Critical Criteria Recommendations: Return to Sport After ACL reconstruction requires evaluation of time after surgery of 8 months, >2 functional tests, psychological readiness, and quadriceps/hamstring strength

Published:October 07, 2022DOI:



      The purpose of this study was to examine the factors commonly used to determine readiness for RTS in the ACL-R patient population and assess which were most influential to successfully returning to sport and avoiding re-tear.


      The PUBMED, EMBASE and Cochrane Library databases were queried for studies related to RTS in ACL-R. Inclusion and exclusion criteria were applied to identify studies with greater than 1-year outcomes detailing the rate of return and re-tear given a described RTS protocol. Data of interest was extracted and studies were stratified based on level of evidence and selected study features. Meta-analysis and/or subjective synthesis of appropriate studies was used to assess over 25 potentially significant variables effecting RTS and re-tear.


      After initial search of 1503 studies, 47 articles were selected for inclusion in the final data analysis including a total of 1432 patients (31.4% females, 68.6% male). A meta-analysis of re-tear rate for included Level of Evidence 1 studies was calculated to be 2.8%. Subgroups including protocols containing a strict time until RTS, strength testing, and ≥2 dynamic tests demonstrated decreased RTS and re-tear heterogeneity from the larger group. Time to RTS, strength testing, dynamic functional testing, and knee stability were also found to be among the most prevalent reported criteria in RTS protocol studies.


      This study suggests a multifactorial clinical algorithm for successful evaluation of RTS. The “critical criteria” recommended by the authors to be part of the postoperative RTS criteria include time since surgery of 8 months, use of >2 functional tests, psychological readiness testing, and quadriceps/hamstring strength testing in addition to the modifying patient factors of age and female gender.

      Level Of Evidence

      Level IV, Systematic Review of Level IV or better investigations
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        • Paterno M.V.
        • Rauh M.J.
        • Schmitt L.C.
        • Ford K.R.
        • Hewett T.E.
        Incidence of Second ACL Injuries 2 Years After Primary ACL Reconstruction and Return to Sport.
        Am J Sports Med. Jul. 2014; 42: 1567-1573
        • Mather 3rd, R.C.
        • Koenig L.
        • Kocher M.S.
        • et al.
        Societal and economic impact of anterior cruciate ligament tears.
        J Bone Joint Surg Am. Oct 2 2013; 95: 1751-1759
        • Wiggins A.J.
        • Grandhi R.K.
        • Schneider D.K.
        • Stanfield D.
        • Webster K.E.
        • Myer G.D.
        Risk of Secondary Injury in Younger Athletes After Anterior Cruciate Ligament Reconstruction: A Systematic Review and Meta-analysis.
        Am J Sports Med. Jul. 2016; 44: 1861-1876
        • Webster K.E.
        • Feller J.A.
        • Leigh W.B.
        • Richmond A.K.
        Younger patients are at increased risk for graft rupture and contralateral injury after anterior cruciate ligament reconstruction.
        Am J Sports Med. Mar 2014; 42: 641-647
        • Paterno M.V.
        • Weed A.M.
        • Hewett T.E.
        A between sex comparison of anterior-posterior knee laxity after anterior cruciate ligament reconstruction with patellar tendon or hamstrings autograft: a systematic review.
        Sports Med. Feb 1 2012; 42: 135-152
        • Grindem H.
        • Snyder-Mackler L.
        • Moksnes H.
        • Engebretsen L.
        • Risberg M.A.
        Simple decision rules can reduce reinjury risk by 84% after ACL reconstruction: the Delaware-Oslo ACL cohort study.
        Br J Sports Med. Jul 2016; 50: 804-808
        • Lai C.C.H.
        • Ardern C.L.
        • Feller J.A.
        • Webster K.E.
        Eighty-three per cent of elite athletes return to preinjury sport after anterior cruciate ligament reconstruction: a systematic review with meta-analysis of return to sport rates, graft rupture rates and performance outcomes.
        Br J Sports Med. Jan 2018; 52: 128-138
        • Gudas R.
        • Jurkonis R.
        • Smailys A.
        Comparison of Return to Pre-Injury Sport After 10 mm Size Bone-Patellar Tendon-Bone (BPTB) versus 8 mm Hamstring Anterior Cruciate Ligament Reconstruction: A Retrospective Study with a Two-Year Follow-Up.
