***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: The purpose of this study is to clinical ly evaluate hamstring tendon anterior cruciate ligament (ACL)-reconstruction using femoral fixation with bioresorbable interference screws and with a bioresorbable transfixation device . The ACL-reconstruction using the transfixation device at the femoral side leads to less knee laxity and therefore to a better clinical outcome for the patient . Prospect i ve r and omized clinical outcome study . From February 2002 to December 2002 , a total of 68 patients with hamstring ACL reconstruction using a femoral fixation once with TransFix ( n=38 ; m:22 and f:16 ; median age=28.5 range 15–47 ) and the second with bioscrew ( BS ) ( n=30 ; m:20 , f:10 ; median age=25.5 range 13–61 ) completed the follow-up period . Patients in each group got a clinical assessment at 3 , 6 , and 12 months after surgery . The measurement of anterior translation of the tibia has been performed using the Rolimeter ® device . No significant differences in the knee laxity testing using the Rolimeter device were seen between both groups and over time within these groups . Ninety percent of all patients had functionally normal or near normal International Knee Documentation Committee ( IKDC ) knee ligament ratings . The TF-group included 17 grade A , 19 grade B , and 2 grade C knees , and the BS-group had 12 grade A , 13 grade B , and 5 grade C knees .  The IKDC rating , the OAK-score , the Tegner-activity-score , and the Lysholm-score did not show significant differences between the TF-group and the BS-group . We disproved our hypothesis that the transfixation technique leads to less laxity and therefore to a better clinical outcome when compared to the use of BS . The clinical results in this study clarified that this technique is an effective and safe method for femoral hamstring fixation in ACL-reconstruction . However , this technique revealed no advantage compared to the bioscrew fixation technique within the short-term follow-up Introduction Correct placement of both tibial and femoral tunnels is one of the main factors for a favorable clinical outcome after anterior cruciate ligament ( ACL ) reconstruction . We used an original system of computer assisted surgery ( CAS ) . The system , based on fluoroscopic guidance combined with special graphical software of image analyzing , showed to the surgeon , before drilling , the recommended placement of tibial and femoral tunnel centers . We compared the first anatomical and clinical results of this procedure to the usual one single incision technique . Material s and methods We conducted a prospect i ve study on 73 patients ; 37 patients were operated on with CAS and 36 without CAS , by the same senior surgeon . The mean age was 27 years for both groups . Every patient was review ed at an average of 2.2 years ( range 1–4.5 ) by an independent observer , using IKDC scoring system , KT-1000 , and passive stress radiographs . Results Time between ACL rupture and reconstruction averaged 30 months for both groups . CAS needed 9.3 min extra surgery time . Clinical evaluation was grade d from A to C as per the IKDC scoring system : 67.6 % A , 29.7 % B , 2.7 % C with CAS ; and 60 % A , 37.1 % B , 2.9 % C without CAS . IKDC subjective knee evaluation score averaged 89.7 with CAS and 89.5 without CAS . Pre operative KT-1000 maxi manual differential laxity averaged 7 . At revision time , all the patients after CAS had a differential laxity less than 2 and 97.7 % without CAS . Stress X-rays differential laxity averaged 2.4 mm with CAS and 3 mm without CAS . The area of dispersion of the tunnels ’ center was smaller on the femoral side using the CAS method . There was no statistically significant difference between both groups using IKDC score , KT-1000 and passive stress radiographs . Conclusions The CAS method provided a more accurate and reproducible tunnels placement without clinical significant effect PURPOSE The purpose of this study was to compare the clinical results of a double-bundle anterior cruciate ligament ( ACL ) reconstruction with 4 str and s versus 8 str and s of hamstring tendon graft . METHODS Seventy-six patients with chronic ACL rupture were r and omly separated into two groups for double-bundle ACL reconstruction . In the 4-str and hamstring graft ( 4SHG ) group , the semitendinosus tendon was used to make two 2-str and ed hamstring tendon grafts , whereas in the 8-str and hamstring graft ( 8SHG ) group , the semitendinosus tendon was used to make one 4SHG and the gracilis tendon was used to make the other 4SHG .  