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: Abstract  Anterior knee pain is one of the major short-term complaints after TKA . Since the introduction of the mobile-bearing TKA , numerous studies have attempted to confirm the theoretical advantages of a mobile-bearing TKA over a fixed-bearing TKA but most show little or no actual benefits . The concept of self-alignment for the mobile bearing suggests the posterior-stabilized mobile-bearing TKA would provide a lower incidence of anterior knee pain compared with a fixed-bearing TKA . We therefore asked whether the posterior-stabilized mobile-bearing knee would in fact reduce anterior knee pain . We r and omized 103 patients scheduled for cemented three-component TKA for osteoarthrosis in a prospect i ve , double-blind clinical trial . With a 1-year followup , more patients experienced persistent anterior knee pain in the posterior-stabilized fixed-bearing group ( 10 of 53 , 18.9 % ) than in the posterior-stabilized mobile-bearing group ( two of 47 , 4.3 % ) . No differences were observed for range of motion , visual analog scale for pain , Oxford 12-item question naire , SF-36 , or the American Knee Society score . The posterior-stabilized mobile-bearing knee therefore seems to provide a short-term advantage compared with the posterior-stabilized fixed-bearing knee . Level of Evidence : Level I , therapeutic study . See the Guidelines for Authors for a complete description of levels 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 A prospect i ve , r and omized , controlled , double-blind trial was performed to compare outcomes between 61 mobile- and 58 fixed-bearing primary TKAs in patients aged 70 years or older . At last follow-up , no difference was found for Knee Society score . The mobile-bearing group had greater knee flexion at 3 and 6 months , but this was similar at 2 years . The patient satisfaction was better in the mobile-bearing group than in fixed-bearing group , with respect to Knee Society functional score , Western Ontario MacMasters University score , Short-Form 12 score , and visual analog scale score . A multivariate analysis confirmed that the only independent factors predictive of postoperative quality of life were early postoperative flexion . We believe that better perception and satisfaction with mobile-bearing in older patients was due to the earlier regain of their knee flexion . Our results justify the use of mobile-bearing design in the older population 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 Background On theoretical grounds mobile bearing total knees should reduce the micromotion of the tibial component relative to the bone . Patients and methods We used radiostereometric analysis to measure the three-dimensional micromotion in  42 tibial components  during 2 years of follow-up . The patients had been r and omized as to whether they would receive a mobile bearing ( MB ) or posterior stabilized ( PS ) design .  We expected that the MB knee would facilitate dissipation of forces from the prosthesis-bone interface by the motion of the bearing and by load sharing with the soft tissues , leading to less micromotion . In the PS design s , limited free rotation caused by the campost articulation might cause additional stress at the bone-prosthesis interface . Results We found no significant differences between the MB and PS group at the 2-year follow-up evaluation with respect to Knee Society scores and radiographic results . The PS group had a higher variability in subsidence and anterior-posterior tilting of the component than the MB group . Interpretation The low variability of the data in the MB knee prosthesis group suggests that this design is more predictable and forgiving with respect to micromotion of the tibial component 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 Concern about polyethylene wear and related osteolysis after knee arthroplasty has developed in the last years . Mobile-bearing knee prostheses were design ed in order to reduce the influence of this critical factor on long-term success of total knee replacement . We present a prospect i ve study comparing clinical and radiological results with a mobile-bearing ( Ceragyr ) and a fixed-bearing knee prosthesis ( posterior stabilized Hermes ) . Clinical results did not show any significant differences in Knee Society scores . We found better results in the mobile-bearing group for pain scores and subjective preference , but the difference did not reach statistical significance . Within the time limits of this study , radiological analysis showed no osteolysis in either group , but longer follow-up will be needed to confirm this We have developed a 12-item question naire for patients having a total knee replacement ( TKR ) . We made a prospect i ve study of 117 patients before operation and at follow-up six months later , asking them to complete the new question naire and the form SF36 . Some also filled in the Stanford Health Assessment Question naire ( HAQ ) . An orthopaedic surgeon completed the American Knee Society ( AKS ) clinical score . The single score derived from the new question naire had high internal consistency , and its reproducibility , examined by test-retest reliability , was found to be satisfactory . Its validity was established by obtaining significant correlations in the expected direction with the AKS scores and the relevant parts of the SF36 and HAQ . Sensitivity to change was assessed