        Medical Science Monitor. 2018; 24: 987-996
        • Samitier G.
        • Marcano A.I.
        • Alentorn-Geli E.
        • Cugat R.
        • Farmer K.W.
        • Moser M.W.
        Failure of Anterior Cruciate Ligament Reconstruction.
        Arch Bone Jt Surg. Oct 2015; 3: 220-240
        • Rosso F.
        • Bonasia D.E.
        • Cottino U.
        • Cambursano S.
        • Dettoni F.
        • Rossi R.
        Factors Affecting Subjective and Objective Outcomes and Return to Play in Anterior Cruciate Ligament Reconstruction: A Retrospective Cohort Study.
        Joints. Mar. 2018; 6: 23-32
        • Ardern C.L.
        • Glasgow P.
        • Schneiders A.
        • et al.
        2016 Consensus statement on return to sport from the First World Congress in Sports Physical Therapy, Bern.
        Br J Sports Med. Jul 2016; 50: 853-864
        • Barfod K.W.
        • Feller J.A.
        • Hartwig T.
        • Devitt B.M.
        • Webster K.E.
        Knee extensor strength and hop test performance following anterior cruciate ligament reconstruction.
        Knee. Jan. 2019; 26: 149-154
        • Jenny J.Y.
        • Clement X.
        Patient-based decision for resuming activity after ACL reconstruction: a single-centre experience.
        Eur J Orthop Surg Traumatol. Dec. 2016; 26: 929-935
        • King E.
        • Richter C.
        • Jackson M.
        • et al.
        Factors Influencing Return to Play and Second Anterior Cruciate Ligament Injury Rates in Level 1 Athletes After Primary Anterior Cruciate Ligament Reconstruction: 2-Year Follow-up on 1432 Reconstructions at a Single Center.
        Am J Sports Med. Mar. 2020; 48: 812-824
        • Webster K.E.
        • McPherson A.L.
        • Hewett T.E.
        • Feller J.A.
        Factors Associated With a Return to Preinjury Level of Sport Performance After Anterior Cruciate Ligament Reconstruction Surgery.
        Am J Sports Med. Sep. 2019; 47: 2557-2562
        • Doege J.
        • Ayres J.M.
        • Mackay M.J.
        • et al.
        Defining Return to Sport: A Systematic Review.
        Orthop J Sports Med. Jul. 2021; 923259671211009589
        • Lynch A.D.
        • Logerstedt D.S.
        • Grindem H.
        • et al.
        Consensus criteria for defining 'successful outcome' after ACL injury and reconstruction: a Delaware-Oslo ACL cohort investigation.
        Br J Sports Med. Mar 2015; 49: 335-342
        • Reiman M.P.
        • Peters S.
        • Sylvain J.
        • Hagymasi S.
        • Mather R.C.
        • Goode A.P.
        Femoroacetabular impingement surgery allows 74% of athletes to return to the same competitive level of sports participation but their level of performance remains unreported: a systematic review with meta-analysis.
        Br J Sports Med. Aug 2018; 52: 972-981
      1. Marom N, Xiang W, Wolfe I, Jivanelli B, Williams RJ 3rd, Marx RG. High variability and lack of standardization in the evaluation of return to sport after ACL reconstruction: a systematic review. Knee Surg Sports Traumatol Arthrosc. 2022 Apr;30(4):1369-1379. Epub 2021 May 12. PMID: 33978778.20. Moher D, Liberati A, Tetzlaff J, Altman DG. Preferred reporting items for systematic reviews and meta-analyses: the PRISMA statement. PLoS Med. Jul 21 2009;6(7):e1000097. doi:10.1371/journal.pmed.1000097.

        • Chona D.
        • Eriksson K.
        • Young S.W.
        • Denti M.
        • Sancheti P.K.
        • Safran M.
        • Sherman S.
        Return to sport following anterior cruciate ligament reconstruction: the argument for a multimodal approach to optimise decision-making: current concepts.
        J ISAKOS. 2021 Nov; 6: 344-348
        • Cheney S.
        • Chiaia T.A.
        • de Mille P.
        • Boyle C.
        • Ling D.
        Readiness to Return to Sport After ACL Reconstruction: A Combination of Physical and Psychological Factors.
