At all levels of American football, knee injuries are common, with injuries to the anterior cruciate ligament (ACL) making up a significant proportion. Historically, ACL injuries were career-altering for professional players, but innovative techniques in surgery and rehabilitation have returned many to the field. While there is a consensus on surgical techniques for ACL reconstruction, significant discrepancies remain on injury prevention and rehabilitation programs. This review article describes the burden of ACL injury on players in the National Football League, best practices in injury prevention and rehabilitation, and evidence-based recommendations for preparing injured athletes to return to play.
ArlianiGGPereiraVLLeãoRGLaraPSEjnismanBCohenM. Treatment of anterior cruciate ligament injuries in professional soccer players by orthopedic surgeons. Rev Bras Ortop. 2019;54(6):703–708.
2.
ArundaleAJHBizziniMGiordanoA, et al. Exercise-based knee and anterior cruciate ligament injury prevention. J Orthop Sports Phys Ther. 2018;48(9):A1–A42. Available at: https://www.jospt.org/doi/full/10.2519/jospt.2018.0303. Accessed May 19, 2022.
3.
ArundaleAJHCapinJJZarzyckiRSmithAHSnyder-MacklerL. Two year ACL reinjury rate of 2.5%: outcomes report of the men in a secondary ACL injury prevention program. Int J Sports Phys Ther. 2018;13(3):422–431.
4.
AyalaFPomares-NogueraCRobles-PalazónFJ, et al. Training effects of the FIFA 11+ and harmoknee on several neuromuscular parameters of physical performance measures. Int J Sports Med. 2017;38(4):278–289. Available at: http://www.thieme-connect.de/DOI/DOI?10.1055/s-0042-121260. Accessed May 25, 2022.
5.
BadawyCRJanKBeckEC, et al. Contemporary principles for postoperative rehabilitation and return to sport for athletes undergoing anterior cruciate ligament reconstruction. Arthrosc Sports Med Rehabil. 2022;4(1):e103–e113.
6.
BakshiNKKhanMLeeS, et al. Return to play after multiligament knee injuries in National Football League athletes. Sports Health. 2018;10(6):495–499.
7.
BediAWarrenRFWojtysEM, et al. Restriction in hip internal rotation is associated with an increased risk of ACL injury. Knee Surg Sports Traumatol Arthrosc. 2016;24(6):2024–2031.
8.
BeynnonBDJohnsonRJNaudS, et al. Accelerated versus nonaccelerated rehabilitation after anterior cruciate ligament reconstruction: a prospective, randomized, double-blind investigation evaluating knee joint laxity using roentgen stereophotogrammetric analysis. Am J Sports Med. 2011;39(12):2536–2548.
9.
BisciottiGNChamariKCenaECarimatiGVolpiP. ACL injury in football: a literature overview of the prevention programs. Muscles Ligaments Tendons J. 2016;6(4):473–479.
10.
BisciottiGNChamariKCenaE, et al. Anterior cruciate ligament injury risk factors in football. J Sports Med Phys Fitness. 2019;59(10):1724–1738.
11.
BlechaKNuelleCWSmithPAStannardJPMaR. Efficacy of prophylactic knee bracing in sports. J Knee Surg. 2022;35(3):242–248.
12.
BradleyJPKlimkiewiczJJRytelMJPowellJW. Anterior cruciate ligament injuries in the National Football League: epidemiology and current treatment trends among team physicians. Arthroscopy. 2002;18(5):502–509.
13.
BriemKRagnarsdóttirAMÁrnasonSISveinssonT. Altered medial versus lateral hamstring muscle activity during hop testing in female athletes 1-6 years after anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2016(1);24:12–17.
14.
BrophyRHGillCSLymanSBarnesRPRodeoSAWarrenRF. Effect of anterior cruciate ligament reconstruction and meniscectomy on length of career in National Football League athletes: a case control study. Am J Sports Med. 2009;37(11):2102–2107.
15.
BrophyRHWojtysEMMackCDHawaldarKHerzogMMOwensBD. Factors associated with the mechanism of ACL tears in the National Football League: a video-based analysis. Orthop J Sports Med. 2021;9(11):1–6.
16.
BuckthorpeMDanelonFLa RosaGNanniGStrideMDella VillaF. Recommendations for hamstring function recovery after ACL reconstruction. Sports Med. 2021;51(4):607–624.
17.
BurgiCRPetersSArdernCL, et al. Which criteria are used to clear patients to return to sport after primary ACL reconstruction? a scoping review. Br J Sports Med. 2019;53(18):1154–1161.
18.
CareyJLHuffmanGRParekhSGSennettBJ. Outcomes of anterior cruciate ligament injuries to running backs and wide receivers in the National Football League. Am J Sports Med. 2006;34(12):1911–1917.
CochraneJLLloydDGButtfieldASewardHMcGivernJ. Characteristics of anterior cruciate ligament injuries in Australian football. J Sci Med Sport. 2007;10(2):96–104.
