title: Rheumatoid arthritis and hydroxyapatite-coated hip prostheses: five-year results. International ABG Study Group. Long-term comparison of Charnley and Stanmore design total hip replacements. Cementless Acetabular Replacement in the Young: A 5- to 10-Year Prospective Study The Charnley versus the Spectron hip prosthesis: radiographic evaluation of a randomized, prospective study of 2 different hip implants. Poor outcome of the PCA and Harris-Galante hip prostheses. Randomized study of 171 arthroplasties with 9-year follow-up. Cementless primary total hip replacement. Four to eight year results with the Zweymüller-Alloclassic prosthesis. The effect of surface coating of femoral prostheses implanted without cement: a 2- to 4-year follow-up study. Poor eight-year survival of cemented zirconia-polyethylene total hip replacements. Migration of the uncemented Harris-Galante acetabular cup: results of the einbildroentgenanalyse (EBRA) method. Primary Total Hip Arthroplasty with a Porous-Coated Acetabular Component. Seven-to-Ten-Year Results* The hydroxyapatite-ABG hip system: 5- to 7-year results from an international multicentre study. The International ABG Study Group. Outcome after total hip arthroplasty: Part II. Disease-specific follow-up and the Swedish National Total Hip Arthroplasty Register Comparison of collared and collarless femoral components in primary uncemented total hip arthroplasty. Hydroxyapatite-Coated Total Hip Femoral Components in Patients Less Than Fifty Years Old. Clinical and Radiographic Results after Five to Eight Years of Follow-up* Precoated femoral component in total hip arthroplasty. Results of 5- to 9-year followup. The Charnley versus the Spectron hip prosthesis: clinical evaluation of a randomized, prospective study of 2 different hip implants. A comparison of collared and collarless femoral components in primary cemented total hip arthroplasty: a randomized clinical trial. Loosening of matt and polished cemented femoral stems. Stanmore compared with Charnley total hip replacement. A prospective study of 413 arthroplasties. Hydroxyapatite and tricalcium phosphate-coated cups with and without screw fixation: a randomized study of 64 hips. Total Hip Arthroplasty with the Charnley Prosthesis in Patients Fifty-five Years Old and Less. Fifteen to Twenty-one-Year Results* Survival of Hip Replacements: A Comparison of a Randomized Trial and a Registry Early failure of a press-fit carbon fiber hip prosthesis with a smooth surface. Remodeling of Bone around Hydroxyapatite-Coated Femoral Stems* Effects of Design Changes on Cemented Tapered Femoral Stem Fixation Hydroxyapatite-coated total hip arthroplasty in osteoporotic patients. Six-year results of a cementless stem with prophylaxis against heterotopic bone. Hydroxyapatite in Total Hip Arthroplasty: Clinical Results and Critical Issues Hybrid Total Hip Arthroplasty with a Precoated Offset Stem: Four to Nine-Year Results* Life Expectancy and Cost Utility After Total Hip Replacement
abstract: Medium- and long-term results from  cemented total hip arthroplasty ( THA ) in patients with rheumatoid arthritis ( RA ) show a higher incidence of infection and aseptic loosening when compared to other diagnoses . Early results using uncemented prostheses are variable . Hydroxyapatite ( HA ) coatings are thought to improve early osseointegration in uncemented THA . In a prospect i ve , international , multicenter clinical study , 32 RA patients who received 33 uncemented HA-coated prostheses  were followed up for a minimum of 5 years . Medium-term clinical results are excellent . No infection or aseptic loosening has been recorded . Excellent osseointegration was observed radiographically . Bone remodeling was consistent with mainly proximal to midstem stress transfer . We conclude that uncemented , proximally HA-coated prostheses are a promising alternative to cemented prostheses for RA patients We review ed the records of the long-term outcome of 208 Charnley and 982 Stanmore total hip replacements ( THR ) performed by or under the supervision of one surgeon from 1973 to 1987 . The Stanmore implant had a better survival rate before revision at 14 years ( 86 % to 79 % , p = 0.004 ) , but the difference only became apparent at ten years . The later Stanmore implants did better than the early ones ( 97 % to 92 % at ten years , p = 0.005 ) , the improvement coinciding with the introduction of a new cementing technique using a gun . Most of the Charnley implants were done before most of the Stanmore implants so that the difference between the results may in part be explained by improved methods , but this is not the complete explanation since a difference persisted for implants carried out during the same period of time . We conclude that improved techniques have reduced failure rates substantially . This improvement was much greater than that observed between these two design s of implant . Proof of the difference would require a very large r and omised controlled trial over a ten-year period This article presents a prospect i ve clinical and radiologic review of 55 total hip replacements in 50 patients in which the cementless Harris-Galante porous-coated acetabular component was used . All patients were 50 years of age or younger . The cups were inserted by 15 different surgeons . The minimum followup was 5 years , with a mean of 7 years . No acetabular component has been