human
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The purpose of this prospect i ve , r and omised study was to evaluate the clinical and radiological results comparing the identical cemented or cementless NexGen total knee prostheses implanted bilaterally in the same patient . Sequential simultaneous bilateral total knee replacements  were performed in 50 patients ( 100 knees ) . There were 39 women and 11 men with a mean age of 58.4 years ( 51 to 67 ) who received a cemented prosthesis in one knee and a cementless prosthesis in the other .  The mean follow-up was 13.6 years ( 13 to 14 ) . At final review , the mean Knee Society scores ( 96.2 ( 82 to 100 ) versus 97.7 ( 90 to 100 ) ) , the mean Western Ontario and McMaster Universities osteoarthritis index ( 34.5 ( 4 to 59 ) versus 35.6 ( 5 to 51 ) ) , the mean ranges of knee movement ( 124 ° ( 100 ° to 140 ° ) versus 128 ° ( 110 ° to 140 ° ) ) , mean patient satisfaction ( 8.1 ( SD 1.9 ) versus 8.3 ( SD 1.7 ) ) , and radiological results were similar in both groups . The rate of survival of the femoral components was 100 % in both groups at 14 years . The rate of survival of the cemented tibial component was 100 % and 98 % in the cementless tibial component .  No osteolysis was identified in either group . Our data have shown no advantage of cementless over cemented components in total knee replacement A significant increase in younger patients undergoing total knee arthroplasty raises the theoretical concern for revision secondary to micromotion and fixation failure with cemented components . We prospect ively studied 100 consecutive tantalum monoblock uncemented tibial components and 312 concurrent cemented controls . Patients younger than 55 years with adequate bone stock were enrolled . This cementless patient group was younger and had higher preoperative functional status . Prostheses were posterior-substituting uncemented femoral and tibial components with a cemented patellar button .  Knee Society pain and function scores and radiographs were obtained , and a cost analysis was performed . Knee Society scores were excellent and equivalent beyond 6 months . There was no significant difference in perioperative blood loss , complication rates , or cost . There was a significant decrease in operative time in the uncemented group . Radiographs revealed no failures of ingrowth at last follow-up . There were 3 uncemented group failures , but none were due to failure of fixation . The use of a porous tantalum tibia at minimum 5 years has yielded promising clinical and radiographic results in a younger patient population We report the long-term survival of a prospect i ve r and omised consecutive series of 501 primary knee replacements using the press-fit condylar posterior cruciate ligament-retaining prosthesis .  Patients received either cemented ( 219 patients , 277 implants ) or cementless ( 177 patients , 224 implants ) fixation . Altogether , 44 of 501 knees ( 8.8 % ) underwent revision surgery ( 24 cemented vs 20 cementless ) . For cemented knees the 15-year survival rate was 80.7 % ( 95 % confidence interval ( CI ) 71.5 to 87.4 ) and for cementless knees it was 75.3 % ( 95 % CI 63.5 to 84.3 ) . There was no significant difference between the two groups ( cemented vs cementless ; hazard ratio ( HR ) 0.83 , 95 % CI 0.45 to 1.52 , p = 0.55 ) . When comparing the covariates there was no significant difference in the rates of survival between the side of operation ( HR 0.58 , p = 0.07 ) , age ( HR 0.97 , p = 0.10 ) and diagnosis ( HR 1.25 p = 0.72 ) . However , there was a significant gender difference , with males having a higher failure rate with cemented fixation ( HR 2.48 , p = 0.004 ) . Females had a similar failure rate in both groups . This single-surgeon series , with no loss to follow-up , provides reliable data of the revision rates of one of the most commonly-used total knee replacements . The survival of the press-fit condylar total knee replacement remained good at 15 years , irrespective of the method of fixation We have carried out a long-term survival analysis of a prospect i ve , r and omised trial comparing cemented with cementless fixation of press-fit condylar primary total knee replacements . A consecutive series of 501 replacements received either cemented ( 219 patients , 277 implants ) or cementless ( 177 patients , 224 implants ) fixation .  