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Systematic Review| Volume 4, ISSUE 4, e1513-e1521, August 2022

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Autograft and Nonirradiated Allograft for Anterior Cruciate Ligament Reconstruction Demonstrate Similar Clinical Outcomes and Graft Failure Rates: An Updated Systematic Review

Open AccessPublished:June 06, 2022DOI:https://doi.org/10.1016/j.asmr.2022.04.008
Autograft and Nonirradiated Allograft for Anterior Cruciate Ligament Reconstruction Demonstrate Similar Clinical Outcomes and Graft Failure Rates: An Updated Systematic Review
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      Purpose

      To perform an updated systematic review comparing the clinical outcomes of autograft versus nonirradiated allograft for anterior cruciate ligament reconstruction (ACLR).

      Methods

      A systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines by searching PubMed, the Cochrane Library, and Embase to identify comparative studies directly comparing outcomes of primary ACLR with autograft versus nonirradiated allograft with a minimum 2-year follow-up. The search terms used were: “anterior cruciate ligament” AND autograft AND allograft AND (irradiation OR non-irradiated). Patients were evaluated based on graft failure rates, the Objective International Knee Documentation Committee (IKDC) score, anteroposterior laxity, and patient-reported outcomes (Subjective IKDC score, the visual analog scale [VAS], the Cincinnati Knee Rating System, Lysholm, and Tegner scores). Risk of bias was assessed using the ROBINS-I and Cochrane Collaboration’s risk of bias tool for non-randomized and randomized studies, respectively.

      Results

      Sixteen studies (3 Level I, 7 Level II, 6 Level III) met inclusion criteria, including a total of 15,502 patients undergoing ACLR with autograft and 1,577 with nonirradiated allograft. The average follow-up ranged from 24.0 to 132.0 months. Graft failure ranged from 0% to 9.4% of patients in the autograft group and 0% to 26.5% in the allograft group. Two studies showed greater failure rates among younger patients in the allograft group. There were no significant differences between the Objective IKDC score, anteroposterior laxity, or patient-reported outcomes between the groups within any of the included studies (P > .05).

      Conclusions

      Autograft and nonirradiated allograft for primary ACLR demonstrate similar patient-reported outcomes and graft failure rates.