revised for loosening , and none have migrated . Three ( 5.5 % ) cups have progressive bone-component radiolucent lines , two ( 3.6 % ) of which are complete . Six ( 10.9 % ) acetabular liners have been replaced for excessive polyethylene wear , and an additional four ( 7.3 % ) show sufficient wear to produce obvious radiographic eccentricity of the femoral head . All of the revised liners had 32-mm femoral heads and an initial polyethylene thickness of less than 6 mm . Although the results reflect excellent fixation of this component in the medium term , the incidence of exchange of the polyethylene liner for excessive wear is unacceptably high . The reduction in polyethylene thickness associated with the use of a metal-backed component and a 32-mm articulation was one of the factors contributing to the accelerated wear patterns seen in this series A total of 410 hips were r and omized to treatment with either a Charnley ( 206 hips ) or a Spectron ( 204 hips ) total hip arthroplasty .  The patients were operated on by a st and ardized procedure using a contemporary cementing technique and were followed after 1 , 3 , 5 to 6 , and 10 years . The postoperative radiographs showed a significantly increased rate of malalignment and consequently low grade of cement mantle quality of the Charnley stem compared to the Spectron . No differences concerning cement mantle quality or positioning were found between the Charnley ogee cup and the metal-backed Spectron . Evaluation of the follow-up radiographs revealed 10 loose Charnley stems and 1 loose Spectron stem and 4 loose Charnley ogee cups and 23 loose Spectron metal-backed cups . The differences of revision rate for the femoral and acetabular components of the 2 prostheses were significant ( P = .03 , Charnley femoral component more frequent ; P = .03 , Spectron acetabular component more frequent ) . The radiographic evaluation strengthened this disparity . Poor wear characteristics of the metal-backed Spectron cup are perhaps the main reason for the highly significant difference in mechanical failure rate between the 2 cups . We therefore propose that metal-backing of cemented cups should be avoided , at least when combined with larger femoral heads . The difficulty in positioning the Charnley stem with an adequate cement mantle , especially in the absence of trochanteric osteotomy , might explain the inferior Charnley stem longevity in this study 155 patients ( 171 hips ) with a mean age of 50 years ( 24 - 64 ) were r and omized to uncemented PCA ( 84 hips ) or Harris-Galante type I ( 87 hips ) total hip arthroplasty .  Clinical and radiographic evaluations were done regularly . The improvements in the Harris hip and pain scores did not differ . Osteolysis developed in 5 PCA and 17 Harris-Galante hips . 13 hips in the PCA and 16 in the Harris-Galante ( HG ) group were revised because of mechanical failures and 1 hip ( HG ) because of infection after a mean follow-up of 9 years . Decreased 10-year survival rate , based on revision as end-point , was noted for the PCA ( 85 % ) , compared with the Harris-Galante cup ( 99 % ) . The corresponding survival rate of the PCA stem ( 96 % ) was higher than that observed for the Harris-Galante design ( 86 % ) . When radiographic failures were included , the survival rates of the 4 different components dropped to between 73 % and 94 % . These findings indicate that further revisions will be necessary and continuous radiographic follow-up is indicated to enable revision before severe bone destruction has occurred . Although the PCA and the Harris-Galante design s differed as regards the survival of the individual components , the overall clinical and radiographic survival rates of these cementless total hip arthroplasties were poor One hundred and twenty-nine consecutive cementless primary total hip arthroplasties with Zweymüller-Alloclassic grit-blasted titanium components  were evaluated prospect ively at an average follow-up of 5.9 years . The clinical results were grade d as excellent or good in 116 hips ( 90 % ) , fair in 12 , and poor in one due to a fracture of the femoral shaft at operation leading to early stem loosening and delayed ring loosening . Failure was defined as definite aseptic loosening , and the final survivorship at 8 years was 99.3 % for the SL-stem , and 99.1 % for the CSF-threaded cup . These early results compare favourably with those of total hip arthroplasties using new cementing techniques A r and omized , concurrently controlled , prospect i ve , single-blinded , multicenter study was done to evaluate the effect of proximal surface coating of a femoral prosthesis on clinical and radiographic results of  cementless total hip arthroplasty ( THA ) .  The Profile femoral prosthesis ( DePuy , Warsaw , IN ) , an anatomic titanium alloy stem , was used in one of three configurations : ( 1 ) smooth , ( 2 ) porous coated , or ( 3 ) hydroxyapatite ( HA ) coated .  