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 .
Effects of Design Changes on Cemented Tapered Femoral Stem Fixation
The effects of matte finish and modularity on loosening of tapered stems using the same cementing technique were studied prospect ively . In 80 patients , 82 cemented Exeter primary stems were implanted at total hip revision by one surgeon using the same surgical and cementing technique throughout the series . The polished stems behaved differently than the matte surfaced stems behaved . Polished stems subsided in the cement mantle an average of 1 mm at 2 years after implantation , but without subsequent loosening of stems at as long as 12 years after implantation . Matte surfaced stems with metal central izers had a higher loosening rate , and loss of fixation at the prosthesis to cement interface was identified as an early sign of loosening of these stems . At a mean 6-year followup , there were no revisions nor was there radiographic evidence of loosening of the polished modular stems . It is concluded that matte finish results in increased loosening of tapered stems but the introduction of modularity did not
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 .