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: Purpose This study was design ed to compare clinical , radiological , and general health results of two prostheses ( mobile vs. fixed weight-bearing devices ) that are used in total knee arthroplasty with a 5-year follow-up . Methods This r and omized controlled study was conducted from 2004 to 2010 in the Department of Orthopedic Surgery at two university hospitals in Isfahan , Iran . Three hundred patients with expected primary total knee arthroplasty ( TKA ) without severe deformity ( a fixed varus or valgus deformity greater than 20 ° ) received fixed weight-bearing ( n = 150 ) or mobile weight-bearing ( n = 150 ) devices . Clinical , radiological , and quality of life outcomes were compared between the two groups at six-month intervals for the first year , after which the comparisons were made annually for the next 4 years . Results Both groups had similar baseline characteristics . Although there was significant improvement in both groups , there was no significant difference between the groups with regard to the means of the Knee Society Scores , which were 92 ( SD : 12.1 ) for the fixed weight-bearing device and 93 ( SD : 14.2 ) for the mobile weight-bearing device ( n.s . ) at the final follow-up point . Radiographs showed that there was no significant difference in prosthetic alignment and no evidence of loosening . After TKA , the SF-36 score increased in both groups , but there was no statistical difference between the groups in quality of life at the final follow-up ( 62 ( 12.2 ) vs. 64 ( 14.3 ) , n.s . ) . There was no revision after 5 years . Conclusions In terms of clinical , radiological or general health outcomes for people who underwent TKA , the results of this study showed no clear advantage of mobile weight-bearing over the fixed weight-bearing prosthesis at the five-year follow-up . Level of evidence A prospect i ve study was performed to compare the clinical and radiological results of mobile- and fixed-bearing total knee arthroplasty  with specific attention to rotational alignment and range of motion . Sixty-one knees were assigned to total knee arthroplasty with either the NexGen LPS Flex fixed-bearing or with the NexGen LPS Flex mobile-bearing prosthesis . Postoperatively , knees were compared with regard to range of motion , clinical score , and radiographic findings . Rotational alignment of the femoral and tibial components was evaluated by computed tomography . The median follow-up period was 5.9 years ( range 2.1–8.8 years ) . Median postoperative Knee Society scores were 99 points ( 68–100 ) for the fixed-bearing group and 100 points ( 66–100 ) for the mobile-bearing group ( n.s . ) . The median postoperative flexion angles of 120 ° ( 90 ° –150 ° ) for the fixed-bearing group and 125 ° ( 90 ° –145 ° ) for the mobile-bearing group were not significantly different from each other ( n.s . ) . No knee required revision surgery due to wear of polyethylene or loosening of the component in either group . Computed tomography showed that 11 knees had rotational mismatches of more than 10 ° between the femoral and tibial components , but no significant difference was found in the postoperative extension and flexion angles or in the clinical score between the two treatment groups . Using the identical design for both fixed- and mobile-bearing prostheses , this prospect i ve , r and omized study did not show any clinical advantages of the mobile-bearing knee . Analysis of rotational alignment by CT scan did not reveal a particular advantage of the self-aligning mechanism of mobile-bearing implants Background : The mobile bearing design s have not yet been shown to improve clinical outcome of total knee arthroplasty ( TKA ) . In this prospect i ve r and omized study , we compared the short-term clinical results of a mobile bearing implant with those of the fixed bearing version of the same implant . Methods : We r and omized 100 knees into two double-blind groups who received either the fixed ( FB , 52 knees ) or the mobile bearing ( MB , 48 knees ) version of the same implant .  We used navigation to st and ardize the surgical technique . For up to one year , we recorded the Knee Society ( KSS ) and Oxford ( OXF ) scores . We performed an exploratory analysis of variance ( ANOVA ) to determine the influence of baseline scores as covariate and the extent of improvement in clinical outcome over time . Results : After one year , we did not detect any statistically significant difference between the two groups . The KSS scores differed by 2 points , the OXF scores by 1.1 points . Conclusion : Even with identical geometry of implant surfaces and a navigated surgical technique , first-year results do not support a preference for either a fixed or a mobile design The aim of this study was to determine whether there is a difference in functional outcome between the PFC Sigma fixed-bearing and rotating-platform total knee replacement systems .  