Ninety-one cases were enrolled in the study , with seven cases lost to follow-up and 79 cases available for clinical review with 24- to 48-month follow-up . The study shows that HA-coated stems performed as well , if not better than , porous-coated or smooth stems . Results show HA-costed stems with statistically superior total Harris hip scores ( microHA = 96.0 ) than smooth stems ( microS = 85.1 ) ( Student 's t-test , P = 0.004 ) . This was primarily due to differences between the functional score of the two groups ( microHA - 31.6 ; microS = 27.9 , P = 0.003 ) . Porous-coated stems were intermediate in performance ( microPC = 89.8 ) , with hip scores that were statistically indistinguishable from both smooth and HA-coated stems . Our data support the hypothesis that clinical differences exist and are attributable to the type of surface coating used for the cementless femoral components in THA Between January 1988 and January 1991 we performed 100 consecutive cemented total hip replacements using a zirconia head , a titanium alloy stem and a polyethylene cup .  We review ed 78 of these hips in 61 patients in detail at a mean of 5.8 years ( 1 to 9 ) . Aseptic loosening was seen in 11 hips ( 14 % ) . Eight needed revision . In total , 37 cups ( 47.5 % ) showed radiolucent lines , all at the cement-bone interface , with 18 ( 23 % ) involving all the interface . Of the 78 femoral implants , 17 ( 21.7 % ) showed radiolucent lines , and two , which had a complete line of more than 1 mm thick , definite endocortical osteolyses . There was also an abnormally high incidence of osteolysis of more than 2 mm at the calcar . Survivorship analysis showed that only 63 % were in situ at eight years . These worrying results led us to ab and on the use of zirconia heads , since at the same hospital , using the same femoral stem , cement and polyethylene cup , but with alumina femoral heads , the survival rate was 93 % at nine years . We discuss the possible reasons for the poor performance of zirconia ceramic Seventy primary total hip arthroplasties using the Harris-Galante acetabular cup ( Zimmer , Warsaw , IN ) were prospect ively examined . Over the entire period of 65.4+/-7.8 months ,  radiologic migration analysis  was performed using the  Einbildroentgenanalyse  ( EBRA ) method at an accuracy of 1 mm . Although there was clinical ly no suspicion of prosthetic loosening in any case , in 8 implants ( 11.4 % ) migration of more than 1 mm was observed . Cranial migration occurred in 3 cases ( 1.1 , 1.3 and 1.6 mm ) , medial migration in 3 cases ( 1.1 , 1.1 , and 2.9 mm ) , and lateral migration in 2 cases ( 1.1 and 1.1 mm ) . In the other 62 cases , however , no migration was traceable . Compared with measurements of other implant systems by means of the EBRA method published recently by other groups , the migration rate of the Harris-Galante cup was without exception lower and provided excellent midterm implant stability 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 A proximally hydroxyapatite (HA)-coated hip prosthesis design ed for proximal stem bonding and stress transfer was studied in a consecutive series of 398 patients in an ongoing , prospect i ve multicenter study . Follow-up was 5 to 7 years . The clinical results were excellent with a mean preoperative Merle d'Aubigné score of 8.5 and 17.3 at 5 years . Only mild thigh pain not necessitating analgesics or a walking stick was reported in 3.6 % at 5 years . Three cups and 3 stems had to be revised , all before the 2-year assessment and mainly for technical reasons . No components needed revision after 2 years . The 5-year HA-coated component  survival was 99.2 % . Serial radiographs showed excellent osseointegration , which was independent of pre-existing bone stock . The rate of radiographic bone remodeling was highest during the first 3 years , and positive bone remodeling ( bone formation ) preceded negative bone remodeling ( bone resorption ) . The concept of transitional load transfer from proximal to distal could be acknowledged , with proximal load transfer highest in 77 % . The combination of anatomic stem design with distal overreaming and proximal HA coating was thought to be the reason for these excellent results . Proximal circumferential osseointegration seems to be real because no linear or distal osteolysis was observed The Swedish National Total Hip Arthroplasty Register records primary hip replacements , revisions and surgical technique/environmental factors . The end-point for failure is revision . A prosthesis still in place , however , does not mean success . Clinical and radiographic outcomes should describe in more detail the efficacy of hip replacement surgery instead of the relatively blunt outcome measure that the register can provide . We performed a clinical outcome analysis on patients with primary total hip replacement thus testing the adequacy of the end-point for failure in the Swedish register . 1,113 r and omly selected patients who had had total hip replacement surgery between 1986 and 1995 answered a diseasespecific self-administered question naire ( WOMAC ) . A cohort of 344 patients was studied , using the  Harris Hip Score and a conventional radiographic examination  as outcome measures . We found clinical failure rates of 13 % and 20 % for all implants after 10 years , using 60 points or revision as the definition of failure in the Harris Hip Score and WOMAC , respectively . The result , according to the register during the same period , was a 7 % revision rate . The clinical failure rate depended on the type of evaluation tool , definition of failure and demographics , which made it difficult to decide whether there was a need for revision . With the exception of pain measured by the Harris Hip Score , the results showed no significant correlation between clinical failure and radiographic failure . Hence , with the knowledge that there is a difference between the revision rate according to the register and clinical outcome , the strict definition of failure in the register is useful as an end-point for primary hip replacement surgery Two hundred three consecutive primary uncemented total hip arthroplasties were prospect ively r and omized using collared and collarless versions of an identical titanium stem . Identical 28-mm titanium heads were implanted in all cases .  