        Sports Med Arthrosc Rev. 2020 Jun; 28 (PMID: 32345928): 66-70
        • Liu Y.
        • Cui G.
        • Yan H.
        • Yang Y.
        • Ao Y.
        Comparison Between Single- and Double-Bundle Anterior Cruciate Ligament Reconstruction With 6- to 8-Stranded Hamstring Autograft: A Prospective, Randomized Clinical Trial.
        Am J Sports Med. Sep 2016; 44: 2314-2322
        • Gupta R.
        • Bahadur R.
        • Malhotra A.
        • et al.
        Outcome of Hamstring Autograft With Preserved Insertions Compared With Free Hamstring Autograft in Anterior Cruciate Ligament Surgery at 2-Year Follow-up.
        Arthroscopy. Dec 2017; 33: 2208-2216
        • Smith P.A.
        • Cook C.S.
        • Bley J.A.
        All-Inside Quadrupled Semitendinosus Autograft Shows Stability Equivalent to Patellar Tendon Autograft Anterior Cruciate Ligament Reconstruction: Randomized Controlled Trial in Athletes 24 Years or Younger.
        Arthroscopy. Jun 2020; 36: 1629-1646
        • Beischer S.
        • Gustavsson L.
        • Senorski E.H.
        • et al.
        Young Athletes Who Return to Sport Before 9 Months After Anterior Cruciate Ligament Reconstruction Have a Rate of New Injury 7 Times That of Those Who Delay Return.
        J Orthop Sports Phys Ther. Feb 2020; 50: 83-90
        • Muller B.
        • Bowman Jr., K.F.
        • Bedi A.
        ACL graft healing and biologics.
        Clin Sports Med. Jan 2013; 32: 93-109
        • Ekdahl M.
        • Wang J.H.
        • Ronga M.
        • Fu F.H.
        Graft healing in anterior cruciate ligament reconstruction.
        Knee Surg Sports Traumatol Arthrosc. Oct 2008; 16: 935-947
        • Claes S.
        • Verdonk P.
        • Forsyth R.
        • Bellemans J.
        The "ligamentization" process in anterior cruciate ligament reconstruction: what happens to the human graft? A systematic review of the literature.
        Am J Sports Med. Nov 2011; 39: 2476-2483
        • Kyritsis P.
        • Bahr R.
        • Landreau P.
        • Miladi R.
        • Witvrouw E.
        Infographic. Avoid ACL graft rupture. Meet discharge criteria.
        Br J Sports Med. Aug 2016; 50: 952
        • Barber-Westin S.D.
        • Noyes F.R.
        Objective criteria for return to athletics after anterior cruciate ligament reconstruction and subsequent reinjury rates: a systematic review.
        Phys Sportsmed. Sep 2011; 39: 100-110
        • Zwolski C.
        • Schmitt L.C.
        • Quatman-Yates C.
        • Thomas S.
        • Hewett T.E.
        • Paterno M.V.
        The influence of quadriceps strength asymmetry on patient-reported function at time of return to sport after anterior cruciate ligament reconstruction.
        Am J Sports Med. Sep 2015; 43: 2242-2249
        • Hsu C.J.
        • Meierbachtol A.
        • George S.Z.
        • Chmielewski T.L.
        Fear of Reinjury in Athletes.
        Sports Health. Mar/Apr 2017; 9: 162-167
        • Burland J.P.
        • Toonstra J.L.
        • Howard J.S.
        Psychosocial Barriers After Anterior Cruciate Ligament Reconstruction: A Clinical Review of Factors Influencing Postoperative Success.
        Sports Health. Nov/Dec 2019; 11: 528-534
        • Kitaguchi T.
        • Tanaka Y.
        • Takeshita S.
        • Tsujimoto N.
        • Kita K.
        • Amano H.
        • Kinugasa K.
        • Tachibana Y.
        • Natsuume T.
        • Horibe S.
        Importance of functional performance and psychological readiness for return to preinjury level of sports 1 year after ACL reconstruction in competitive athletes.
        Knee Surg Sports Traumatol Arthrosc. 2020 Jul; 28 (Epub 2019 Nov 2. PMID: 31679068): 2203-2212
        • Aizawa J.
        • Hirohata K.
        • Ohji S.
        • Ohmi T.
