Early migration predicts late aseptic failure of hip sockets. Cementless coated and noncoated Mathys acetabular cups: radiographic and histologic evaluation. Effect of augmented cup fixation on stability, wear, and osteolysis: a 5-year follow-up of total hip arthroplasty with RSA. A Dual-mobility Cup Reduces Risk of Dislocation in Isolated Acetabular Revisions A prospective study of the migration of two acetabular components High long-term loosening rate of conical screw cups Migration of the acetabular component: Effect of cement pressurization and significance of early radiolucency Acetabular reconstruction using a Kerboull cross-plate, structural allograft and cemented dual-mobility cup in revision THA at a minimum 5-year follow-up. No Migration of Acetabular Cups after Prophylaxis for Heterotopic Ossification Reduction in variability of acetabular cup abduction using computer assisted surgery: a prospective and randomized study. Good diagnostic performance of early migration as a predictor of late aseptic loosening of acetabular cups: results from ten years of follow-up with Roentgen stereophotogrammetric analysis (RSA). No difference in migration or wear between cemented low-profile cups and standard cups : A randomized radiostereographic study of 53 patients over 3 years Migration of press-fit cups fixed with poly-L-lactic acid or titanium screws: a randomized study using radiostereometry. Bioactive cement or ceramic/porous coating vs. conventional cement to obtain early stability of the acetabular cup. Randomised study of 96 hips followed with radiostereometry. No Increased Migration in Cups with Ceramic-on-Ceramic Bearing: An RSA Study Ten-year results with the Morscher press-fit cup: an uncemented, non-modular, porous-coated cup inserted without screws Five-year clinical, radiological and postmortem results of the Cambridge Cup in patients with displaced fractures of the neck of the femur.
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 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 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 Background Isolated acetabular revisions using st and ard cups are at risk of dislocation . The introduction of a nonconstrained dual-mobility cup was design ed to improve prosthetic stability without increasing loosening rates , but it is unclear whether the risk of dislocation is reduced . Questions / purpose sWe therefore determined : ( 1 ) if the rate of dislocation in isolated acetabular revisions is lower with a dual-mobility cup , ( 2 ) implant survival , ( 3 ) patient function , and ( 4 ) radiographic incidence of migration , loosening , and osteolysis . Methods We prospect ively followed 33 selected patients who underwent isolated acetabular revisions with a minimum of 2 years ’ followup ( mean , 3 years ; range , 2–5 years ) . In 24 patients a stainless steel dual-mobility cup was cemented into an antiprotrusio cage , whereas in nine we used a hyaluronan dual-mobility revision cup with a foramen hook and superior and posterior flanges screw fixations . We determined Harris hip ( HHS ) and WOMAC scores and examined radiographs for migration , loosening , and osteolysis . Results There were no dislocations . Survivorship rates of the femoral and acetabular components were 97 % at 5 years ; the rerevision rate for any reason was 3 % . At last followup , the mean HHS increased from 48 points preoperatively to 86 points . No patients had progressive osteolysis , component migration , or loosening on radiographs . Conclusion In this select group of isolated acetabular revisions , our data suggest the use of a dual-mobility cup reduced the risk of dislocation without increasing loosening from 2 to 5 years . Level of Evidence Level IV , therapeutic study . See the Guidelines for Authors for a complete description of levels of evidence 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 Background  Acetabular screw cups  seem to give high primary stability . We analyzed the migration and loosening behavior of a first-generation screw cup in a longterm follow-up . Patients and methods We examined 92 uncemented titanium alloy conical screw cups prospect ively .  Implant migration was assessed with a digital high-precision method ( EBRA ) with an accuracy of 1.0 mm . Results After mean 11 ( 0.5–18 ) years , 87 patients were available for examination and 5 patients had died . 