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: Background : Mobile-bearing ankle replacements have become popular outside of the United States over the past two decades . The goal of the present study was to perform a prospect i ve evaluation of the safety and efficacy of a mobile-bearing prosthesis to treat end stage ankle arthritis . We report the results of three separate cohorts of patients : a group of Sc and anavian Total Ankle Replacement ( STAR ) patients and a control group of ankle fusion patients ( the Pivotal Study Groups ) and another group of STAR total ankle patients ( Continued Access Group ) whose surgery was performed following the completion of enrollment in the Pivotal Study . Material s and Methods : The Pivotal Study design was a non-inferiority study using ankle fusion as the control . A non-r and omized multi-centered design with concurrent fusion controls was used . We report the initial perioperative findings up to 24 months following surgery . For an individual patient to be considered an overall success , all of the following criteria needed to be met : a ) a 40-point improvement in total Buechel-Pappas ankle score , b ) no device failures , revisions , or removals , c ) radiographic success , and d ) no major complications . In the Pivotal Study ( 9/00 to 12/01 ) , 158 ankle replacement and 66 arthrodesis procedures were performed ; in the Continued Access Study ( 4/02 to 10/06 ) , 448 ankle replacements were performed , of which 416 were at minimum 24 months post-surgery at time of the data base closure . Results : Major complications and need for secondary surgical intervention were more common in the Pivotal Study arthroplasty group than the Pivotal Study ankle fusion group . In the Continued Access Group , secondary procedures performed on these arthroplasty patients decreased by half when compared with the Pivotal Arthroplasty Group . When the Pivotal Groups were compared , treatment efficacy was higher for the ankle replacement group due to improvement in functional scores . Pain relief was equivalent between fusion and replacement patients . The hypothesis of non-inferiority of ankle replacement was met for overall patient success . Conclusion : By 24 months , ankles treated with STAR ankle replacement ( in both the Pivotal and Continued Access Groups ) had better function and equivalent pain relief as ankles treated with fusion . Level of Evidence : II , Prospect i ve Controlled Comparative Surgical BACKGROUND Interest in mobile-bearing total ankle arthroplasty  has increased in recent years . However , to our knowledge , no study has focused exclusively on patients with the diagnosis of inflammatory joint disease or has provided a detailed analysis of the risk factors for failure . METHODS A prospect i ve observational study of the results of cementless mobile-bearing total ankle arthroplasty  in patients with inflammatory joint disease ( mainly rheumatoid arthritis ) was conducted at two centers . Ninety-three total ankle arthroplasties were performed . The LCS ( low contact stress ) prosthesis was used initially , in nineteen ankles , between 1988 and 1992 , and a modification of the LCS prosthesis , the Buechel-Pappas design , was used in seventy-four ankles between 1993 and 1999 . Clinical and radiographic follow-up was performed at yearly intervals . Three clinical scoring systems were used , and any complication was recorded throughout follow-up . Actuarial survival ( with revision as the end point ) , multivariate analysis , and a competing risk approach were used to describe the long-term outcome . RESULTS The clinical result at one year after surgery showed a significant improvement in the scores on all three scoring systems ( p < 0.05 ) . Ankle dorsiflexion ( mean , 7 degrees ) also improved significantly ( p < 0.05 ) compared with the preoperative state . The most frequent complication was a malleolar fracture , which occurred in twenty ankles . Only when it occurred in combination with a deformity in the frontal plane did this complication have an adverse effect on the end result . At a mean follow-up of eight years , seventeen patients ( twenty-one ankles ) had died and fifteen ankles had been revised because of aseptic loosening ( six ankles ) , primary or secondary axial deformity with edge-loading ( six ankles ) , deep infection ( two ankles ) , and a severe wound-healing problem ( one ankle ) , leaving fifty-seven ankles ( 61 % ) that were evaluated . The mean overall survival rate at eight years was 84 % . An increased failure rate was encountered in ankles with a preoperative deformity in the frontal plane of > 10 degrees ( p = 0.03 ) and in ankles in which an undersized tibial component had been implanted ( p = 0.02 ) . CONCLUSIONS Mobile-bearing total ankle arthroplasty is a valid treatment option for the rheumatoid ankle if proper indications are used . Aseptic loosening and persistent deformity are the most important modes of failure Interest in mobile-bearing total ankle arthroplasty has increased in recent years . Clinical studies show favorable but varying results , with survival rates between 70 % and 90 % at 10-year followup . Design -specific differences in early migration patterns might explain variations in the results and modes of failure . Using radiostereometric analysis ( RSA ) we prospect ively followed 15 RA patients with a cementless mobile-bearing total ankle arthroplasty .  