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 . This study documented postoperative morbidity during the first 4 months following  anterior cruciate ligament ( ACL ) reconstruction  using either patellar tendon or hamstring tendon autograft .  Sixty-five patients undergoing primary arthroscopically assisted single-incision ACL reconstruction  were r and omized to have a central third bone patellar tendon bone autograft ( PT ) or a doubled semitendinosus/doubled gracilis autograft ( HS ) . Postoperatively patients undertook a st and ard ' accelerated ' rehabilitation protocol . Patients were review ed after 2 weeks , 8 weeks , and 4 months . At each review the location and severity of general knee pain and the presence and severity of anterior knee pain ( AKP ) were recorded as were the presence and size of an effusion as well as the active and passive flexion and passive extension deficits compared to the contralateral limb . Pain on kneeling , KT-1000 measured side to side difference in anterior tibial displacement , isokinetic assessment of quadriceps and hamstring peak torque deficits , IKDC score and Cincinnati sports activity level were also recorded after 4 months . After 2 weeks more patients in the PT group complained of AKP and reported that the pain was more severe . After 8 weeks there was no significant difference between the groups for any variable . After 4 months the severity of general pain experienced and the incidence of pain on kneeling were greater in the PT group . The PT group also demonstrated a significantly greater quadriceps peak torque deficit at 240 ° /s . IKDC scores were higher in the HS group , but Cincinnati sports activity scores were higher in the PT group . Although we observed a lower morbidity in the HS group , primarily related to pain , the severity of pain in both groups was relatively low and , in light of the higher mean sports activity level observed in the PT group at 4 months the clinical impact of the difference may not be significant BACKGROUND There are no controlled , prospect i ve studies comparing the 10-year outcomes of anterior cruciate ligament ( ACL ) reconstruction using patellar tendon ( PT ) and 4-str and hamstring tendon ( HT ) autografts . HYPOTHESIS Comparable results are possible with HT and PT autografts . STUDY DESIGN Cohort study ; Level of evidence , 2 . METHODS One hundred eighty ACL-deficient knees that met inclusion criteria underwent ACL reconstruction ( 90 HT autograft , 90 PT autograft ) by one surgeon and were treated with an accelerated rehabilitation program . All knees were observed in a prospect i ve fashion with subjective , objective , and radiographic evaluation at 2 , 5 , 7 , and 10-year intervals . RESULTS At 10 years , there were no differences in graft rupture rates ( 7/90 PT vs. 12/90 HT , P = .24 ) . There were 20 contralateral ACL ruptures in the PT group , compared with 9 in the HT group ( P = .02 ) . In all patients , graft rupture was associated with instrumented laxity > 2 mm at 2 years ( P = .001 ) . Normal or near-normal function of the knee was reported in 97 % of patients in both groups . In the PT group , harvest-site symptoms ( P = .001 ) and kneeling pain ( P = .01 ) were more common than in the HT group . More patients reported pain with strenuous activities in PT knees than in HT knees ( P = .05 ) . Radiographic osteoarthritis was more common in PT knees than the HT-reconstructed knees ( P = .04 ) . The difference , however , was composed of patients with mild osteoarthritis . Other predictors of radiographic osteoarthritis were < 90 % single-legged hop test at 1 year and the need for further knee surgery . An " ideal " outcome , defined as an overall International Knee Documentation Committee grade of A or B and a radiographic grade of A at 10 years after ACL reconstruction , was associated with <3 mm of instrumented laxity at 2 years , the absence of additional surgery in the knee , and HT grafts . CONCLUSIONS It is possible to obtain excellent results with both HT and PT autografts . We recommend HT reconstructions to our patients because of decreased harvest-site symptoms and radiographic osteoarthritis Two commercially available knee ligament arthrometers ( KT-1000 MEDmetric Corporation , San Diego , California and Kneelax MR Systems , Haarlem , The Netherl and s ) were used to measure anterior tibial translation . In this study 91 subjects with no history of knee pathology were tested using both devices . Both normal knees were tested and comparison of recorded anterior translation ( millimeters ) was