CLINICAL REPORT

Anterior Cruciate Ligament Injuries: Diagnosis,Treatment, and Prevention

abstractThe number of anterior cruciate ligament (ACL) injuries reported inathletes younger than 18 years has increased over the past 2 decades.Reasons for the increasing ACL injury rate include the growing numberof children and adolescents participating in organized sports, inten-sive sports training at an earlier age, and greater rate of diagnosisbecause of increased awareness and greater use of advanced medicalimaging. ACL injury rates are low in young children and increasesharply during puberty, especially for girls, who have higher ratesof noncontact ACL injuries than boys do in similar sports. Intrinsic riskfactors for ACL injury include higher BMI, subtalar joint overpronation,generalized ligamentous laxity, and decreased neuromuscular controlof knee motion. ACL injuries often require surgery and/or many monthsof rehabilitation and substantial time lost from school and sports par-ticipation. Unfortunately, regardless of treatment, athletes with ACLinjuries are up to 10 times more likely to develop degenerative arthritisof the knee. Safe and effective surgical techniques for children and ado-lescents continue to evolve. Neuromuscular training can reduce risk ofACL injury in adolescent girls. This report outlines the current state ofknowledge on epidemiology, diagnosis, treatment, and prevention of ACLinjuries in children and adolescents. Pediatrics 2014;133:e1437e1450

INTRODUCTION

Anterior cruciate ligament (ACL) injuries are a serious concern forphysically active children and adolescents. The ACL is 1 of the 4 majorligaments that stabilize the knee joint (Fig 1). Its main function is toprevent the tibia from sliding forward relative to the femur. The ACLalso assists with preventing excessive knee extension, knee varus andvalgus movements, and tibial rotation.1,2 An intact ACL protects themenisci from shearing forces that occur during athletic maneuvers,such as landing from a jump, pivoting, or decelerating from a run.

Physicians caring for young athletes have noted an increase in thenumbers of ACL injuries over the past 2 decades.3,4 Reasons for theincrease in ACL injury rate include the growing number of childrenand adolescents participating in organized sports, increased partic-ipation in high-demand sports at an earlier age, and a greater rate ofdiagnosis as a result of increased awareness that ACL injuries canoccur in skeletally immature patients and more frequent use of ad-vanced medical imaging.48

Cynthia R. LaBella, MD, FAAP, William Hennrikus, MD, FAAP,Timothy E. Hewett, PhD, FACSM, COUNCIL ON SPORTSMEDICINE AND FITNESS, and SECTION ON ORTHOPAEDICS

KEY WORDSknee injuries, athletes, sports, adolescents

ABBREVIATIONSACLanterior cruciate ligamentCIconfidence interval

This document is copyrighted and is property of the AmericanAcademy of Pediatrics and its Board of Directors. All authorshave filed conflict of interest statements with the AmericanAcademy of Pediatrics. Any conflicts have been resolved througha process approved by the Board of Directors. The AmericanAcademy of Pediatrics has neither solicited nor accepted anycommercial involvement in the development of the content ofthis publication.

The guidance in this report does not indicate an exclusivecourse of treatment or serve as a standard of medical care.Variations, taking into account individual circumstances, may beappropriate.

All policy statements from the American Academy of Pediatricsautomatically expire 5 years after publication unless reaffirmed,revised, or retired at or before that time.

www.pediatrics.org/cgi/doi/10.1542/peds.2014-0623

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EPIDEMIOLOGY OF ACL INJURY

The incidence of ACL injuries in thegeneral population can be estimatedfrom national registries, which wereestablished in Norway (2004), Denmark(2005), and Sweden (2006) to monitorthe outcomes of ACL reconstructionsurgery. Between 2006 and 2009, allNorwegian hospitals participated in theregistry, with a total compliance of 97%.In the 10- to 19-year age group, theannual incidence of primary ACLreconstructions was 76 per 100 000girls and 47 per 100 000 boys.9 Thisnumber underestimates the true in-cidence of ACL injuries, however, be-cause it does not include those treatednonoperatively.

