The beneficial effect of hydroxyapatite lasts 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). Early migration predicts late aseptic failure of hip sockets. [What effect does the hydroxyapatite coating have in cementless knee arthroplasty?]. Early migration and late aseptic failure of proximal femoral prostheses. Hydroxyapatite coating versus cemented fixation of the tibial component in total knee arthroplasty: prospective randomized comparison of hydroxyapatite-coated and cemented tibial components with 5-year follow-up using radiostereometry. The Johnson-Elloy (Accord) total knee replacement. Poor results at 8 to 12 years. Denosumab reduces early migration in total knee replacement Fixation of high-flexion total knee prostheses: five-year follow-up results of a four-arm randomized controlled clinical and roentgen stereophotogrammetric analysis study. Primary Total Hip Arthroplasty with a Porous-Coated Acetabular Component. Seven-to-Ten-Year Results* Migration of a cemented fixed-bearing, polished titanium tibial baseplate (Genesis II) at ten years : a radiostereometric analysis. The Mayo Cementless Femoral Component in Active Patients with Osteoarthritis Clodronate prevents prosthetic migration: A randomized radiostereometric study of 50 total knee patients Cemented tibial component fixation performs better than cementless fixation Results of Charnley total hip arthroplasty at a minimum of thirty years. A concise follow-up of a previous report. Problems With Cementless Total Knee Arthroplasty at 11 Years Followup Cemented versus cementless Oxford unicompartmental knee arthroplasty using radiostereometric analysis: a randomised controlled trial. Hydroxyapatite-Enhanced Tibial Prosthetic Fixation Early Migration Pattern of the Uncemented CLS Stem in Total Hip Arthroplasties Proximally cemented versus uncemented Freeman-Samuelson knee arthroplasty. A prospective randomised study. Early Migration of the Tibial Component of the Buechel-Pappas Total Ankle Prosthesis Highly Crosslinked Polyethylene Does Not Reduce Aseptic Loosening in Cemented THA 10-year Findings of a Randomized Study Systematic review automation technologies
Background and purpose In contrast to early migration , the long-term migration of hydroxyapatite- ( HA- ) coated tibial components in TKA has been scantily reported . This r and omized controlled trial investigated the long-term migration measured by radiostereometric analysis ( RSA ) of HA-coated , uncoated , and cemented tibial components in TKA . Patients and methods 68 knees were r and omized to HA-coated ( n = 24 ) , uncoated ( n = 20 ) , and cemented ( n = 24 ) components .  All knees were prospect ively followed for 11–16 years , or until death or revision .  RSA  was used to evaluate migration at yearly intervals . Clinical and radiographic evaluation was according to the Knee Society system . A generalized linear mixed model ( GLMM , adjusted for age , sex , diagnosis , revisions , and BMI ) was used to take into account the repeated-measurement design . Results The present study involved 742 RSA analyses . The mean migration at 10 years was 1.66 mm for HA , 2.25 mm for uncoated and 0.79 mm for the cemented group ( p < 0.001 ) . The reduction of migration by HA as compared to uncoated components was most pronounced for subsidence and external rotation . 3 tibial components were revised for aseptic loosening ( 2 uncoated and 1 cemented ) , 3 for septic loosening ( 2 uncoated and 1 cemented ) , and 1 for instability ( HA-coated ) . 2 of these cases were revised for secondary loosening after a period of stability : 1 case of osteolysis and 1 case of late infection . There were no statistically significant differences between the fixation groups regarding clinical or radiographic scores .  Interpretation HA reduces migration of uncemented tibial components . This beneficial effect lasts for more than 10 years . Cemented components showed the lowest migration . Longitudinal follow-up of TKA with RSA allows early detection of secondary loosening 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 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 The goal of this study was to compare the migration of  noncemented diffusion sintered titanium fibermesh-coated tibial components with ( HA group ) and without ( non-HA group ) additional hydroxyapatite coating .  