performed . Absolute numbers at forces of 67N , 89N , 134N , and manual maximum displacements were recorded . Side-to-side differences were calculated and data were compared . There was a significant difference found between the absolute values of each device . The KT-1000 was found to record greater values in millimeters of translation . Although the absolute values were significantly different , the side-to-side differences were not significantly different between devices Background : Numerous studies have compared patellar tendon ( PT ) and hamstring tendon ( HS ) anterior cruciate ligament ( ACL ) reconstructions in the short to midterm , but fewer long-term results have been published . Hypothesis : There will be no difference in functional outcome between ACL reconstruction performed with PT and HS grafts , but PT grafts will have more donor site morbidity . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : Sixty-five patients undergoing ACL reconstruction were r and omized to receive either a PT graft or a 4-str and HS graft . Early results were reported at 4 , 8 , 12 , 24 , and 36 months . Forty-seven patients ( 22 of 31 PT and 25 of 34 HS ) were review ed at a mean of 15.3 years . Results : Four graft ruptures ( 1 PT , 3 HS ) and 6 contralateral ACL injuries ( 4 PT , 2 HS ) occurred in the group that was review ed . There was no statistically significant difference between the groups for any of the variables measured . There was a similar incidence of anterior knee pain and kneeling pain in both groups . The previously observed increased extension deficit in the PT group at 3 years was not present at 15 years , and there was no significant between-group difference in knee laxity . A higher proportion of patients in the PT group were participating in sport on a weekly basis ( 73 % PT , 48 % HS ; P = .05 ) . There was no difference in the degree of osteoarthritis between the groups . Conclusion : This r and omized controlled trial showed that HS and PT ACL reconstructions have comparable results at an average 15-year follow-up . Contrary to the study hypothesis , some of the graft differences seen at earlier review were not present at 15 years , and patients with PT grafts were more active in sport participation . Overall , both graft types provided good long-term subjective and objective outcomes Background : Short-term and mid-term differences between hamstring and patellar tendon autografts for anterior cruciate ligament ( ACL ) reconstruction are well documented . Systematic review s highlight the lack of long-term results between the two grafts . Hypothesis : Seventeen years after ACL reconstruction , no difference will be found in functional outcome , quality of life , and graft failure between patients with patellar tendon ( PT ) or semitendinosus and gracilis tendon ( STG ) autografts ;  however , a significant difference will be seen in the prevalence of osteoarthritis . Study Design : R and omized controlled trial ; Level of evidence , 2 . Methods : Sixty-four patients were included in this prospect i ve study ( 32 in each group ) . A single surgeon performed primary ACL reconstruction in alternating sequence . Forty-eight patients ( 24 in each group ) were evaluated 17 years after ACL reconstruction :  A clinical assessment was made based on the International Knee Documentation Committee ( IKDC ) form , instrumented laxity was measured with KT-1000 arthrometer , and radiography of the operated knee was conducted and assessed for degenerative disease . The Lysholm question naire and the Short Form–36 version 2 question naire were filled out by the patients . Results : At the 17-year follow-up , no statistically significant differences were seen with respect to graft failure ( 2 reruptures in the semitendinosus and gracilis tendon [ STG ] group [ 6.3 % ] and 3 reruptures in the PT group [ 9.4 % ] ) and functional outcome . Increased instrumented laxity ( > 3 mm ) measured with KT-1000 arthrometer was seen in significantly more patients in the STG group ( 8 in the STG group compared with 2 in the PT group ; P = .03 ) with a mean side-to-side difference of 2.17 ± 1.86 mm in the STG group compared with 1.33 ± 1.93 mm in the PT group . A significant difference was found in frequency of knee osteoarthritis (OA)—100 % in the PT group compared with 71 % in the STG group ( P = .004 ) . Patients in the PT group tended to have higher grade OA according to the IKDC grading system , with an average grade of 1.46 in the PT group compared with 1 in the STG group ( P = .055 ) . The degenerative changes