      Level of Evidence

      III, systematic review of level I-III studies.
      Anterior cruciate ligament reconstruction (ACLR) remains one of the most common procedures performed among orthopaedic sports medicine specialists.
      • Herzog M.M.
      • Marshall S.W.
      • Lund J.L.
      • Pate V.
      • Mack C.D.
      • Spang J.T.
      Trends in incidence of ACL reconstruction and concomitant procedures among commercially insured individuals in the United States, 2002-2014.
      Sports Health. 2018; 10: 523-531
      ,
      • Longo U.G.
      • Nagai K.
      • Salvatore G.
      • et al.
      Epidemiology of anterior cruciate ligament reconstruction surgery in Italy: A 15-year nationwide registry study.
      J Clin Med. 2021; 10: 223
      When performing ACLR, graft choice is an important factor to consider and may depend on patient age, sports participation, and patient/surgeon preference.
      • Bowman E.N.
      • Limpisvasti O.
      • Cole B.J.
      • ElAttrache N.S.
      Anterior cruciate ligament reconstruction graft preference most dependent on patient age: A survey of United States surgeons.
      Arthroscopy. 2021; 37: 1559-1566
      , 
      • Houck D.A.
      • Kraeutler M.J.
      • Vidal A.F.
      • et al.
      Variance in anterior cruciate ligament reconstruction graft selection based on patient demographics and location within the Multicenter Orthopaedic Outcomes Network cohort.
      J Knee Surg. 2018; 31: 472-478
      , 
      • Salminen M.
      • Kraeutler M.J.
      • Freedman K.B.
      • et al.
      Choosing a graft for anterior cruciate ligament reconstruction: Surgeon influence reigns supreme.
      Am J Orthop (Belle Mead NJ). 2016; 45: E192-197
      There are several autograft and allograft options for ACLR, with multiple studies demonstrating increased graft rupture rates with allograft compared with autograft, particularly in younger patients.
      • Cruz Jr., A.I.
      • Beck J.J.
      • Ellington M.D.
      • et al.
      Failure rates of autograft and allograft ACL reconstruction in patients 19 years of age and younger: A systematic review and meta-analysis.
      JBJS Open Access. 2020; 5e20.00106
      , 
      • Kaeding C.C.
      • Aros B.
      • Pedroza A.
      • et al.
      Allograft versus autograft anterior cruciate ligament reconstruction: Predictors of failure from a MOON prospective longitudinal cohort.
      Sports Health. 2011; 3: 73-81
      , 
      • Kraeutler M.J.
      • Bravman J.T.
      • McCarty E.C.
      Bone-patellar tendon-bone autograft versus allograft in outcomes of anterior cruciate ligament reconstruction: A meta-analysis of 5182 patients.
      Am J Sports Med. 2013; 41: 2439-2448
      , 
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      One of the factors thought to be involved in the greater failure rate of allografts is the graft-processing method, namely the use of radiation sterilization due to its detrimental biomechanical effects on allograft tissue.
      • Lansdown D.A.
      • Riff A.J.
      • Meadows M.
      • Yanke A.B.
      • Bach Jr., B.R.
      What factors influence the biomechanical properties of allograft tissue for ACL reconstruction? A systematic review.
      Clin Orthop Relat Res. 2017; 475: 2412-2425
      ,
      • Schmidt T.
      • Hoburg A.
      • Broziat C.
      • et al.
      Sterilization with electronic beam irradiation influences the biomechanical properties and the early remodeling of tendon allografts for reconstruction of the anterior cruciate ligament (ACL).
      Cell Tissue Bank. 2012; 13: 387-400
      While studies have repeatedly demonstrated inferior outcomes with irradiated allografts compared with autografts,
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      , 
      • Li J.
      • Wang J.
      • Li Y.
      • Shao D.
      • You X.
      • Shen Y.
      A prospective randomized study of anterior cruciate ligament reconstruction with autograft, γ-irradiated allograft, and hybrid graft.
      Arthroscopy. 2015; 31: 1296-1302
      , 
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic anterior cruciate ligament reconstruction with at least 2.5 years’ follow-up comparing hamstring tendon autograft and irradiated allograft.
      Arthroscopy. 2011; 27: 1195-1202
      , 
      • Tian S.
      • Wang B.
      • Liu L.
      • et al.
      Irradiated hamstring tendon allograft versus autograft for anatomic double-bundle anterior cruciate ligament reconstruction: Midterm clinical outcomes.
      Am J Sports Med. 2016; 44: 2579-2588
      these findings have not been consistently found in studies limited to nonirradiated allografts.
      • Lamblin C.J.
      • Waterman B.R.
      • Lubowitz J.H.
      Anterior cruciate ligament reconstruction with autografts compared with non-irradiated, non-chemically treated allografts.
      Arthroscopy. 2013; 29: 1113-1122
      , 
      • Mariscalco M.W.
      • Magnussen R.A.
      • Mehta D.
      • Hewett T.E.
      • Flanigan D.C.
      • Kaeding C.C.
      Autograft versus nonirradiated allograft tissue for anterior cruciate ligament reconstruction: A systematic review.
      Am J Sports Med. 2014; 42: 492-499
      , 
      • Wang S.
      • Zhang C.
      • Cai Y.
      • Lin X.
      Autograft or allograft? Irradiated or not? A contrast between autograft and allograft in anterior cruciate ligament reconstruction: A meta-analysis.
      Arthroscopy. 2018; 34: 3258-3265
      Advantages of allograft use include smaller incisions, reduced postoperative pain/less donor-site morbidity, larger graft availability, earlier postoperative knee range of motion, and decreased surgical time.
      • Dashe J.
      • Parisien R.L.
      • Cusano A.
      • Curry E.J.
      • Bedi A.
      • Li X.
      Allograft tissue irradiation and failure rate after anterior cruciate ligament reconstruction: A systematic review.
      World J Orthop. 2016; 7: 392-400
      Disadvantages include risk of immunogenic reaction, bacterial infection, and disease transmission from the graft donor. Another cited disadvantage of allograft use is increased laxity over time, which can result in knee joint instability and failure to return to previous level of activities despite an “intact” graft.
      • Dashe J.
      • Parisien R.L.
      • Cusano A.
      • Curry E.J.
      • Bedi A.
      • Li X.
      Allograft tissue irradiation and failure rate after anterior cruciate ligament reconstruction: A systematic review.
      World J Orthop. 2016; 7: 392-400
      The purpose of this study was to perform an updated systematic review comparing the clinical outcomes of autograft versus nonirradiated allograft for ACLR. The authors hypothesized that no significant differences would be found between groups in terms of graft rupture rates or patient-reported outcomes (PROs).

      Methods

      This systematic review was conducted according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using a PRISMA checklist. Two independent reviewers (J.D., J.W.B.) searched PubMed, Embase, and the Cochrane Library up to August 8, 2021. The electronic search strategy used was as follows: "anterior cruciate ligament" AND autograft AND allograft AND (irradiation OR non-irradiated). A total of 113 studies were reviewed by title and/or abstract to determine study eligibility based on inclusion criteria. In cases of disagreement, a third reviewer (M.J.K.) made the final decision. The inclusion criteria were nonoverlapping human studies directly comparing autograft versus nonirradiated allograft with a minimum 2-year follow-up. Exclusion criteria included noncomparative studies, studies unrelated to the knee, and studies that did not distinguish outcomes between irradiated and nonirradiated allograft. Data extraction from each study was performed independently and then reviewed by a second author (M.J.K.). There was no need for funding or a third party to obtain any of the collected data. Risk of bias for 7 randomized studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      , 
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      , 
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      , 
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      , 
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      , 
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      was assessed according to the Cochrane Collaboration’s risk of bias tool,
      • Higgins J.P.
      • Altman D.G.
      • Gøtzsche P.C.
      • et al.
      The Cochrane Collaboration's tool for assessing risk of bias in randomised trials.
      BMJ. 2011; 343: 5928
      which incorporates an assessment of randomization, blinding, completeness of outcomes data, selection of outcomes reported, and other sources of bias. Risk of bias for the 9 remaining nonrandomized studies
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      , 
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      , 
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      , 
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      , 
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      , 
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      was assessed according to the ROBINS-I (i.e., (Risk Of Bias In Non-randomized Studies - of Interventions)) risk of bias tool,
      • Sterne J.A.
      • Hernan M.A.
      • Reeves B.C.
      • et al.
      ROBINS-I: a tool for assessing risk of bias in non-randomised studies of interventions.
      BMJ. 2016; 355: i4919
      which incorporates an assessment of bias due to confounding, selection of participants, deviations from intended interventions, completeness of outcomes data, selection of outcomes reported, and other sources of bias. A score of <0.20 indicates poor agreement; 0.21-0.40, fair agreement; 0.41-0.60, moderate agreement; 0.61-0.80, good agreement; and 0.81-1.00, very good agreement.
      • McHugh M.L.
      Interrater reliability: The kappa statistic.
      Biochem Med (Zagreb). 2012; 22: 276-282