One hundred twenty patients were r and omised to receive either a fixed-bearing or rotating-platform PFC Sigma total knee replacement .  Range of movement ( ROM ) , Oxford knee score ( OKS ) and Knee Society score ( KSS ) were assessed independently before and one year after surgery . Weight-bearing X-rays were taken immediately and one year post surgery to determine the incidence of osteolysis and loosening . At a mean follow-up of 13.4 months there was no statistically significant difference in mean ROM , OKS and KSS between the two groups . There was no evidence of osteolysis or loosening in either of the groups and no revision for infection or implant failure . This study shows that there is no statistically significant difference in functional outcome between the two types of implants at short-term follow-up Purpose The primary goal of this study was to assess the difference in active flexion between patients with a mobile versus a fixed bearing , cruciate retaining , and total knee arthroplasty .  The study was design ed as a r and omised controlled multi-centre trial . Methods Participants were assigned to interventions by using block-stratified , r and om allocation . Outcome parameters were active flexion , passive flexion , and Knee Society Score ( KSS ) . Outcome parameters were assessed preoperatively and at 3 , 6 , and 12 months postoperatively by an independent nurse . Results Ninety-two patients from one centre were included , 46 in each group . Active flexion was comparable for the two groups , 99.9 ° for the mobile bearing group and 101 ° for the fixed bearing group with a baseline controlled difference of 1.0 ( 95 % CI −3.9 to 5.8 , n.s . ) . The Clinical KSS was comparable between the two bearing groups ( Mobile 90.0 vs. fixed 92.4 , n.s . ) . The functional KSS showed a difference that was attributable to the stair climbing subscore , which showed a difference in favour of the fixed bearing design between preoperative and 3 months ( 7.3 point difference ; 95 % CI 2.3–12.5 ; P = 0.005 ) as well as 12 months ( 4.8 point difference ; 95 % CI 0.1–9.6 ; P = 0.045 ) . Conclusions There were no short-term differences in active flexion  between fixed bearing and mobile bearing total knee arthroplasty . Level of evidence INTRODUCTION  Total knee prostheses  with a mobile-bearing insert were developed to provide nonconstrained joint range of motion while reducing friction forces . The purpose of this study was , based on weightbearing X-rays , to evaluate the mobility of the polyethylene tibial insert in relation to the femoral and tibial components . We studied the results of a cementless total knee arthroplasty ( TKA ) retaining the posterior cruciate ligament ( PCL ) , with a mobile-bearing platform in rotation and anteroposterior translation ( Innex Anterior-Posterior Glide , Zimmer ) with a mean 23-month follow-up duration after surgery . HYPOTHESIS Both anterior-posterior tibiofemoral translation and intraprosthetic axial rotation occur between the mobile polyethylene insert and the tibial endplate . MATERIAL AND METHOD In a series of 51 primary TKA , the three-dimensional ( 3D ) kinematics of the femoral , tibial , and mobile insert components were determined using a computerized matching system between the prosthetic 3D models and the radiographic images of the implants on three lateral follow-up weightbearing knee X-rays : films were taken in full extension , at 45 degrees flexion , and at maximum flexion . RESULTS There was a statistically significant increase in the internal rotation of the mobile tray with flexion , ( up to a mean -3+/-3 degrees between the femoral box and the mobile tray [ p<0.0001 ] and up to a mean -5+/-7 degrees between the tibial tray and the mobile tray [ p<0.0001 ] ) . The mobile tray did not translate in relation to the tibial endplate from extension to 45 degrees flexion ( 0+/-2 mm [ range : -5 to 6 mm ] ) . However , from 45 degrees to maximum flexion , a statistically significant mean 1+/-2 mm ( range : -2 to 9 mm ) of anterior translation ( p<0.0001 ) was found . DISCUSSION The extent of insert mobility varies from one study to another . Some have reported relatively limited mobility stemming from a superior surface that is not highly congruent , ( thus allowing anterior-posterior and mediolateral translation through gliding of the femur in contact with the insert ) . Other studies have reported mobile-bearing tray mobility in relation to the tibial endplate and minimal rotation at the femoral component level . In this series of PCL retaining TKA with a mobile-bearing platform , the mobile-bearing platform showed a progressive increase in internal rotation during flexion . Most of this rotational mobility occurred between the mobile platform and the tibial endplate , confirming our hypothesis . However , with flexion , the femoral component increased its mobility relatively to the platform . During flexion , an anterior-posterior translation occurred between the femoral implant and the tibial insert , and between the tibial insert and the tibial endplate , but the direction of the mobile tibial insert translation remained unpredictable with this nonconstrained implant design used . LEVEL OF EVIDENCE Level IV . Prospect i ve non-controlled therapeutic study Introduction In a prospect i ve r and omized study , we compared the results after implantation of the mobile bearing high flex TKA with a fixed bearing posterior stabilized TKA in 60 patients ( 30 patients each group ) . Method We evaluated the hospital for special surgery-score ( HSS ) and different radiological parameters preoperatively , as well as 3 months , 3 and 5 years postoperatively . Result Three months postoperatively , the high flex group showed better results in scores for pain , ROM ( 122.5 ° vs. 107.33 ° ) , as well as in the overall HSS ( 87.21 vs. 82.68 points ) . Three and 5 years postoperatively , there were no differences between both the groups in all scores , but the HSS is still increasing . Conclusion The theoretical advantages of the mobile bearing knee prostheses were reflected in the clinical results , only partly and temporarily Purpose The purpose of this study was to determine whether the floating platforms ( FP ) were superior to rotating platforms ( RP ) in computer-navigated total knee  arthroplasty ( TKA ) comparing the range of motion ( ROM ) as well as clinical and subjective function of the knee . Methods This retrospective non-r and omized single-centre cohort study includes 255 patients with a primary implanted computer-navigated e.motion ™ ( Aesculap B. Braun ) TKA system , implanted because of clinical and radiological verified gonarthrosis . In 129 patients , the FP platform was implanted  , and in 126 patients , the RP platform . As statistical procedures for differences between inlay type RP/FP in ROM and Knee Society Score ( KSS ) after 3- and 24-month follow-up , an analysis of covariance ( with risk factors gender , age , BMI , preoperative ROM and preoperative KSS ) was performed . Results Although preoperative ROM and knee society function score ( KSS partII ) were significantly higher in the FP group before surgery , there was no significant difference between RP and FP  in ROM and KSS at 3- and 24-month follow-up . Conclusion The FP platform design did not have an advantage in ROM as well as in clinical and subjective knee function compared with the RP platform in computer-navigated TKA neither in early follow-up examinations at 3 months postoperatively nor at long-time follow-up at 24 months postoperatively . Level of evidence Therapeutic study , Level III BACKGROUND For some surgeons , rotating-platform total knee design s are an intellectually appealing option to use for total knee arthroplasty because of the contention that they can self-align and accommo date small mismatches in the rotational position of the tibial and femoral components . We carried out a r and omized clinical trial to determine if a posterior-stabilized , rotating-platform knee design provided better maximum knee flexion , better function , or better durability at five years of follow-up when compared with a fixed-bearing design . METHODS This r and omized clinical trial of 240 primary total knee arthroplasties involved a single type of distal femoral implant ( posterior-stabilized ) and three different types of tibial implant ( all-polyethylene fixed-bearing , modular-metal-backed fixed-bearing , and rotating-platform ) . The three tibial implant groups were balanced dynamically with a computerized r and omization 
    Output:
    
agent
Similarly , no difference was revealed between the groups for radiological outcomes or general health results .