in the PT group were more common in the medial and patellofemoral compartments ( P = .003 and P = .04 , respectively ) . Conclusion : Both autografts provided good to excellent subjective outcomes . No significant differences were noted in graft failure and clinical instability . However , significantly more patients in the STG group had increased instrumented anteroposterior translation measured with KT-1000 arthrometer , and there was a greater prevalence of knee OA at 17 years after surgery in the PT group Background Functional outcome question naires have become a common part of patient follow-up in the orthopaedic community . The modified Cincinnati Knee Rating System and the International Knee Documentation Committee ( IKDC ) subjective scale were design ed to provide clinicians with information regarding a patient ’s functional and clinical status after knee surgery . Hypothesis The functional outcome data reported on the modified Cincinnati Knee Rating System and the IKDC subjective question naire are equivalent . Study Design Cohort study ( diagnosis ) ; Level of evidence , 2 . Methods Between 2000 and 2007 , all patients with complex knee disorders seen in our orthopaedic clinic were prospect ively followed and given simultaneously the modified Cincinnati Knee Rating System and the IKDC subjective question naires to report their functional outcomes . The total scores of each instrument were compared at each time of evaluation . As a measure of responsiveness , the st and ardized response means were calculated . A second within-patient analysis was also performed to determine if the results would be different when looked at by the patient . Results There were a total of 130 patients with a total of 444 modified Cincinnati Knee Rating System question naires and 462 IKDC subjective complete question naires included in the study .  Overall total scores on both the modified Cincinnati Knee Rating System and the IKDC subjective question naires were equivalent in a population analysis . Overall total scores showed improvement in function over time from preoperative measurement through the 2-year follow-up . The individual patient analysis demonstrated that , for a specific patient , it was possible that up to 34 % of the population would report a total score of more than 10 points difference , depending on the scale selected . Conclusion The modified Cincinnati Knee Rating System and the IKDC subjective rating question naires reported by patient population provide similar results . The practitioner who is not performing a population -based study but following individual patients for recovery will find that the individual question naires may offer different functional limitations . Individual differences were lost in the population means , with the approximate balance of positive and negative score differences masking the individual patient differences PURPOSE To evaluate the subjective outcomes , knee stability , and donor-site morbidity after  revision ACL reconstruction using either autologous ipsilateral quadriceps tendon or contralateral semitendinosus-gracilis tendon . METHODS A sample size calculation suggested that we needed 25 patients in each group to detect e quality between both groups . Therefore , we evaluated 30 consecutive patients who underwent an ACL revision surgery with ipsilateral bone-quadriceps tendon grafts and 30 consecutive patients with the contralateral semitendinosus-gracilis grafts between January 2010 and December 2012 . Because of follow-up and exclusion criteria , finally 51 patients were evaluated . All patients were followed prospect ively for at least 2 years with KT1000 arthrometer testing and the International Knee Documentation Committee ( IKDC ) objective grading . At the 24-month follow-up , additional clinical scores were evaluated : the Knee Injury Osteoarthritis Outcome Score ( KOOS ) , the Lysholm score , assessing pain during kneeling , and anterior knee pain . RESULTS The KT1000 postoperative arthrometer side-to-side difference was 2.0 ± 1.2 mm for the quadriceps group and 3.0 ± 2.9 mm for the semitendinosus-gracilis group . The difference was not statistically significant ( P = .461 ) . There was also no difference in the rate of positive pivot-shift tests between groups ( P = .661 ) . The Lysholm score was 82.5 ± 18 in the quadriceps group and 73.8 
    Output:
    
agent
The QT autograft detected comparable rate of Lachman test > 3 mm , Pivot shift test > 3 m and instrumental laxity > 3 mm .
The QT autograft showed a lower rate of autograft failure above all .