32 implants had been revised and 7 cases showed radiographic evidence of loosening . The 10-year survival rate was 71 % . Migration of more than 1 mm occurred in 53 hips . Implant survival was strongly associated with an annual migration of greater than 0.2 mm . Interpretation The long-term behavior of this cup is not satisfactory . In spite of extraordinarily high primary implant stability , secondary osseointegration of this cup often fails . The annual migration rate represents a valid parameter for prediction of implant survival Background Cementing technique is a crucial factor in prosthesis fixation . No r and omized studies have been published , however , comparing the outcome of conventional fingerpacking with the outcome of pressurization of the cement prior to cup insertion . Patients and methods We r and omized 50 THAs to either fingerpacking or sequential pressurization ( including individual pressurization of each anchorage hole ) and followed the patients with RSA for 5 years . The penetration of cement into the anchorage holes was measured on digital radiographs . Postoperative radiolucent lines around the cup were correlated to later RSA results . For clinical evaluation , we used SF-36 and HHS . Results The pressurized group of THAs was more stable regarding changes in inclination . We found no other difference in the migratory behavior . The cement penetration into the anchorage holes was deeper with the pressurization technique than with fingerpacking . For the whole group taken together , there was a strong relation between the presence of radiolucent lines as measured on the postoperative radiograph and later migration observed by RSA at 2 and 5 years . Interpretation Pressurization of the cement produced better cement penetration and increased the cup stability in terms of changes in inclination . Early findings of radiolucent lines can predict later unfavorable cup migration The current study aim ed to evaluate the outcome of a continuous and prospect i ve series of 61 revision THAs with AAOS grade III and IV acetabular bone defect reconstruction using a Kerboull cross-plate , structural allograft and cemented dual mobility cup ( Saturne , Amplitude , Valence , France ) . At a 7.5-year mean follow-up , no instability was reported after revision . In addition , no failure of the acetabular reconstruction was observed in 98 % of the patients with complete allograft osseointegration and no evidence of mechanical rupture of the Kerboull cross-plate and /or loosening of the cemented dual mobility cup . In conclusion , such reconstruction technique demonstrated excellent results at mid-term follow-up in terms of prevention of instability after revision , restoration of the acetabular bone stock , and stable cemented fixation of the dual mobility cup The possibility of migration of cementless cups in total joints after prophylaxis of heterotopic ossification with irradiation or nonsteroidal antiinflammatory drugs  is a concern . Data investigating component stability with digital methods are lacking . This prospect i ve study analyzed the migration of cementless cups  after indomethacin and irradiation prophylaxis  with the digital Einzel-Bild-Röntgen-Analyse tool . The irradiation group ( 106 hips ) and the indomethacin group ( 98 hips ) were compared with 82 hips that did not receive any prophylaxis . The same cementless acetabular implants were used in all cases , and patients were observed clinical ly and radiographically at 2 and 5 years . At the 5-year followup , the number of cups that showed migration greater than 1 mm in the irradiation group ( five ) , the indomethacin group ( three ) , and the control group ( four ) were not different . No cup was considered loose on the radiographs and no patient underwent revision surgery . The results of our study indicate irradiation or short-course use of indomethacin for prophylaxis of heterotopic ossification did not negatively affect the stability of cementless cups in primary total hip arthroplasties . Level of Evidence : Level II , prognostic study . See the Guidelines for Authors for a complete description of levels of evidence Optimal orientation of the acetabular component of a  total hip prosthesis  is an important factor in determining the early and long-term result of a  total hip arthroplasty ( THA ) . Conventional positioning of the cup component is usually done using a free-h and method , or with the help of a mechanical acetabular alignment guide . However , these methods have proven to be inaccurate , and a great variation in orientation of the cup is found postoperatively . In this study , we wished to determine if the variability of the abduction angle of acetabular cups could be reduced with the use of computer navigation . The abduction angles of the acetabular components of three groups of 50 THAs were assessed . In the first group , a free-h and method was used to position the cup component . This group was operated in the period before we started using computer navigation for hip surgery . In the second group , CT-based computer navigation was used to plan and help position the cup . The third group consisted of 50 THA cases in which a free-h and method was used to position the cup , although these procedures were performed in the period after we had begun using the Computer Assisted Surgery ( CAS ) system . The variability in cup abduction angle was assessed in all three groups