For this purpose  digital radiostereometry ( DIRSA ) was used to compare the migration after 2 and 9 years for the two groups . After 2 years the mean maximum subsidence of the HA-coated components ( 0.24+/-0.18 mm ) was about one-half of the mean maximum subsidence of the non-HA-coated group ( 0.55+/-0.55 mm ) . After 9 years the maximum subsidence of the HA-coated components was still smaller , but not as pronounced as before . The same trend was also found for the endpoint maximum total point motion ( MTPM ) . After 2 years the mean MTPM of the HA-coated components was 0.66+/-0.38 mm and of the non-HA group 0.73+/-0.50 mm . After 9 years the mean MTPM for the HA-coated components was 0.54+/-0.15 mm and for the non-HA-coated components 0.74+/-0.20 mm . None of the HA-coated tibial components but one of the non-HA group had to be revised and exchanged due to aseptic loosening The  vertical migration of four configurations of a proximal femoral prosthesis , followed for up to nine years , was measured on st and ard radiographs . The same implant was used without cement ( group 1 ) and with cement ( group 2 ) . The migration of both groups was linear from six months onwards . The mean migration rate and the incidence of late aseptic loosening were both greater in group 1 . Survival analysis of the two groups , however , showed no statistically significant difference . In both groups , hips later destined for revision migrated more rapidly from the initial postoperative period onwards , than did the remainder . A threshold migration of 1.2 mm/year during the first two years after implantation detected hips likely to fail with a specificity of 86 % and a sensitivity of 78 % . This ' migration test ' was applied to the results in two further groups of patients in which a modified femoral prosthesis had been implanted without hydroxyapatite coating ( group 3 ) and with hydroxyapatite coating  ( group 4 ) . The test distinguished between the four groups and suggested that at least two fixation procedures should be ab and oned . We conclude that vertical migration measured on st and ard radiographs in the first two years after implantation can be used to predict late aseptic loosening . New prosthetic configurations should be evaluated by migration measurements before their general release . Our observations support the view that one cause of late aseptic loosening is imperfect initial fixation Fifty-three consecutive patients ( 57 knees ; mean age , 69 years ) entered a prospect i ve r and omized study to compare the fixation of hydroxyapatite (HA)-coated ( 29 knees ) with cemented ( 28 knees ) tibial components in the Tricon II total knee arthroplasty . The quality of the fixation during 5 years postoperatively was evaluated with radiostereometric analysis ( RSA ) . Three HA-coated implants were revised : 2 owing to infection , and 1 owing to early delamination of the coating and clinical loosening . Eight patients ( 9 knees ) died , 1 patient sustained a stroke  , and 1 patient refused investigations after 1 year . In the 40 patients ( 19 HA-coated , 21 cemented ) remaining at 5 years , the magnitude of the micromotion between the HA-coated and cemented groups did not differ . The HA-coated implants displayed most of the migration within the initial 3 months then stabilized , whereas the cemented implants showed an initially lower , but over time continuously increasing migration . Between 1 and 2 years , 4 of 24 HA-coated and 10 of 23 cemented implants  migrated > 0.2 mm and were categorized unstable , which has been shown to have a prognostic value as regards future aseptic loosening . Progressive radiolucent lines developed in 2 cemented knees , which both were categorized unstable . If HA-coated implants can sustain the forces that threaten the fixation in the early period after implantation , a strong and enduring fixation may be obtained We have found poor mid-term results in a multisurgeon series of 94 Johnson-Elloy ( Accord ) total knee replacements .  A total of 27 knees ( 29 % ) has required revision , in 26 for aseptic loosening . Only 18 ( 19 % ) remain in situ , and these give poor function , are painful and most show radiological evidence of early failure . At 12 to 13 years the survival rate is 43 % ( confidence interval 29 to 57 ) with failure requiring revision as the endpoint . Proximal migration of the femoral component is associated with considerable loss of bone stock . We believe that all patients who have this implant should be recalled for regular review in order to anticipate this problem Background and purpose — Aseptic loosening is a main cause of late revision in total knee replacement ( TKR ) . Migration of implants as measured by radiostereometric analysis ( RSA ) can predict future loosening . This migration is associated with bone resorption . Denosumab is a human monoclonal antibody that binds to receptors on osteoclast precursors and osteoclasts . This prevents osteoclast formation , result ing in less bone resorption in cortical and trabecular bone . We investigated whether denosumab can reduce migration of TKR , as measured with RSA . Patients and methods — In this 2-center , r and omized , double-blind  placebo-controlled  trial , 50 patients with osteoarthritis of the knee were treated with an injection of either denosumab ( 60 mg ) or placebo 1 day after knee replacement surgery and again after 6 months . RSA was performed postoperatively and after 6 , 12 , and 24 months . The primary effect variable was RSA maximal total point motion ( MTPM ) after 12 months . We