The American Orthopaedic Foot and Ankle Society ankle score and radiostereometric radiographs  were evaluated immediately postoperatively , 6 weeks postoperatively , 3 months , 6 months , and 12 months postoperatively and yearly thereafter . The postoperative clinical results improved . We observed increased migration of the tibial component during the first 3 months , but this stabilized by the 6 month followup . The mean lateral-medial migration was 0.8 mm , distal-proximal migration was 0.9 mm , and posteroanterior migration was −0.5 mm . The latter implies the total result ant migration was in anterior and valgus tilting of this tibial component . However , migration stabilized at 6 months postoperatively . We believe the surgical technique ( anterior cortical window for placement ) and the method of tibial fixation likely explain this migration . Level of Evidence : Therapeutic , Level IV . See Guidelines for Authors for a complete description of levels of evidence Background : Forty-seven consecutive patients treated for ankle arthritis with a Sc and inavian total ankle replacement ( STAR ) by one surgeon were investigated retrospectively . Material s and Methods : A modification of the Foot Function Index ( FFI ) , which scores pain and task difficulties , was followed prospect ively . Patients were assessed clinical ly and radiologically . Failure was defined as revision of the prosthesis or arthrodesis for any reason . Results : In 47 patients ( 16 male , 31 female ) 49 total ankle replacements were carried out between May 1999 and June 2004 . Indication for surgery was end stage arthritis for rheumatoid arthritis in 29 cases , post-traumatic arthritis in 12 , osteoarthritis in five and arthritis secondary to degenerative flatfoot in three . Mean followup time was 28 ( 12 to 67 ) months . The modified FFI ( range , 0 to 100 , a high score meaning more pain and disability ) improved significantly from 59 before to 35 after surgery . The mean postoperative Kofoed ankle score was 68 . Sixteen procedures were complicated by fractures or temporary neurological damage . At the time of followup , 45 prostheses survived , while four replacements had failed . Radiological examination at followup showed radiolucent lines , osteolysis , and malposition of the components in 31 cases . Conclusion : Our results are comparable with those reported in the literature . The clinical outcome improved significantly . Due to aseptic and septic loosening , 8.2 % of the prosthesis failed Background : Because of specific method ological difficulties in conducting r and omized trials , surgical research remains dependent predominantly on observational or non‐r and omized studies . Few vali date d instruments are available to determine the method ological quality of such studies either from the reader 's perspective or for the purpose of meta‐ analysis . The aim of the present study was to develop and vali date such an instrument A Foot Function Index ( FFI ) was developed to measure the impact of foot pathology on function in terms of pain , disability and activity restriction . The FFI is a self-administered index consisting of 23 items divided into 3 sub-scales . Both total and sub-scale scores are produced . The FFI was examined for test-retest reliability , internal consistency , and construct and criterion validity . A total of 87 patients with rheumatoid arthritis were used in the study .  Test-retest reliability of the FFI total and sub-scale scores ranged from 0.87 to 0.69 . Internal consistency ranged from 0.96 to 0.73 . With the exception of two items , factor analysis supported the construct validity of the total index and the sub-scales . Strong correlation between the FFI total and sub-scale scores and clinical measures of foot pathology supported the criterion validity of the index . The FFI should prove useful for both clinical and research purpose The established treatment for severe rheumatoid arthritis in the ankle is arthrodesis . Numerous reports in the literature describe outcomes in patients with degenerative and posttraumatic arthrosis and rheumatoid disease . This has led to results that are difficult to interpret . In addition , in the few studies that have evaluated patients with rheumatoid