The 4SHG group comprised 33 patients and the 8SHG group comprised 35 patients , with a minimum follow-up of 2 years . International Knee Documentation Committee ( IKDC ) and Lysholm scales were used to evaluate the clinical results . RESULTS In the 4SHG group the side-to-side difference was less than 3 mm in 26 patients ( 78.8 % ) , 3 to 5 mm in 4 patients ( 12.1 % ) , and 6 to 10 mm in 3 patients ( 9.0 % ) , with a mean value of 2.8 + /- 0.5 mm ; the pivot-shift test was negative in 29 patients ( 89.9 % ) and positive in 4 ( 12.1 % ) . In the 8SHG group the side-to-side difference was less than 3 mm in 32 patients ( 91.4 % ) , 3 to 5 mm in 2 patients ( 5.7 % ) , and 6 mm in 1 patient ( 2.9 % ) ( P = .004 ) , with a mean value of 1.3 + /- 0.4 mm ( P = .0003 ) ; the pivot-shift test was negative in 34 patients ( 97.1 % ) and positive in 1 ( 2.9 % ) . According to the IKDC scale , 29 patients ( 87.9 % ) in the 4SHG group and 33 patients ( 94.3 % ) in the 8SHG group had a grade of normal or nearly normal . In the 4SHG and 8SHG groups the mean IKDC subjective knee evaluation results were 86.4 + /- 4.2 and 96.3 + /- 2.8 ( P = .0007 ) , respectively , and the mean Lysholm scores were 89.6 + /- 3.7 and 96.5 + /- 2.9 ( P = .0006 ) , respectively . CONCLUSIONS On the basis of KT-1000 examination ( MEDmetric , San Diego , CA ) and clinical measures , double-bundle ACL reconstruction with 8SHG yields significantly better results than double-bundle ACL reconstruction with 4SHG , with a mean side-to-side difference in anterior knee laxity of 1.3 + /- 0.4 mm versus 2.8 + /- 0.5 mm ( P = .0003 ) , IKDC subjective result of 96.3 + /- 2.8 versus 86.4 + /- 4.2 ( P = .0007 ) , and Lysholm score of 96.5 + /- 2.9 versus 89.6 + /- 3.7 ( P = .0006 ) . LEVEL OF EVIDENCE Level II , lesser- quality r and omized controlled trial Background New devices for graft fixation in anterior cruciate ligament reconstruction are released to clinical use without clinical follow-up data . Hypothesis There is similar clinical outcome after either cross-pin or absorbable interference screw fixation in anterior cruciate ligament reconstruction with hamstring tendons . Study Design R and omized controlled clinical trial ; Level of evidence , 1 . Methods A total of 120 patients were r and omized into 4 different groups ( 30 each ) for anterior cruciate ligament reconstruction with hamstring tendons :  femoral Rigidfix cross-pin and Intrafix tibial expansion sheath with a tapered expansion screw ; Rigidfix femoral and BioScrew interference screw tibial fixation , BioScrew femoral and Intrafix tibial fixation ; or BioScrew fixation into both tunnels . The evaluation methods were clinical examination , knee scores , and instrumented laxity measurements . Results Ten patients were completely lost to follow-up and 3 revisions were done before the 2-year follow-up , leaving 107 of 120 ( 89 % ) patients for analysis . No statistically significant differences between the groups were seen 2 years postoperatively , and all but 2 patients in the Rigidfix/Intrafix and Rigidfix/BioScrew groups , respectively , were classified into International Knee Documentation Committee A or B categories . A revision reconstruction was performed before the 2-year follow-up in 2 cases after a high-energy injury caused a rerupture ( 1 in Rigidfix/Intrafix and 1 in BioScrew/BioScrew groups ) . In addition , there were 4 nontraumatic failures revised before the 2-year follow-up ( 2 in Rigidfix/Intrafix and 1 each in Rigidfix/BioScrew and BioScrew/BioScrew ) . Conclusion There were no statistically or clinical ly relevant differences in the results 2 years postoperatively , and all 4 techniques improved patient performance Although allograft use for primary anterior cruciate ligament reconstruction has continued to increase during the last 10 years , concerns remain regarding the long-term function of allografts ( primarily that they may stretch with time ) and clinical efficacy compared with autograft tendons . We attempted to address these issues by prospect ively comparing identical