***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 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 Background : Recent literature has demonstrated that involvement in pivoting sports at the time of injury , increased posterior-inferior tibial slope ( PITS ) , anterolateral capsular ligament ( ALCL ) disruptions , and combined lateral meniscal lesions all contribute to a higher grade of pivot shift after acute anterior cruciate ligament ( ACL ) injuries . Purpose : To identify risk factors associated with grade 3 pivot shift after acute ACL injuries . Study Design : Case-control study ; Level of evidence , 3 . Methods : A data base of patients undergoing primary ACL reconstruction from 2009 to 2015 after acute ACL injuries was retrospectively review ed . A total of 30 patients ( 30 knees ) with grade 3 pivot shift were identified as the study group . Moreover , 30 patients ( 30 knees ) with grade 1 and 30 patients ( 30 knees ) with grade 2 pivot shift were r and omly chosen as the 2 control groups . All pivot-shift tests were performed with the patients under anesthesia . Predictors of grade 3 pivot shift that were explored included patient age , sex , time from injury to surgery , pivoting sports involvement at the time of injury , lateral PITS , medial PITS , ALCL disruptions , preoperative KT-1000 arthrometer side-to-side difference , and combined lateral or medial meniscal lesions . Comparisons were performed between the study group and the 2 control groups . Univariable and multivariable logistic regressions were used to identify independent risk factors that were associated with grade 3 pivot shift . Results : Univariable and multivariable logistic regressions between the study group and the 2 control groups showed that  pivoting sports involvement  at the time of injury ( odds ratio1 [ OR1 ; grade 3 vs grade 1 pivot shift with grade 1 = reference ] , 11.88 ; 95 % CI , 1.94 - 149.91 ; OR2 [ grade 3 vs grade 2 pivot shift with grade 2 = reference ] , 3.41 ; 95 % CI , 1.92 - 22.60 ) , abnormal degree of lateral PITS ( OR1 , 14.41 ; 95 % CI , 1.69 - 174.78 ; OR2 , 6.41 ; 95 % CI , 1.48 - 47.70 ) , ALCL disruptions ( OR1 , 8.28 ; 95 % CI , 1.71 - 117.14 ; OR2 , 4.96 ; 95 % CI , 1.07 - 28.75 ) , and combined lateral meniscal lesions ( OR1 , 27.56 ; 95 % CI , 5.48 - 240.52 ; OR2 , 5.83 ; 95 % CI , 1.21 - 38.56 ) were independent risk factors of grade 3 pivot shift after acute ACL injuries . Conclusion : For acute ACL injuries , the best set of predictors of grade 3 pivot shift were pivoting sports involvement at the time of injury , abnormal lateral PITS , ALCL disruptions , and combined lateral meniscal lesions . These results may provide additional information for counseling patients on residual laxity and risks for graft rerupture after ACL reconstruction Background The risk of tear of the intact anterior cruciate ligament in the contralateral knee after anterior cruciate ligament reconstruction of the opposite knee and the incidence of rupturing the anterior cruciate ligament graft during the first 2 years after surgery have not been extensively studied in a prospect i ve manner . Clinicians have hypothesized that the opposite normal knee is at equal or increased risk compared with the risk of anterior cruciate ligament graft rupture in the operated knee . Hypothesis The risk of anterior cruciate ligament graft rupture and contralateral normal knee anterior cruciate ligament rupture at 2-year follow-up is equal . Study Design Cohort study ; Level of evidence , 2 . Methods The Multicenter Orthopaedic Outcome Network ( MOON ) data base of a prospect i ve longitudinal cohort of anterior cruciate ligament reconstructions  was used to determine the number of anterior cruciate ligament graft ruptures  and tears of the intact anterior cruciate ligament in the contralateral knee at 2-year follow-up . Two-year follow-up consisted of a phone interview and review of operative reports . Results Two-year data were obtained for 235 of 273 patients ( 86 % ) . There were 14 ligament disruptions . Of these , 7 were tears of the intact anterior cruciate ligament in the contralateral knee ( 3.0 % ) and 7 were anterior cruciate ligament graft failures ( 3.0 % ) . Conclusion The contralateral normal knee anterior cruciate ligament is at a similar risk of anterior cruciate ligament tear ( 3.0 % ) as the anterior cruciate ligament graft after primary anterior cruciate ligament reconstruction ( 3.0 % ) Background : There is a lack of prospect i ve studies comparing the long-term outcome of endoscopic  anterior cruciate ligament ( ACL ) reconstruction  with either a patellar tendon or hamstring tendon autograft . Purpose : This prospect i ve longitudinal study compared the results of isolated endoscopic ACL reconstruction utilizing a 4-str and hamstring tendon ( HT ) or patellar tendon ( PT ) autograft over a 15-year period with respect to reinjury , clinical outcomes , and the development of osteoarthritis . Study Design : Cohort study ; Level of evidence , 2 . Methods : Ninety consecutive patients with isolated ACL rupture were reconstructed  with a PT autograft , and 90 patients received an HT autograft  , with an identical surgical technique . Patients