21.
Della VillaFHägglundMDella VillaSEkstrandJWaldénM. High rate of second ACL injury following ACL reconstruction in male professional footballers: an updated longitudinal analysis from 118 players in the UEFA Elite Club Injury Study. Br J Sports Med. 2021;55(23):1379–1380.
22.
DonnellyCJLloydDGElliottBCReinboltJA. Optimizing whole-body kinematics to minimize valgus knee loading during sidestepping: implications for ACL injury risk. J Biomech. 2012;45(8):1491–1497.
23.
DragooJLBraunHJDurhamJLChenMRHarrisAH. Incidence and risk factors for injuries to the anterior cruciate ligament in National Collegiate Athletic Association football: data from the 2004-2005 through 2008-2009 National Collegiate Athletic Association Injury Surveillance System. Am J Sports Med. 2012;40(5):990–995.
24.
DragooJLBraunHJHarrisAH. The effect of playing surface on the incidence of ACL injuries in National Collegiate Athletic Association American Football. Knee. 2013;20(3):191–195.
25.
EisensteinEDRawickiNLRensingNJKusnezovNALanziJT. Variables affecting return to play after anterior cruciate ligament injury in the National Football League. Orthop J Sports Med. 2016;4(10):1–5.
26.
EricksonBJHarrisJDFillinghamYA, et al. Anterior cruciate ligament reconstruction practice patterns by NFL and NCAA football team physicians. Arthroscopy. 2014;30(6):731–738.
27.
EricksonBJHarrisJDHeningerJR. Performance and return-to-sport after ACL reconstruction in NFL quarterbacks. Orthopedics. 2014;37(8):e728–e734.
28.
GagnierJJMorgensternHChessL. Interventions designed to prevent anterior cruciate ligament injuries in adolescents and adults: a systematic review and meta-analysis. Am J Sports Med. 2013;41(8):1952–1962. https://doi.org/10.1177/0363546512458227.
29.
GokelerABisschopMBenjaminseAMyerGDEppingaPOttenE. Quadriceps function following ACL reconstruction and rehabilitation: implications for optimisation of current practices. Knee Surg Sports Traumatol Arthrosc. 2014;22(5):1163–1174.
30.
GreenbergEMGreenbergETAlbaughJStoreyEGanleyTJ. Rehabilitation practice patterns following anterior cruciate ligament reconstruction: a survey of physical therapists. J Orthop Sports Phys Ther. 2018;48(10):801–811.
31.
GrindemHSnyder-MacklerLMoksnesHEngebretsenLRisbergMA. Simple decision rules can reduce reinjury risk by 84% after ACL reconstruction: the Delaware-Oslo ACL cohort study. Br J Sports Med. 2016;50(13):804–808.
32.
HughesLRosenblattBHaddadF, et al. Comparing the effectiveness of blood flow restriction and traditional heavy load resistance training in the post-surgery rehabilitation of anterior cruciate ligament reconstruction patients: a UK National Health Service randomised controlled trial. Sports Med. 2019;49(11):1787–1805.
33.
JeongJChoiD-HShinCS. Core strength training can alter neuromuscular and biomechanical risk factors for anterior cruciate ligament injury. Am J Sports Med. 2021;49(1):183–192.
34.
KhairMRibohJSolisJ, 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. 2020;8(10):1–7.
35.
KianiAHellquistEAhlqvistKGedeborgRBybergL. Prevention of soccer-related knee injuries in teenaged girls. Arch Intern Med. 2010;170(1):43-49. https://doi.org/10.1001/archinternmed.2009.289.
36.
LeetunDTIrelandMLWillsonJDBallantyneBTDavisIM. Core stability measures as risk factors for lower extremity injury in athletes. Med Sci Sports Exerc. 2004;36(6):926–934.
37.
LoughranGJVulpisCTMurphyJP, et al. Incidence of knee injuries on artificial turf versus natural grass in National Collegiate Athletic Association American football: 2004-2005 through 2013-2014 seasons. Am J Sports Med. 2019;47(6):1294–1301.
38.
MackCDHershmanEBAndersonRB, et al. Higher rates of lower extremity injury on synthetic turf compared with natural turf among national football league athletes: epidemiologic confirmation of a biomechanical hypothesis. Am J Sports Med. 2019;47(1):189–196.
39.
ManoharanABartonDKhwajaALattLD. Return to play rates in NFL wide receivers and running backs after ACL reconstruction: an updated analysis. Orthop J Sports Med. 2021;9(1):1–6.
40.
NagelliCVHewettTE. Should return to sport be delayed until 2 years after anterior cruciate ligament reconstruction? biological and functional considerations. Sports Med. 2017;47(2):221–232.
41.
OwoeyeOBAAkinboSRATellaBAOlawaleOA. Efficacy of the FIFA 11+ warm-up programme in male youth football: a cluster randomised controlled trial. J Sports Sci Med. 2014;13(2):321–328.