The QT autograft detected the reduced rate of AKP than the PT .
Quadriceps tendon autograft may represent a feasible option for primary ACL reconstruction .
***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 . This study documented postoperative morbidity during the first 4 months following  anterior cruciate ligament ( ACL ) reconstruction  using either patellar tendon or hamstring tendon autograft .  Sixty-five patients undergoing primary arthroscopically assisted single-incision ACL reconstruction  were r and omized to have a central third bone patellar tendon bone autograft ( PT ) or a doubled semitendinosus/doubled gracilis autograft ( HS ) . Postoperatively patients undertook a st and ard ' accelerated ' rehabilitation protocol . Patients were review ed after 2 weeks , 8 weeks , and 4 months . At each review the location and severity of general knee pain and the presence and severity of anterior knee pain ( AKP ) were recorded as were the presence and size of an effusion as well as the active and passive flexion and passive extension deficits compared to the contralateral limb . Pain on kneeling , KT-1000 measured side to side difference in anterior tibial displacement , isokinetic assessment of quadriceps and hamstring peak torque deficits , IKDC score and Cincinnati sports activity level were also recorded after 4 months . After 2 weeks more patients in the PT group complained of AKP and reported that the pain was more severe . After 8 weeks there was no significant difference between the groups for any variable . After 4 months the severity of general pain experienced and the incidence of pain on kneeling were greater in the PT group . The PT group also demonstrated a significantly greater quadriceps peak torque deficit at 240 ° /s . IKDC scores were higher in the HS group , but Cincinnati sports activity scores were higher in the PT group . Although we observed a lower morbidity in the HS group , primarily related to pain , the severity of pain in both groups was relatively low and , in light of the higher mean sports activity level observed in the PT group at 4 months the clinical impact of the difference may not be significant BACKGROUND There are no controlled , prospect i ve studies comparing the 10-year outcomes of anterior cruciate ligament ( ACL ) reconstruction using patellar tendon ( PT ) and 4-str and hamstring tendon ( HT ) autografts . HYPOTHESIS Comparable results are possible with HT and PT autografts . STUDY DESIGN Cohort study ; Level of evidence , 2 . METHODS One hundred eighty ACL-deficient knees that met inclusion criteria underwent ACL reconstruction ( 90 HT autograft , 90 PT autograft ) by one surgeon and were treated with an accelerated rehabilitation program . All knees were observed in a prospect i ve fashion with subjective , objective , and radiographic evaluation at 2 , 5 , 7 , and 10-year intervals . RESULTS At 10 years , there were no differences in graft rupture rates ( 7/90 PT vs. 12/90 HT , P = .24 ) . There were 20 contralateral ACL ruptures in the PT group , compared with 9 in the HT group ( P = .02 ) . In all patients , graft rupture was associated with instrumented laxity > 2 mm at 2 years ( P = .001 ) . Normal or near-normal function of the knee was reported in 97 % of patients in both groups . In the PT group , harvest-site symptoms ( P = .001 ) and kneeling pain ( P = .01 ) were more common than in the HT group . More patients reported pain with strenuous activities in PT knees than in HT knees ( P = .05 ) . Radiographic osteoarthritis was more common in PT knees than the HT-reconstructed knees ( P = .04 ) . The difference , however , was composed of patients with mild osteoarthritis . Other predictors of radiographic osteoarthritis were < 90 % single-legged hop test at 1 year and the need for further knee surgery . An " ideal " outcome , defined as an overall International Knee Documentation Committee grade of A or B and a radiographic grade of A at 10 years after ACL reconstruction , was associated with <3 mm of instrumented laxity at 2 years , the absence of additional surgery in the knee , and HT grafts . CONCLUSIONS It is possible to obtain excellent results with both HT and PT autografts . We recommend HT reconstructions to our patients because of decreased harvest-site symptoms and radiographic osteoarthritis Two commercially available knee ligament arthrometers ( KT-1000 MEDmetric Corporation , San Diego , California and Kneelax MR Systems , Haarlem , The Netherl and s ) were used to measure anterior tibial translation . In this study 91 subjects