were assessed at 2 , 5 , 7 , 10 , and 15 years . Assessment included the International Knee Documentation Committee ( IKDC ) knee ligament evaluation including radiographic evaluation , KT-1000 arthrometer testing , and Lysholm knee score . Results : Patients who received the PT graft had significantly worse outcomes compared with those who received the HT graft at 15 years for the variables of radiologically detectable osteoarthritis ( grade A : 46 % in PT and 69 % in HT ; P = .04 ) , motion loss ( extension deficit < 3 ° : 79 % in PT and 94 % in HT ; P = .03 ) , single-legged hop test ( grade A : 65 % in PT and 92 % in HT ; P = .001 ) , participation in strenuous activity ( very strenuous or strenuous : 62 % of PT and 77 % of HT ; P = .04 ) , and kneeling pain ( moderate or greater pain : 42 % of PT and 26 % of HT ; P = .04 ) . There was no significant difference between the HT and PT groups in overall IKDC grade ( grade A : 47 % of PT and 57 % of HT ; P = .35 ) . An ACL graft rupture occurred in 17 % of the HT group and 8 % of the PT group ( P = .07 ) . An ACL graft rupture was associated with nonideal tunnel position ( odds ratio [ OR ] , 5.0 ) and male sex ( OR , 3.2 ) . Contralateral ACL rupture occurred in significantly more PT patients ( 26 % ) than HT patients ( 12 % ) ( P = .02 ) and was associated with age ≤18 years ( OR , 4.1 ) and the PT graft ( OR , 2.6 ) . Conclusion : Anterior cruciate ligament reconstruction using ipsilateral autograft continues to show excellent results in terms of patient satisfaction , symptoms , function , activity level , and stability . The use of HT autograft does , however , show better outcomes than the PT autograft in all of these outcome measures . Additionally , at 15 years , the HT graft – reconstructed ACLs have shown a lower rate of radiological osteoarthritis Background : There is recent evidence that use of allograft tendons for anterior cruciate ligament ( ACL ) reconstruction in young patients may result in increased failure rates compared with autologous grafts . Hypothesis : Allograft ACL reconstruction will result in higher failure rates in young athletes compared with autograft reconstruction . Study Design : Cohort study ; Level of evidence , 2 . Methods : A prospect i ve cohort study of cadets at the United States Military Academy ( USMA ) was performed to assess performance of ACL reconstructions performed before entrance to service . Members of the classes of 2007 through 2013 who had undergone prior ACL reconstruction were identified through the Department of Defense Medical Evaluation Review Board reporting and waiver process and evaluated on the first day of matriculation . These participants were followed during their tenure at the academy with revision ACL reconstruction as the primary outcome measure of interest . Kaplan-Meier survival analysis was performed for all graft types using STATA with significance set as P < .05 . Results : A total of 120 cadets underwent 122 ACL reconstructions  ( 2 bilateral ) before matriculation and compose the prospect i ve cohort . This cohort included 30 female and 90 male cadets . Of these 122 knees with prior ACL reconstructions , the grafts used were 61 bone – patellar tendon – bone ( BTB ) , 45 hamstring , and 16 allograft . A total of 20 failures occurred among this cohort at an average of 545 days from matriculation . Of the failures requiring revision , 7 were BTB ( 11 % of all BTB ) , 7 were allograft ( 44 % of all allograft ) , and 6 were hamstring ( 13 % of all hamstring ) . There was no significant difference in the graft failure between the BTB and hamstring autograft groups . In contrast , those who entered the USMA with an allograft were 7.7 times more likely to experience a subsequent graft failure during the follow-up period when compared with the BTB autograft group ( hazard ratio = 7.74 ; 95 % confidence interval [ CI ] , 2.67 - 22.38 ; P < .001 ) . When allografts were compared with all autografts combined , a similar increase failure was noted in the allograft group ( hazard ratio = 6.71 ; 95 % CI , 2.64 - 17.06 ; P < .001 ) . Conclusion : In this young active cohort , individuals having undergone an allograft ACL reconstruction were significantly more likely to experience clinical failure requiring revision reconstruction compared with those who underwent autologous graft reconstruction . The authors recommend the use of autograft in  ACL reconstruction  in young athletes Background : The aim of this prospect i ve r and omized study was to compare the outcomes of the anatomic double-bundle ( DB ) and anatomic single-bundle ( SB ) techniques 5 years after anterior cruciate ligament ( ACL ) reconstruction . Since more effective restoration of rotational laxity is considered the main advantage of the DB technique , the pivot-shift test was the primary outcome variable of the study . Hypothesis : Double-bundle ACL reconstruction will result in a better outcome in terms of the pivot-shift test . Study Design : R and omized controlled trial ; Level of evidence , 1 . Method 
    Output:
    
In 2017 , it is not clear if an anterolateral ligament reconstruction is needed in the setting of primary anterior cruciate ligament reconstruction