***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 aim of this study was to evaluate whether  anterior cruciate ligament ( ACL ) reconstruction using the double bundle technique ( DB ) improves stability in the knee compared with the single bundle technique ( SB ) with the femoral tunnel in a more horizontal position ( 2 or 10 o’clock ) . We conducted a r and omized , prospect i ve study . Forty patients were r and omized to the DB group ( 20 patients ) and the SB group ( 20 patients ) .  Four-str and ed semitendinosus and gracilis autologous grafts were used in the SB group and in the DB group the conventional four tunnel technique was carried out using the same tendons . The IKDC complete form was used for the preoperative evaluation , and in the follow-up the IKDC subjective knee evaluation form , IKDC current health assessment form and IKDC knee examination form were used . Anteroposterior ( AP ) laxity was evaluated by st and ardised and forced radiology in all patients . No significant preoperative between-group differences were found . During the follow-up , no differences were found between groups , except for significant between-group differences ( P < 0.05 ) between the preoperative and postoperative evaluations . The IKDC index also showed significant differences in the 2-year follow-up . Median scores increased from 48 ( range 41–54 ) to 81 ( range 75–87 ) ( P = 0.01 ) in the SB group and from 52 ( range 46–58 ) to 80 ( range 72–88 ) ( P = 0.02 ) in the DB group . There were no significant differences between the groups in terms of functional scores . In conclusion , the 2 and 10 o’clock placements showed no significant differences between SB and DB techniques in the pivot-shift test , manual and radiological anterior posterior laxity and IKDC scores . However , significant between-group differences were found between the preoperative and postoperative evaluations Twenty-six patients with anteroposterior ( AP ) laxity of the knee , associated with torn anterior cruciate ligament ( ACL ) , were prospect ively r and omized for arthroscopic lower femoral tunnel placed single- or double-bundle reconstruction using hamstring tendons . We evaluated AP and rotational stabilities under regular loads ( a 100-N anterior load and a 1.5-N m external – internal load ) before and after ACL reconstruction , comparing single- and double-bundle reconstruction with our original device for applying quantitative tibial rotation and the navigation system intraoperatively . No significant differences were found between the two groups in AP displacement and total range of tibial rotation at 30 ° and 60 ° of knee flexion . We found that a lower femoral tunnel placed single-bundle reconstruction  reproduced AP and rotational stability as well as double-bundle reconstruction after reconstruction intraoperatively We conducted a prospect i ve r and omised study of anatomical single-bundle ( A-SB group ) versus double-bundle ( A-DB group ) anterior cruciate ligament ( ACL ) reconstruction using the hamstrings tendons . Twenty patients with unilateral ACL deficiency were r and omised into two groups . We created the bone tunnels at the position of the original insertion of the anteromedial bundle footprint and posterolateral bundle footprint in the A-DB group and at the central position between these two bundles in the A-SB group . All of the patients were tested before ACL reconstruction and one year after surgery . The KT-1000 measurements , isokinetic muscle peak torque and heel-height difference were evaluated and the general knee condition was assessed by Lysholm score . For pre- and postoperative stability assessment , we used the six-degrees-of-freedom of knee kinematic measurement system using an electromagnetic device ( the EMS ) for quantitative assessment during the Lachman test and the pivot shift test . There were no significant differences in the KT-1000 measurements , isokinetic muscle peak torque , heel-height difference , and Lysholm score at one-year follow-up between these two groups . The EMS data showed there were significant differences in the acceleration of the pivot shift test between the operated knee and the contralateral normal knees in the A-SB group . In conclusion , clinical outcomes were equally good in both groups . However , the EMS data showed the anatomical double-bundle ACL reconstruction tended to be biomechanically superior to the single-bundle reconstruction Purpose The purpose of this study was to compare subjective , objective and radiographic outcome of the lateralized single-bundle bone-patellar tendon-bone autograft with a non-anatomical double-bundle hamstring tendons autograft anterior cruciate ligament ( ACL ) reconstruction technique at long-term follow-up . Methods Seventy-nine non-consecutive r and omized patients ( 42 men ; 37 women ) with unilateral ACL insufficiency were prospect ively evaluated , before and after ACL reconstruction by means of the above-mentioned techniques , with a minimum follow-up of 8 years ( range 8–10 years ; mean 8.6 years ) . In the double-bundle hamstrings technique , we used one tibial and one femoral