disease many techniques of arthrodesis are reported , further confounding assessment of one fusion method . One technique of 20 ankle fusions in patients with rheumatoid disease was evaluated . A modified Wagner arthrodesis was used through a transfibular approach using parallel compression screws . The scoring systems of Mazur et al , Moran et al , and the Short-Form-36 were used to evaluate the outcome . The mean time to followup was 3 years 10 months . Eighteen of 20 fusions obtained a solid talocrural union ( 90 % ) . No correlation was found between the scores of Mazur et al and Moran et al. Correlation was achieved between the scores for the Short Form-36 and Moran et al. The modified Wagner ankle arthrodesis is a simple , reliable , reproducible technique with a 90 % union rate . The value of the technique has been confirmed in patients with rheumatoid arthritis by evaluating the outcome using a scoring system that is vali date d and relevant to this population We report a new method of ankle arthrodesis which combines an anterior approach with a dowel technique of bone grafting and screw fixation . In 20 ankles of 20 patients , ten with osteoarthritis , eight with rheumatoid arthritis and two others , we achieved 19 solid bony fusions  and one painless fibrous ankylosis . The average time to union was 12.5 weeks . Patient satisfaction was high and the functional results were as good as for other reported methods , with fewer complications Research on surgical interventions is associated with several method ological and practical challenges of which few , if any , apply only to surgery . However ,  surgical evaluation  is especially dem and ing because many of these challenges coincide . In this report , the second of three on surgical innovation and evaluation , we discuss obstacles related to the study design of r and omised controlled trials and non-r and omised studies assessing surgical interventions . We also describe the issues related to the nature of surgical procedures -for example , their complexity , surgeon-related factors , and the range of outcomes . Although difficult , surgical evaluation is achievable and necessary . Solutions tailored to surgical research and a framework for generating evidence on which to base surgical practice are essential 
    Output:
    
agent
Regardless of the method ological limitations it can be concluded that both interventions show clinical improvement and in line with current literature neither procedure is superior to the other
***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: Background : Mobile-bearing ankle replacements have become popular outside of the United States over the past two decades . The goal of the present study was to perform a prospect i ve evaluation of the safety and efficacy of a mobile-bearing prosthesis to treat end stage ankle arthritis . We report the results of three separate cohorts of patients : a group of Sc and anavian Total Ankle Replacement ( STAR ) patients and a control group of ankle fusion patients ( the Pivotal Study Groups ) and another group of STAR total ankle patients ( Continued Access Group ) whose surgery was performed following the completion of enrollment in the Pivotal Study . Material s and Methods : The Pivotal Study design was a non-inferiority study using ankle fusion as the control . A non-r and omized multi-centered design with concurrent fusion controls was used . We report the initial perioperative findings up to 24 months following surgery . For an individual patient to be considered an overall success , all of the following criteria needed to be met : a ) a 40-point improvement in total Buechel-Pappas ankle score , b ) no device failures , revisions , or removals , c ) radiographic success , and d ) no major complications . In the Pivotal Study ( 9/00 to 12/01 ) , 158 ankle replacement and 66 arthrodesis procedures were performed ; in the Continued Access Study ( 4/02 to 10/06 ) , 448 ankle replacements were performed , of which 416 were at minimum 24 months post-surgery at time of the data base closure . Results : Major complications and need for secondary surgical intervention were more common in the Pivotal Study arthroplasty group than the Pivotal Study ankle fusion group . In the Continued Access Group , secondary procedures performed on these arthroplasty patients decreased by half when compared with the Pivotal Arthroplasty Group . When the Pivotal Groups were compared , treatment efficacy was higher for the ankle replacement group due to improvement in functional scores . Pain relief was equivalent between fusion and replacement patients . The hypothesis of non-inferiority of ankle replacement was met for overall patient success . Conclusion : By 24 months , ankles treated with STAR ankle replacement ( in both the Pivotal and Continued Access