      Reporting Outcomes

      Outcomes assessed included graft failure, PROs, anteroposterior (AP) laxity, and the Objective International Knee Documentation Committee (IKDC) score.
      • Hefti F.
      • Müller W.
      • Jakob R.P.
      • Stäubli H.U.
      Evaluation of knee ligament injuries with the IKDC form.
      Knee Surg Sports Traumatol Arthrosc. 1993; 1: 226-234
      PROs included the Subjective IKDC score,
      • Irrgang J.J.
      • Anderson A.F.
      • Boland A.L.
      • et al.
      Development and validation of the International Knee Documentation Committee Subjective Knee Form.
      Am J Sports Med. 2001; 29: 600-613
      Lysholm score,
      • Lysholm J.
      • Gillquist J.
      Evaluation of knee ligament surgery results with special emphasis on use of a scoring scale.
      Am J Sports Med. 1982; 10: 150-154
      Tegner activity score,
      • Tegner Y.
      • Lysholm J.
      Rating systems in the evaluation of knee ligament injuries.
      Clin Orthop Relat Res. 1985; : 43-49
      VAS for pain, and the Cincinnati Knee Rating System.
      • Barber-Westin S.D.
      • Noyes F.R.
      • McCloskey J.W.
      Rigorous statistical reliability, validity, and responsiveness testing of the Cincinnati Knee Rating System in 350 subjects with uninjured, injured, or anterior cruciate ligament-reconstructed knees.
      Am J Sports Med. 1999; 27: 402-416
      An attempt was made to perform a subanalysis of outcomes in younger patients, but this was not possible, as only one study
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      reported outcomes based on age.

      Study Methodology Assessment

      The Modified Coleman Methodology Score (MCMS)
      • Coleman B.D.
      • Khan H.M.
      • Maffulli N.
      • Cook J.L.
      • Wark J.D.
      Studies of surgical outcome after patellar tendinopathy: Clinical significance of methodological deficiencies and guidelines for future studies. Victorian Institute of Sport Tendon Study Group.
      Scand J Med Sci Sports. 2000; 10: 2-11
      was used to evaluate study methodology quality. The MCMS has a scaled potential score ranging from 0 to 100. Scores ranging from 85 to 100 are excellent, 70 to 84 are good, 55 to 69 are fair, and less than 55 are poor. The primary outcomes assessed by the MCMS are study size and type, follow-up time, attrition rates, number of interventions per group, and proper description of study methodology.

      Results

      Sixteen studies met inclusion and exclusion criteria (Fig 1). A total of 17,079 patients were included in this systematic review, including 15,502 patients undergoing ACLR with an autograft and 1,577 with a nonirradiated allograft. Patient age ranged from 13.0 to 64.0 years and the mean follow-up time ranged from 24 to 132 months (Table 1). The percentage of male patients ranged from 49.4% to 90.9%. Twelve studies
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      , 
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      , 
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      , 
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      , 
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      , 
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      , 
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      , 
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      , 
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      , 
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      ,
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      did not report the use of any irradiated allografts. In addition to the nonirradiated allografts analyzed in this review, irradiated allografts were used in the remaining 4 studies in 32 patients,
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      68 patients,
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      874 patients,
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      and 3,022 patients.
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      Figure thumbnail gr1
      Fig 1Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram.
      Table 1Studies Included
      StudyLevel of Evidencen (Auto, Allo)Patient Age (Auto, Allo), y (Range)Follow-up, mo (Range)Sex, % Male
      Bottoni et al., 2015
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      		I48, 4928.9, 29.2 (20.6-42.5)126 (120-132)86.6
      Noh et al., 2011
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      		I33, 3223.0, 22.0 (20-55)29.8 (NR)86.2
      Yoo et al., 2017
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      		I68, 6430.0, 24.0 (13-62)33.6 (25.3-59.5)90.9
      Edgar et al., 2008
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      		II37, 4627.0, 31.0 (15-55)49.8 (36.0-74.0)55.4
      Lawhorn et al., 2012
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      		II74, 7332.0, 33.3 (16-53)NR68.0
      Maletis et al., 2017
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      		II4,557; 155NRNRNR
      Maletis et al., 2017
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      		II10,264; 729NRNRNR
      Sun et al., 2009
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      		II33, 3429.7, 31.8 (19-64)30.8 (NR)68.7
      Sun et al., 2011
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      		II91, 9529.6, 31.2 (18-59)94.8 (72-120)80.1
      Tian et al., 2016
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      		II62, 5930.5, 29.9 (15-56)55.2 (48-66)79.3
      Barber et al., 2014
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      		III53, 2818.6, 20.1 (13-25)34.0 (24-132)49.4
      Barrett et al., 2005
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      		III25, 3844.5, 47.1 (40-58)NR55.6
      Guo et al., 2012
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      		III41, 3325.0, 25.3 (16-40)80.4 (50.4-98.4)63.5
      Kane et al., 2016
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      		III60, 5919.8, 20.6 (NR)NRNR
      Kustos et al., 2004
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      		III26, 5324.5, 25.6 (NR)38.0 (NR)75.9
      Peterson et al., 2001
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      		III30, 3025.0, 28.0 (15-55)63.6 (55-78)55.0
      NOTE. n refers to the number of knees that underwent ACL reconstruction with either autograft or nonirradiated allograft in each study. Patient age and follow-up are reported as mean (range).
      ACL, anterior cruciate ligament; Allo, nonirradiated allograft; Auto, autograft; NR, not reported.