tunnel combined with one “ over-the-top ” passage , cortical staple ’s fixation and we left intact hamstrings ’ tibial insertion . Patients were evaluated subjectively and objective ly , using IKDC score , Tegner level , manual maximum displacement test with KT-2000 ™ arthrometer . Radiographic evaluation was performed according to IKDC grading system , and re-intervention rate for meniscal lesions was also recorded . Results The subjective and objective IKDC were similar in both groups while double-bundle hamstrings group showed significantly higher Tegner level ( P = 0.0007 ) , higher passive range of motion recovery ( P = 0.0014 ) , faster sport resumption ( P = 0.0052 ) , lower glide pivot-shift phenomenon ( P = 0.0302 ) and lower re-intervention rate ( P = 0.0116 ) compared with patellar tendon group . Radiographic evaluation showed significant lower objective degenerative changes in double-bundle hamstrings group at final follow-up ( P = 0.0056 ) . Conclusion Although both techniques provide satisfactory results , double-bundle ACL reconstruction shows better functional results , with a faster return to sport activity , a lower re-operation rate and lower degenerative knee changes Adequate reporting of r and omized , controlled trials ( RCTs ) is necessary to allow accurate critical appraisal of the validity and applicability of the results . The CONSORT ( Consoli date d St and ards of Reporting Trials ) Statement , a 22-item checklist and flow diagram , is intended to address this problem by improving the reporting of RCTs . However , some specific issues that apply to trials of nonpharmacologic treatments ( for example , surgery , technical interventions , devices , rehabilitation , psychotherapy , and behavioral intervention ) are not specifically addressed in the CONSORT Statement . Furthermore , considerable evidence suggests that the reporting of nonpharmacologic trials still needs improvement . Therefore , the CONSORT group developed an extension of the CONSORT Statement for trials assessing nonpharmacologic treatments . A consensus meeting of 33 experts was organized in Paris , France , in February 2006 , to develop an extension of the CONSORT Statement for trials of nonpharmacologic treatments . The participants extended 11 items from the CONSORT Statement , added 1 item , and developed a modified flow diagram . To allow adequate underst and ing and implementation of the CONSORT extension , the CONSORT group developed this elaboration and explanation document from a review of the literature to provide examples of adequate reporting . This extension , in conjunction with the main CONSORT Statement and other CONSORT extensions , should help to improve the reporting of RCTs performed in this field A total of 108 patients with unilateral instability of the knee , associated with rupture of the anterior cruciate ligament , was prospect ively r and omised for arthroscopic single- or double-bundle reconstruction of the ligament using hamstring tendons . The same post-operative rehabilitation protocol was used for all . The patients were followed up for a mean of 32 months ( 24 to 36 ) . We measured the anterior laxity and joint position sense at different angles of flexion of the knee to determine whether both bundles in the double-bundle reconstruction contributed to the stability of the joint and proprioception . No significant difference was found between the two groups with regard to anterior laxity measured by the KT-2000 arthrometer with the knee at 20 degrees or 70 degrees flexion nor with regard to proprioception . A notchplasty was required less often in the double- compared with the single-bundle reconstruction . We did not find any advantage in a double-bundle as opposed to a single-bundle reconstruction in terms of stability or proprioception Double-bundle  anterior cruciate ligament ( ACL ) reconstruction is intended to replicate the anatomy and the function of the anteromedial and posterolateral bundles of the native ACL to improve patients ' satisfaction and knee stability . We prospect ively assigned 75 consecutive patients with an isolated ACL lesion to one of three sequential groups of 25 patients each . Group I received a single-bundle , single-incision transtibial ACL reconstruction . Groups II and III received a double-bundle reconstruction with a single-incision transtibial technique or a double-bundle , twoincision outside-in technique , respectively . We obtained subjective International Knee Documentation Committee and Knee Injury and Osteoarthritis Outcome Score evaluations and objective International Knee Documentation Committee scores and KT-1000 measurements preoperatively and at followup . All patients reached a minimum followup of 2 years . KT side-to-side difference in Groups I , II , and III were 2.4 , 1.6 and 1.4 mm , respectively . Group III had fewer patients with a positive pivot shift than Group I. The double-bundle double-incision outside-in ACL reconstruction result ed in improved anteroposterior stability and less residual pivot shift than single-incision single-bundle technique . Level of Evidence : Level II , therapeutic