and compared . There was a significant reduction in variability in the CAS group compared to the first group . There was also a reduction in variability in the CAS group compared to the third group , although this was not statistically significant . It is concluded that the use of computer navigation helped the surgeon to place the cup component with less variability of the abduction angle , and , more importantly , we found that no cups were placed in the more extreme positions ( outliers ) BACKGROUND Excessive early migration of femoral stems following total hip arthroplasty and tibial components following total knee arthroplasty is associated with their long-term survival and allows reliable early evaluation of implant performance . However , a similar relationship involving acetabular components following hip arthroplasty has not been evaluated . This prospect i ve , long-term study with clinical and Roentgen stereophotogrammetric analysis ( RSA ) follow-up establishes the existence of this relationship and its associated diagnostic performance . METHODS Thirty-nine consecutive patients ( forty-one hips ) who underwent total hip arthroplasty with a cemented Exeter stem and a cemented Exeter all-polyethylene cup had prospect i ve clinical and RSA follow-up . Patients were evaluated postoperatively at six weeks , at three , six , and twelve months , and annually thereafter . Conventional anteroposterior and lateral radiographs were made at six weeks and at two , five , and ten years postoperatively as well as when indicated . The mean duration of follow-up ( and st and ard deviation ) was 9.4 ± 3.2 years . No patients were lost to follow-up ; fifteen patients died during the follow-up period . RESULTS Eleven acetabular components were observed to be loose on conventional radiographs after a mean of seventy-six months ( range , twelve to 140 months ) . During the first two postoperative years , the failed acetabular components showed markedly greater and more rapid cranial translation and sagittal rotation . Both cranial translation ( hazard ratio = 19.9 [ 95 % confidence interval , 4.94 to 80.0 ] , p < 0.001 ) and sagittal rotation ( hazard ratio = 11.1 [ 95 % confidence interval , 2.83 to 43.9 ] , p = 0.001 ) were strong risk factors for late aseptic loosening . Eight of the eleven failed components showed a distinctive pattern of excessive cranial translation combined with excessive sagittal rotation . The associated diagnostic performance of two-year cranial translation and /or sagittal rotation for predicting late aseptic loosening of the acetabular component was good ( area under the receiver operating characteristic curve , 0.88 [ 95 % confidence interval , 0.74 to 1.00 ; p < 0.001 ] and 0.84 [ 95 % confidence interval , 0.68 to 1.00 ; p = 0.001 ] , respectively ) . CONCLUSIONS Early migration , as measured by RSA at two years postoperatively , has good diagnostic capabilities for the detection of acetabular components at risk for future aseptic loosening , and this method appears to be an appropriate means of assessing the performance of new implants or implant-related changes Background Minor design changes may cause major changes in implant performance . Thus , as part of a stepwise introduction of a new low-profile cup , we performed a r and omized trial comparing it to a well-docu-mented st and ard cup . Patients and methods 60 patients , stratified according to sex , weight , and age , underwent cemented total hip arthroplasty using a Lubinus SP2 stem with ceramic head  and were r and omized to either the new low-profile Lubinus Flanged Anti-Luxation cup ( FAL ) or the Lubinus St and ard Eccentric cup ( St and ard ) .  7 patients were excluded and 53 ( 28 FAL ) were evaluated at 3 , 6 , 12 , and 36 months postoperatively . Primary outcome variables , cup migration ( MTPM ) , and wear ( total 3-dimensional femoral head penetration ) were measured with radiostereometry ( RSA ) . Clinical outcome was evaluated with the western Ontario and McMaster osteoarthritis index ( Womac ) and the visual analog pain score ( VAS ) . Results We found no difference in migration between the FAL and St and ard cups . There was no difference in wear between the two cups and there was no correlation between wear and migration . 3 cups ( 2 FAL and 1 St and ard ) showed continuous migration of a magnitude that indicated an increased risk of early loosening . Clinical outcome was excellent , without any difference between the 2 groups The early migration of porous acetabular cups was studied in 43 patients with osteoarthrosis . The patients were r and omly allocated to additional fixation of the cup with either biodegradable poly-L-lactic acid screws or titanium screws .  