by analysing the differences between the preoperative scores and those at follow-up . We also compared change in scores with the patients ' retrospective judgement of change in their condition . The effect size for the new question naire compared favourably with those for the relevant parts of the SF36 . The change scores for the new knee question naire were significantly greater ( p < 0.0001 ) for patients who reported the most improvement in their condition . The new question naire provides a measure of outcome for TKR that is short , practical , reliable , valid and sensitive to clinical ly important changes over time We compared patient-reported outcomes of the Kinemax fixed- and mobile-bearing total knee replacement in a multi-centre r and omised controlled trial . Patients were  r and omised to the fixed- or the mobile-bearing prosthesis via a sealed envelope method after the bone cuts had been made in the operating theatre . R and omisation was stratified by centre and diagnosis . Patients were assessed pre-operatively and at eight to 12 weeks , one year and two years post-operatively . Vali date d question naires were used which included the Western Ontario MacMasters University , Short-Form 12 , Mental Health Index-5 , Knee Injury and Osteoarthritis Outcome Score for Knee-Related Quality of Life and Function in Sport and Recreation scales and a vali date d scale of satisfaction post-operatively . In total , 242 patients ( 250 knees ) with a mean age of 68 years ( 40 to 80 ) were recruited from four NHS orthopaedic centres . Of these , 132 patients ( 54.5 % ) were women . No statistically significant differences could be identified in any of the patient-reported outcome scores between patients who received the fixed-bearing or the mobile-bearing knee up to two-years post-operatively 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 BACKGROUND Proponents of mobile-bearing total knee arthroplasty believe that it has potential advantages over a fixed-bearing design in terms of diminished wear and improved motion and /or function , but these advantages have not been demonstrated in a r and omized clinical comparison to our knowledge . We conducted a patient-blinded , prospect i ve , r and omized clinical trial to compare mobile-bearing and fixed-bearing cruciate-substituting total knee arthroplasties of the same design . METHODS Patients between the ages of sixty and eighty-five years were prospect ively r and omized to receive a cruciate-substituting rotating-platform design or a fixed-bearing design with an all-polyethyl 
    Output:
    
agent
Meta-analyses showed no clinical ly relevant differences in terms of revision rates , clinical outcome scores or patient-reported outcome measures between MB and FB TKRs .
It appears that theoretical assumptions of superiority of MB over FB TKR are not borne out in clinical practice
***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: Abstract  Anterior knee pain is one of the major short-term complaints after TKA . Since the introduction of the mobile-bearing TKA , numerous studies have attempted to confirm the theoretical advantages of a mobile-bearing TKA over a fixed-bearing TKA but most show little or no actual benefits . The concept of self-alignment for the mobile bearing suggests the posterior-stabilized mobile-bearing TKA would provide a lower incidence of anterior knee pain compared with a fixed-bearing TKA . We therefore asked whether the posterior-stabilized mobile-bearing knee would in fact reduce anterior knee pain . We r and omized 103 patients scheduled for cemented three-component TKA for osteoarthrosis in a prospect i ve , double-blind clinical trial . With a 1-year followup , more patients experienced persistent anterior knee pain in the posterior-stabilized fixed-bearing group ( 10 of 53 , 18.9 % ) than in the posterior-stabilized mobile-bearing group ( two of 47 , 4.3 % ) . No differences were observed for range of motion , visual analog scale for pain , Oxford 12-item question naire , SF-36 , or the American Knee Society score . The posterior-stabilized mobile-bearing knee therefore seems to provide a short-term advantage compared with the posterior-stabilized fixed-bearing knee . Level of Evidence : Level I , therapeutic study . See the Guidelines for Authors for a complete description of levels 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 A prospect i ve , r and omized , controlled , double-blind trial was performed to compare outcomes between 61 mobile- and 58 fixed-bearing primary TKAs in patients aged 70 years or older . At last follow-up , no difference was found for Knee Society score . The mobile-bearing group had greater knee flexion at 3 and 6 months , but this was similar at 2 years . The patient satisfaction was better in the mobile-bearing group than in fixed-bearing group , with respect to Knee Society functional score , Western Ontario MacMasters University score , Short-Form 12 score , and visual analog scale score . A multivariate analysis confirmed that the only independent factors predictive of postoperative quality of life were early postoperative flexion . We believe that better perception and satisfaction with mobile-bearing in older patients was due to the earlier regain of their knee flexion . Our results justify the use of mobile-bearing design in the older population 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 Background On theoretical grounds mobile bearing total knees should reduce the micromotion of the tibial component relative to the bone . Patients and methods We used radiostereometric analysis to measure the three-dimensional micromotion in  42 tibial components  during 2 years of follow-up . The patients had been r and omized as to whether they would receive a mobile bearing ( MB ) or posterior stabilized ( PS ) design .  