***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 
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    Input: We present medium-term results in 30 prospect ively followed patients aged over 50 years at the time of ACL reconstruction ( 31 procedures ) ; mean follow-up time was 46 months ( range 24–95 ) . Mean Lysholm score improved significantly from 63 pre-operatively to 93 at final review Cincinnati score from 49 to 89 . In IKDC score 25 knees ( 81 % ) were considered normal or nearly normal and 6 abnormal ; there were no severely abnormal results . Mean Tegner activity scores improved from pre-operatively from 3.7 to 5.2 at review . Mean side-to-side difference measured by the KT-1000 at maximal manual pressure was 2.7 mm ; two knees had . a measured difference greater than 5 mm . The mean torque ratio for isokinetic flexion strength was 102 % and for extension strength 94 % . Poor results as determined by the three scoring systems were associated mainly with advanced articular degenerative changes ( Outerbridge grade 3 or 4 ) seen at the time of reconstruction . Despite this all patients reported improvement in stability and overall function of the knee . Degenerative change itself was associated with increased time to surgery from injury . This study demonstrates that the ACL can be reliably reconstructed in patients over the age of 50 years with good symptomatic relief , restoration of function and return to sporting activity In a two-centre study , 164 patients with unilateral instability of the anterior cruciate ligament were prospect ively r and omised to arthroscopic reconstruction with either a patellar tendon graft using interference screw fixation or a quadruple semitendinosus graft using an endobutton fixation technique . The same postoperative rehabilitation protocol was used for all patients and follow-up at a median of 31 months ( 24 to 59 ) was carried out by independent observers . Four patients ( 2 % ) were lost to follow-up . No significant differences were found between the groups regarding the Stryker laxity test , one-leg hop test , Tegner activity level , Lysholm score , patellofemoral pain score , International Knee Documentation Committee ( IKDC ) score or visual analogue scale , reflecting patient satisfaction and knee function . Slightly decreased extension , compared with the non-operated side , was found in the patellar tendon group ( p < 0.05 ) . Patients with associated meniscal injuries had lower IKDC , visual analogue ( p < 0.01 ) and Lysholm scores ( p < 0.05 ) than those without such injuries . Patients in whom reconstruction had been carried out less than five months after the injury had better final IKDC scores than the more chronic cases ( p < 0.05 ) . We conclude that patellar tendon and quadruple semitendinous tendon grafts have similar outcomes in the medium term . Associated meniscal pathology significantly affects the final outcome and early reconstruction seems to be beneficial BACKGROUND The aim of the study was to compare the results after arthroscopic anterior cruciate ligament ( ACL ) reconstruction  using central -third bone-patellar tendon-bone ( BTB ) autografts and triple/quadruple semitendinosus ( ST ) autografts . HYPOTHESIS In the long-term , ACL reconstruction using BTB autografts will render more donor-site problems than ST autografts . STUDY DESIGN R and omized controlled trial ; Level of evidence , 1 . METHODS A r and omized series of 71 patients ( 22 women and 49 men ) with a unilateral ACL rupture who underwent reconstructive surgery were included in the study . The BTB graft was used in 34 patients ( BTB group ) and the ST-tendon graft was used in 37 patients ( ST group ) . The patients were examined a median of 86 months ( range , 68 to 114 months ) after the reconstruction . RESULTS Sixty-eight of 71 patients ( 96 % ) were examined at follow-up . The clinical assessment s at follow-up revealed no significant differences between the BTB group and the ST group in terms of the Lysholm score , Tegner activity level , International Knee Documentation Committee evaluation system , 1-legged hop test , KT-1000 arthrometer laxity measurements , manual Lachman test , and range of motion . A significant improvement was seen in both groups compared with the preoperative values in terms of most clinical assessment s. Donor-site morbidity in the form of knee-walking ability , kneeling ability , and area of disturbed anterior knee sensitivity revealed no significant differences between the groups . CONCLUSION Seven years after ACL reconstruction , the subjective and