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 .
Treatment for acetabular dysplasia using the uncemented RM acetabular component - a 20 year follow-up.
Our study reports a sub-group of patients with developmental dysplasia from a previously published larger series , with particular emphasis on the use of the uncemented RM acetabular component . We evaluated the long term results of 93 consecutive uncemented THAs in 80 patients using the titanium-coated RM acetabular component and the CLS femoral component in a prospect i ve study . Eighteen hips in 16 patients had osteoarthritis secondary to developmental dysplasia of the hip . The mean follow-up was 19.6 years ( 18.2 to 20.9 ) . Fourteen patients with 15 hips were clinical ly and radiographically examined and evaluated . Two patients with 3 hips died . No patient was lost to follow-up . No implant had to be revised , and no cases showed evidence of radiographic loosening . Nine acetabular components were not completely covered by host bone but this did not affect the outcome . At the latest follow-up the mean Harris Hip Score was 92 ( 81 to 100 ) . The mean annual wear rate was 0.12 mm . The RM acetabular component performed well over 20 years in this selected group of patients . Complete acetabular containment was not needed , thus allowing reliable reconstruction of the anatomical centre of rotation
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 .