One hundred three collared hips  were compared with 100 collarless hips .  Follow-up periods averaged 45.7 months in both groups . Intraoperative , early , and late complications were similar . Hip scores , including thigh pain , at final follow-up visit were also similar . No significant differences were noted in acetabular or femoral radiolucencies , subsidence , osteolysis , or proximal femoral remodeling . At 5 years , more collarless stems revealed pedestal formation ( 57.1 % vs 33.9 % ) . The presence of a collar had no effect on the adequacy of fixation , proximal femoral osteopenia , or clinical scores at 5 years One hundred and thirty-three patients ( 152 hips ) who were an average of thirty-nine years old ( range , sixteen to forty-nine years old ) received a proximally hydroxyapatite-coated femoral prosthesis as part of a total hip arthroplasty and were followed for a minimum of five years ( average , 6.4 years ; range , five to 8.3 years ) or until revision . The average Harris hip score was 47 points ( range , 22 to 77 points ) preoperatively and 93 points ( range , 49 to 100 points ) at the time of the latest clinical evaluation . Two patients who had a well fixed femoral implant had activity-limiting pain in the thigh at the time of the most recent examination . Radiographic changes consistent with bone-remodeling ( cortical hypertrophy and bone condensation ) typically were seen around the mid-part of the shaft of the prosthesis . Forty-eight ( 32 per cent ) of the 148 hips that were included in the radiographic analysis demonstrated a small amount of erosive scalloping in either zone 1 or zone 7 of Gruen et al. , and intramedullary osteolysis was suspected in only one hip . All stems were radiographically osseointegrated according to a modification of the criteria described by Engh et al. Four stems were revised , but none of the revisions were performed because of mechanical failure ( two stems were revised in conjunction with a revision of the cup because of pain ; one , because of an infection ; and one , after a traumatic femoral fracture that occurred six years postoperatively ) . Thus , the rates of aseptic and mechanical failure were both 0 per cent . The combined rate of failure , which included the two stems that were revised because of pain and the two stems that were associated with pain that limited activity , was 2.6 per cent ( four of 152 stems ) . The over-all clinical results associated with hydroxyapatite-coated femoral components were excellent in this group of young patients after intermediate-term follow-up . A review of serial radiographs showed mechanically stable implants with osseous ingrowth , evidence of stress transmission at the middle part of the stem , and minimum endosteal osteolysis One hundred nineteen consecutive primary hybrid total hip arthroplasties with a precoated femoral component were performed by one surgeon in 100 patients and followed up prospect ively . Ninety-eight hips in 82 patients ( mean age , 67 years ) were evaluated clinical ly and radiographically at a mean of 6.5 years ( range , 5 - 9 years ) . The hips were evaluated clinical ly using the Harris hip score , and radiographs were evaluated for femoral cement grade , loosening , and osteolysis . Ninety-five hips remained in place at the most recent followup . Two femoral components were revised for definite loosening , and one well fixed femoral component was removed because of late hematogenous infection . Excluding the three hips that were revised , the clinical result was excellent or good in 79 hips ( 83 % ) , fair in 12 hips ( 13 % ) , and poor in four hips ( 4 % ) . All other femoral components were well fixed . There were defects of the cement mantles ( C1 and C2 ) in 90 hips . No femoral component had a stem and cement radiolucent line . Focal femoral osteolysis was seen in only two hips . One acetabular component was removed at 5 years because of late hematogenous infection . One acetabular component had asymptomatic migration . The remaining 96 acetabular components were well fixed . Focal acetabular osteolysis was present in four hips . The mean linear polyethylene wear rate was 0.06 ( + /- 0.05 ) mm per year . In contrast to other reports of early failure and osteolysis , the use of a precoated femoral component in this study did not adversely affect the fixation of hybrid total hip arthroplasty , with definite failure of only 2 % ( two of 98 ) of the femoral components Prospect i ve , r and omized studies must be performed when new surgical techniques or implants are evaluated . In this study , a new implant system was compared with the Charnley prosthesis , which over the years has been the most used hip implant in Sweden . Between 1985 and 1989 , 410 hips were r and omized to treatment with a Charnley or a Spectron total hip arthroplasty : 206 Charnley and 204 Spectron prostheses were implanted . The patients were operated on by a st and ardized