objective outcomes were similar after using the central -third BTB autograft and triple/quadruple ST autograft . Furthermore , no difference in terms of donor-site morbidity was found between the 2 groups PURPOSE The aim of this study was to compare the results after arthroscopic anterior cruciate ligament ( ACL ) reconstruction using central -third , bone-patellar tendon-bone ( BPTB group ) , 3-str and semitendinosus ( ST group ) , or 4-str and semitendinosus/gracilis ( ST/G group ) autografts . TYPE OF STUDY Prospect i ve r and omized trial . METHODS A r and omized series of 134 patients , all with unilateral ACL rupture was included in the study . In all 3 groups , interference screw fixation of the graft was used at both ends and 125 of 134 ( 93 % ) of the patients returned for the follow-up examination after 26 months ( range , 20 to 43 months ) . The preoperative assessment s in all 3 groups were similar in terms of gender , Tegner activity level , Lysholm score , KT-1000 measurements , 1-leg hop test , and the knee-walking test . RESULTS At follow-up , the knee-walking test was significantly worse in the BPTB group than in the ST group ( P = .0004 ) and ST/G group ( P < .0001 ) . Furthermore , the knee-walking test was significantly worse at follow-up than preoperatively in the BPTB group ( P < .0001 ) . The corresponding findings were not made in the other 2 groups . A significant reduction in knee laxity and an increase in activity level compared with the preoperative assessment s were found in all 3 groups , without any significant differences between the groups . CONCLUSIONS Two years after ACL reconstruction , the use of ST and ST/G autografts rendered significantly less discomfort during the knee-walking test than the use of BPTB autografts . However , in terms of functional outcome and knee laxity , the groups displayed no significant differences . LEVEL OF EVIDENCE Level Seventy patients with patellar tendon or hamstring tendon autografts for single-incision anterior cruciate ligament reconstruction were evaluated at least 2 years after surgery . All reconstructions were performed by the same surgeon , and metal interference screws were used for fixation of all grafts . No significant differences were noted between groups for Lysholm score , reduction in activity , KT-1000 arthrometer findings , quadriceps muscle size , return to sports , or ability to jump and do hard cuts and pivots . Significantly more patients in the patellar tendon group had patellofemoral pain at 6 months after surgery than did the hamstring tendon patients ( 48 % versus 20 % ) , and at last follow-up the incidence of patellofemoral pain was 42 % and 20 % , respectively . Fourteen patients in the patellar tendon group and seven in the hamstring tendon group had loss of motion ( approximately 5 ° ) . Four patients ( two in each group ) had treatment failures and their results were not included in the clinical examination data . At 2 years ’ follow-up , 97 % of patients with patellar tendon grafts and 100 % of patients with hamstring tendon grafts rated their results as good or excellent . We found that hamstring tendon grafts performed similarly to patellar tendon grafts , although fewer patients in the hamstring tendon group had patellofemoral pain and loss of motion UNLABELLED The aim of our prospect i ve r and omised study was to evaluate the clinical results after arthroscopical reconstruction of the ACL using the midthird patellar ligament or semitendinosus tendon . METHODS Forty patients were followed up two years postoperatively . Twenty of them received either a patellar ligament graft ( BTB-group ) or doubled semiteninosus tendon ( SET-group ) . The clinical evaluation included the preoperative and two years postoperative assessment , based on the IKDC-Score , Tegener-Score and Mc-Carroll-Score . The a.p.-translation was evaluated using the KT-1000 . RESULTS Sixteen ( 80 % ) patients of the SET-group and 10 ( 50 % ) patients of the BTB-group showed good and excellent results in the over all assessment with the IKDC-Score . The mean side to side KT-1000 difference yielded 1.6 mm ( -2 - 4 mm ) in the BTB-group and 2.7 mm ( 0 - 7 mm ) in the SET-group ( p < 0.05 ) . The retropatellar pain syndrome based on the Mc-Caroll-Score showed 17.4 points in the BTB-group in comparison to 19.5 points in the SET-group ( p < 0.05 ) . The level of activity using the Tegner-score showed preoperatively for both the SET- and BTB-group 6.9 points and postoperatively for the SET-group 6.7 points and for the BTB-group 5.6 points . CONCLUSIONS Despite the inferior a.p.