***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: Objective To compare , in young active adults with an acute anterior cruciate ligament ( ACL ) tear , the mid-term ( five year ) patient reported and radiographic outcomes between those treated with rehabilitation plus early ACL reconstruction and those treated with rehabilitation and optional delayed ACL reconstruction . Design Extended follow-up of prospect i ve r and omised controlled trial . Setting Orthopaedic departments at two hospitals in Sweden . Participants 121 young , active adults ( mean age 26 years ) with acute ACL injury to a previously uninjured knee . One patient was lost to five year follow-up . Intervention All patients received similar structured rehabilitation . In addition to rehabilitation , 62 patients were assigned to early ACL reconstruction and 59 were assigned to the option of having a delayed ACL reconstruction if needed . Main outcome measure The main outcome was the change from baseline to five years in the mean value of four of the five subscales of the knee injury and osteoarthritis outcome score ( KOOS4 ) . Other outcomes included the absolute KOOS4 score , all five KOOS subscale scores , SF-36 , Tegner activity scale , meniscal surgery , and radiographic osteoarthritis at five years . Results Thirty ( 51 % ) patients assigned to optional delayed ACL reconstruction had delayed ACL reconstruction  ( seven between two and five years ) . The mean change in KOOS4 score from baseline to five years was 42.9 points for those assigned to rehabilitation plus early ACL reconstruction and 44.9 for those assigned to rehabilitation plus optional delayed reconstruction ( between group difference 2.0 points , 95 % confidence interval −8.5 to 4.5 ; P=0.54 after adjustment for baseline score ) . At five years , no significant between group differences were seen in KOOS4 ( P=0.45 ) , any of the KOOS subscales ( P≥0.12 ) , SF-36 ( P≥0.34 ) , Tegner activity scale ( P=0.74 ) , or incident radiographic osteoarthritis of the index knee ( P=0.17 ) . No between group differences were seen in the number of knees having meniscus surgery ( P=0.48 ) or in a time to event analysis of the proportion of meniscuses operated on ( P=0.77 ) . The results were similar when analysed by treatment actually received . Conclusion In this first high quality r and omised controlled trial with minimal loss to follow-up , a strategy of rehabilitation plus early ACL reconstruction did not provide better results at five years than a strategy of initial rehabilitation with the option of having a later ACL reconstruction . Results did not differ between knees surgically reconstructed early or late and those treated with rehabilitation alone . These results should encourage clinicians and young active adult patients to consider rehabilitation as a primary treatment option after an acute ACL tear . Trial registration Current Controlled Trials IS RCT N84752559 We performed a prospect i ve , double-blind , r and omised , clinical trial to investigate the efficacy of two regimes of rehabilitation for knees with anterior cruciate ligament deficiency ( ACLD ) . Fifty ACLD patients were r and omly allocated to one of two treatment groups : a programme of muscle strengthening ( T ) or a programme design ed to enhance proprioception and improve hamstring contraction reflexes ( P ) . An indirect measure of proprioception , the reflex hamstring contraction latency ( RHCL ) , and a functional scoring system were used to record the status of the knee before and after the 12-week course of physiotherapy . Sagittal knee laxity was also measured . There was improvement in mean RHCL and in the mean functional score in both groups after treatment . The improvement in group P was significantly greater than that in group T. There was no significant change in joint laxity after treatment in either group . In both groups there was a positive correlation between improvement in RHCL and functional gain BACKGROUND The optimal management of a torn anterior cruciate ligament ( ACL ) of the knee is unknown . METHODS We conducted a r and omized , controlled trial involving 121 young , active adults with acute ACL injury in which we compared two strategies : structured rehabilitation plus early ACL reconstruction and structured rehabilitation with the option of later ACL reconstruction if needed . The primary outcome was the change from baseline to 2 years in the average score on four subscales of the Knee Injury and Osteoarthritis Outcome Score (KOOS)--pain , symptoms , function in sports and recreation , and knee-related quality of life ( KOOS(4 ) ; range of scores , 0 [ worst ] to 100 [ best ] ) . Secondary outcomes included results on all five KOOS subscales , the Medical Outcomes Study 36-Item Short-Form Health Survey , and the score on the Tegner Activity Scale . RESULTS Of 62 subjects assigned to rehabilitation plus early ACL reconstruction , 1 did not undergo surgery . Of 59 assigned to rehabilitation plus optional delayed