Most ACL injuries are sports-related;therefore, injury rates are higher inathletes. The National Collegiate AthleticAssociation Injury Surveillance Systemhas compiled data for 16 sports (8mens and 8 womens) over 16 yearsfrom a sample of colleges and univer-sities (approximately 15%).2 ACL injuryrates were highest in mens springfootball and womens gymnastics (33

per 100 000 athlete-exposures) (Fig 2).In womens sports, ACL injury ratesrepresented a larger proportion oftotal injuries than in mens sports(3.1% vs 1.9%), with womens basket-ball and womens gymnastics toppingthe list at 4.9% of total injuries.10

Overall, high school athletes have lowerrates of ACL injuries than do collegiateathletes (5.5 vs 15 per 100 000 athlete-exposures) but a similar injury distri-bution across sports.2,11 Since 2005,the National High School Sports-Related Injury Surveillance Study hascompiled data on the incidence of ACLinjuries in 18 sports.11 From 2007 to2012, ACL injury rates were highest ingirls soccer and boys football (11.7and 11.4 per 100 000 athlete-exposures,respectively) (Fig 3).

No well-designed epidemiologic studiesto document ACL injury rates have beenconducted in children younger than 14years. Although there have been reportsof sport-related ACL injuries in childrenas young as 5 years, the limited dataavailable suggest that ACL disruptions inchildren younger than 12 years arerare.1216 McCarroll et al16 found that ofthe 1722 ACL injuries diagnosed over

a 6-year period at their sports medicinecenter, 57 (3%) were in children 14years and younger. The Norwegian ACLSurgical Registry collects data for allACL surgeries performed at participat-ing institutions nationwide. From 2004to 2011, this registry recorded a total ofonly 8 to 9 ACL surgeries each year forchildren 11 to 13 years of age. Thisrepresents a small fraction (0.6%) of thetotal number of ACL surgeries recordedeach year (1441) in this registry acrossall age groups. For the children whohad surgery, the age at the time of in-jury ranged from 9 to 13 years.

The ACL surgery rate for 12- to 13-year-olds (3.5 per 100 000 citizens) wassubstantially lower than that for 16- to39-year-olds (85 surgeries per 100 000citizens), the age group at highest risk.9

Again, these numbers underestimatethe actual injury rates, because they donot account for those treated non-operatively.

Gender Differences

ACL injury risk begins to increase sig-nificantly at 12 to 13 years of age in girlsand at 14 to 15 years of age in boys.9,12

Female athletes between 15 and 20

FIGURE 1Anatomic structures of the knee. LCL, lateralcollateral ligament; MCL, medial collateral ligament;PCL, posterior cruciate ligament. (Reproducedwith permission from Harris SS, Anderson SJ,eds. Care of the Young Athlete. 2nd ed. Elk GroveVillage, IL: American Academy of Pediatrics andAmerican Academy of Orthopedic Surgeons;2009:410.)

FIGURE 2Collegiate ACL injury rates per 1000 athlete-exposures by sport. (Reproduced with permission fromRenstrom P, Ljungqvist A, Aremdt E, et al. Non-contact ACL injuries in female athletes: an internationalOlympic committee current concepts statement. Br J Sports Med. 2008;42(6):395.10)

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years of age account for the largestnumbers of ACL injuries reported(Fig 4). The gender disparity in ACL in-jury rates among athletes begins toappear around the time of the growthspurt (1214 years of age for girls and1416 years of age for boys), peaksduring adolescence, then declines inearly adulthood.10,12 At the high schoollevel, ACL injury rates in gender-comparable sports (soccer, basketball,baseball/softball, track, volleyball) are

2.5 to 6.2 times higher in girls comparedwith boys.10,11,17 In college athletics,ACL injury rates are 2.4 to 4.1 timeshigher for women, and at the pro-fessional level, ACL injury rates for menand women are essentially equal.4,10,18

In high school sports, ACL injuriesrepresent a higher proportion of allinjuries in female versus male athletes(4.6% vs 2.5%), with girls basketballtopping the list (6%), followed by girlssoccer, girls gymnastics, and girls

volleyball (each 5%). Compared withboys, girls are more likely to havesurgery and less likely to return tosports after an ACL injury.17,19 Amongfemale high school basketball players,knee injuries were the most commoncause of permanent disability, ac-counting for up to 91% of season-ending injuries and 94% of injuriesrequiring surgery.20,21

CONSEQUENCES OF ACL INJURY

An ACL injury at an early age is a life-changing event. In addition to surgeryand many months of rehabilitation, thetreatment costs can be substantial($17 000$25 000 per injury), and thetime lost from school and sports par-ticipation can have considerable effectson the athletes mental health and ac-ademic performance.22,23 Although ACLinjuries account for approximately 3%of all injuries in college sports, theyaccount for 88% of injuries associatedwith 10 or more days of time lost fromsports participation. Freedman et al24

examined the academic transcripts ofcollege students who underwent ACLreconstruction surgery. Compared withan age-matched control group, thosewho had surgery had a significant dropin grade point average of 0.3 pointsduring the semester of injury (P = .04).Similarly, Trentacosta et al25 found thatathletes 18 years and younger who hadACL reconstruction surgery during theschool year reported that it had a neg-ative effect on their grades.

