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 .
Precoated femoral component in total hip arthroplasty. Results of 5- to 9-year followup.
One hundred nineteen consecutive primary hybrid total hip arthroplasties with a precoated femoral component were performed by one surgeon in 100 patients and followed up prospect ively . Ninety-eight hips in 82 patients ( mean age , 67 years ) were evaluated clinical ly and radiographically at a mean of 6.5 years ( range , 5 - 9 years ) . The hips were evaluated clinical ly using the Harris hip score , and radiographs were evaluated for femoral cement grade , loosening , and osteolysis . Ninety-five hips remained in place at the most recent followup . Two femoral components were revised for definite loosening , and one well fixed femoral component was removed because of late hematogenous infection . Excluding the three hips that were revised , the clinical result was excellent or good in 79 hips ( 83 % ) , fair in 12 hips ( 13 % ) , and poor in four hips ( 4 % ) . All other femoral components were well fixed . There were defects of the cement mantles ( C1 and C2 ) in 90 hips . No femoral component had a stem and cement radiolucent line . Focal femoral osteolysis was seen in only two hips . One acetabular component was removed at 5 years because of late hematogenous infection . One acetabular component had asymptomatic migration . The remaining 96 acetabular components were well fixed . Focal acetabular osteolysis was present in four hips . The mean linear polyethylene wear rate was 0.06 ( + /- 0.05 ) mm per year . In contrast to other reports of early failure and osteolysis , the use of a precoated femoral component in this study did not adversely affect the fixation of hybrid total hip arthroplasty , with definite failure of only 2 % ( two of 98 ) of the femoral components
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 .