42.
PalmieriRMTomJAEdwardsJE, et al. Arthrogenic muscle response induced by an experimental knee joint effusion is mediated by pre- and post-synaptic spinal mechanisms. J Electromyogr Kinesiol. 2004;14(6):631–640.
43.
Palmieri-SmithRMLepleyLK. Quadriceps strength asymmetry after anterior cruciate ligament reconstruction alters knee joint biomechanics and functional performance at time of return to activity. Am J Sports Med. 2015;43(7):1662–1669.
44.
Palmieri-SmithRMMackCDBrophyRH, et al. Epidemiology of anterior cruciate ligament tears in the National Football League. Am J Sports Med. 2021;49(7):1786–1793.
Rahnemai-AzarAAYaseenZvan EckCFIrrgangJJFuFHMusahlV. Increased lateral tibial plateau slope predisposes male college football players to anterior cruciate ligament injury. J Bone Joint Surg Am. 2016;98(12):1001–1006.
48.
ReadPJMichael AuliffeSWilsonMGGraham-SmithP. Lower limb kinetic asymmetries in professional soccer players with and without anterior cruciate ligament reconstruction: nine months is not enough time to restore “functional” symmetry or return to performance. Am J Sports Med. 2020;48(6):1365–1373.
49.
RossBJSavage-ElliottIBrownSMMulcaheyMK. Return to play and performance after primary ACL reconstruction in American football players: a systematic review. Orthop J Sports Med. 2020;8(10):1–12.
50.
RovereGDHauptHAYatesCS. Prophylactic knee bracing in college football. Am J Sports Med. 1987;15(2):111–116.
51.
SadigurskyDBraidJADe LiraDNLMachadoBABCarneiroRJFColavolpePO. The FIFA 11+ injury prevention program for soccer players: a systematic review. BMC Sports Sci Med Rehabil. 2017;9:18. https://doi.org/10.1186/s13102-017-0083-z.
52.
SadoghiPvon KeudellAVavkenP. Effectiveness of anterior cruciate ligament injury prevention training programs. J Bone Joint Surg Am. 2012;94(9):769–776.
53.
SandersTLMaradit KremersHBryanAJ, et al. Incidence of anterior cruciate ligament tears and reconstruction: a 21-year population-based study. Am J Sports Med. 2016;44(6):1502–1507.
54.
ScrantonPEJrWhiteselJPPowellJW, et al. A review of selected noncontact anterior cruciate ligament injuries in the National Football League. Foot Ankle Int. 1997;18(12):772–776.
55.
SepúlvedaFSánchezLAmyEMicheoW. Anterior cruciate ligament injury: return to play, function and long-term considerations. Curr Sports Med Rep. 2017;16(3):172–178.
56.
SheaKGCareyJL. Management of anterior cruciate ligament injuries: evidence-based guideline. J Am Acad Orthop Surg. 2015;23(5):e1–e5.
SitlerMRyanJHopkinsonW, et al. The efficacy of a prophylactic knee brace to reduce knee injuries in football. A prospective, randomized study at West Point. Am J Sports Med. 1990;18(3):310–315.
60.
TorgJSQuedenfeldTCLandauS. The shoe-surface interface and its relationship to football knee injuries. J Sports Med. 1974;2(5):261–269.
61.
UrbachDNebelungWBeckerRAwiszusF. Effects of reconstruction of the anterior cruciate ligament on voluntary activation of quadriceps femoris a prospective twitch interpolation study. J Bone Joint Surg Br. 2001;83(8):1104–1110.
62.
van GrinsvenSvan CingelREHHollaCJMvan LoonCJM. Evidence-based rehabilitation following anterior cruciate ligament reconstruction. Knee Surg Sports Traumatol Arthrosc. 2010;18(8):1128–1144.
63.
VascellariAGokelerAGrassiACanataGLZaffagniniSJonesH. Functional progression milestones following anterior cruciate ligament reconstruction are more appropriate than time-based criteria: a survey among the ESSKA. Knee Surg Sports Traumatol. 2020;28(11):3647–3654.
64.
VerstegenMFalsoneSOrrRSmithS. Suggestions from the field for return to sports participation following anterior cruciate ligament reconstruction: American football. J Orthop Sports Phys Ther. 2012;42(4):337–344.
65.
VillwockMRMeyerEGPowellJWFoutyAJHautRC. Football playing surface and shoe design affect rotational traction. Am J Sports Med. 2009;37(3):518–525.
66.
WhiteKDi StasiSLSmithAHSnyder-MacklerL. Anterior cruciate ligament-specialized post-operative return-to-sports (ACL-SPORTS) training: a randomized control trial. BMC Musculoskelet Disord. 2013;14:108.
67.
YangJHodaxJDMachanJT, et al. National Football League skilled and unskilled positions vary in opportunity and yield in return to play after an anterior cruciate ligament injury. Orthop J Sports Med. 2017;5(9):1–8.
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