      Surgical Technique

      Table 2 shows the types of autograft/allografts used for ACLR in the 16 included studies. Nine studies
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      ,
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      ,
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      , 
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      , 
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      , 
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      ,
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      used a transtibial approach for femoral tunnel drilling. Two studies
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      ,
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      used an anteromedial portal approach. Five studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      ,
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      did not report their method of femoral tunnel drilling (Table 2).
      Table 2Surgical Details
      StudyAutograft/AllograftMethod of Femoral Tunnel DrillingMethod of Graft FixationIndication for Graft Type
      Bottoni et al., 2015
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      		Hamstring/tibialis posteriorTTBioabsorbable interference screwRandomized
      Noh et al., 2011
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      		Hamstring/AchillesTTCortical button/bioabsorbable interference screwRandomized
      Yoo et al., 2017
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      		Hamstring/tibialis anterior or posteriorTTCortical button/bioabsorbable interference screwRandomized
      Edgar et al., 2008
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      		Hamstring/hamstringTTBioabsorbable interference screwRandomized/patient choice
      Lawhorn et al., 2012
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      		Hamstring/tibialis anteriorTTMetal interference screwRandomized
      Maletis et al., 2017
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      		BPTB/BPTBNRNRNR
      Maletis et al., 2017
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      		BPTB or hamstring/soft tissueNRNRNR
      Sun et al., 2009
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      		BPTB/BPTBNRMetal/bioabsorbable interference screwRandomized
      Sun et al., 2011
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      		Hamstring/hamstringAM portalCortical button/bioabsorbable interference screwRandomized
      Tian et al., 2016
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      		Hamstring/hamstringAM portalBioabsorbable interference screwRandomized
      Barber et al., 2014
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      		BPTB/BPTBTTBioabsorbable interference screwPatient choice
      Barrett et al., 2005
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      		BPTB/BPTBTTCortical button/bioabsorbable interference screwNR
      Guo et al., 2012
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      		BPTB/BPTBTTBioabsorbable interference screwPatient choice
      Kane et al., 2016
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      		BPTB/BPTBTTBioabsorbable interference screwPatient choice
      Kustos et al., 2004
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      		BPTB/BPTBNRBioabsorbable interference screwPatient choice
      Peterson et al., 2001
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      		BPTB/BPTBNRMetal interference screwPatient choice
      AM, anteromedial; BPTB, bone–patellar tendon–bone; NR, not reported; TT, transtibial.
      Seven studies
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      ,
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      ,
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      , 
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      , 
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      used bioabsorbable interference screws for graft fixation. Two studies
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      ,
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      used a metal interference screw for graft fixation. One study
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      used either a metal or bioabsorbable interference screw. Four studies
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      ,
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      ,
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      ,
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      used a cortical button (ENDOBUTTON; Smith & Nephew, Andover, MA) to fix the graft on the femoral side and a bioabsorbable interference screw on the tibial side. Two studies
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      ,
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      did not detail their method of graft fixation. In 6 of the nonrandomized studies,
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      ,
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      ,
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      ,
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      ,
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      the graft type was chosen based on patient choice (Table 2).

      Graft Failure

      Two studies
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      ,
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      defined graft failure as graft rupture, whereas 12 studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      ,
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      ,
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      ,
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      ,
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      ,
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      ,
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      , 
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      defined graft failure as the need for a revision ACL reconstruction. Overall, graft failure ranged from 0.0% to 9.4% in the autograft group and 0.0% to 26.5% in the allograft group (Table 3). In one study,
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      among patients 21 years old and younger, the graft failure rate was 2.9% in the autograft group and 11.4% in the allograft group. In patients 22 years old and older, the graft failure rate was 0.9% in the autograft group and 1.7% in the allograft group. Three studies
      • Dashe J.
      • Parisien R.L.
      • Cusano A.
      • Curry E.J.
      • Bedi A.
      • Li X.
      Allograft tissue irradiation and failure rate after anterior cruciate ligament reconstruction: A systematic review.
      World J Orthop. 2016; 7: 392-400
      ,
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      ,
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      found a significantly greater graft failure rate in the nonirradiated allograft group at final follow-up, one of which
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      limited inclusion to patients aged 25 years or younger.
      Table 3Graft Failure Rates
      StudyAutoAlloTotal
      Peterson et al., 2001
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      		1/30 (3.3%)1/30 (3.3%)2/60 (3.3%)
      Kustos et al., 2004
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      		1/26 (3.8%)2/53 (3.8%)3/79 (3.8%)
      Barrett et al., 2005
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      		0/25 (0%)1/38 (2.6%)1/63 (1.6%)
      Edgar et al., 2008
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      		3/37 (8.1%)2/46 (4.3%)5/83 (6.0%)
      Sun et al., 2009
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      		2/33 (6.1%)3/34 (8.8%)5/67 (7.5%)
      Guo et al., 2012
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      		0/41 (0%)0/33 (0%)0/74 (0%)
      Lawhorn et al., 2012
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      		0/74 (0%)0/73 (0%)0/147 (0%)
      Barber et al., 2014
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      		5/53 (9.4%)2/28 (7.1%)7/81 (8.6%)
      Bottoni et al., 2015
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      		4/48 (8.3%)13/49 (26.5%)17/97 (17.5%)
      Yoo et al., 2017
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      		1/68 (1.5%)1/64 (1.6%)2/132 (1.5%)
      Tian et al., 2016
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      		0/62 (0%)0/59 (0%)0/121 (0%)
      Kane et al., 2016
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      		1/60 (1.7%)12/59 (20.3%)13/119 (10.9%)
      Maletis et al., 2017
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      		85/4,557 (1.9%)5/155 (3.2%)90/4,712 (1.9%)
      Maletis et al., 2017
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      		217/10,264 (2.1%)12/729 (1.6%)229/10,993 (2.1%)
      NOTE. Each cell includes the number of graft failures/total number of ACLRs performed (%) within each group.
      ACLR, anterior cruciate ligament reconstruction; Allo, nonirradiated allograft; Auto, autograft.