procedure using a contemporary cementing technique . The patients were followed prospect ively by an independent observer after 1 , 3 , 5 to 6 , and 10 years . Harris Hip Score and patient satisfaction were recorded in the outcome evaluation . A total of 144 patients with 164 hips were deceased , and 15 patients ( 8 Charnley and 7 Spectron ) have required a revision . Nine hips were revised because of aseptic loosening ( 5 Charnley stems and 4 Spectron metal-backed cups ) . The Charnley stem as well as the metal-backed Spectron cup had a higher risk for revision because of aseptic loosening . The Charnley ogee cup and the Spectron stem have performed remarkably well with no revision of these components . Seven Charnley prostheses dislocated , but no dislocation was recorded in the Spectron group . Survivorship calculations with a mean follow-up of 10 years revealed an overall 11-year survivorship of 94.5 % + /- 3.4 % ( Charnley , 93.2 % + /- 5.8 % ; Spectron , 95.9 % + /- 3.0 % ) . The clinical outcome did not differ between the 2 systems . The overall results in this old population , using a contemporary surgical technique , illustrate that cemented hip arthroplasty is an excellent treatment alternative for elderly patients Between July 1986 and November 1989 , 437 consecutive primary cemented total hip arthroplasties were performed using a straight-stemmed titanium alloy femoral component . Collared and collarless versions of this identical stem were r and omly chosen by computer allowing a comparison between 213 collared stems ( 198 patients ) and 224 collarless stems ( 209 patients ) . Diagnosis , sex , weight , and average age ( 72.8 years , collared ; 72.0 years , collarless ) were similar . Follow-up averaged 76 months ( collared ) and 72 months ( collarless ) with 49 patients followed for at least 10 years . Calcar-collar contact was noted in 205 hips ( 96 % ) on the initial postoperative radiograph . Early complications , including dislocations ( 5 % each group ) , were similar . Late complications included 3 deep infections ( 2 collared , 1 collarless ) and 2 postoperative femur fractures ( 1 each ) . Hip scores at the most recent follow-up averaged 91.2 and 90.1 in the collared and collarless groups . No or slight pain was noted in 93 % of collared and 91.5 % of collarless hips . Although no radiographic differences were noted in distal cortical hypertrophy , stem subsidence , and osteolysis , collarless hips lost significantly more medial femoral neck cortical bone ( average 0.90 mm vs 0.63 mm ) . A higher incidence of radiolucent lines in femoral zone VI ( 20.7 % vs 9.4 % ) was also noted in collarless hips We have compared prospect ively the incidence of loosening of 20 femoral stems with a matt surface with that of 20 polished stems of an otherwise identical tapered , non-modular design of Exeter hip replacement .  The stems were inserted using the same technique at operation and radiographs showed no difference in the adequacy of the cement mantle or of fixation . All the patients were review ed regularly and none was lost to follow-up . After a minimum follow-up of nine years , four matt but no polished stems had been revised for aseptic loosening .  Polished stems  subsided slightly within the cement mantle early , but did not loosen From 1982 to 1987 , we r and omised prospect ively 413 patients requiring primary total hip replacements to receive either a Stanmore or Charnley prosthesis .  They were review ed by an independent observer in an attempt to correlate a number of factors including femoral head size with longevity . There were 213 Stanmore hips and 200 Charnley prostheses .  At five to ten years ( mean 6.5 ) 76 patients had died and 16 arthroplasties had required revision . Seven were radiologically loose in asymptomatic patients . There was only one case of deep infection . We found no difference statistically in the clinical outcome or in the revision rate of 4 % in the two types of prosthesis . The revision rate was greater for trainees than for senior operating surgeons , and there were recognisable technical errors in seven of the nine Stanmore , and four of the seven Charnley replacements which required revision . Retrospective radiological analysis of a r and om subset of 51 Charnely and 57 Stanmore femoral components showed no difference in femoral subsidence , but in 14 patients who had had bilateral replacements with one femoral component of each type , there was greater early subsidence of the Stanmore prosthesis . Our results confirm that conventional cemented total hip replacements give acceptable results in a general teaching unit , and we found no evidence of any effect of the size of the femoral head on wear or loosening at five to ten years Sixty-two patients ( 64 hips ) were provided with porous press-fit cups ( Trilogy ) , plasma-sprayed with a coating consisting of 70 % hydroxyapatite and 30 % tricalcium phosphate . The patients were r and omized to a cup with cluster holes for adjunctive screw fixation ( n = 30 ) or to a cup without holes ( n = 34 ) .  