also measured other RSA variables and the knee osteoarthritis outcome score ( KOOS ) . Results — The primary effect variable , MTPM after 12 months , showed that migration in the denosumab group was statistically significantly less than in the controls . Denosumab  MTPM 12 months was reduced by one-third ( denosumab : median 0.24 mm , 10 % and 90 % percentiles : 0.15 and 0.41 ; placebo : median 0.36 mm , 10 % and 90 % percentiles : 0.20 and 0.62 ) . The secondary MTPM variables ( 6 and 24 months ) also showed a statistically significant reduction in migration . There was no significant difference in MTPM for the period 12–24 months . KOOS sub-variables were similiar between denosumab and placebo after 12 and 24 months . Interpretation — Denosumab reduces early migration in total knee replacement , as in previous trials using bisphosphonates . As migration is related to the risk of late loosening , denosumab may be beneficial for long-term results BACKGROUND High-flexion total knee arthroplasty was introduced to meet the dem and s of daily activity requiring increased knee flexion . However , concerns have been raised regarding the fixation of high-flexion total knee arthroplasty components and increased rates of loosening have been reported . To date , migration , and thus fixation , of high-flexion total knee arthroplasty components has not been analyzed and the preferential bearing type ( mobile or fixed ) is unknown . METHODS Of eighty-six consecutive eligible patients , seventy-four patients ( seventy-eight knees ) scheduled for total knee arthroplasty were r and omized to one of four  Legacy Posterior Stabilized ( LPS ) total knee prosthesis design s : ( 1 ) LPS-Flex mobile , ( 2 ) LPS-Flex fixed , ( 3 ) LPS mobile , and ( 4 ) LPS fixed . The primary outcome was component migration measured with use of Roentgen stereophotogrammetric analysis , and secondary outcomes were postoperative knee flexion and extension and Knee Society Score . Patients were evaluated postoperatively at six , twelve , twenty-six , and fifty-two weeks and annually thereafter . At the five-year follow-up , eight patients had died and two patients were lost to follow-up . Seventy-seven tibial and forty-two femoral components were suitable for migration measurements . RESULTS The overall five-year migration of the seventy-seven tibial components was not significantly different among the four total knee prosthesis design s ( compared with the LPS fixed design , the range of overall mean differences for the other three design s was 0.02 to 0.25 mm ) and migration was comparable at the two and five-year follow-up . Migration stabilized in all but three components ( two LPS-Flex mobile and one LPS fixed ) ; one of these components has already been revised and was aseptically loose . The overall five-year migration of the forty-two femoral components was comparable among the four design s ( compared with the LPS fixed design , the range of overall mean differences for the other three design s was 0.01 to 0.18 mm ) and was similar at two and five years postoperatively . One femoral component ( LPS-Flex mobile ) migrated excessively . In patients who had a mean postoperative flexion of ≥ 125 ° or a maximum flexion of ≥ 135 ° during the one to five-year follow-up period , migration of high-flexion components was comparable with that of conventional components and indicative of appropriate fixation . Postoperative flexion , extension , Knee Society Score , and Knee Society Score function were comparable during the five-year follow-up period and at the two and five-year follow-up . CONCLUSIONS The LPS-Flex total knee prosthesis with either a mobile or a fixed bearing had migration comparable that of with its conventional counterpart and is expected to have similar ( excellent ) long-term survival in these patients . LEVEL OF EVIDENCE Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence One hundred and eighty-four patients who had been managed , between 1984 and 1985 , with a total of 204 consecutive primary total hip arthroplasties with insertion of a Harris-Galante type-I acetabular component without cement were prospect ively studied . There were eighty-two men ( 45 per cent ) and 102 women ( 55 per cent ) . The mean age at the time of the operation was fifty-two years ( range , twenty to eighty-four years ) . One hundred and fifty-seven patients ( 173 hips ) were available for clinical review at a mean of 104 months ( range , seventy-eight to 126 months ) . At this time , the mean preoperative Harris hip score of 52 points ( range , 12 to 79 points ) had improved to a mean of 90 points ( range , 44 to 100 points ) . Two patients ( two hips ) had had an exchange of an excessively worn polyethylene liner . One patient ( one hip ) had had débridement and grafting of an area of massive retroacetabular osteolysis . Two stable acetabular components ( 1 per cent ) had been revised at the time of femoral revision . None of the