      Patient-Reported Outcomes (PROs)

      Seven studies
      • Kraeutler M.J.
      • Bravman J.T.
      • McCarty E.C.
      Bone-patellar tendon-bone autograft versus allograft in outcomes of anterior cruciate ligament reconstruction: A meta-analysis of 5182 patients.
      Am J Sports Med. 2013; 41: 2439-2448
      ,
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      ,
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      ,
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      ,
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      ,
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      ,
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      reported results of the Subjective IKDC score (Table 4). No study found a significant difference in comparison of postoperative scores between the groups.
      Table 4Subjective IKDC Score
      StudyAuto (Preoperative)Auto (Postoperative)Allo (Preoperative)Allo (Postoperative)P Value
      Edgar et al., 2008
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      		57.5 ± 8.487.6 ± 10.254.9 ± 13.187.0 ± 11.7.82
      Sun et al., 2009
      • Kraeutler M.J.
      • Bravman J.T.
      • McCarty E.C.
      Bone-patellar tendon-bone autograft versus allograft in outcomes of anterior cruciate ligament reconstruction: A meta-analysis of 5182 patients.
      Am J Sports Med. 2013; 41: 2439-2448
      		NR88.0 ± 11NR89.0 ± 9>.05
      Sun et al., 2011
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      		NR89.0 ± 12NR90.0 ± 14.548
      Lawhorn et al., 2012
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      		NR91.0NR90.9>.05
      Bottoni et al., 2015
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      		NR77.2 ± 25.4NR73.7 ± 25.9.51
      Tian et al., 2016
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      		NR90.0 ± 11NR89.0 ± 12.63
      Kane et al., 2016
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      		NR95.4NR95.4>.05
      NOTE. Scores are reported as a mean ± SD (when reported) at latest follow-up. Reported P values indicate comparison of postoperative scores between groups.
      Allo, nonirradiated allograft; Auto, autograft; IKDC, International Knee Documentation Committee; NR, not reported; SD, standard deviation.
      Twelve studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      , 
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      , 
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      , 
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      , 
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      , 
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      , 
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      , 
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      ,
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      reported results of the Lysholm score (Table 5). No study found a significant difference in comparison of postoperative scores between the groups.
      Table 5Lysholm Score
      StudyAuto (Preoperative)Auto (Postoperative)Allo (Preoperative)Allo (Postoperative)P Value
      Peterson et al., 2001
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      		NR88.6NR90.0>.05
      Kustos et al., 2004
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      		NR89.9 ± 8.1NR84.1 ± 18.6>.05
      Barrett et al., 2005
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      		55.092.054.091.0>.05
      Edgar et al., 2008
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      		71.3 ± 8.691.0 ± 7.767.7 ± 1792.7 ± 10.75
      Sun et al., 2009
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      		NR90.0 ± 9NR91.0 ± 8>.05
      Noh et al., 2011
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      		54.098.056.099.0>.05
      Sun et al., 2011
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      		60.0 ± 1289.0 ± 959.0 ± 1090.0 ± 8.60
      Guo et al., 2012
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      		52.1 ± 6.286.6 ± 9.543.3 ± 5.785.6 ± 10.1.74
      Barber et al., 2014
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      		44.887.060.389.9.43
      Yoo et al., 2017
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      		NR96.0NR93.0>.05
      Tian et al., 2016
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      		58.0 ± 1090.0 ± 1057.0 ± 889.0 ± 11.6
      Kane et al., 2016
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      		NR95.0NR95.0>.05
      NOTE. Scores are reported as a mean ± SD (when reported) at latest follow-up. Reported P values indicate comparison of postoperative scores between groups.
      Allo, nonirradiated allograft; Auto, autograft; NR, not reported; SD, standard deviation.
      Ten studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      ,
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      , 
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      , 
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      , 
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      ,
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      ,
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      ,
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      reported results of the Tegner score (Table 6). No study found a significant difference in comparison of postoperative scores between the groups.
      Table 6Tegner Score
      StudyAuto (Preoperative)Auto (Postoperative)Allo (Preoperative)Allo (Postoperative)P Value
      Peterson et al., 2001
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      		NR6.1NR5.4>.05
      Barrett et al., 2005
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      		3.94.34.34.1>.05
      Edgar et al., 2008
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      		7.2 ± 1.16.8 ± 1.26.8 ± 1.36.9 ± 1.3.08
      Sun et al., 2009
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      		NR7.7 ± 1.3NR7.5 ± 1.5>.05
      Noh et al., 2011
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      		6.06.07.06.0>.05
      Sun et al., 2011
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      		3.0 ± 1.37.7 ± 1.83.1 ± 1.57.6 ± 1.5.94
      Guo et al., 2012
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      		2.1 ± 0.74.5 ± 1.12.4 ± 0.94.1 ± 0.8.42
      Bottoni et al., 2015
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      		NR4.8 ± 2.3NR4.5 ± 2.2.51
      Yoo et al., 2017
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      		NR5.0NR5.0>.05
      Tian et al., 2016
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      		2.8 ± 0.77.9 ± 0.82.9 ± 0.87.8 ± 1.0.54
      NOTE. Scores are reported as a mean ± SD (when reported) at latest follow-up. Reported P values indicate comparison of postoperative scores between groups.
      Allo, nonirradiated allograft; Auto, autograft; NR, not reported; SD, standard deviation.
      Three studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      reported results for the Cincinnati Knee Rating System. No study found a significant difference in comparison of postoperative scores between the groups.
      One study
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      reported results of the VAS scale for pain and found no significant difference between groups pre- or postoperatively (P > .05).