        • Koga H.
        • Yagishita K.
        Factors Associated With Psychological Readiness to Return to Sports With Cutting, Pivoting, and Jump-Landings After Primary ACL Reconstruction.
        Orthop J Sports Med. Nov 2020; 82325967120964484
        • Lim D.G.W.
        • Chou A.C.C.
        • Chang P.C.C.
        • Tan E.T.S.
        • Lie D.T.T.
        Delayed Surgery, Low Presurgery Activity, and Poor Preoperative IKDC Scores Are Correlated with Lower Rates of Return to Sports after ACL Reconstruction in an Asian Population.
        J Knee Surg. Jan 3 2021;
        • Paterno M.V.
        • Flynn K.
        • Thomas S.
        • Schmitt L.c.
        Self-reported fear predicts functional performance and second ACL injury after ACL reconstruction and return to sport: a pilot study.
        Sports health. 2018; 10: 228-233
        • Hasenboehler E.A.
        • Choudhry I.K.
        • Newman J.T.
        • Smith W.R.
        • Ziran B.H.
        • Stahel P.F.
        Bias towards publishing positive results in orthopedic and general surgery: a patient safety issue?.
        Patient Saf Surg. Nov 27 2007; 1: 4
        • Arundale A.J.H.
        • Cummer K.
        • Capin J.J.
        • Zarzycki R.
        • Snyder-Mackler L.
        Report of the Clinical and Functional Primary Outcomes in Men of the ACL-SPORTS Trial: Similar Outcomes in Men Receiving Secondary Prevention With and Without Perturbation Training 1 and 2 Years After ACL Reconstruction.
        Clin Orthop Relat Res. Oct 2017; 475: 2523-2534
        • Astur D.C.
        • Novaretti J.V.
        • Cavalcante E.L.B.
        • et al.
        Pediatric Anterior Cruciate Ligament Reruptures Are Related to Lower Functional Scores at the Time of Return to Activity: A Prospective, Midterm Follow-up Study.
        Orthop J Sports Med. Dec 2019; 72325967119888888
        • Berdis A.S.
        • Veale K.
        • Fleissner Jr., P.R.
        Outcomes of Anterior Cruciate Ligament Reconstruction Using Biologic Augmentation in Patients 21 Years of Age and Younger.
        Arthroscopy. Nov 2019; 35: 3107-3113
        • Britt E.
        • Ouillette R.
        • Edmonds E.
        • et al.
        The Challenges of Treating Female Soccer Players With ACL Injuries: Hamstring Versus Bone-Patellar Tendon-Bone Autograft.
        Orthop J Sports Med. Nov 2020; 82325967120964884
        • Curran M.T.
        • Bedi A.
        • Kujawa M.
        • Palmieri-Smith R.
        A Cross-sectional Examination of Quadriceps Strength, Biomechanical Function, and Functional Performance From 9 to 24 Months After Anterior Cruciate Ligament Reconstruction.
        Am J Sports Med. Aug 2020; 48: 2438-2446
        • Curran M.T.
        • Lepley L.K.
        • Palmieri-Smith R.M.
        Continued Improvements in Quadriceps Strength and Biomechanical Symmetry of the Knee After Postoperative Anterior Cruciate Ligament Reconstruction Rehabilitation: Is It Time to Reconsider the 6-Month Return-to-Activity Criteria?.
        J Athl Train. Jun 2018; 53: 535-544
        • Ellis H.B.
        • Sabatino M.
        • Nwelue E.
        • Wagner 3rd, K.J.
        • Force E.
        • Wilson P.
        The Use of Psychological Patient Reported Outcome Measures to Identify Adolescent Athletes at Risk for Prolonged Recovery Following an ACL Reconstruction.
        J Pediatr Orthop. Oct 2020; 40: e844-e852
        • Failla M.J.
        • Logerstedt D.S.
        • Grindem H.
        • et al.
        Does Extended Preoperative Rehabilitation Influence Outcomes 2 Years After ACL Reconstruction? A Comparative Effectiveness Study Between the MOON and Delaware-Oslo ACL Cohorts.
        Am J Sports Med. Oct 2016; 44: 2608-2614
        • Gagliardi A.G.
        • Carry P.M.
        • Parikh H.B.
        • Albright J.C.