***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: Purpose This study was design ed to compare clinical , radiological , and general health results of two prostheses ( mobile vs. fixed weight-bearing devices ) that are used in total knee arthroplasty with a 5-year follow-up . Methods This r and omized controlled study was conducted from 2004 to 2010 in the Department of Orthopedic Surgery at two university hospitals in Isfahan , Iran . Three hundred patients with expected primary total knee arthroplasty ( TKA ) without severe deformity ( a fixed varus or valgus deformity greater than 20 ° ) received fixed weight-bearing ( n = 150 ) or mobile weight-bearing ( n = 150 ) devices . Clinical , radiological , and quality of life outcomes were compared between the two groups at six-month intervals for the first year , after which the comparisons were made annually for the next 4 years . Results Both groups had similar baseline characteristics . Although there was significant improvement in both groups , there was no significant difference between the groups with regard to the means of the Knee Society Scores , which were 92 ( SD : 12.1 ) for the fixed weight-bearing device and 93 ( SD : 14.2 ) for the mobile weight-bearing device ( n.s . ) at the final follow-up point . Radiographs showed that there was no significant difference in prosthetic alignment and no evidence of loosening . After TKA , the SF-36 score increased in both groups , but there was no statistical difference between the groups in quality of life at the final follow-up ( 62 ( 12.2 ) vs. 64 ( 14.3 ) , n.s . ) . There was no revision after 5 years . Conclusions In terms of clinical , radiological or general health outcomes for people who underwent TKA , the results of this study showed no clear advantage of mobile weight-bearing over the fixed weight-bearing prosthesis at the five-year follow-up . Level of evidence A prospect i ve study was performed to compare the clinical and radiological results of mobile- and fixed-bearing total knee arthroplasty  with specific attention to rotational alignment and range of motion . Sixty-one knees were assigned to total knee arthroplasty with either the NexGen LPS Flex fixed-bearing or with the NexGen LPS Flex mobile-bearing prosthesis . Postoperatively , knees were compared with regard to range of motion , clinical score , and radiographic findings . Rotational alignment of the femoral and tibial components was evaluated by computed tomography . The median follow-up period was 5.9 years ( range 2.1–8.8 years ) . Median postoperative Knee Society scores were 99 points ( 68–100 ) for the fixed-bearing group and 100 points ( 66–100 ) for the mobile-bearing group ( n.s . ) . The median postoperative flexion angles of 120 ° ( 90 ° –150 ° ) for the fixed-bearing group and 125 ° ( 90 ° –145 ° ) for the mobile-bearing group were not significantly different from each other ( n.s . ) . No knee required revision surgery due to wear of polyethylene or loosening of the component in either group . Computed tomography showed that 11 knees had rotational mismatches of more than 10 ° between the femoral and tibial components , but no significant difference was found in the postoperative extension and flexion angles or in the clinical score between the two treatment groups . Using the identical design for both fixed- and mobile-bearing prostheses , this prospect i ve , r and omized study did not show any clinical advantages of the mobile-bearing knee . Analysis of rotational alignment by CT scan did not reveal a particular advantage of the self-aligning mechanism of mobile-bearing implants Background : The mobile bearing design s have not yet been shown to improve clinical outcome of total knee arthroplasty ( TKA ) . In this prospect i ve r and omized study , we compared the short-term clinical results of a mobile bearing implant with those of the fixed bearing version of the same implant . Methods : We r and omized 100 knees into two double-blind groups who received either the fixed ( FB , 52 knees ) or the mobile bearing ( MB , 48 knees ) version of the same implant .  