study . See Guidelines for Authors for a complete description of levels of evidence Several investigators have reported the presence of biomechanical , kinematic , anatomic , fiber orientation patterns and biological differences between the anteromedial bundle and the posterolateral bundle of ACL . The purpose of this prospect i ve r and omized study was to compare the clinical , instrumental and X-ray outcome of two ACL reconstruction techniques with hamstring tendons : one with a single intra-articular bundle associated to an extra-articular sling , the second with a more anatomic double-bundle technique that reproduces better the native ACL function . From an initial group of 100 patients who underwent ACL reconstruction , 72 patients ( 35 single bundle plus lateral plasty and 37 double bundle )  were evaluated with IKDC , Tegner score , KT2000 arthrometer , Activity Rating Scale , Psychovitality Question naire and Ahlback radiographic score at a mean 3 years follow-up . Double-bundle group showed significantly better results regarding IKDC , ROM , Activity Rating Scale and time to return to sport . Also KT 2000 showed significant differences in objective stability . The double-bundle technique for ACL reconstruction described in this paper has demonstrated significantly better subjective , objective and functional results compared with a double-str and ed hamstrings plus extra-articular sling at a minimum 3-year follow-up Double-bundle  anterior cruciate ligament ( ACL ) reconstruction reproduces anteromedial and posterolateral bundles , and thus has theoretical advantages over conventional single-bundle reconstruction in controlling rotational torque in vitro . However , its superiority in clinical practice has not been proven . We analyzed rotational stability with three reconstruction techniques in 60 consecutive patients who were r and omly divided into three groups ( double-bundle , anteromedial single-bundle , posterolateral single-bundle ) . In the reconstructive procedure , the hamstring tendon was harvested and used as a free tendon graft . Followup examinations were performed 1 year after surgery . Anteroposterior laxity of the knee was examined with a KT-1000 arthrometer , whereas rotatory instability , as elicited by the pivot shift test , was assessed using a new measurement system incorporating three-dimensional electromagnetic sensors . Routine clinical evaluations , including KT examination , demonstrated no differences among the three groups . However , using the new measurement system , patients with double-bundle ACL reconstruction showed better pivot shift control of complex instability than patients with anteromedial and posterolateral single-bundle reconstruction . Level of Evidence : Level II , therapeutic study . See the Guideline for Authors for a complete description of levels of evidence Anatomical observation and biomechanical studies have shown that the anterior cruciate ligament ( ACL ) mainly consists of two distinct bundles , the anteromedial ( AM ) bundle and posterolateral ( PL ) bundle . Conventional single-bundle ACL reconstruction techniques have focused on the restoration of the AM bundle while giving limited attention to the PL bundle . The purpose of this prospect i ve , r and omized clinical study is to compare the outcomes of ACL reconstruction when using either double-bundle or single-bundle technique and bioabsorbable interference screw fixation , and similar rehabilitation with both techniques . Sixty-five patients were r and omized into either double-bundle ( n = 35 ) or single-bundle ( n = 30 ) ACL reconstruction with hamstring tendons and bioabsorbable screw ( Hexalon , Inion Company , Tampere , Finl and ) fixation in both groups . The evaluation methods were clinical examination , KT-1000 arthrometer measurements , radiographic evaluation , as well as International Knee Documentation Committee and Lysholm knee scores . There were no differences between the study groups preoperatively . For an average of 14 months of follow-up ( range 12–20 months ) , 30 patients of the double-bundle group and 29 patients of the single-bundle group were available ( 91 % ) . At the follow-up , the rotational stability , as evaluated by pivot shift test , was significantly better in the double- 
    Output:
    
Data for pooling individual outcomes were available for a maximum of nine trials and 54 % of participants .There were no statistically or clinical ly significant differences between double-bundle and single-bundle reconstruction in the subjective functional knee scores ( subjective IKDC score , Tegner activity score , Lysholm score ) in the intermediate ( six months up to two years since surgery ) or long term ( two to five years from surgery ) .
There is insufficient evidence to determine the relative effectiveness of double-bundle and single-bundle reconstruction for anterior cruciate ligament rupture in adults , although there is limited evidence that double-bundle ACL reconstruction has some superior results in objective measurements of knee stability and protection against repeat ACL rupture or a new meniscal injury .