        Outcomes of Quadriceps Tendon With Patellar Bone Block Anterior Cruciate Ligament Reconstruction in Adolescent Patients With a Minimum 2-Year Follow-up.
        Am J Sports Med. Jan 2020; 48: 93-98
        • Graziano J.
        • Chiaia T.
        • de Mille P.
        • Nawabi D.H.
        • Green D.W.
        • Cordasco F.A.
        Return to Sport for Skeletally Immature Athletes After ACL Reconstruction: Preventing a Second Injury Using a Quality of Movement Assessment and Quantitative Measures to Address Modifiable Risk Factors.
        Orthop J Sports Med. Apr 2017; 52325967117700599
        • Gupta R.
        • Kapoor A.
        • Soni A.
        • Khatri S.
        • Masih G.D.
        Anterior cruciate ligament reconstruction with bone-patellar tendon-bone graft is associated with higher and earlier return to sports as compared to hamstring tendon graft.
        Knee Surg Sports Traumatol Arthrosc. Nov 2020; 28: 3659-3665
        • Gupta R.
        • Sood M.
        • Malhotra A.
        • et al.
        Low re-rupture rate with BPTB autograft and semitendinosus gracilis autograft with preserved insertions in ACL reconstruction surgery in sports persons.
        Knee Surg Sports Traumatol Arthrosc. Aug 2018; 26: 2381-2388
        • Huang H.
        • Nagao M.
        • Nishio H.
        • et al.
        Remnant preservation provides good clinical outcomes after anterior cruciate ligament reconstruction.
        Knee Surg Sports Traumatol Arthrosc. Jan 2 2021;
        • Khair M.
        • Riboh J.
        • Solis J.
        • et al.
        Return to Play Following Isolated and Combined Anterior Cruciate Ligament Reconstruction: 25+ Years of Experience Treating National Football League Athletes.
        Orthop J Sports Med. Oct 2020; 82325967120959004
        • Klasan A.
        • Putnis S.E.
        • Grasso S.
        • Kandhari V.
        • Oshima T.
        • Parker D.A.
        Tegner level is predictive for successful return to sport 2 years after anterior cruciate ligament reconstruction.
        Knee Surg Sports Traumatol Arthrosc. Oct 28 2020;
      2. Kyritsis P, Bahr R, Landreau P, Miladi R, Witvrouw E. Likelihood of ACL graft rupture: not meeting six clinical discharge criteria before return to sport is associated with a four times greater risk of rupture. Br J Sports Med. Aug 2016;50(15):946-951. doi:10.1136/bjsports-2015-095908.

        • Lanzetti R.M.
        • Pace V.
        • Ciompi A.
        • et al.
        Over the top anterior cruciate ligament reconstruction in patients with open physes: a long-term follow-up study.
        Int Orthop. Apr 2020; 44: 771-778
        • Leister I.
        • Kulnik S.T.
        • Kindermann H.
        • et al.
        Functional performance testing and return to sport criteria in patients after anterior cruciate ligament injury 12-18 months after index surgery: A cross-sectional observational study.
        Phys Ther Sport. May 2019; 37: 1-9
        • McGrath T.M.
        • Waddington G.
        • Scarvell J.M.
        • et al.
        An Ecological Study of Anterior Cruciate Ligament Reconstruction, Part 1: Clinical Tests Do Not Correlate With Return-to-Sport Outcomes.
        Orthop J Sports Med. Nov. 2016; 42325967116672208
        • McGrath T.M.
        • Waddington G.
        • Scarvell J.M.
        • et al.
        An Ecological Study of Anterior Cruciate Ligament Reconstruction, Part 2: Functional Performance Tests Correlate With Return-to-Sport Outcomes.
        Orthop J Sports Med. Feb. 2017; 52325967116688443
        • Nawasreh Z.
        • Logerstedt D.
        • Cummer K.
        • Axe M.
        • Risberg M.A.
        • Snyder-Mackler L.
        Functional performance 6 months after ACL reconstruction can predict return to participation in the same preinjury activity level 12 and 24 months after surgery.
        Br J Sports Med. Mar 2018; 52: 375
        • Novaretti J.V.
        • Franciozi C.E.
        • Forgas A.
        • Sasaki P.H.
        • Ingham S.J.M.
        • Abdalla R.J.
