Results Best evidence analysis showed no difference in polyethylene wear rate , the frequency of cup migration , and aseptic loosening between monoblock and modular acetabular components .
No convincing evidence was found for the cl aim that lower frequencies of acetabular osteolysis are observed with the use of monoblock cups compared with modular uncemented cups .
Conclusions The purported benefits of monoblock cups were not substantiated by this systematic review of controlled studies in that polyethylene wear rates and frequencies of cup failure and acetabular osteolysis were similar to those observed with modular implants .
Background Monoblock acetabular components used in uncemented total hip arthroplasty ( THA ) have certain mechanical characteristics that potentially reduce acetabular osteolysis and polyethylene wear .
However , the degree to which they achieve this goal is not well documented .
Questions / purpose sThe purpose of this study was to use a systematic review of controlled trials to test the hypothesis that monoblock cups have superior ( 1 ) polyethylene wear rate ; ( 2 ) frequency of cup migration ; ( 3 ) frequency of acetabular osteolysis ; and ( 4 ) frequency of aseptic loosening compared with modular components used in uncemented THA .
Effect of augmented cup fixation on stability, wear, and osteolysis: a 5-year follow-up of total hip arthroplasty with RSA.
To evaluate different modes of cementless fixation of hemispherical cups , we operated on 87 hips in 81 patients using 4 different means of cup fixation . The hips were r and omly assigned to fixation with press-fit technique only ( PF ) , or with augmentation with screws ( S ) , pegs ( P ) , or hydroxyapatite ( HA ) coating . The patients were evaluated with radiostereometric analysis ( RSA ) for cup migration and wear , conventional radiography for osteolysis , and Harris Hip Score for clinical outcome over 5 years . The fixation of the cups did not differ between the groups , but HA showed a tendency to decrease proximal migration . HA-coated cups displayed the best interface with hardly any signs of radiolucent lines , indicating a superior sealing effect of the HA coating . Cups with screws or pegs had more radiolucent lines and osteolytic lesions than the other groups . Radiolucent lines were correlated to higher proximal migration , young age , and female gender ( r2=.2 ) . The wear rate of the ethylene oxide-sterilized polyethylene liner was high ( 0.2 mm/y ) but did not differ between the groups . Two cups with a perioperative fracture of the acetabular rim showed large initial migration but stabilized thereafter
Results Best evidence analysis showed no difference in polyethylene wear rate , the frequency of cup migration , and aseptic loosening between monoblock and modular acetabular components .
No convincing evidence was found for the cl aim that lower frequencies of acetabular osteolysis are observed with the use of monoblock cups compared with modular uncemented cups .
Conclusions The purported benefits of monoblock cups were not substantiated by this systematic review of controlled studies in that polyethylene wear rates and frequencies of cup failure and acetabular osteolysis were similar to those observed with modular implants .
Background Monoblock acetabular components used in uncemented total hip arthroplasty ( THA ) have certain mechanical characteristics that potentially reduce acetabular osteolysis and polyethylene wear .
However , the degree to which they achieve this goal is not well documented .
Questions / purpose sThe purpose of this study was to use a systematic review of controlled trials to test the hypothesis that monoblock cups have superior ( 1 ) polyethylene wear rate ; ( 2 ) frequency of cup migration ; ( 3 ) frequency of acetabular osteolysis ; and ( 4 ) frequency of aseptic loosening compared with modular components used in uncemented THA .