Radiostereometry  was used to study migration and wear . Up to 2 years median translations and rotations < 0.2 mm and < 0.2 degrees were recorded in the 2 groups , without any difference . The median annual proximal wear ( 0.11 and 0.12 mm ) was within the expected range despite the use of a ceramic coating , and it did not differ between the 2 design s. Radiolucent lines were frequently seen postoperatively but diminished during the follow-up without any sign of migration into the gaps . At 2 years , the median Harris scores were 99 points ( range , 51 - 100 points ) in the group with and 98 points ( range , 69 - 100 points ) in the group without screws . The results indicate that early fixation can be achieved for ceramic-coated press-fit cups without using additional screw fixation Data on 240 primary Charnley total hip arthroplasties , performed in 211 patients from October 1968 to July 1974 , were recorded prospect ively . Fifty-two prostheses were implanted in forty-six patients who were thirty-four to fifty-five years old , and 188 prostheses were implanted in 165 patients who were more than fifty-five years old . The results for the younger patients were compared with those for the older patients . Twenty hips were revised over-all , and all five of the infections and four of the five fractures of the femoral stem that occurred in this group were in the older patients . However , the rate of aseptic loosening was similar for the two age-groups ( three of the hips in the younger patients and five in the older patients ) . The probability of revision after twenty years for the two groups , as determined with Kaplan-Meier analysis , was 11.7 per cent for the younger patients and 10.7 per cent for the older patients . There was no significant difference between the two groups with regard to either the number of revisions or the percentage of patients who had radiographic signs of loosening . The median Charnley hip scores during the course of the study were also similar for the two groups . We recommend that Charnley low-friction arthroplasty be used even in younger patients , as the long-term results were excellent and were comparable with those in the elderly age-group At the authors ' hospital , 410 primary total hip replacements were performed on 372 patients between September 1 , 1985 , and May 31 , 1989 . All hips were assigned r and omly to receive a Charnley prosthesis with an ogee flanged cup or a Spectron prosthesis with a metal backed cup .  Eleven-year survivor analysis , using revision as the end point definition of failure , revealed a survival rate of 93.2 % ± 5.8 % for the Charnley replacement and 95.9 % ± 3.0 % for the Spectron . If each component of the systems was analyzed ( concerning aseptic loosening ) , the ogee cup and the Spectron stem had 100 % survival . The survivorship for all 410 hips was 94.5 % ± 3.4 % . If the end point definition of failure was exp and ed to include patient dissatisfaction , the survival rate decreased to 86.3 % ± 4.9 % . These survival rates were compared with the rates obtained by the Swedish National Hip Registry . The national cohort included all patients in Sweden who were treated surgically with a Charnley ( 14,053 patients ) or Spectron ( metal backed cup ) prosthesis ( 726 patients ) between September 1 , 1985 , and May 31 , 1989 .  Eleven-year survivor analysis revealed a national survival rate of 92.1 % ± 0.7 % for the Charnley replacement and 88.6 % ± 6.1 % for the Spectron . The analyses from the Swedish Registry are based on more than 160,000 primary operations and 11,500 revisions . Despite the enormous amount of data , there are drawbacks , and registries never can replace the prospect i ve , r and omized trial . One reason is the Swedish National Registry is unable to discriminate between the individual cup and stem components when analyzing the cause of revision , and no clinical or radiographic information is collected . A potential drawback for the r and omized trial is performance bias because surgeons from specialized centers might perform better than the general orthopaedic surgeon We investigated a press-fit anatomically shaped hip stem made of carbon fiber-reinforced composite material in a prospect i ve clinical study . The intention of the design was that a surface of interlaced carbon fibers in the proximal part would achieve metaphyseal fixation . A total of 51 carbon stems were implanted in 48 patients ( 30 women and 22 men ) . Mean age at operation was 59 years . The patients were followed clinical ly , radiologically , and with computed tomography . At 6-year follow-up , aseptic loosening was observed in 47 hips ( 92 % ) . Forty stems were revised on average 30 months ( range , 9 - 58 months ) postoperatively . All revised carbon stems showed fibrous fixation without any bony on-growth . No osteolysis was seen . Histologically , no carbon wear or inflammatory reactions were observed . Only 4 cases had a good clinical result with bony fixation on computed tomography scan . The carbon fiber prosthesis without effective ingrowth or on-growth irregularities showed a high rate of early loosening Two hundred and twenty-four total hip arthroplasties were performed in 201 patients with use of a femoral component with hydroxyapatite coating of the proximal portion of the stem . The mean duration of follow-up was seventy-one months ( range , fifty-eight to eighty-seven months ) . Of the 224 arthroplasties , 208 ( 93 per cent ; 190 patients ) yielded a good or excellent clinical result . Four patients ( 2 per cent ) reported mild-to-moderate activity-related pain in the thigh , and two ( 1 per cent ) had aseptic loosening . The radiographic findings of progressive new-bone formation ( cancellous