cups had been revised because of aseptic loosening . Radiographic examination of 150 patients ( 165 hips ) at a mean of 104 months ( range , seventy-eight to 126 months ) revealed that 156 cups ( 95 per cent ) were stable . Eight cups ( 5 per cent ) were considered to be possibly unstable , with a radiolucent line between the prosthesis and the bone that was one millimeter wide or less in at least four of five zones ; two of the eight had a complete radiolucent line in all zones . One component , which had been implanted with a bulk allograft from a femoral head , migrated more than two millimeters in the first two years and then stabilized without complication . Osteolysis was seen in seven acetabula ( 4 per cent ) and was limited to the periphery of the cup in six . Survivorship analysis at ten years revealed that the acetabular component had a 99 per cent chance of survival ( 95 per cent confidence interval , 0.98 to 1.0 ) with revision or aseptic loosening as the end point and a 97 per cent chance of survival ( 95 per cent confidence interval , 0.95 to 1.0 ) with revision , aseptic loosening , or reoperation because of a problem related to the acetabular component as the end point AIMS The purpose of the present study was to examine the long-term fixation of a cemented fixed-bearing polished titanium tibial baseplate ( Genesis ll ) . PATIENTS AND METHODS Patients enrolled in a previous two-year prospect i ve trial ( n = 35 ) were recalled at ten years . Available patients ( n = 15 ) underwent radiostereometric analysis ( RSA ) imaging in a supine position using a conventional RSA protocol . Migration of the tibial component in all planes was compared between initial and ten-year follow-up . Outcome scores including the Knee Society Score , Western Ontario and McMaster Universities Arthritis Index , 12-item Short Form Health Survey , Forgotten Joint Score , and University of California , Los Angeles Activity Score were recorded . RESULTS At ten years , the mean migration of the tibial component was less than 0.1 mm and 0.1 ° in all planes relative to the post-operative RSA exam . Maximum total point movement increased with time ( p = 0.002 ) from 0.23 mm ( sd 0.18 ) at six weeks to 0.42 mm ( sd 0.20 ) at ten years . CONCLUSION The low level of tibial baseplate migration found in the present study correlates to the low rate of revision for this implant as reported in individual studies and in joint replacement registries . TAKE HOME MESSAGE Overall , the implant was found to be well fixed at ten years , supporting its continued clinical use and the predictive power of RSA for determining long-term fixation of implants . Cite this article : Bone Joint J 2016;98-B:616 - 21 This prospect i ve study reports the clinical and radiological results of a single-surgeon series using the Mayo conservative hip stem in a district hospital . 30 total hip arthroplasties were performed in 26 physically active patients . There were 18 women and 8 men , with a mean age of 57.4 years ( range 36–79 ) . 4 cases were bilateral . The operation was performed for severe primary or secondary osteoarthritis of the hip . Duration of follow-up ranged from 67–87 months ( mean 81 months ) . There were no early complications relating to the surgical procedure . There was one case of traumatic fracture of the femur during rehabilitation , while late complications included two cases of late infection ( 4 months and 16 months after surgery ) both revised in two-stage procedures . There was considerable improvement in Merle d'Aubigne score following surgery . There were no revisions for aseptic loosening , but we identified 2 implants with significant radiolucent lines and subsidence six years after the index operation . Neither patient experienced pain in the hip or restriction of activity . Therefore , the aseptic loosening survival rate was 100 % ( end point = revision operation ) . Taking radiological loosening as the end point survivorship was 93.3 % . The use of the Mayo short stem component in active patients may preserve bone and enable subsequent revision operations to proceed using primary implants . Our results suggest that conservative design s of this type may be of benefit in selected individuals In a double-blind study , we r and omized 50 patients to receive peroral clodronate medication or placebo from 3 weeks before until 6 months after a total knee replacement with a cemented NexGen implant .  