Beyond these more immediate effects,an ACL injury also has long-term healthconsequences. Regardless of the typeof treatment, athletes with ACL injuryare up to 10 times more likely to de-velop early-onset degenerative kneeosteoarthritis, a condition that not onlylimits ones ability to participate insports but also often leads to chronicpain and disability.26,27 A systematicreview of a series of long-term studiessuggests the rates of degenerative

FIGURE 3High School ACL injury rates per 100 000 athlete exposures (AEs) by sport. (Data from the NationalHigh School Sports-Related Injury Surveillance Study, 200708 to 201112 school years. Reproducedwith permission from Comstock R, Collins C, McIlvain N. National High-School Sports-Related InjurySurveillance Study, 20092010 School Year Summary. Columbus, OH: The Research Institute at Na-tionwide Childrens Hospital; 2010. Available at: http://www.nationwidechildrens.org/cirp-rio-study-reports.11)

FIGURE 4Distribution of patients in the Norwegian National Knee Ligament Registry by age and gender.a

(Reproduced with permission from Renstrom P, Ljungqvist A, Aremdt E, et al. Non-contact ACLinjuries in female athletes: an international Olympic committee current concepts statement. Br JSports Med. 2008;42(6):395.10) aNumber of cases (y-axis) indicates number of ACL reconstructions.

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knee osteoarthritis 10 to 20 years af-ter ACL injury are more than 50%.27

This means children and teenagerswho suffer ACL injuries are likely toface chronic pain and functional limi-tations from knee osteoarthritis intheir 20s and 30s. None of thesestudies, however, demonstrated thatACL reconstruction lowered the riskfor osteoarthritis. In fact, one 5-yearprospective study showed that patientswho had ACL reconstruction had ahigher level of knee arthrosis on radio-graphs and bone scans, compared withpatients who did not undergo ACL re-construction.28

INJURY MECHANISMS

The mechanism of ACL injuries inathletes is likely multifactorial. Pro-posed theories to explain the mecha-nisms underlying ACL injury includeextrinsic (physical and visual pertur-bations, bracing, and shoe-surfaceinteraction) and intrinsic (anatomic,hormonal, neuromuscular, and bio-mechanical) variables. Identification ofextrinsic and intrinsic risk factorsassociated with the ACL injury mech-anism provides direction for targetedinterventions to high-risk individuals.

At least 70% of ACL injuries are non-contact in nature29,30; however, thespecific definition of a noncontact ACLinjury varies from study to study. Somedefine a noncontact ACL injury as onethat occurs in the absence of a player-to-player (body-to-body) contact. Othersdefine noncontact ACL injury as onethat occurs in the absence of a directblow to the knee. An ACL injury result-ing from body-to-body contact but withno direct blow to the knee may beclassified as noncontact ACL injurywith perturbation.

Video analysis of ACL injury duringcompetitive sports play indicatesa common body position associatedwith noncontact ACL injury (Fig 5) inwhich (1) the hip is internally rotated,

(2) the knee is close to full extension,(3) the foot is planted, and (4) thebody is decelerating, leading to ap-parent valgus collapse of the knee ordynamic knee valgus.3133 ACL injuryis also observed to occur when thebodys center of mass is behind andaway from the base of support or thearea of foot-to-ground contact.31

RISK FACTORS

ACL injury risk in young athletes islikely multifactorial. Injury data frommany fields demonstrate that numerousphysical and psychological parametersaffect ACL injury rates.

Genetics

Genetic factors likely play a role, al-though the genetic underpinnings ofincreased ACL injury risk have onlyrecently begun to be examined.34

Hormones

Hormonal factors also likely play a role;however, results of studies investigat-ing hormonal factors are both equivo-cal and controversial.35 Although thefemale knee appears to get slightlymore lax, on the order of 0.5 mm, atmidmenstrual cycle, injuries tend tocluster near the start of menses at thepolar opposite time in the cycle.36,37

Previous Injury

Similar to other musculoskeletalinjuries, one of the single best pre-dictors of future ACL injury is previousACL injury. One study found the in-cidence rate of ACL injury in athleteswho have had ACL reconstruction was15 times greater than that of controlsubjects.38 Female athletes were 4times more likely to suffer a secondACL injury in either knee and 6 times

FIGURE 5Dynamic knee valgus: hips are internally rotated and adducted, tibiae are externally rotated, and feetare everted.

