral implants , 17 ( 21.7 % ) showed radiolucent lines , and two , which had a complete line of more than 1 mm thick , definite endocortical osteolyses . There was also an abnormally high incidence of osteolysis of more than 2 mm at the calcar . Survivorship analysis showed that only 63 % were in situ at eight years . These worrying results led us to ab and on the use of zirconia heads , since at the same hospital , using the same femoral stem , cement and polyethylene cup , but with alumina femoral heads , the survival rate was 93 % at nine years . We discuss the possible reasons for the poor performance of zirconia ceramic
The Charnley prosthesis had by far the best and most comprehensive evidence base with better than 90 % implant survival after about 10 years .
Some uncemented stems have shown promising medium-term outcome , but no combination of uncemented cup and stem fulfilled the benchmark criterion of > or = 90 % implant survival at 10 years , which we propose as a minimum requirement for unrestricted clinical use for prostheses used in primary THR .
We have conducted a systematic review of the scientific literature concerning outcome and clinical effectiveness of  prostheses used for primary total hip replacement ( THR ) in Norway .