-stability for the patients who received doubled semitendinosus tendon grafts they presented clinical ly superior results compared to the BTB-group . Therefore this technique seems to be the alternative method . In order to improve the stability we recommend the usage of three or four str and ed grafts and an improved fixation technique Abstract A prospect i ve study was performed with 36 patients who underwent an anterior cruciate ligament ( ACL ) reconstruction with the use of a fresh-frozen bone-patellar tendon-bone ( BPTB ) allograft .  A group of 26 patients who underwent the same operation conducted by the same surgeon in the same period but with the use of an autograft BPTB served as controls . The average follow-up was 46 ( range 30–64 ) months in the allograft group and 52 ( range 42–74 ) months in the autograft group . The  allograft group consisted of 17 men and 19 women with a mean age of 28 years ( mean trauma to reconstruction interval was 55 months ) . The  autograft group consisted of 9 men and 17 women with a mean age of 28 years ( mean trauma to reconstruction interval was 30 months ) . Clinical and functional evaluation was performed according to the IKDC guidelines . Analysis of tibial tunnel placement with respect to the Blumenstaat line on a lateral radiograph with the knee in hyperextension was done in relation to an extension deficit and clinical score . In the autograft group 18 ( 70 % ) patients had a normal or nearly normal knee and 8 , a fair result . In the allograft group 30 ( 85 % ) patients had a normal or nearly normal knee , 5 ( 13 % ) patients had a fair result , and one ( 2 % ) knee was poor . The difference between the two groups was not significant . The allograft BPTB is a good alternative graft in ACL reconstruction We did a retrospective review and follow-up examina tion to investigate the incidence , risk factors , and out come of patients who developed loss of motion after arthroscopic anterior cruciate ligament reconstruction . Two hundred forty-four patients with a minimum fol lowup of 1 year were review ed . Loss of motion ( defined as a loss of extension of more than I0 ° or flexion of less than 125 ° ) was identified in 27 patients for an overall incidence of 11.1 % . Factors associated with loss of motion included acute reconstruction ( less than 1 month from initial injury ) , male sex , and concomitant medial collateral ligament repair or posterior oblique ligament reefing or both . Twenty-one patients required surgery to regain their motion ; three patients required a second procedure . Twenty-one of 27 patients with loss of motion under went a detailed followup and were compared with 24 r and omly chosen controls who had a normal range of motion after anterior cruciate ligament reconstruction .  At followup , patients who experienced loss of motion had a significant decrease in noninvolved to involved knee extension and flexion compared to the control patients . There was no difference between our patients and the controls regarding patellofemoral problems , anterior knee laxity , and functional strength . Sixty- seven percent of patients with loss of motion had a good or excellent result in comparison to 80 % of the controls PURPOSE The purpose of the study was to quantify the amount of agreement among orthopaedic surgeons regarding the natural history of the anterior cruciate ligament (ACL)-deficient knee , surgery , and rehabilitation , and the treatment of these patients . TYPE OF STUDY Physician mail survey . METHODS Orthopaedic surgeons were r and omly selected from the American Academy of Orthopaedic Surgeons ( AAOS ) directory . Only individuals who treated or referred ACL-insufficient patients for treatment within the past year were asked to complete the 3-page survey . The survey included 25 questions regarding clinical opinion . Clinical agreement was present when 80 % or more of the surgeons agreed on the same response option . RESULTS The total number of surgeons who responded to the survey was 397 ( response rate , 54.8 % ) and the number who had treated or referred ACL-insufficient patients in 
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There were few complications , and failure rate was similar in younger patients .
Conclusion : The data confirm that ACL reconstruction can be recommended to patients older than 40 years who wish to maintain an active lifestyle or have symptomatic instability with daily activities .
Patient-based outcomes scores were better in the operative studies compared with the single nonoperative study in this patient population