The patients were contacted at a mean follow-up of 7.4 years ( 2.7 to 13.0 ) to establish the rate of survival of the implant . The ten-year survival was compared using life-table and Cox 's proportional hazard analysis . No patient was lost to follow-up . The survival at ten years was 95.3 % ( 95 % CI 90.3 to 97.8 ) and 95.6 % ( 95 % CI 89.5 to 98.2 ) in the cemented and cementless groups , respectively . The hazard ratio for failure in cemented compared with cementless prostheses was 0.97 ( 95 % CI 0.36 to 2.6 ) . A comparison of the clinical outcome at ten years in 80 knees showed no difference between the two groups . The survival of the press-fit condylar total knee replacement at ten years is good irrespective of the method of fixation and brings into question the use of more expensive cementless implants Purpose : The objective of this prospect i ve study was to evaluate the medium-term clinical and radiological results after navigated cementless implantation , without patella resurfacing , of a total knee endoprosthesis with tibial and femoral press-fit components , with a focus on survival rate and clinical outcome . The innovation is the non-cemented fixation together with the use of a navigation system . Scope and Methods : Sixty patients with gonarthrosis were included consecutively in this study . In all cases , the cementless Columbus total knee endoprosthesis with a coating out of pure titanium was implanted , using a navigation system . The Knee Society Score showed a statistically significant increase from 75 ( ± 21.26 ) before surgery to 180 ( ± 16.15 ) after a mean follow-up of 5.6 ( ± 0.25 ) years . The last radiological examination revealed no osteolysis . No radiolucent lines were seen at any time in the area of the femoral prosthetic components . In the tibial area , radiolucent lines were seen in 24.4 % of the cases , mostly in the distal uncoated part of the stem . During follow-up , no prosthesis had to be replaced because of aseptic loosening while in 2 cases revision surgery was necessary due to septic loosening and in 1 case due to unexplainable pain . Results and Conclusions : Navigated cementless implantation of the Columbus total knee endoprosthesis yielded good clinical and radiological results in the medium term . The excellent radiological osteointegration of the prosthetic components , coated with a microporous pure titanium layer and implanted with a press-fit technique , should be emphasized We have carried out a prospect i ve study comparing the results at five years in patients older than 75 years of age undergoing hydroxyapatite-coated , cementless total knee replacement ( TKR ) with those who were younger . The Knee Society clinical rating scores were recorded before and after operation . Of 559 patients undergoing TKR , 135 were in the elderly age group . The knee scores at five years or more showed comparable results , with patients under 75 years of age reaching a score of 183 and those aged 75 years or over reaching 174 . These differences were predominantly due to the functional component of the score . We conclude that elderly patients do just as well as the younger group using this prosthesis We carried out a prospect i ve study of 118 hydroxyapatite-coated , cementless total knee replacements in patients who were < /= 55 years of age and who had primary ( 92 ; 78 % ) or post-traumatic ( 26 ; 22 % ) osteoarthritis . The mean period of follow-up was 7.9 years ( 5 to 12.5 ) . The Knee Society clinical scores improved from a pre-operative mean of 98 ( 0 to 137 ) to a mean of 185 ( 135 to 200 ) at five years , and 173 ( 137 to 200 ) at ten years . There were two revisions of the tibial component because of aseptic loosening , and one case of polyethylene wear requiring further surgery . There was no osteolysis or progressive radiological loosening of any other component . At 12 years , the overall rate of implant survival was 97.5 % ( excluding exchange of spacer ) and 92.1 % ( including exchange of spacer ) . Cementless total knee replacement can achieve excellent long-term results in young , active patients with osteoarthritis . In contrast to total hip replacement , polyethylene wear , osteolysis and loosening of the prosthesis were not major problems for these patients , although it is possible that this observation could change with longer periods of follow-up A prospect ively studied group of 59 knees with cementless fixation were compared to a retrospectively studied but matched group of 59 knees with cement fixation using a Press Fit Condylar prosthesis .  The only significant preoperative difference between the patient groups was mean age ; the cemented group was on average nine years older than the cementless group ( p < 0.0001 ) . At an average of 2.8 years after surgery , there were no significant differences in knee scores between the two groups . Radiolucent lines adjacent to the tibial component were similar in both groups . The complication rate of 20 % in the cementless knees was higher than the 12 % rate in the cemented knees ; this was primarily related to polyethylene wear of metal-backed patellar components . Cement or cementless fixation of this prosthesis appears to provide equivalent early results This study examines the early clinical and radiographic results of the first 216 cases of a cementless fixed bearing tibial tray without screw holes in 191 patients . We hypothesize that stable fixation can be achieved without the use of screws . There were 16 cases lost to follow-up , leaving 200 cases with known outcome . The Hospital for Special Surgery knee scores improved from an average preoperative score of 54/100 to 82/100 postoperatively . Three patients had incomplete radiolucent lines involving the medial aspect of the tibial tray . All of the tibial components review ed radiographically were bone ingrown . We conclude that the tray