with no history of knee pathology were tested using both devices . Both normal knees were tested and comparison of recorded anterior translation ( millimeters ) was performed . Absolute numbers at forces of 67N , 89N , 134N , and manual maximum displacements were recorded . Side-to-side differences were calculated and data were compared . There was a significant difference found between the absolute values of each device . The KT-1000 was found to record greater values in millimeters of translation . Although the absolute values were significantly different , the side-to-side differences were not significantly different between devices Background : Numerous studies have compared patellar tendon ( PT ) and hamstring tendon ( HS ) anterior cruciate ligament ( ACL ) reconstructions in the short to midterm , but fewer long-term results have been published . Hypothesis : There will be no difference in functional outcome between ACL reconstruction performed with PT and HS grafts , but PT grafts will have more donor site morbidity . Study Design : R and omized controlled trial ; Level of evidence , 1 . Methods : Sixty-five patients undergoing ACL reconstruction were r and omized to receive either a PT graft or a 4-str and HS graft . Early results were reported at 4 , 8 , 12 , 24 , and 36 months . Forty-seven patients ( 22 of 31 PT and 25 of 34 HS ) were review ed at a mean of 15.3 years . Results : Four graft ruptures ( 1 PT , 3 HS ) and 6 contralateral ACL injuries ( 4 PT , 2 HS ) occurred in the group that was review ed . There was no statistically significant difference between the groups for any of the variables measured . There was a similar incidence of anterior knee pain and kneeling pain in both groups . The previously observed increased extension deficit in the PT group at 3 years was not present at 15 years , and there was no significant between-group difference in knee laxity . A higher proportion of patients in the PT group were participating in sport on a weekly basis ( 73 % PT , 48 % HS ; P = .05 ) . There was no difference in the degree of osteoarthritis between the groups . Conclusion : This r and omized controlled trial showed that HS and PT ACL reconstructions have comparable results at an average 15-year follow-up . Contrary to the study hypothesis , some of the graft differences seen at earlier review were not present at 15 years , and patients with PT grafts were more active in sport participation . Overall , both graft types provided good long-term subjective and objective outcomes Background : Short-term and mid-term differences between hamstring and patellar tendon autografts for anterior cruciate ligament ( ACL ) reconstruction are well documented . Systematic review s highlight the lack of long-term results between the two grafts . Hypothesis : Seventeen years after ACL reconstruction , no difference will be found in functional outcome , quality of life , and graft failure between patients with patellar tendon ( PT ) or semitendinosus and gracilis tendon ( STG ) autografts ;  however , a significant difference will be seen in the prevalence of osteoarthritis . Study Design : R and omized controlled trial ; Level of evidence , 2 . Methods : Sixty-four patients were included in this prospect i ve study ( 32 in each group ) . A single surgeon performed primary ACL reconstruction in alternating sequence . Forty-eight patients ( 24 in each group ) were evaluated 17 years after ACL reconstruction :  A clinical assessment was made based on the International Knee Documentation Committee ( IKDC ) form , instrumented laxity was measured with KT-1000 arthrometer , and radiography of the operated knee was conducted and assessed for degenerative disease . The Lysholm question naire and the Short Form–36 version 2 question naire were filled out by the patients . Results : At the 17-year follow-up , no statistically significant differences were seen with respect to graft failure ( 2 reruptures in the semitendinosus and gracilis tendon [ STG ] group [ 6.3 % ] and 3 reruptures in the PT group [ 9.4 % ] ) and functional outcome . Increased instrumented laxity ( > 3 mm ) measured with KT-1000 arthrometer was seen in significantly more patients in the STG group ( 8 in the STG group compared with 2 in the PT group ; P = .03 ) with a mean side-to-side difference of 2.17 ± 1.86 mm in the STG group compared with 1.33 ± 1.93 mm in the PT group . A significant difference was found in frequency of knee osteoarthritis (OA)—100 % in the PT group compared with 71 % in the STG group ( P = .004 ) . Patients in the PT