ACL reconstruction , 23 underwent delayed ACL reconstruction ; the other 36 underwent rehabilitation alone . The absolute change in the mean KOOS(4 ) score from baseline to 2 years was 39.2 points for those assigned to rehabilitation plus early ACL reconstruction and 39.4 for those assigned to rehabilitation plus optional delayed reconstruction ( absolute between-group difference , 0.2 points ; 95 % confidence interval , -6.5 to 6.8 ; P=0.96 after adjustment for the baseline score ) . There were no significant differences between the two treatment groups with respect to secondary outcomes . Adverse events were common in both groups . The results were similar when the data were analyzed according to the treatment actually received . CONCLUSIONS In young , active adults with acute ACL tears , a strategy of rehabilitation plus early ACL reconstruction was not superior to a strategy of rehabilitation plus optional delayed ACL reconstruction . The latter strategy substantially reduced the frequency of surgical reconstructions . ( Funded by the Swedish Research Council and the Medical Faculty of Lund University and others ; Current Controlled Trials number , IS RCT N84752559 . BACKGROUND AND PURPOSE Treatment techniques involving perturbations of support surfaces may induce compensatory muscle activity that could improve knee stability and increase the likelihood of returning patients to high-level physical activity . The purpose of this study was to determine the efficacy of augmenting st and ard nonoperative anterior cruciate ligament ( ACL ) rehabilitation programs with a perturbation training program . SUBJECTS Twenty-six patients with acute ACL injury or ruptures of ACL grafts participated in the study . Subjects had to have a unilateral ACL injury , be free of concomitant multiple ligament or meniscal damage requiring surgical repair , and pass a screening examination design ed to identify patients who had the potential to return to high-level physical activity with nonoperative treatments . Subjects also had to be regular participants in level I activities ( eg , soccer , football , basketball ) or level II activities ( eg , racquet sports , skiing , construction work ) . METHODS Subjects were r and omly assigned to either a group that received a st and ard rehabilitation program ( st and ard group ) or a group that received the st and ard program augmented with a perturbation training program ( perturbation group ) . Treatment outcome was determined from scores on the Knee Outcome Survey 's Activities of Daily Living Scale ( ADLS ) and Sports Activity Scale , a global rating of knee function , scores on a series of single-limb hop tests , measurements of maximum isometric quadriceps femoris muscle force output , and the group frequency of unsuccessful rehabilitation . Unsuccessful rehabilitation was defined as the occurrence of an episode of giving way of the knee or failure to maintain the functional status of a rehabilitation c and i date on retesting . RESULTS More subjects had unsuccessful rehabilitation in the st and ard group compared with the perturbation group . There was a within-group x time interaction for the ADLS , global rating of knee function , and crossover hop test scores . These scores decreased from posttraining to the 6-month follow-up for the st and ard group . CONCLUSION AND DISCUSSION Although both the st and ard program and the perturbation training program may allow subjects to return to high-level physical activity , the perturbation training program appears to reduce the risk of continued episodes of giving way of the knee during athletic participation and allows subjects to maintain their functional status for longer periods We investigated whether preoperative perturbation training would help anterior cruciate ligament ( ACL ) deficient individuals who complain of knee instability ( " non-copers " ) regain quadriceps strength and walk normally after ACL reconstruction . Nineteen non-copers with acute ACL injury were r and omly assigned into a perturbation group ( PERT ) or a strengthening group ( STR ) . The PERT group received specialized neuromuscular training and progressive quadriceps strength training , whereas the STR group received progressive quadriceps strength training only . We compared quadriceps strength indexes and knee excursions during the mid-stance phase of gait preoperatively to data collected 6 months after ACL reconstruction . Analyses of Variance with repeated measures ( time/limb ) were conducted to compare quadriceps strength index values over time ( time x group ) and differences in knee excursions in limbs between groups over time ( limb x time x group ) . If significance was found , post hoc analyses were performed using paired and independent t-tests . Quadriceps strength indexes before intervention ( Pert : 87.2 % ; Str : 75.8 % ) improved 6 months after ACL reconstruction in both groups ( Pert : 97.1 % ; Str : 94.4 % ) . Non-copers who received perturbation training preoperatively