condensation and cortical hypertrophy ) throughout the zones adjacent to the middle and distal portions of the stem were evidence of early , extensive proximal fixation of the implant , with distal stress transfer through the implant , which is stiffer than the surrounding bone . Remodeling of the femur began early , was predictable , and progressed throughout the follow-up period . Cortical hypertrophy about the middle and distal portions of the stem occurred predominantly in the mediolateral plane ( in 105 hips [ 47 per cent ] , compared with thirteen hips [ 6 per cent ] in the anteroposterior plane ) , and it was more common in patients who had had poorer bone quality preoperatively . Intramedullary osteolysis was present in one femur ( 0.4 per cent ) at five years ; the osteolytic area was less than five millimeters in its greatest dimension and had not progressed at the time of the six-year follow-up evaluation . This low rate of osteolysis suggests that a circumferential coating of hydroxyapatite may effectively minimize migration of wear debris along the femoral stem . The progressive remodeling of the femur about the middle and distal portions of the stem , as evidence d by cancellous condensation and cortical hypertrophy , has not , to our knowledge , been described previously to this magnitude in association with proximally coated ( porous or hydroxyapatite-coated ) femoral implants The effects of matte finish and modularity on loosening of tapered stems using the same cementing technique were studied prospect ively . In 80 patients , 82 cemented Exeter primary stems were implanted at total hip revision by one surgeon using the same surgical and cementing technique throughout the series . The polished stems behaved differently than the matte surfaced stems behaved . Polished stems subsided in the cement mantle an average of 1 mm at 2 years after implantation , but without subsequent loosening of stems at as long as 12 years after implantation . Matte surfaced stems with metal central izers had a higher loosening rate , and loss of fixation at the prosthesis to cement interface was identified as an early sign of loosening of these stems . At a mean 6-year followup , there were no revisions nor was there radiographic evidence of loosening of the polished modular stems . It is concluded that matte finish results in increased loosening of tapered stems but the introduction of modularity did not A prospect i ve review was performed on 22 osteoporotic patients ( rated from 1 to 3 on the Singh Index ) with hydroxyapatite-coated total hip replacements .  These results were compared with a control group ( Singh Index 4 to 6 ) of 45 patients ( 48 hips ) with respect to clinical and radiographic data . Surgery was performed over a six-year period ( 1991 to 1996 ) and the time to follow-up evaluation averaged 5 years ( range : 2 to 7 years ) . All patients , in both groups , were over 65 years old with an average age of 71 and 73 years , respectively . The pre-operative diagnoses and Harris hip scores were also similar for both groups . Clinical evaluation was based on the Harris Hip score and radiographic evaluations using Engh 's criteria . There was no significant difference between the final average Harris hip score in the osteoporotic bone group , which was 87 points , and that for the control group , which was 91 points ( p > 0.05 ) . Radiographic evaluation demonstrated confirmed bone ingrowth in most patients in each group ; one patient in each group had suspected bone ingrowth . No stems were revised for aseptic loosening and no endosteal lysis was found . Progressive bone formation was seen around the femoral stem proximally . The acetabular components demonstrated no sign of mechanical loosening or osteolysis . Bone formation was found in most patients in zone I , and in a few patients also in zone III . On the basis of the results of this study , it is believed that osteoporotic bone as a factor by itself should not compromise the early results of hydroxyapatite total hip arthroplasty and should provide good results in the long term The hypothesis of a possibly diminished bony ingrowth revealed by the development of radiolucency or a radiodense line with time around a cementless femoral stem subsequent to indomethacin administration for prevention of heterotopic ossification was investigated . Eighty prospect i ve patients with indomethacin prophylaxis were compared with 82 patients without indomethacin prophylaxis chosen retrospectively . The same cementless implant was used in all cases , and patients were observed clinical ly and radiologically for a minimum of 6 years . The mean postoperative Harris hip score at 6 years was 91 versus 88 points , respectively , and there were significantly more excellent results ( Harris hip score > 90 ) in the indomethacin group . None of the patients underwent revision surgery . Radiologic signs such as loss of bone density and radiodense lines were observed around the shoulder of the prosthesis in a similar percentage in both groups . Significant subsidence of the stem was observed in one instance in the indomethacin group and in three instances in the control group . The results of this study are a strong indication that indomethacin does not influence the development of radiolucency or other radiologic changes around a cementless stem after 6 years Surgeons who perform arthroplasties