Groups ) had better function and equivalent pain relief as ankles treated with fusion . Level of Evidence : II , Prospect i ve Controlled Comparative Surgical BACKGROUND Interest in mobile-bearing total ankle arthroplasty  has increased in recent years . However , to our knowledge , no study has focused exclusively on patients with the diagnosis of inflammatory joint disease or has provided a detailed analysis of the risk factors for failure . METHODS A prospect i ve observational study of the results of cementless mobile-bearing total ankle arthroplasty  in patients with inflammatory joint disease ( mainly rheumatoid arthritis ) was conducted at two centers . Ninety-three total ankle arthroplasties were performed . The LCS ( low contact stress ) prosthesis was used initially , in nineteen ankles , between 1988 and 1992 , and a modification of the LCS prosthesis , the Buechel-Pappas design , was used in seventy-four ankles between 1993 and 1999 . Clinical and radiographic follow-up was performed at yearly intervals . Three clinical scoring systems were used , and any complication was recorded throughout follow-up . Actuarial survival ( with revision as the end point ) , multivariate analysis , and a competing risk approach were used to describe the long-term outcome . RESULTS The clinical result at one year after surgery showed a significant improvement in the scores on all three scoring systems ( p < 0.05 ) . Ankle dorsiflexion ( mean , 7 degrees ) also improved significantly ( p < 0.05 ) compared with the preoperative state . The most frequent complication was a malleolar fracture , which occurred in twenty ankles . Only when it occurred in combination with a deformity in the frontal plane did this complication have an adverse effect on the end result . At a mean follow-up of eight years , seventeen patients ( twenty-one ankles ) had died and fifteen ankles had been revised because of aseptic loosening ( six ankles ) , primary or secondary axial deformity with edge-loading ( six ankles ) , deep infection ( two ankles ) , and a severe wound-healing problem ( one ankle ) , leaving fifty-seven ankles ( 61 % ) that were evaluated . The mean overall survival rate at eight years was 84 % . An increased failure rate was encountered in ankles with a preoperative deformity in the frontal plane of > 10 degrees ( p = 0.03 ) and in ankles in which an undersized tibial component had been implanted ( p = 0.02 ) . CONCLUSIONS Mobile-bearing total ankle arthroplasty is a valid treatment option for the rheumatoid ankle if proper indications are used . Aseptic loosening and persistent deformity are the most important modes of failure Interest in mobile-bearing total ankle arthroplasty has increased in recent years . Clinical studies show favorable but varying results , with survival rates between 70 % and 90 % at 10-year followup . Design -specific differences in early migration patterns might explain variations in the results and modes of failure . Using radiostereometric analysis ( RSA ) we prospect ively followed 15 RA patients with a cementless mobile-bearing total ankle arthroplasty .  The American Orthopaedic Foot and Ankle Society ankle score and radiostereometric radiographs  were evaluated immediately postoperatively , 6 weeks postoperatively , 3 months , 6 months , and 12 months postoperatively and yearly thereafter . The postoperative clinical results improved . We observed increased migration of the tibial component during the first 3 months , but this stabilized by the 6 month followup . The mean lateral-medial migration was 0.8 mm , distal-proximal migration was 0.9 mm , and posteroanterior migration was −0.5 mm . The latter implies the total result ant migration was in anterior and valgus tilting of this tibial component . However , migration stabilized at 6 months postoperatively . We believe the surgical technique ( anterior cortical window for placement ) and the method of tibial fixation likely explain this migration . Level of Evidence : Therapeutic , Level IV . See Guidelines for Authors for a complete description of levels of evidence Background : Forty-seven consecutive patients treated for ankle arthritis with a Sc and inavian total ankle replacement ( STAR ) by one surgeon were investigated retrospectively . Material s and Methods : A modification of the Foot Function Index ( FFI ) , which scores pain and task difficulties , was followed prospect ively . Patients were assessed clinical ly and radiologically . Failure was defined as revision of the prosthesis or arthrodesis for any reason . Results : In 47 patients ( 16 male , 31 female ) 49 total ankle replacements were carried out between May 1999 and June 2004 . Indication for surgery was end stage arthritis for rheumatoid arthritis in 29 cases , post-traumatic arthritis in 12 , osteoarthritis in five and arthritis