Migration of the tibial components was measured by radiostereometry at 1 year . Clodronate reduced prosthetic migration , as measured by maximum total point motion , from 0.40 mm to 0.29 mm ( p = 0.01 ) . This confirms that the early postoperative migration is related to bone resorption and thus the biology of the bone bed . Since early migration is related to late loosening , 6 months of clodronate medication might reduce the risk of loosening Background The question whether the tibial component of a total knee arthroplasty  should be fixed to bone with or without bone cement has not yet been definitely answered . We studied movements between the tibial component and bone by radiostereometry ( RSA ) in total knee replacement ( TKR ) for 3 different types of fixation : cemented fixation ( C-F ) , uncemented porous fixation ( UC-F ) and uncemented porous hydroxyapatite fixation ( UCHA-F ) . Patients 116 patients with osteoarthrosis , who had 146 TKRs , were included in 2 r and omized series . The first series included 86 unilateral TKRs stratified into 1 of the 3 types of fixation . The second series included 30 patients who had simultaneous bilateral TKR surgery , and who were stratified into 3 subgroups of pairwise comparisons of the 3 types of fixation . Results After 5 years 2 knees had been revised , neither of which were due to loosening . 1 UCHA-F knee in the unilateral series showed a large and continuous migration and a poor clinical result , and is a pending failure . The C-F knees rotated and migrated less than UC-F and UCHA-F knees over 5 years . UCHA-F  migrated less than UC-F after 1 year . Interpretation Cementing of the tibial component offers more stable bone-implant contact for 5 years compared to uncemented fixation . When using uncemented components , however , there is evidence that augmenting a porous surface with hydroxyapatite may mean less motion between implant and bone after the initial postoperative year The purpose of the current study was to up date the results of a prospect i ve , single-surgeon series of primary Charnley total hip arthroplasties performed with cement . This investigation is one of the first studies in which hips treated with total hip arthroplasty with cement  were followed for a minimum of thirty years . Twenty-seven patients ( thirty-four [ 10.3 % ] of the hips in the initial study group ) were alive at a minimum of thirty years postoperatively . These patients served as the focus of the present study .  Revision because of aseptic loosening of the acetabular component was performed in 7.3 % ( twenty-three ) of the hips from the original study group ( excluding those revised because of infection or dislocation ) and 26 % ( eight ) of the hips in the living cohort .  Revision  because of aseptic loosening of the femoral component was performed in 3.2 % ( ten ) of the hips from the original study group ( excluding those revised because of infection or dislocation ) and 10 % ( three ) of the hips in the living patients . Since the twenty-five-year review , three hips were revised ( one because of acetabular loosening , one because of femoral loosening , and one because of instability ) . This end- result study demonstrated the remarkable durability of cemented Charnley total hip replacements over a span of three decades , with 88 % of the original prostheses intact at the time of the final follow-up or at the patient 's death One hundred two patients with 131 consecutive cementless total knee arthroplasties that retained the posterior cruciate ligament were followed up prospect ively . The average age of the patients was 58 years ( range , 32–75 years ) . The mean followup on the surviving knee arthroplasties was 11 years ( range , 7–16 years ) . The patellar component was metal-backed in the first 112 ( 85 % ) knees , cementless all-polyethylene in the last 17 ( 13 % ) knees , and two knees had a prior patellectomy . Forty-four metal-backed patellar components ( 48 % ) were revised ; nine were loose , and 35 had polyethylene wear through . Thirteen femoral components ( 12 % ) were revised because of femoral abrasion from a failed metal-backed patellar component . No other femoral component was revised , loose , or had osteolysis develop . Nine ( 8 % ) tibial components had failure of ingrowth ; eight have been revised . Partial radiolucencies occurred in 53 % of the tibias . Thirteen ( 12 % ) small osteolytic lesions developed , all around screws or screw holes in the tibial components . At an average of 11 years followup , cementless fixation yielded mixed results : cementless femoral fixation was excellent and metal-backed patellar components had a 48 % patellar revision rate . Cementless tibial components had an 8 % aseptic loosening rate and a 12 % incidence of small osteolytic lesions . Based on these results , the authors have ab and oned cementless fixation in total knee arthroplasty The most common reasons for revision of unicompartmental knee arthroplasty ( UKA ) are loosening and pain . Cementless components may reduce the revision rate . The aim of this study was to compare the fixation and clinical outcome of cementless and cemented Oxford UKAs .  