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 .
Cementless primary total hip replacement. Four to eight year results with the Zweymüller-Alloclassic prosthesis.
One hundred and twenty-nine consecutive cementless primary total hip arthroplasties with Zweymüller-Alloclassic grit-blasted titanium components  were evaluated prospect ively at an average follow-up of 5.9 years . The clinical results were grade d as excellent or good in 116 hips ( 90 % ) , fair in 12 , and poor in one due to a fracture of the femoral shaft at operation leading to early stem loosening and delayed ring loosening . Failure was defined as definite aseptic loosening , and the final survivorship at 8 years was 99.3 % for the SL-stem , and 99.1 % for the CSF-threaded cup . These early results compare favourably with those of total hip arthroplasties using new cementing techniques
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 .