secondary to degenerative flatfoot in three . Mean followup time was 28 ( 12 to 67 ) months . The modified FFI ( range , 0 to 100 , a high score meaning more pain and disability ) improved significantly from 59 before to 35 after surgery . The mean postoperative Kofoed ankle score was 68 . Sixteen procedures were complicated by fractures or temporary neurological damage . At the time of followup , 45 prostheses survived , while four replacements had failed . Radiological examination at followup showed radiolucent lines , osteolysis , and malposition of the components in 31 cases . Conclusion : Our results are comparable with those reported in the literature . The clinical outcome improved significantly . Due to aseptic and septic loosening , 8.2 % of the prosthesis failed Background : Because of specific method ological difficulties in conducting r and omized trials , surgical research remains dependent predominantly on observational or non‐r and omized studies . Few vali date d instruments are available to determine the method ological quality of such studies either from the reader 's perspective or for the purpose of meta‐ analysis . The aim of the present study was to develop and vali date such an instrument A Foot Function Index ( FFI ) was developed to measure the impact of foot pathology on function in terms of pain , disability and activity restriction . The FFI is a self-administered index consisting of 23 items divided into 3 sub-scales . Both total and sub-scale scores are produced . The FFI was examined for test-retest reliability , internal consistency , and construct and criterion validity . A total of 87 patients with rheumatoid arthritis were used in the study .  Test-retest reliability of the FFI total and sub-scale scores ranged from 0.87 to 0.69 . Internal consistency ranged from 0.96 to 0.73 . With the exception of two items , factor analysis supported the construct validity of the total index and the sub-scales . Strong correlation between the FFI total and sub-scale scores and clinical measures of foot pathology supported the criterion validity of the index . The FFI should prove useful for both clinical and research purpose The established treatment for severe rheumatoid arthritis in the ankle is arthrodesis . Numerous reports in the literature describe outcomes in patients with degenerative and posttraumatic arthrosis and rheumatoid disease . This has led to results that are difficult to interpret . In addition , in the few studies that have evaluated patients with rheumatoid disease many techniques of arthrodesis are reported , further confounding assessment of one fusion method . One technique of 20 ankle fusions in patients with rheumatoid disease was evaluated . A modified Wagner arthrodesis was used through a transfibular approach using parallel compression screws . The scoring systems of Mazur et al , Moran et al , and the Short-Form-36 were used to evaluate the outcome . The mean time to followup was 3 years 10 months . Eighteen of 20 fusions obtained a solid talocrural union ( 90 % ) . No correlation was found between the scores of Mazur et al and Moran et al. Correlation was achieved between the scores for the Short Form-36 and Moran et al. The modified Wagner ankle arthrodesis is a simple , reliable , reproducible technique with a 90 % union rate . The value of the technique has been confirmed in patients with rheumatoid arthritis by evaluating the outcome using a scoring system that is vali date d and relevant to this population We report a new method of ankle arthrodesis which combines an anterior approach with a dowel technique of bone grafting and screw fixation . In 20 ankles of 20 patients , ten with osteoarthritis , eight with rheumatoid arthritis and two others , we achieved 19 solid bony fusions  and one painless fibrous ankylosis . The average time to union was 12.5 weeks . Patient satisfaction was high and the functional results were as good as for other reported methods , with fewer complications Research on surgical interventions is associated with several method ological and practical challenges of which few , if any , apply only to surgery . However ,  surgical evaluation  is especially dem and ing because many of these challenges coincide . In this report , the second of three on surgical innovation and evaluation , we discuss obstacles related to the study design of r and omised controlled trials and non-r and omised studies assessing surgical interventions . We also describe the issues related to the nature of surgical procedures -for example , their complexity , surgeon-related factors , and the range of outcomes . Although difficult , surgical evaluation is achievable and necessary . Solutions tailored to surgical research and a framework for generating evidence on which to base surgical practice are essential 
    Output:
    