      AP Knee Laxity

      Five studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      ,
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      ,
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      measured AP knee laxity, with 3 studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      measuring mean side-to-side differences in tibial translation (Table 7). No study found a significant difference in comparison of postoperative measurements between the groups. Two studies
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      used KT-1000 and one study
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      used KT-2000.
      Table 7AP Knee Laxity
      StudyAuto (Preoperative)Auto (Postoperative)Allo (Preoperative)Allo (Postoperative)P Value
      Edgar et al., 2008
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      		6.0 ± 1.31.6 ± 1.55.8 ± 1.51.4 ± 1.3.33
      Sun et al., 2009
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      		NR2.4 ± 0.6NR2.6 ± 0.9>.05
      Guo et al., 2012
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      		5.9 ± 0.72.3 ± 0.36.3 ± 0.82.6 ± 0.4.85
      NOTE. Measurements are reported as a mean ± SD (when reported) side-to-side difference (in millimeters) at latest follow-up. Reported P values indicate comparison of postoperative measurements between groups.
      Allo, nonirradiated allograft; AP, anteroposterior; Auto, autograft; NR, not reported; SD, standard deviation.

      Objective IKDC

      Four studies
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      ,
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      , 
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      , 
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      reported results for the Objective IKDC score and found no significant difference between the 2 groups at final follow-up (P = .71, P > .05, P > .05, and P > .87, respectively).

      Modified Coleman Methodology Score

      Table 8 shows the MCMS scores from the 16 included studies. One study
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      received an excellent score, 7 studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      ,
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      ,
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      ,
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      ,
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      ,
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      received good scores, and 8 studies
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      ,
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      ,
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      , 
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      received fair scores.
      Table 8Modified Coleman Methodology Score (MCMS)
      StudyMCMS
      Peterson et al., 2001
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      		76
      Kustos et al., 2004
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      		59
      Barrett et al., 2005
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      		60
      Edgar et al., 2008
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      		77
      Sun et al., 2009
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      		79
      Noh et al., 2011
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      		79
      Sun et al., 2011
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      		88
      Guo et al., 2012
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      		69
      Lawhorn et al., 2012
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      		66
      Barber et al., 2014
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      		60
      Bottoni et al., 2015
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      		71
      Yoo et al., 2017
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      		73
      Tian et al., 2016
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      		80
      Kane et al., 2016
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      		63
      Maletis et al., 2017
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      		68
      Maletis et al., 2017
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      		68