provides excellent primary stability , allowing early bone ingrowth , free from osteolysis and with good clinical outcomes . All of the tibial components were bone ingrown by radiographic criteria The Miller-Galante I knee replacement was inserted in 25 women and three men ( 33 knees ) with osteoarthrosis . All patients received a TiAlV femoral component with a commercially pure titanium fiber-mesh undersurface . Cemented or cementless fixation was used based on a r and omization protocol . Micromotions of the femoral components were recorded with roentgen stereophotogrammetric analysis during the first 2 postoperative years . The magnitude of migration did not differ between cemented and uncemented fixation . The number of nonmigrating prostheses decreased from 21 ( 12 cemented and nine uncemented ) at 3 months to six ( three cemented and three uncemented ) at 24 months . In both groups , the magnitude of prosthetic tilting about the longitudinal axis ( internal-external rotation ) was as large as that about the transverse axis ( flexion-extension ) . Rotation into extension was as common as rotation into flexion . The largest translations were recorded at either of the posterior condyles . In 10 uncemented components , radiolucent lines were seen at the distal interface postoperatively . Proximal migration of the femoral component was recorded in these knees , and the width of the lines decreased or the lines disappeared totally at 24 months . After 2 years , lines were noted around four cemented and four uncemented replacements , mainly anteriorly or distally . All of these prostheses migrated . One prosthesis , revised because of malalignment , displayed pronounced migration after an initial period of stability . Bone ingrowth was observed anteriorly and anterodistally despite the presence of motions of 1 mm or more We performed a prospect i ve study of 54 patients ( 76 knees ) who underwent Osteonics series 3000 cruciate-retaining cementless total knee arthroplasty between December 1990 and June 1993 . Five patients ( seven knees ) were lost to follow-up ( 90.7 % completion ) . One patient required revision at 10.5 years after operation . The rate of survival was 100 % at ten years and 96.7 % at 13 years . The mean ten-year knee and function scores were 79 and 59 respectively . Both were significantly better than the pre-operative scores . The range of movement also improved . Although a radiolucent line around the tibial component enlarged in six knees ( 20.7 % 
    Output:
    
agent
Implant survivorship for cementless TKA was comparable to the current gold st and ard cemented TKAs
***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: The purpose of this prospect i ve , r and omised study was to evaluate the clinical and radiological results comparing the identical cemented or cementless NexGen total knee prostheses implanted bilaterally in the same patient . Sequential simultaneous bilateral total knee replacements  were performed in 50 patients ( 100 knees ) . There were 39 women and 11 men with a mean age of 58.4 years ( 51 to 67 ) who received a cemented prosthesis in one knee and a cementless prosthesis in the other .  The mean follow-up was 13.6 years ( 13 to 14 ) . At final review , the mean Knee Society scores ( 96.2 ( 82 to 100 ) versus 97.7 ( 90 to 100 ) ) , the mean Western Ontario and McMaster Universities osteoarthritis index ( 34.5 ( 4 to 59 ) versus 35.6 ( 5 to 51 ) ) , the mean ranges of knee movement ( 124 ° ( 100 ° to 140 ° ) versus 128 ° ( 110 ° to 140 ° ) ) , mean patient satisfaction ( 8.1 ( SD 1.9 ) versus 8.3 ( SD 1.7 ) ) , and radiological results were similar in both groups . The rate of survival of the femoral components was 100 % in both groups at 14 years . The rate of survival of the cemented tibial component was 100 % and 98 % in the cementless tibial component .  No osteolysis was identified in either group . Our data have shown no advantage of cementless over cemented components in total knee replacement A significant increase in younger patients undergoing total knee arthroplasty raises the theoretical concern for revision secondary to micromotion and fixation failure with cemented components . We prospect ively studied 100 consecutive tantalum monoblock uncemented tibial components and 312 concurrent cemented controls . Patients younger than 55 years with adequate bone stock were enrolled . This cementless patient group was younger and had higher preoperative functional status . Prostheses were posterior-substituting uncemented femoral and tibial components with a cemented patellar button .  Knee Society pain and function scores and radiographs were obtained , and a cost analysis was performed . Knee Society scores were excellent and equivalent beyond 6 months . There was no significant difference in perioperative blood loss , complication rates , or cost . There was a significant decrease in operative time in the uncemented group . Radiographs revealed no failures of ingrowth at last follow-up . There were 3 uncemented group failures , but none were due to failure of fixation . The use of a porous tantalum tibia at minimum 5 years has yielded promising clinical and radiographic results in a younger patient population We report the long-term survival of a prospect i ve r and omised consecutive series of 501 primary knee replacements using the press-fit condylar posterior cruciate ligament-retaining prosthesis .  