We used navigation to st and ardize the surgical technique . For up to one year , we recorded the Knee Society ( KSS ) and Oxford ( OXF ) scores . We performed an exploratory analysis of variance ( ANOVA ) to determine the influence of baseline scores as covariate and the extent of improvement in clinical outcome over time . Results : After one year , we did not detect any statistically significant difference between the two groups . The KSS scores differed by 2 points , the OXF scores by 1.1 points . Conclusion : Even with identical geometry of implant surfaces and a navigated surgical technique , first-year results do not support a preference for either a fixed or a mobile design The aim of this study was to determine whether there is a difference in functional outcome between the PFC Sigma fixed-bearing and rotating-platform total knee replacement systems .  One hundred twenty patients were r and omised to receive either a fixed-bearing or rotating-platform PFC Sigma total knee replacement .  Range of movement ( ROM ) , Oxford knee score ( OKS ) and Knee Society score ( KSS ) were assessed independently before and one year after surgery . Weight-bearing X-rays were taken immediately and one year post surgery to determine the incidence of osteolysis and loosening . At a mean follow-up of 13.4 months there was no statistically significant difference in mean ROM , OKS and KSS between the two groups . There was no evidence of osteolysis or loosening in either of the groups and no revision for infection or implant failure . This study shows that there is no statistically significant difference in functional outcome between the two types of implants at short-term follow-up Purpose The primary goal of this study was to assess the difference in active flexion between patients with a mobile versus a fixed bearing , cruciate retaining , and total knee arthroplasty .  The study was design ed as a r and omised controlled multi-centre trial . Methods Participants were assigned to interventions by using block-stratified , r and om allocation . Outcome parameters were active flexion , passive flexion , and Knee Society Score ( KSS ) . Outcome parameters were assessed preoperatively and at 3 , 6 , and 12 months postoperatively by an independent nurse . Results Ninety-two patients from one centre were included , 46 in each group . Active flexion was comparable for the two groups , 99.9 ° for the mobile bearing group and 101 ° for the fixed bearing group with a baseline controlled difference of 1.0 ( 95 % CI −3.9 to 5.8 , n.s . ) . The Clinical KSS was comparable between the two bearing groups ( Mobile 90.0 vs. fixed 92.4 , n.s . ) . The functional KSS showed a difference that was attributable to the stair climbing subscore , which showed a difference in favour of the fixed bearing design between preoperative and 3 months ( 7.3 point difference ; 95 % CI 2.3–12.5 ; P = 0.005 ) as well as 12 months ( 4.8 point difference ; 95 % CI 0.1–9.6 ; P = 0.045 ) . Conclusions There were no short-term differences in active flexion  between fixed bearing and mobile bearing total knee arthroplasty . Level of evidence INTRODUCTION  Total knee prostheses  with a mobile-bearing insert were developed to provide nonconstrained joint range of motion while reducing friction forces . The purpose of this study was , based on weightbearing X-rays , to evaluate the mobility of the polyethylene tibial insert in relation to the femoral and tibial components . We studied the results of a cementless total knee arthroplasty ( TKA ) retaining the posterior cruciate ligament ( PCL ) , with a mobile-bearing platform in rotation and anteroposterior translation ( Innex Anterior-Posterior Glide , Zimmer ) with a mean 23-month follow-up duration after surgery . HYPOTHESIS Both anterior-posterior tibiofemoral translation and intraprosthetic axial rotation occur between the mobile polyethylene insert and the tibial endplate . MATERIAL AND METHOD In a series of 51 primary TKA , the three-dimensional ( 3D ) kinematics of the femoral , tibial , and mobile insert components were determined using a computerized matching system between the prosthetic 3D models and the radiographic images of the implants on three lateral follow-up weightbearing knee X-rays : films were taken in full extension , at 45 degrees flexion , and at maximum flexion . RESULTS There was a statistically significant increase in the internal rotation of the mobile tray with flexion , ( up to a mean -3+/-3 degrees between the femoral box and the mobile tray [ p<0.0001 ] and up to a mean -5+/-7 degrees between the tibial tray and the mobile tray [ p<0.0001 ] ) . The mobile tray did not translate in relation to the tibial endplate from extension to 45 degrees flexion ( 0+/-2 mm [ range : -5 to 6 mm ] ) . However , from 45 degrees to maximum flexion , a statistically significant mean 1+/-2 mm ( range : -2 to 9 mm ) of anterior translation ( p<0.0001 ) was