A total of 43 patients were r and omised to receive either a cemented or a cementless Oxford UKA and were followed for two years with radiostereometric analysis ( RSA ) , radiographs aligned with the bone-implant interfaces and clinical scores . The femoral components migrated significantly during the first year ( mean 0.2 mm ) but not during the second . There was no significant difference in the extent of migration between cemented and cementless femoral components in either the first or the second year . In the first year the cementless tibial components  subsided significantly more than the cemented components ( mean 0.28 mm ( sd 0.17 ) vs. 0.09 mm ( sd 0.19 mm ) ) . In the second year , although there was a small amount of subsidence ( mean 0.05 mm ) there was no significant difference ( p = 0.92 ) between cemented and cementless tibial components . There were no femoral radiolucencies . Tibial radiolucencies were narrow ( < 1 mm ) and were significantly ( p = 0.02 ) less common with cementless ( 6 of 21 ) than cemented ( 13 of 21 ) components at two years . There were no complete radiolucencies with cementless components , whereas five of 21 ( 24 % ) cemented components had complete radiolucencies . The clinical scores at two years were not significantly different ( p = 0.20 ) . As second-year migration is predictive of subsequent loosening , and as radiolucency is suggestive of reduced implant-bone contact , these data suggest that fixation of the cementless components is at least as good as , if not better than , that of cemented devices Sixty-two knees ( 60 patients ) were r and omized to four noncemented groups . In Groups 1 , 3 , and 4 , the bone cuts were made with a cooled saw blade . In Group 1 , 15 patients were operated on with the porous coated Osteonic 7000 tibial component . In Group 2 , 15 patients were operated on with the same tibial component as in Group 1 but with the use of a st and ard saw blade . In Group 3 , 16 patients were operated on with the hydroxyapatite-coated Osteonic tibial component , and in Group 4 , 16 patients were operated on with the hydroxyapatite Duracon tibial component . All patients were followed up clinical ly and with roentgenstereometric analysis . There were no differences among the groups regarding clinical outcome . One knee was revised ( Group 2 ) after 1 year because of loosening of the tibial component . The maximum migration at 1 year was 1.7 mm in Group 1 , 1.9 mm in Group 2 , 1.3 mm in Group 3 , and 1 mm in Group 4 . At the 2-year followup , the migrations were 1.8 mm , 1.5 mm , 1.4 mm , and 1 mm in Groups 1 , 2 , 3 , and 4 , respectively . The inducible displacement that occurred at 1 year was 0.6 mm in Group 1 , 0.5 mm in Group 2 , 0.4 mm in Group 3 , and 0.4 mm in Group 4 . The hydroxyapatite coating had a strong positive effect on the tibial component fixation . No prosthesis in the hydroxyapatite groups showed continuous migration We performed this investigation to determine the possible migration starting immediately after surgery and the effect of different weightbearing regimens on the migration pattern of an uncemented hip stem ( CLS ) . Stem migration was determined with radiostereometry analysis with baseline when the patients still were anesthetized . Subsequent examinations were done up to 1 year . Twenty-nine patients ( mean age , 55 years ; range , 26 - 63 years ) were r and omized to either unrestricted weightbearing combined with intensive physiotherapy  from the first day after surgery or to partial weightbearing and a conservative training regimen for the first 3 months after surgery . At 1 week , subsidence was −0.03 mm in the unrestricted weightbearing group and 0.01 mm in the partial weightbearing group . At 1 year , subsidence was 1.01 mm in the unrestricted weightbearing group and 0.51 mm in the partial weightbearing group . One patient in the unrestricted weightbearing group had revision surgery because of aseptic loosening at 1.5 years after surgery . The CLS stem did not have any migration from the end the surgery until 1 week , but there was small migration from 1 week to 3 months after which the stem remained stable . The degree of early weightbearing did not affect the migration pattern . Level of Evidence : Level I , therapeutic study ( r and omized study ) . See the Guidelines for Authors for a complete description of levels of evidence We studied the effect of a layer of cement placed under the tibial component of Freeman-Samuelson total knee prostheses  with a metal back and an 80 mm intramedullary stem , using roentgen stereophotogrammetry to measure the migration of the tibial component during one year in 13 uncemented and 16 cemented knees . The addition of cement produced a significant reduction in migration at one year , from a mean of 1.5 mm to one of 0.5 mm ( p less than 0.01 ) , including a significant reduction in pure subsidence . One year postoperatively the clinical results were similar between the groups , but , at three years , one uncemented knee had required revision Interest in mobile-bearing total ankle arthroplasty has increased in recent years . Clinical studies show favorable but varying results , with survival rates between 70 % and 90 % at 10-year followup . Design -specific differences in early migration patterns might explain variations in the results and modes of failure . Using radiostereometric analysis ( RSA ) we prospect ively followed 15 RA patients with a cementless mobile-bearing total ankle arthroplasty .  