We expected that the MB knee would facilitate dissipation of forces from the prosthesis-bone interface by the motion of the bearing and by load sharing with the soft tissues , leading to less micromotion . In the PS design s , limited free rotation caused by the campost articulation might cause additional stress at the bone-prosthesis interface . Results We found no significant differences between the MB and PS group at the 2-year follow-up evaluation with respect to Knee Society scores and radiographic results . The PS group had a higher variability in subsidence and anterior-posterior tilting of the component than the MB group . Interpretation The low variability of the data in the MB knee prosthesis group suggests that this design is more predictable and forgiving with respect to micromotion of the tibial component 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 Concern about polyethylene wear and related osteolysis after knee arthroplasty has developed in the last years . Mobile-bearing knee prostheses were design ed in order to reduce the influence of this critical factor on long-term success of total knee replacement . We present a prospect i ve study comparing clinical and radiological results with a mobile-bearing ( Ceragyr ) and a fixed-bearing knee prosthesis ( posterior stabilized Hermes ) . Clinical results did not show any significant differences in Knee Society scores . We found better results in the mobile-bearing group for pain scores and subjective preference , but the difference did not reach statistical significance . Within the time limits of this study , radiological analysis showed no osteolysis in either group , but longer follow-up will be needed to confirm this We have developed a 12-item question naire for patients having a total knee replacement ( TKR ) . We made a prospect i ve study of 117 patients before operation and at follow-up six months later , asking them to complete the new question naire and the form SF36 . Some also filled in the Stanford Health Assessment Question naire ( HAQ ) . An orthopaedic surgeon completed the American Knee Society ( AKS ) clinical score . The single score derived from the new question naire had high internal consistency , and its reproducibility , examined by test-retest reliability , was found to be satisfactory . Its validity was established by obtaining significant correlations in the expected direction with the AKS scores and the relevant parts of the SF36 and HAQ . Sensitivity to change was assessed by analysing the differences between the preoperative scores and those at follow-up . We also compared change in scores with the patients ' retrospective judgement of change in their condition . The effect size for the new question naire compared favourably with those for the relevant parts of the SF36 . The change scores for the new knee question naire were significantly greater ( p < 0.0001 ) for patients who reported the most improvement in their condition . The new question naire provides a measure of outcome for TKR that is short , practical , reliable , valid and sensitive to clinical ly important changes over time We compared patient-reported outcomes of the Kinemax fixed- and mobile-bearing total knee replacement in a multi-centre r and omised controlled trial . Patients were  r and omised to the fixed- or the mobile-bearing prosthesis via a sealed envelope method after the bone cuts had been made in the operating theatre . R and omisation was stratified by centre and diagnosis . Patients were assessed pre-operatively and at eight to 12 weeks , one year and two years post-operatively . Vali date d question naires were used which included the Western Ontario MacMasters University , Short-Form 12 , Mental Health Index-5 , Knee Injury and Osteoarthritis Outcome Score for Knee-Related Quality of Life and Function in Sport and Recreation scales and a vali date d scale of satisfaction post-operatively . In total , 242 patients ( 250 knees ) with a mean age of 68 years ( 40 to 80 ) were recruited from four NHS orthopaedic centres . Of these , 132 patients ( 54.5 % ) were women . No statistically significant differences could be identified in any of the patient-reported outcome scores between patients who received the fixed-bearing or the mobile-bearing knee up to two-years post-operatively 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 BACKGROUND Proponents of mobile-bearing total knee arthroplasty believe that it has potential advantages over a fixed-bearing design in terms of diminished wear and improved motion and /or function , but these advantages have not been demonstrated in a r and omized clinical comparison to our knowledge . We conducted a patient-blinded , prospect i ve , r and omized clinical trial to compare mobile-bearing and fixed-bearing cruciate-substituting total knee arthroplasties of the same design . METHODS Patients between the ages of sixty and eighty-five years were prospect ively r and omized to receive a cruciate-substituting rotating-platform design or a fixed-bearing design with an all-polyethyl 
    Output:
    