        Quadriceps Strength Deficit at 6 Months After ACL Reconstruction Does Not Predict Return to Preinjury Sports Level.
        Sports Health. May/Jun 2018; 10: 266-271
        • Ohsawa T.
        • Kimura M.
        • Chikuda H.
        Patient-reported evaluation on giving way is important for return to preinjury activity level after Anterior Cruciate Ligament reconstruction.
        Knee Surg Sports Traumatol Arthrosc. Apr. 2021; 29: 1128-1136
        • Ovigue J.
        • Bouguennec N.
        • Graveleau N.
        Arthroscopic anterior cruciate ligament reconstruction is a reliable option to treat knee instability in patients over 50 years old.
        Knee Surg Sports Traumatol Arthrosc. Nov. 2020; 28: 3686-3693
        • Patel N.K.
        • Sabharwal S.
        • Hadley C.
        • Blanchard E.
        • Church S.
        Factors affecting return to sport following hamstrings anterior cruciate ligament reconstruction in non-elite athletes.
        Eur J Orthop Surg Traumatol. Dec. 2019; 29: 1771-1779
        • Smith A.H.
        • Capin J.J.
        • Zarzycki R.
        • Snyder-Mackler L.
        Athletes With Bone-Patellar Tendon-Bone Autograft for Anterior Cruciate Ligament Reconstruction Were Slower to Meet Rehabilitation Milestones and Return-to-Sport Criteria Than Athletes With Hamstring Tendon Autograft or Soft Tissue Allograft : Secondary Analysis From the ACL-SPORTS Trial.
        J Orthop Sports Phys Ther. May. 2020; 50: 259-266
        • Sousa P.L.
        • Krych A.J.
        • Cates R.A.
        • Levy B.A.
        • Stuart M.J.
        • Dahm D.L.
        Return to sport: Does excellent 6-month strength and function following ACL reconstruction predict midterm outcomes?.
        Knee Surg Sports Traumatol Arthrosc. May 2017; 25: 1356-1363
        • Webster K.E.
        • Nagelli C.V.
        • Hewett T.E.
        • Feller J.A.
        Factors Associated With Psychological Readiness to Return to Sport After Anterior Cruciate Ligament Reconstruction Surgery.
        Am J Sports Med. Jun. 2018; 46: 1545-1550
        • Webster K.E.
        • Feller J.A.
        Return to Level I Sports After Anterior Cruciate Ligament Reconstruction: Evaluation of Age, Sex, and Readiness to Return Criteria.
        Orthop J Sports Med. Aug. 2018; 62325967118788045
        • Webster K.E.
        • Feller J.A.
        Expectations for Return to Preinjury Sport Before and After Anterior Cruciate Ligament Reconstruction.
        Am J Sports Med. Mar. 2019; 47: 578-583
      3. Welling W, Benjaminse A, Lemmink K, Gokeler A. Passing return to sports tests after ACL reconstruction is associated with greater likelihood for return to sport but fail to identify second injury risk. Knee. Jun 2020;27(3):949-957. doi:10.1016/j.knee.2020.03.007.

        • Wellsandt E.
        • Failla M.J.
        • Snyder-Mackler L.
        Limb Symmetry Indexes Can Overestimate Knee Function After Anterior Cruciate Ligament Injury.
        J Orthop Sports Phys Ther. May. 2017; 47: 334-338
        • Weng C.J.
        • Yeh W.L.
        • Hsu K.Y.
        • et al.
        Clinical and Functional Outcomes of Anterior Cruciate Ligament Reconstruction With Autologous Hamstring Tendon in Patients Aged 50 Years or Older.
        Arthroscopy. Feb. 2020; 36: 558-562
        • Zanovello J.
        • Rosso F.
        • Bistolfi A.
        • Rossi R.
        • Castoldi F.
        Combined Intra- and Extra-Articular Technique in Revision Anterior Cruciate Ligament Reconstruction.
        Joints. Sep 2017; 5: 156-163
        • Cote M.P.
        • Lubowitz J.H.
        • Rossi M.J.
        • Brand J.C.
        Reviews Pooling Heterogeneous, Low-Evidence, High-Bias Data Result in Incorrect Conclusions: But Heterogeneity is an Opportunity to Explore.
        Arthroscopy. 2018 Dec; 34 (PMID: 30509420): 3126-3128