The American Orthopaedic Foot and Ankle Society ankle score and radiostereometric radiographs  were evaluated immediately postoperatively , 6 weeks postoperatively , 3 months , 6 months , and 12 months postoperatively and yearly thereafter . The postoperative clinical results improved . We observed increased migration of the tibial component during the first 3 months , but this stabilized by the 6 month followup . The mean lateral-medial migration was 0.8 mm , distal-proximal migration was 0.9 mm , and posteroanterior migration was −0.5 mm . The latter implies the total result ant migration was in anterior and valgus tilting of this tibial component . However , migration stabilized at 6 months postoperatively . We believe the surgical technique ( anterior cortical window for placement ) and the method of tibial fixation likely explain this migration . Level of Evidence : Therapeutic , Level IV . See Guidelines for Authors for a complete description of levels of evidence Background Polyethylene ( PE ) wear particles are believed to cause aseptic loosening and thereby impair function in hip arthroplasty .  Highly crosslinked polyethylene ( XLPE ) has low short- and medium-term wear rates . However , the long-term wear characteristics are unknown and it is unclear whether reduced wear particle burden improves function and survival of cemented hip arthroplasty . Questions / purpose sWe asked whether XLPE wear rates remain low up to 10 years and whether this leads to improved implant fixation , periprosthetic bone quality , and clinical function compared to conventional PE . Methods We r and omized 60 patients ( 61 hips ) to receive either PE or XLPE cemented cups combined with a cemented stem .  At 10 years postoperatively , 51 patients ( 52 hips ) were evaluated for polyethylene wear and component migration estimation by radiostereometry , for radiolucent lines , bone densitometry , and Harris hip and pain scores . Revisions were recorded . Results XLPE cups had a lower mean three-dimensional wear rate between 2 and 10 years compared to conventional PE hips : 0.005 mm/year versus 0.056 mm/year . We found no differences in cup migration , bone mineral density , radiolucencies , functional scores , and revision rate . There was a trend toward improved stem fixation in the XLPE group . The overall stem failure rate was comparably high , without influencing wear rate in XLPE hips . Conclusions XLPE displayed a low wear rate up to 10 years when used in cemented THA , but we found no clear benefits in any other parameters . Further research is needed to determine whether cemented THA design s with XLPE are less prone to stem loosening . Level of Evidence Level I , therapeutic study . See the Instructions for Authors for a complete description of levels of evidence Systematic review s , a cornerstone of evidence -based medicine , are not produced quickly enough to support clinical practice . The cost of production , availability of the requisite expertise and timeliness are often quoted as major contributors for the delay . This detailed survey of the state of the art of information systems design ed to support or automate individual tasks in the systematic review , and in particular systematic review s of r and omized controlled clinical trials , reveals trends that see the convergence of several parallel research projects . We surveyed literature describing informatics systems that support or automate the processes of systematic review or each of the tasks of the systematic review . Several projects focus on automating , simplifying and /or streamlining specific tasks of the systematic review . Some tasks are already fully automated while others are still largely manual . In this review , we describe each task and the effect that its automation would have on the entire systematic review process , summarize the existing information system support for each task , and highlight where further research is needed for realizing automation for the task . Integration of the systems that automate systematic review tasks may lead to a revised systematic review workflow . We envisage the optimized workflow will lead to system in which each systematic review is described as a computer program that automatically retrieves relevant trials , appraises them , extracts and synthesizes data , evaluates the risk of bias , performs meta- analysis calculations , and produces a report in real time
INTERPRETATION There was a clinical ly relevant association between early migration of TKPs and late revision for loosening .
PURPOSE We performed two parallel systematic review s and meta-analyses to determine the association between early migration of tibial components and late aseptic revision .