Patients received either cemented ( 219 patients , 277 implants ) or cementless ( 177 patients , 224 implants ) fixation . Altogether , 44 of 501 knees ( 8.8 % ) underwent revision surgery ( 24 cemented vs 20 cementless ) . For cemented knees the 15-year survival rate was 80.7 % ( 95 % confidence interval ( CI ) 71.5 to 87.4 ) and for cementless knees it was 75.3 % ( 95 % CI 63.5 to 84.3 ) . There was no significant difference between the two groups ( cemented vs cementless ; hazard ratio ( HR ) 0.83 , 95 % CI 0.45 to 1.52 , p = 0.55 ) . When comparing the covariates there was no significant difference in the rates of survival between the side of operation ( HR 0.58 , p = 0.07 ) , age ( HR 0.97 , p = 0.10 ) and diagnosis ( HR 1.25 p = 0.72 ) . However , there was a significant gender difference , with males having a higher failure rate with cemented fixation ( HR 2.48 , p = 0.004 ) . Females had a similar failure rate in both groups . This single-surgeon series , with no loss to follow-up , provides reliable data of the revision rates of one of the most commonly-used total knee replacements . The survival of the press-fit condylar total knee replacement remained good at 15 years , irrespective of the method of fixation We have carried out a long-term survival analysis of a prospect i ve , r and omised trial comparing cemented with cementless fixation of press-fit condylar primary total knee replacements . A consecutive series of 501 replacements received either cemented ( 219 patients , 277 implants ) or cementless ( 177 patients , 224 implants ) fixation .  The patients were contacted at a mean follow-up of 7.4 years ( 2.7 to 13.0 ) to establish the rate of survival of the implant . The ten-year survival was compared using life-table and Cox 's proportional hazard analysis . No patient was lost to follow-up . The survival at ten years was 95.3 % ( 95 % CI 90.3 to 97.8 ) and 95.6 % ( 95 % CI 89.5 to 98.2 ) in the cemented and cementless groups , respectively . The hazard ratio for failure in cemented compared with cementless prostheses was 0.97 ( 95 % CI 0.36 to 2.6 ) . A comparison of the clinical outcome at ten years in 80 knees showed no difference between the two groups . The survival of the press-fit condylar total knee replacement at ten years is good irrespective of the method of fixation and brings into question the use of more expensive cementless implants Purpose : The objective of this prospect i ve study was to evaluate the medium-term clinical and radiological results after navigated cementless implantation , without patella resurfacing , of a total knee endoprosthesis with tibial and femoral press-fit components , with a focus on survival rate and clinical outcome . The innovation is the non-cemented fixation together with the use of a navigation system . Scope and Methods : Sixty patients with gonarthrosis were included consecutively in this study . In all cases , the cementless Columbus total knee endoprosthesis with a coating out of pure titanium was implanted , using a navigation system . The Knee Society Score showed a statistically significant increase from 75 ( ± 21.26 ) before surgery to 180 ( ± 16.15 ) after a mean follow-up of 5.6 ( ± 0.25 ) years . The last radiological examination revealed no osteolysis . No radiolucent lines were seen at any time in the area of the femoral prosthetic components . In the tibial area , radiolucent lines were seen in 24.4 % of the cases , mostly in the distal uncoated part of the stem . During follow-up , no prosthesis had to be replaced because of aseptic loosening while in 2 cases revision surgery was necessary due to septic loosening and in 1 case due to unexplainable pain . Results and Conclusions : Navigated cementless implantation of the Columbus total knee endoprosthesis yielded good clinical and radiological results in the medium term . The excellent radiological osteointegration of the prosthetic components , coated with a microporous pure titanium layer and implanted with a press-fit technique , should be emphasized We have carried out a prospect i ve study comparing the results at five years in patients older than 75 years of age undergoing hydroxyapatite-coated , cementless total knee replacement ( TKR ) with those who were younger . The Knee Society clinical rating scores were recorded before and after operation . Of 559 patients undergoing TKR , 135 were in the elderly age group . The knee scores at five years or more showed comparable results , with patients under 75 years of age reaching a score of 183 and those aged 75 years or over reaching 174 . These differences were predominantly due to the functional component of the score . We conclude that elderly patients do just as well as the younger group using this prosthesis We carried out a prospect i ve study of 118 hydroxyapatite-coated , cementless total