title: Eight- to ten-year clinical and radiographic outcome of a porous tantalum monoblock acetabular component. Early migration predicts late aseptic failure of hip sockets. Ten-year results with the Morscher press-fit cup: an uncemented, non-modular, porous-coated cup inserted without screws A prospective study of the migration of two acetabular components Treatment for acetabular dysplasia using the uncemented RM acetabular component - a 20 year follow-up. Effect of augmented cup fixation on stability, wear, and osteolysis: a 5-year follow-up of total hip arthroplasty with RSA. Cementless coated and noncoated Mathys acetabular cups: radiographic and histologic evaluation.
abstract: In a prospect i ve study , the authors used a porous tantalum monoblock acetabular component for primary total hip arthroplasty between November 1997 and June 1999 . A total of 156 consecutive primary total hip arthroplasty were done in 143 patients younger than 75 years . A total of 151 hips had a follow-up time from 8 to 10 years . The average preoperative total Harris hip score of 44.0 + /- 13.8 increased to 97.0 + /- 6.2 at the latest follow-up . The average preoperative Oxford hip score of 43.3 + /- 6.5 improved to 13.9 + /- 2.3 at the latest follow-up . Radiographic evaluation including the Ein-Bild-Röntgen-Analyse ( EBRA ) digital system showed no radiographic evidence of gross polyethylene wear , progressive radiolucencies , osteolytic lesions , acetabular fracture , or component subsidence . There were 7 ( 4.5 % ) postoperative complications all unrelated to the acetabular component We report a prospect i ve , stratified study of 60 PCA-cups and 60 RM-polyethylene cups which have been followed for a median time of 90 months , with annual radiography .  The radiological migration of cups was measured by the computer-assisted EBRA method . A number of threshold migration rates from 1 mm in the first year to 1 mm in five years have been assessed and related to clinical ly determined revision rates . A total of 28 cups showed a total migration of 1 mm or more within the first two years ; 13 of these cups have required revision and been exchanged . The survival curves of cups which had previously shown early migration were considerably different from those without early migration . For cups with a migration of less than 1 mm within the first two years the mean survival at 96 months was 0.96 + /- 0.02 ; for migrating cups , it was 0.63 + /- 0.11 ( log-rank test , p=0.0001 ; chi-square value=39.4 ) . Early migration is a good predictor for late loosening of hip sockets Total  hip arthroplasty ( THA )  with well design ed cementless acetabular implants has shown excellent results . The purpose of this study was to assess our clinical and radiological outcomes using an uncemented cup . We conducted a prospect i ve cohort study including all consecutive primary THAs performed with the Morscher press-fit cup , an uncemented non-modular acetabular component , between March 1996 and December 1998 . Patients were evaluated at ten years with clinical and radiological follow-up , patient satisfaction and question naire assessment using the Harris hip score ( HHS ) , Merle d’Aubigné and Postel score , the UCLA score , the 12-item short-form health survey ( SF-12 ) and a visual analog scale .  Five hundred sixty-one THAs were performed in 518 patients . At 120 months ( ± 7.3 months ) , 303 patients with 335 THAs were still available for follow-up . None of the patients had required cup revision for aseptic loosening . At ten years , the cup survivorship was 98.8 % ( 95 % CI 97.4–99.5 ) with cup revision for any cause as an endpoint . No radiolucencies were seen around the cups , but osteolytic defects involved 21 stems ( 8.3 % ) . Mean total linear polyethylene wear was 0.9 mm . The Morscher acetabular replacement cup provides excellent results at ten years . There were no revisions for aseptic loosening of the cup , and no osteolytic defects were found around the cup . Patient satisfaction was high and the clinical results were very good Summary Fifty-nine PCA cups and 61 hydroxyapatite-coated RM cups were included in a prospect i ve r and omised study with a mean follow up of 5.2 years . Clinical evaluation revealed better results with the RM cup . Radiological criteria of loosening could be applied only with considerable restrictions as different parameters were assessed : progressively loosened beads in PCA cups and faded contour in RM cups . Migration was measured by a computer assisted method ( EBRA ) . PCA cups showed significantly more longitudinal migration 2 years after operation and subsequently . High migration values correlated with a limp . Loosening as defined by migration was of clinical relevance , could be measured early and predicted the survival rate . RésuméCinquante-neuf  cotyles PCA et 61 cotyles RM , recouverts d'hydroxyapatite  , ont été rassemblés dans une étude prospect i ve r and omisée . La durée d'observation moyenne est de 5,2 ans . L'évaluation clinique , douleur , mobilité , marche , est en faveur du cotyle RM . Les critères radiologiques d'instabilité sont difficiles à apprécier , d'autant qu'il faut évaluer des paramètres différents : fragments progressivement libérés dans les cotyles PCA et irrégularités des contours dans les cotyles RM . Le déplacement a été étudié selon une nouvelle technique computérisée EBRA . Les cotyles PCA ont présenté une migration appréciable , surtout longitudinale , dès la 2ème année post-opératoire et ultérieurement une migration moyenne de 0,6 mm à 5 ans . Il existe une corrélation entre les déplacements importants et la boiterie . L'instabilité cotyloïdienne définie par le déplacement semble correspondre au résultat clinique , même à un stade précoce 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 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 This study evaluated 185 cementless Mathys coated and uncoated acetabular cups inserted for total hip replacement since September 1984 . All of the cups were high-density polyethylene .  Sixty were uncoated ( group A ) , 96 were coated with hydroxyapatite ( group B ) , and 29 were coated with titanium ( group C ) .  Cup survival was assessed clinical ly , histologically , and radiographically , and a computer-assisted EBRA method was used to evaluate cup migration . After a mean follow-up of 8 years , five cups in group A that had previously shown migration were revised as a result of aseptic loosening , while no loosening of hip sockets occurred in groups B and C. These results suggest that Mathys cups should be used only if coated with hydroxyapatite or titanium . Furthermore , the histologic evaluation in four cups from groups B and C revealed normal bone formation without inflammation or fibrotic tissue around the cups , promising long-term survival
target: 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: 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 .