quadrupled hamstring autografts with allograft constructs for primary anterior cruciate ligament reconstruction in patients with a minimum followup of 3 years . Eighty-four patients ( 37 with autografts and 47 with allografts ) were enrolled ; the mean followup was 52 ± 11 months for the autograft group and 48 ± 8 months for the allograft group . Outcome measurements included objective and subjective International Knee Documentation Committee scores , Lysholm scores , Tegner activity scales , and KT-1000 arthrometer measurements . The two cohorts were similar in average age , acute or chronic nature of the anterior cruciate ligament rupture , and incidence of concomitant meniscal surgeries . At final followup , we found no difference in terms of Tegner , Lysholm , KT-1000 , or International Knee Documentation Committee scores . Five anterior cruciate ligament reconstructions failed : three in the autograft group and two in the allograft group . Our data suggest laxity is not increased in allograft tendons compared with autografts and clinical outcome scores 3 to 6 years after surgery are similar . Level of Evidence : Level II , therapeutic study . See the Guidelines for Authors for a complete description of levels of evidence OBJECTIVE The aim of this prospect i ve , r and omized study was to compare the clinical results of arthroscopic single-bundle ( SB ) and triple-bundle ( TB ) anterior cruciate ligament ( ACL ) reconstruction .  METHODS The study included 105 patients who underwent arthroscopic SB ACL and TB ACL reconstruction . Anterior stress radiographs and the maximal manual muscle test using a KT-2000 arthrometer were used to assess anteroposterior stability and rotational stability was investigated using the lateral pivot shift test at the 24th month follow-up . Clinical results were assessed using the International Knee Documentation Committee ( IKDC ) and Orthopädische Arbeitsgruppe Knie ( OAK ) scores preoperatively and at the 24th month follow-up . Postoperative thigh circumference , strength and range of motion ( ROM ) were compared between groups . RESULTS Rotational stability was significantly superior in the TB group than in the SB group . There were no statistically significant differences with regard to residual anteroposterior laxity determined at the 24th month follow-up . No significant difference in terms of IKDC score , OAK score , thigh circumference , strength and ROM was detected between the two groups . CONCLUSION Both arthroscopic SB and TB ACL reconstruction result ed in satisfactory subjective outcome and objective stability . Rotational stability was significantly superior in the TB group The KT-1000 and similar non-invasive arthrometers are used as a complement to clinical examination in the diagnosis of anterior cruciate ligament ( ACL ) rupture and during the follow-up after surgery . We compared the two methods , KT-1000 and Radiostereometric analysis ( RSA ) , when used to measure anterior-posterior knee laxity ( A-P laxity ) in patients with ACL rupture , before and after the reconstruction of this ligament , in a prospect i ve , comparative study . Twenty-two consecutive patients ( 14 men , 8 women ) with a median age of 24 years ( range 16–41 ) were studied . All the patients had a unilateral ACL rupture and an intact contralateral knee . The patients were operated on by one experienced surgeon using the bone-patellar tendon-bone ( BTB ) autograft . Preoperatively and 2 years after the reconstruction , all the patients were evaluated using  KT-1000 and RSA measurements of A-P laxity . The side-to-side differences between the injured and the intact knees , that is , total A-P laxity for both knees , are presented 
    Output:
    
A difference in ATT is found between healthy , contralateral , ACLR and ACL-injured knees and between chronic and acute ACL injury .
Graft choices and intra-articular injuries are factors which could affect the ATT .
The mean ATT was lowest to highest in ACLR knees using a bone – patella tendon – bone autograft , ACLR knees using a hamstring autograft , contralateral healthy knees , healthy knees , ACLR knees with an allograft and ACL-injured knees .
The clinical relevance is that an autograft ACLR might give better results than an allograft ACLR as knee laxity is greater when using an allograft tendon .