      Methodologic Quality Assessment

      The results of the methodologic quality assessment of the 9 nonrandomized studies using the ROBINS-I risk of bias tool are presented in Figure 2. All 9 studies
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      , 
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      , 
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      , 
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      , 
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      , 
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      showed a moderate risk of bias due to confounding, as there were no prognostic variables that predicted baseline intervention and no patients that switched between interventions during the study period. No studies excluded eligible patients or used variable follow-up times based on intervention (low risk of bias), no studies deviated from the intended intervention (low risk of bias), and all studies clearly classified treatment type (low risk of bias). Two studies
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      ,
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      using blinded outcome assessors showed no systematic differences in the care provided between treatment groups (low risk of bias), whereas 7 studies
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      ,
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      ,
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      , 
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      used nonblinded but identical postoperative protocols (moderate risk of bias). No studies showed bias due to missing data (low risk of bias). Two studies
      • Edgar C.M.
      • Zimmer S.
      • Kakar S.
      • Jones H.
      • Schepsis A.A.
      Prospective comparison of auto and allograft hamstring tendon constructs for ACL reconstruction.
      Clin Orthop Relat Res. 2008; 466: 2238-2246
      ,
      • Peterson R.K.
      • Shelton W.R.
      • Bomboy A.L.
      Allograft versus autograft patellar tendon anterior cruciate ligament reconstruction: A 5-year follow-up.
      Arthroscopy. 2001; 17: 9-13
      demonstrated low risk of bias in measurement of outcomes through use of blinded outcome assessors, whereas 7 studies
      • Guo L.
      • Yang L.
      • Duan X.
      • et al.
      Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft: Comparison of autograft, fresh-frozen allograft, and γ-irradiated allograft.
      Arthroscopy. 2012; 28: 211-217
      ,
      • Barber F.A.
      • Cowden 3rd, C.H.
      • Sanders E.J.
      Revision rates after anterior cruciate ligament reconstruction using bone-patellar tendon-bone allograft or autograft in a population 25 years old and younger.
      Arthroscopy. 2014; 30: 483-491
      ,
      • Barrett G.
      • Stokes D.
      • White M.
      Anterior cruciate ligament reconstruction in patients older than 40 years: Allograft versus autograft patellar tendon.
      Am J Sports Med. 2005; 33: 1505-1512
      ,
      • Kane P.W.
      • Wascher J.
      • Dodson C.C.
      • Hammoud S.
      • Cohen S.B.
      • Ciccotti M.G.
      Anterior cruciate ligament reconstruction with bone–patellar tendon–bone autograft versus allograft in skeletally mature patients aged 25 years or younger.
      Knee Surg Sports Traumatol Arthrosc. 2016; 24: 3627-3633
      , 
      • Kustos T.
      • Bálint L.
      • Than P.
      • Bárdos T.
      Comparative study of autograft or allograft in primary anterior cruciate ligament reconstruction.
      Int Orthop. 2004; 28: 290-293
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with bone–patellar tendon–bone allografts compared with autografts.
      Am J Sports Med. 2017; 45: 1333-1340
      , 
      • Maletis G.B.
      • Chen J.
      • Inacio M.C.S.
      • Love R.M.
      • Funahashi T.T.
      Increased risk of revision after anterior cruciate ligament reconstruction with soft tissue allografts compared with autografts: Graft processing and time make a difference.
      Am J Sports Med. 2017; 45: 1837-1844
      used physicians not blinded to treatment group (serious risk of bias). Finally, no studies showed bias due to selective reporting (low risk of bias). A Cohen’s Kappa score of 0.82 reflected a very good agreement between reviewers.
      Figure thumbnail gr2
      Fig 2Risk of bias graph. Risk of bias is presented as a percentage across all included studies (green, low risk; yellow, unclear; red, high risk).
      The remaining 7 randomized studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      , 
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      , 
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      , 
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      , 
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      , 
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      were assessed for methodologic quality using the Cochrane Collaboration’s risk of bias tool. Sequence generation and allocation were adequately reported by all studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      , 
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      , 
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      , 
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      , 
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      , 
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      (low risk of bias), and 2 studies
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      ,
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      were deemed to be at low risk for detection bias because of the blinding of the outcome assessor. Six studies
      • Sun K.
      • Tian S.
      • Zhang J.
      • Xia C.
      • Zhang C.
      • Yu T.
      Anterior cruciate ligament reconstruction with BPTB autograft, irradiated versus non-irradiated allograft: A prospective randomized clinical study.
      Knee Surg Sports Traumatol Arthrosc. 2009; 17: 464-474
      ,
      • Lawhorn K.W.
      • Howell S.M.
      • Traina S.M.
      • Gottlieb J.E.
      • Meade T.D.
      • Freedberg H.I.
      The effect of graft tissue on anterior cruciate ligament outcomes: A multicenter, prospective, randomized controlled trial comparing autograft hamstrings with fresh-frozen anterior tibialis allograft.
      Arthroscopy. 2012; 28: 1079-1086
      , 
      • Noh J.H.
      • Yi S.R.
      • Song S.J.
      • Kim S.W.
      • Kim W.
      Comparison between hamstring autograft and free tendon Achilles allograft: minimum 2-year follow-up after anterior cruciate ligament reconstruction using EndoButton and Intrafix.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 816-822
      , 
      • Sun K.
      • Zhang J.
      • Wang Y.
      • et al.
      Arthroscopic reconstruction of the anterior cruciate ligament with hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized controlled study.
      Am J Sports Med. 2011; 39: 1430-1438
      , 
      • Tian S.
      • Wang Y.
      • Wang B.
      • et al.
      Anatomic double-bundle anterior cruciate ligament reconstruction with a hamstring tendon autograft and fresh-frozen allograft: A prospective, randomized, and controlled study.
      Arthroscopy. 2016; 32: 2521-2531
      , 
      • Yoo S.H.
      • Song E.K.
      • Shin Y.R.
      • Kim S.K.
      • Seon J.K.
      Comparison of clinical outcomes and second-look arthroscopic findings after ACL reconstruction using a hamstring autograft or a tibialis allograft.
      Knee Surg Sports Traumatol Arthrosc. 2017; 25: 1290-1297
      did not report blinding of either patients or the outcome assessor (high risk of bias). One study
      • Bottoni C.R.
      • Smith E.L.
      • Shaha J.
      • et al.
      Autograft versus allograft anterior cruciate ligament reconstruction: A prospective, randomized clinical study with a minimum 10-year follow-up.
      Am J Sports Med. 2015; 43: 2501-2509
      reported blinding outcome assessors, but not patients (moderate risk of bias). No studies reported significant loss of follow-up (low risk of bias) and no studies was deemed to be at risk of bias for selective reporting or incomplete outcome data (low risk of bias).