have posed some critical questions about hydroxyapatite . Does hydroxyapatite coating enhance bone ingrowth or ongrowth ? Will hydroxyapatite lead to increased polyethylene wear or an increased incidence of osteolysis ? Will the hydroxyapatite coating disappear , and if so , what will be left to maintain implant fixation ? A multicenter study of 316 hips ( 282 patients ) with a proximally hydroxyapatite coated stem and either a hydroxyapatite or porous coated cup were followed up 8.1 years ( range , 5.6 - 9.9 years ) . The average patient age was 50 years ( range , 16 - 81 years ) , and 61 % of the patients were male . One ( 0.3 % ) stem , three ( 2.7 % ) porous coated cups , and 25 ( 11.9 % ) hydroxyapatite coated cups were revised for aseptic loosening . Disappointing results on the acetabular side indicate that substrate design is critical . There were no cases of intramedullary femoral osteolysis , and the incidence of acetabular and proximal femoral osteolysis and polyethylene wear was no greater than that seen with other cementless or cemented components . Based on these clinical results and a critical review of the literature , it is concluded that hydroxyapatite coated hip components do enhance ingrowth or ongrowth with no increased incidence of osteolysis for as many as 10 years . Concern about the disappearance of the hydroxyapatite coating with time seems moot in light of the above clinical findings Background : Use of modern cementing techniques for fixation of femoral components in total hip arthroplasty has had excellent clinical and radiographic results in most patients . However , several authors have described early loosening of femoral components with roughened and precoated finishes . The purpose of this study was to examine the performance of the precoated Iowa stem , which has increased offset , and to compare the results with those of another cemented precoated femoral component with st and ard offset used at our institution . Methods : We carried out a prospect i ve analysis of 102 primary hybrid total hip arthroplasties ( a cementless acetabular component and a cemented femoral component ) performed with use of the Iowa femoral component in ninety-five patients at our institution . The Iowa stem was used in hips that required greater offset than is available with st and ard stems as determined by preoperative templating . The average age of the patients at the time of the index procedure was sixty-nine years . Sixteen patients ( seventeen hips ) died before the forty-eight-month minimum follow-up period had elapsed . Two patients were lost to follow-up , and radiographic follow-up was incomplete for one . The mean duration of clinical and radiographic follow-up of the remaining eighty-two hips in the seventy-six surviving patients was sixty-five months ( range , forty-eight to 104 months ) . Results : The average preoperative Harris hip score of 47 points ( range , 16 to 69 points ) improved to an average of 87 points ( range , 24 to 100 points ) at the time of the review . Two hips underwent femoral component revision . Four femoral stems were radiographically loose at an average of thirty-four months . Femoral osteolysis was seen in five hips ( 6 percent ) at an average of fifty-four months postoperatively . No acetabular component was revised because of aseptic loosening . According to Kaplan-Meier analysis , the seven-year survival rate , with an end point of femoral revision , osteolysis , or stem debonding , was 90.6 percent ( 95 percent confidence interval , 0.87 to 0.94 ) . Conclusions : The prevalence of revision , osteolysis , and loosening after total hip arthroplasty with the  Iowa femoral component  at our institution was higher than that seen in our series of Harris Precoat stems , which had a survival rate of 98.4 percent ( 95 percent confidence interval , 0.97 to 1.00 ) at ten years with the same end points . The design of the Iowa stem may make it difficult to achieve a good cement mantle , and , in combination with the geometry and increased offset of the stem , may compromise the long-term survival of this cemented femoral component In a prospect i ve study of 410 cemented hip replacements in 372 patients with a mean age of 71 years , mortality after 8 years was 33 % .  Mortality for patients with osteoarthrosis  was lower than in an age matched control population , probably because of a preoperative selection of patients . An estimate of costs and adjusted quality of life has shown that total hip replacement has a good cost utility even in the elderly patient . The conclusion of this study is that the indications for hip replacement in the elderly patient can be exp and ed . Such patients should undergo surgery earlier in the course of their disease
target: The Charnley prosthesis had by far the best and most comprehensive evidence base with better than 90 % implant survival after about 10 years .
  Some uncemented stems have shown promising medium-term outcome , but no combination of uncemented cup and stem fulfilled the benchmark criterion of > or = 90 % implant survival at 10 years , which we propose as a minimum requirement for unrestricted clinical use for prostheses used in primary THR .
background: We have conducted a systematic review of the scientific literature concerning outcome and clinical effectiveness of  prostheses used for primary total hip replacement ( THR ) in Norway .