found . DISCUSSION The extent of insert mobility varies from one study to another . Some have reported relatively limited mobility stemming from a superior surface that is not highly congruent , ( thus allowing anterior-posterior and mediolateral translation through gliding of the femur in contact with the insert ) . Other studies have reported mobile-bearing tray mobility in relation to the tibial endplate and minimal rotation at the femoral component level . In this series of PCL retaining TKA with a mobile-bearing platform , the mobile-bearing platform showed a progressive increase in internal rotation during flexion . Most of this rotational mobility occurred between the mobile platform and the tibial endplate , confirming our hypothesis . However , with flexion , the femoral component increased its mobility relatively to the platform . During flexion , an anterior-posterior translation occurred between the femoral implant and the tibial insert , and between the tibial insert and the tibial endplate , but the direction of the mobile tibial insert translation remained unpredictable with this nonconstrained implant design used . LEVEL OF EVIDENCE Level IV . Prospect i ve non-controlled therapeutic study Introduction In a prospect i ve r and omized study , we compared the results after implantation of the mobile bearing high flex TKA with a fixed bearing posterior stabilized TKA in 60 patients ( 30 patients each group ) . Method We evaluated the hospital for special surgery-score ( HSS ) and different radiological parameters preoperatively , as well as 3 months , 3 and 5 years postoperatively . Result Three months postoperatively , the high flex group showed better results in scores for pain , ROM ( 122.5 ° vs. 107.33 ° ) , as well as in the overall HSS ( 87.21 vs. 82.68 points ) . Three and 5 years postoperatively , there were no differences between both the groups in all scores , but the HSS is still increasing . Conclusion The theoretical advantages of the mobile bearing knee prostheses were reflected in the clinical results , only partly and temporarily Purpose The purpose of this study was to determine whether the floating platforms ( FP ) were superior to rotating platforms ( RP ) in computer-navigated total knee  arthroplasty ( TKA ) comparing the range of motion ( ROM ) as well as clinical and subjective function of the knee . Methods This retrospective non-r and omized single-centre cohort study includes 255 patients with a primary implanted computer-navigated e.motion ™ ( Aesculap B. Braun ) TKA system , implanted because of clinical and radiological verified gonarthrosis . In 129 patients , the FP platform was implanted  , and in 126 patients , the RP platform . As statistical procedures for differences between inlay type RP/FP in ROM and Knee Society Score ( KSS ) after 3- and 24-month follow-up , an analysis of covariance ( with risk factors gender , age , BMI , preoperative ROM and preoperative KSS ) was performed . Results Although preoperative ROM and knee society function score ( KSS partII ) were significantly higher in the FP group before surgery , there was no significant difference between RP and FP  in ROM and KSS at 3- and 24-month follow-up . Conclusion The FP platform design did not have an advantage in ROM as well as in clinical and subjective knee function compared with the RP platform in computer-navigated TKA neither in early follow-up examinations at 3 months postoperatively nor at long-time follow-up at 24 months postoperatively . Level of evidence Therapeutic study , Level III BACKGROUND For some surgeons , rotating-platform total knee design s are an intellectually appealing option to use for total knee arthroplasty because of the contention that they can self-align and accommo date small mismatches in the rotational position of the tibial and femoral components . We carried out a r and omized clinical trial to determine if a posterior-stabilized , rotating-platform knee design provided better maximum knee flexion , better function , or better durability at five years of follow-up when compared with a fixed-bearing design . METHODS This r and omized clinical trial of 240 primary total knee arthroplasties involved a single type of distal femoral implant ( posterior-stabilized ) and three different types of tibial implant ( all-polyethylene fixed-bearing , modular-metal-backed fixed-bearing , and rotating-platform ) . The three tibial implant groups were balanced dynamically with a computerized r and omization 
    Output:
    