knee replacements in patients who were < /= 55 years of age and who had primary ( 92 ; 78 % ) or post-traumatic ( 26 ; 22 % ) osteoarthritis . The mean period of follow-up was 7.9 years ( 5 to 12.5 ) . The Knee Society clinical scores improved from a pre-operative mean of 98 ( 0 to 137 ) to a mean of 185 ( 135 to 200 ) at five years , and 173 ( 137 to 200 ) at ten years . There were two revisions of the tibial component because of aseptic loosening , and one case of polyethylene wear requiring further surgery . There was no osteolysis or progressive radiological loosening of any other component . At 12 years , the overall rate of implant survival was 97.5 % ( excluding exchange of spacer ) and 92.1 % ( including exchange of spacer ) . Cementless total knee replacement can achieve excellent long-term results in young , active patients with osteoarthritis . In contrast to total hip replacement , polyethylene wear , osteolysis and loosening of the prosthesis were not major problems for these patients , although it is possible that this observation could change with longer periods of follow-up A prospect ively studied group of 59 knees with cementless fixation were compared to a retrospectively studied but matched group of 59 knees with cement fixation using a Press Fit Condylar prosthesis .  The only significant preoperative difference between the patient groups was mean age ; the cemented group was on average nine years older than the cementless group ( p < 0.0001 ) . At an average of 2.8 years after surgery , there were no significant differences in knee scores between the two groups . Radiolucent lines adjacent to the tibial component were similar in both groups . The complication rate of 20 % in the cementless knees was higher than the 12 % rate in the cemented knees ; this was primarily related to polyethylene wear of metal-backed patellar components . Cement or cementless fixation of this prosthesis appears to provide equivalent early results This study examines the early clinical and radiographic results of the first 216 cases of a cementless fixed bearing tibial tray without screw holes in 191 patients . We hypothesize that stable fixation can be achieved without the use of screws . There were 16 cases lost to follow-up , leaving 200 cases with known outcome . The Hospital for Special Surgery knee scores improved from an average preoperative score of 54/100 to 82/100 postoperatively . Three patients had incomplete radiolucent lines involving the medial aspect of the tibial tray . All of the tibial components review ed radiographically were bone ingrown . We conclude that the tray provides excellent primary stability , allowing early bone ingrowth , free from osteolysis and with good clinical outcomes . All of the tibial components were bone ingrown by radiographic criteria The Miller-Galante I knee replacement was inserted in 25 women and three men ( 33 knees ) with osteoarthrosis . All patients received a TiAlV femoral component with a commercially pure titanium fiber-mesh undersurface . Cemented or cementless fixation was used based on a r and omization protocol . Micromotions of the femoral components were recorded with roentgen stereophotogrammetric analysis during the first 2 postoperative years . The magnitude of migration did not differ between cemented and uncemented fixation . The number of nonmigrating prostheses decreased from 21 ( 12 cemented and nine uncemented ) at 3 months to six ( three cemented and three uncemented ) at 24 months . In both groups , the magnitude of prosthetic tilting about the longitudinal axis ( internal-external rotation ) was as large as that about the transverse axis ( flexion-extension ) . Rotation into extension was as common as rotation into flexion . The largest translations were recorded at either of the posterior condyles . In 10 uncemented components , radiolucent lines were seen at the distal interface postoperatively . Proximal migration of the femoral component was recorded in these knees , and the width of the lines decreased or the lines disappeared totally at 24 months . After 2 years , lines were noted around four cemented and four uncemented replacements , mainly anteriorly or distally . All of these prostheses migrated . One prosthesis , revised because of malalignment , displayed pronounced migration after an initial period of stability . Bone ingrowth was observed anteriorly and anterodistally despite the presence of motions of 1 mm or more We performed a prospect i ve study of 54 patients ( 76 knees ) who underwent Osteonics series 3000 cruciate-retaining cementless total knee arthroplasty between December 1990 and June 1993 . Five patients ( seven knees ) were lost to follow-up ( 90.7 % completion ) . One patient required revision at 10.5 years after operation . The rate of survival was 100 % at ten years and 96.7 % at 13 years . The mean ten-year knee and function scores were 79 and 59 respectively . Both were significantly better than the pre-operative scores . The range of movement also improved . Although a radiolucent line around the tibial component enlarged in six knees ( 20.7 % 
    Output:
    