      Discussion

      Based on the findings of this systematic review, there were no statistically significant differences between use of autograft and nonirradiated allograft for primary ACLR with regard to PROs, AP knee laxity, and the Objective IKDC score at a minimum 2-year follow-up. Furthermore, PROs and graft failure rates were similar between groups at final follow-up. Unfortunately, most studies did not report outcomes based on age, and surgeons are likely weary to further investigate this in future studies of young, active patients.
      Several previous studies have suggested that the greater failure rates we expect with allografts in general do not necessarily occur with nonirradiated allografts. A meta-analysis published in 2018
      • Wang S.
      • Zhang C.
      • Cai Y.
      • Lin X.
      Autograft or allograft? Irradiated or not? A contrast between autograft and allograft in anterior cruciate ligament reconstruction: A meta-analysis.
      Arthroscopy. 2018; 34: 3258-3265
      with a total of 1,172 patients found no significant differences between autograft and nonirradiated allograft groups for primary ACLR in terms of PROs (Subjective IKDC, Lysholm, Tegner scores), with similar failure rates between the 2 groups (autograft: 2.3%, nonirradiated allograft: 2.8%). Likewise, a systematic review from 2014
      • Mariscalco M.W.
      • Magnussen R.A.
      • Mehta D.
      • Hewett T.E.
      • Flanigan D.C.
      • Kaeding C.C.
      Autograft versus nonirradiated allograft tissue for anterior cruciate ligament reconstruction: A systematic review.
      Am J Sports Med. 2014; 42: 492-499
      with 811 patients found no significant differences in graft failure rate, postoperative knee laxity, or PROs between autograft and nonirradiated allograft tissue for ACLR. Lamblin et al.,
      • Lamblin C.J.
      • Waterman B.R.
      • Lubowitz J.H.
      Anterior cruciate ligament reconstruction with autografts compared with non-irradiated, non-chemically treated allografts.
      Arthroscopy. 2013; 29: 1113-1122
      in a 2013 systematic review of 1,002 patients, found similar outcomes between these 2 groups with regard to graft failure, PROs, and Lachman/pivot shift testing. The current systematic review builds upon these previous reviews with additional studies and a larger sample size included for a more robust and updated set of clinical findings.
      Use of autograft tissue for ACLR is not without complications. In terms of hamstring tendon harvesting, there is a high rate of damage to the saphenous nerve, up to 88% in a study by Kjaergaard et al.
      • Kjaergaard J.
      • Faunø L.Z.
      • Faunø P.
      Sensibility loss after ACL reconstruction with hamstring graft.
      Int J Sports Med. 2008; 29: 507-511
      The primary complication for bone–patellar tendon–bone autograft harvesting is anterior knee pain, which is reported in up to 46% of cases.
      • Hardy A.
      • Casabianca L.
      • Andrieu K.
      • Baverel L.
      • Noailles T.
      Junior French Arthroscopy Society
      Complications following harvesting of patellar tendon or hamstring tendon grafts for anterior cruciate ligament reconstruction: Systematic review of literature.
      Orthop Traumatol Surg Res. 2017; 103: S245-S248
      This is especially concerning for patients who kneel frequently, such as those who pray daily or workers such as painters or carpenters.
      • Kraeutler M.J.
      • Bravman J.T.
      • McCarty E.C.
      Bone-patellar tendon-bone autograft versus allograft in outcomes of anterior cruciate ligament reconstruction: A meta-analysis of 5182 patients.
      Am J Sports Med. 2013; 41: 2439-2448
      Other complications can include patellar tendonitis, tendon rupture, or rarely patella fracture.
      • Hardy A.
      • Casabianca L.
      • Andrieu K.
      • Baverel L.
      • Noailles T.
      Junior French Arthroscopy Society
      Complications following harvesting of patellar tendon or hamstring tendon grafts for anterior cruciate ligament reconstruction: Systematic review of literature.
      Orthop Traumatol Surg Res. 2017; 103: S245-S248
      ,
      • Rosenberg T.D.
      • Franklin J.L.
      • Baldwin G.N.
      • Nelson K.A.
      Extensor mechanism function after patellar tendon graft harvest for anterior cruciate ligament reconstruction.
      Am J Sports Med. 1992; 20: 519-525
      Another issue with autograft harvesting is the loss of muscle strength postoperatively. A meta-analysis found an extension strength deficit in patients with bone–patellar tendon–bone autograft and flexion strength deficit in patients with hamstring tendon autograft that persisted at 12 months postoperatively.
      • Xergia S.A.
      • McClelland J.A.
      • Kvist J.
      • Vasiliadis H.S.
      • Georgoulis A.D.
      The influence of graft choice on isokinetic muscle strength 4-24 months after anterior cruciate ligament reconstruction.
      Knee Surg Sports Traumatol Arthrosc. 2011; 19: 768-780
      Thus, the use of allograft tissue would help eliminate these morbidities as well as reducing the operation time.
      • Mistry H.
      • Metcalfe A.
      • Colquitt J.
      • et al.
      Autograft or allograft for reconstruction of anterior cruciate ligament: A health economics perspective.
      Knee Surg Sports Traumatol Arthrosc. 2019; 27: 1782-1790
      Nonirradiated allografts are not without disadvantages as well. These grafts demonstrate decreased osteoinductive and osteoconductive characteristics, as well as a delayed graft incorporation time in comparison with autografts.
      • Barbour S.A.
      • King W.
      The safe and effective use of allograft tissue—an update.
      Am J Sports Med. 2003; : 31791-31797
      Another disadvantage is the risk of disease transmission. Although the risk remains low, there is still potential for viral transmission due to human error as well as window periods of infection where detection is missed through serologic tests.
      • Tomford W.W.
      Transmission of disease through transplantation of musculoskeletal allografts.
      J Bone Joint Surg Am. 1995; 77: 1742-1754
      It is critical to properly sterilize tendon allografts before implantation. A systematic review assessed the different sterilization and disinfection methods and identified gamma or electron beam irradiation, ethylene oxide, supercritical carbon dioxide, and BioCleanse (RTI Surgical, Alachua, FL) as potential methods.
      • Farago D.
      • Kozma B.
      • Kiss R.M.
      Different sterilization and disinfection methods used for human tendons—a systematic review using mechanical properties to evaluate tendon allografts.
      BMC Musculoskelet Disord. 2021; 22: 404