Radiostereometric evaluation was done during the first 2 years after the procedure in 43 hips ( 23 with  poly-L-lactic acid screws and 20 with titanium screws ) . At the 2-year follow-up , cups fixed with poly-L-lactic acid screws had migrated significantly more in the proximal-distal ( p < 0.05 ) and medial-lateral ( p < 0.05 ) directions . Cups with titanium screws displayed more pronounced rotations around the longitudinal axis ( p < 0.05 ) . Postoperatively , on the lateral view , there was an increased occurrence of radiolucencies at the dome of the cups fixed with poly-L-lactic acid screws ( p < 0.05 ) . The clinical result did not differ between the two groups . Inferior implant-bone contact in the poly-L-lactic acid group , local changes of the bone quality , and diminishing support of the poly-L-lactic acid screws  caused by their degradation with time could be reasons for the different pattern of migration observed Ninety patients ( 96 hips ) scheduled for THA were stratified to fixation of the acetabular component in three main groups of about equal size . Fluoride cement , porous coated press-fit cup with ceramic coating or Palacos cum Gentamicin cement were used . All patients received Spectron EF stem .  The migration of the cups and the femoral head penetration into the socket were measured with radiostereometric analysis . At 2 years the choice of fixation did not influence the migration or rotation of the cup .  Patients with compromised bone quality showed increased three-dimensional ( 3D or total ) migration . Proximal and 3D penetration rates were increased in cemented compared with the uncemented cups ( p<0.001 ) , which probably not could be related to the choice of fixation . Appearance of radiolucent lines was almost equal in the two cemented groups . Uncemented cups had less radiolucent lines at 2 years . Fluoride containing cement or uncemented fixation did not improve the early postoperative stability of the socket Ceramic-on-ceramic hip replacements might stress the bone interface more than a metal-polyethylene because of material stiffness , microseparation , and sensitivity to impingement . To ascertain whether this potentially increased stress caused an increased cup migration we compared a ceramic-on-ceramic with a metal-on-polyethylene implant for cup migration . Sixty one patients ( 61 hips ) undergoing THA for osteoarthritis were  r and omized to ceramic on ceramic ( Ce/Ce ) or cobalt-chromium on cross-linked polyethylene bearings ( PE ) in the same uncemented cup shell . Migration was followed with RSA . At 2 years we observed similar mean cup translations in the 3 directions ( 0.07 - 0.40 mm vs. 0.05 - 0.31 mm , Ce/Ce vs. PE ) , as well as similar rotations around the 3 axes ( 0.31 - 0.92 ° vs. 0.57 - 1.40 ° ) . WOMAC and SF-36 scores were also similar and no radiolucent lines or osteolysis found . The large migration seen in some cups in both implant groups will require close monitoring to ascertain the reasons . Mean proximal wear of the polyethylene liners measured 0.016 mm between 2 and 24 months . Our data suggest there is no increased cup migration in the ceramic-on-ceramic implant compared with the metal-on-polyethylene , and they seem an equally safe choice . However , the low wear measured with the more versatile and less expensive cross-linked polyethylene makes it a strong contender . Levels of Evidence : Therapeutic Level I. See the Guidelines for Authors for a complete description of levels of evidence 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 The Cambridge Cup has been design ed to replace the horseshoe-shaped articular cartilage of the acetabulum and the underlying subchondral bone . It is intended to provide physiological loading with minimal resection of healthy bone . The cup has been used in 50 women with displaced , subcapital fractures of the neck of the femur . In 24 cases , the cup was coated with hydroxyapatite . In 26 , the coating was removed before implantation in order to simulate the effect of long-term resorption . The mean Barthel index and the Charnley-modified Merle d'Aubigné scores recovered to their levels before fracture . We review ed 30 women at two years , 21 were asymptomatic and nine reported minimal pain .  The mean scores deteriorated slightly after five years reflecting the comorbidity of advancing age . Patients with the hydroxyapatite-coated components remained asymptomatic , with no wear or loosening . The uncoated components migrated after four years and three required revision . This trial shows good early results using a novel , hydroxyapatite-coated , physiological acetabular component
INTERPRETATION There was a clinical ly relevant association between early migration of acetabular cups  and late revision due to loosening .
BACKGROUND AND PURPOSE The association between excessive early migration of acetabular cups  and late aseptic revision has been scantily reported .
We therefore performed 2 parallel systematic review s and meta-analyses to determine the association between early migration of acetabular cups  and late aseptic revision .