group tended to have higher grade OA according to the IKDC grading system , with an average grade of 1.46 in the PT group compared with 1 in the STG group ( P = .055 ) . The degenerative changes in the PT group were more common in the medial and patellofemoral compartments ( P = .003 and P = .04 , respectively ) . Conclusion : Both autografts provided good to excellent subjective outcomes . No significant differences were noted in graft failure and clinical instability . However , significantly more patients in the STG group had increased instrumented anteroposterior translation measured with KT-1000 arthrometer , and there was a greater prevalence of knee OA at 17 years after surgery in the PT group Background Functional outcome question naires have become a common part of patient follow-up in the orthopaedic community . The modified Cincinnati Knee Rating System and the International Knee Documentation Committee ( IKDC ) subjective scale were design ed to provide clinicians with information regarding a patient ’s functional and clinical status after knee surgery . Hypothesis The functional outcome data reported on the modified Cincinnati Knee Rating System and the IKDC subjective question naire are equivalent . Study Design Cohort study ( diagnosis ) ; Level of evidence , 2 . Methods Between 2000 and 2007 , all patients with complex knee disorders seen in our orthopaedic clinic were prospect ively followed and given simultaneously the modified Cincinnati Knee Rating System and the IKDC subjective question naires to report their functional outcomes . The total scores of each instrument were compared at each time of evaluation . As a measure of responsiveness , the st and ardized response means were calculated . A second within-patient analysis was also performed to determine if the results would be different when looked at by the patient . Results There were a total of 130 patients with a total of 444 modified Cincinnati Knee Rating System question naires and 462 IKDC subjective complete question naires included in the study .  Overall total scores on both the modified Cincinnati Knee Rating System and the IKDC subjective question naires were equivalent in a population analysis . Overall total scores showed improvement in function over time from preoperative measurement through the 2-year follow-up . The individual patient analysis demonstrated that , for a specific patient , it was possible that up to 34 % of the population would report a total score of more than 10 points difference , depending on the scale selected . Conclusion The modified Cincinnati Knee Rating System and the IKDC subjective rating question naires reported by patient population provide similar results . The practitioner who is not performing a population -based study but following individual patients for recovery will find that the individual question naires may offer different functional limitations . Individual differences were lost in the population means , with the approximate balance of positive and negative score differences masking the individual patient differences PURPOSE To evaluate the subjective outcomes , knee stability , and donor-site morbidity after  revision ACL reconstruction using either autologous ipsilateral quadriceps tendon or contralateral semitendinosus-gracilis tendon . METHODS A sample size calculation suggested that we needed 25 patients in each group to detect e quality between both groups . Therefore , we evaluated 30 consecutive patients who underwent an ACL revision surgery with ipsilateral bone-quadriceps tendon grafts and 30 consecutive patients with the contralateral semitendinosus-gracilis grafts between January 2010 and December 2012 . Because of follow-up and exclusion criteria , finally 51 patients were evaluated . All patients were followed prospect ively for at least 2 years with KT1000 arthrometer testing and the International Knee Documentation Committee ( IKDC ) objective grading . At the 24-month follow-up , additional clinical scores were evaluated : the Knee Injury Osteoarthritis Outcome Score ( KOOS ) , the Lysholm score , assessing pain during kneeling , and anterior knee pain . RESULTS The KT1000 postoperative arthrometer side-to-side difference was 2.0 ± 1.2 mm for the quadriceps group and 3.0 ± 2.9 mm for the semitendinosus-gracilis group . The difference was not statistically significant ( P = .461 ) . There was also no difference in the rate of positive pivot-shift tests between groups ( P = .661 ) . The Lysholm score was 82.5 ± 18 in the quadriceps group and 73.8 
    Output:
    