had no differences in knee excursions between their limbs 6 months after ACL reconstruction ( p = 0.14 ) , whereas those who received just strength training continued to have smaller knee excursions during the mid-stance phase of gait ( p = 0.007 ) . Non-copers strength and knee excursions were more symmetrical 6 months postoperatively in the group that received perturbation training and progressive quadriceps strength training than the group who received strength training alone Abstract . Rehabilitation after anterior cruciate ligament ( ACL ) reconstruction has focused over the past decade on closed kinetic chain ( CKC ) exercises due to presumably less strain on the graft than with isokinetic open kinetic chain exercises ( OKC ) ; however , recent reports suggest that there are only minor differences in ACL strain values between some CKC and OKC exercises . We studied  anterior knee laxity , thigh muscle torque , and return to preinjury sports level in 44 patients with unilateral ACL ; group 1 carried out quadriceps strengthening only with CKC while group 2 trained with CKC plus OKC exercises starting from week 6 after surgery . Anterior knee laxity was determined with a KT-1000 arthrometer ; isokinetic concentric and eccentric quadriceps and hamstring muscle torque were studied with a Kin-Com dynamometer before and 6 months after surgery . At an average of 31 months after surgery the patients answered a question naire regarding their current knee function and physical activity/sports to determine the extent and timing of their recovery . No significant differences in anterior knee laxity were noted between the groups 6 months postsurgery . Patients in group 2 increased their quadriceps torque significantly more than those in group 1 , but no differences were found in hamstring torque between the groups . A significantly higher number of patients in group 2 ( n=12 ) than in group 1 ( n=5 ) returned to sports at the same level as before the injury ( P<0.05 ) . Patients from group 2 who returned to sports at the same level did so 2 months earlier than those in group 1 . Thus the addition of OKC quadriceps training after ACL reconstruction results in a significantly better improvement in quadriceps torque without reducing knee joint stability at 6 months and also leads to a significantly higher number of athletes returning to their previous activity earlier and at the same level as before injury BACKGROUND AND PURPOSE Assessment of the quality of r and omized controlled trials ( RCTs ) is common practice in systematic review s. However , the reliability of data obtained with most quality assessment scales has not been established . This report describes 2 studies design ed to investigate the reliability of data obtained with the Physiotherapy Evidence Data base ( PEDro ) scale developed to rate the quality of RCTs evaluating physical therapist interventions . METHOD In the first study , 11 raters independently rated 25 RCTs r and omly selected from the PEDro data base . In the second study , 2 raters rated 120 RCTs r and omly selected from the PEDro data base , and disagreements were resolved by a third rater ; this generated a set of individual rater and consensus ratings . The process was repeated by independent raters to create a second set of individual and consensus ratings . Reliability of ratings of PEDro scale items was calculated using multirater kappas , and reliability of the total ( summed ) score was calculated using intraclass correlation coefficients ( ICC [ 1,1 ] ) . RESULTS The kappa value for each of the 11 items ranged from.36 to.80 for individual assessors and from.50 to.79 for consensus ratings generated by groups of 2 or 3 raters . The ICC for the total score was.56 ( 95 % confidence interval=.47-.65 ) for ratings by individuals , and the ICC for consensus ratings was.68 ( 95 % confidence interval=.57-.76 ) . DISCUSSION AND CONCLUSION The reliability of ratings of PEDro scale items varied from " fair " to " substantial , " and the reliability of the total PEDro score was " fair " to " good . Background There is no consensus regarding the optimal rehabilitation regimen for increasing quadriceps strength after anterior cruciate ligament ( ACL ) injury . Hypothesis A comprehensive rehabilitation program supplemented with quadriceps strengthening in open kinetic chain ( OKC ) exercise will increase quadrice 
    Output:
    
This review found that pre-operative physiotherapy rehabilitation is effective for improving the outcomes of treatment following anterior cruciate ligament injury , including increasing knee-related function and improving muscle strength .
However , whilst there was a significant improvement in quality of life from baseline following intervention , no significant difference in quality of life was found between the control and intervention groups .
Conclusions : There is evidence to suggest that pre-operative physiotherapy rehabilitation is beneficial to patients with anterior cruciate ligament injury