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more likely to suffer a new ACL injuryin the contralateral knee than maleathletes. In fact, subsequent injuriesto the contralateral ACL are twice ascommon as reinjury of the recon-structed ACL (11.8% vs 5.8%).39 Ge-netic, anatomic, and neuromuscularfactors likely play a role.

Age and Gender

Although ACL injury rates increase withage in both genders, girls have higherrates immediately after the growthspurt.912,16 It is likely that the increa-ses in body weight, height, and bonelength during pubertal developmentunderlie the mechanism of increasedrisk of ACL injury with increasing age.During puberty, the tibia and femurgrow at a rapid rate.40 This growth ofthe 2 longest levers in the human bodytranslates into greater torques on theknee.41 Increasing height leads toa higher center of mass, making mus-cular control of this center of massmore challenging. Increasing bodyweight is associated with greater jointforce that is more difficult to balanceand dampen during high-velocity ath-letic movements. In pubertal boys, tes-tosterone mediates significant increasesin muscular power, strength, and co-ordination, which affords them withgreater neuromuscular control of theselarger body dimensions. Pubertal girlsdo not experience this same growthspurt in muscular power, strength, andcoordination, which likely explains theirhigher rates of ACL injuries comparedwith pubertal boys.41 That preado-lescent athletes show no gender dif-ferences in ACL injury rates furthersupports this theory.12

Anatomic/Anthropometric Factors

Greater weight and BMI have beenassociated with increased risk of ACLinjury.31,42 A study of military recruitsfound that body weight or BMI >1 SDabove the mean was associated with

a 3.2 and 3.5 times greater risk of ACLinjury, respectively.42 In a study of fe-male soccer players older than 8years, BMI was a significant risk fac-tor for knee injury.31

An increased quadriceps angle (Q an-gle) has been postulated as a riskfactor, but there have been no pro-spective clinical studies to investigatethe relationship between Q angle andACL injury risk.4345 A narrow inter-condylar notch, where the ACL ishoused, is proposed to increase ACLinjury risk, because a narrow notchtends to be associated with a smaller,weaker ACL and also could cause in-creased elongation of the ACL underhigh tension.46,47 Some studies haveshown that a narrow notch increasesrisk of ACL injury42,47,48; however, oth-ers have shown no association be-tween notch width and ACL injury.18,49,50

Subtalar joint overpronation has beenassociated with noncontact ACL inju-ries,51 likely because overpronationincreases anterior translation of thetibia with respect to the femur, therebyincreasing the strain on the ACL.52

Generalized joint laxity and knee hy-perextension were found to signifi-cantly increase the risk for ACL injuryin female soccer players.53 Patientswith ACL injury have significantlymore knee recurvatum at 10 and 90degrees of hip flexion and an in-creased ability to touch palms tofloor.29 Athletes with generalized jointlaxity had a 2.7 times greater risk ofACL injury than did those withoutgeneralized laxity, and those with in-creased anterior-posterior laxity ofthe knee, as measured by a kneearthrometer, had an approximately 3times greater risk of ACL injury thandid those without such laxity.42 Jointlaxity affects not only sagittal kneemotion (hyperextension) but alsocoronal knee motion (valgus), whichcan strain the ACL and be related toincreased risk in athletes.29,42,54

Neuromuscular Factors

Muscle strength and coordination havea direct effect on themechanical loadingof the ACL during sport movements.55,56

Poor neuromuscular control of the hipand knee and postural stability deficitshave been shown to be risk factors forACL injury.54,57 Landing and pivotingsports involve a great deal of rapiddeceleration and acceleration move-ments that push and pull the tibia an-teriorly and place the ACL under stress.This tibial translation can be modulatedby hamstrings and quadriceps activ-ity.58,59 In vivo studies show when sub-jects were asked to contract theirmuscles, knee laxity is reduced by 50%to 75%.58 Activation of the quadricepsbefore the hamstrings, a pattern morefrequently seen in female individuals,increases the anterior shear force thatdirectly loads the ACL and also could berelated to increased dynamic valgusalignment at initial contact during cut-ting and landing maneuvers.41,6065 Al-though fatigue is often cited as apotential risk factor for ACL injury, thereare relatively few published studies tosupport or refute this.66

MAKING THE DIAGNOSIS

History

The patient with an acute ACL teartypically presents with pain, a knee ef-fusion, a reduction in knee motion, anddifficulty bearing weight. Often a pop isheard or felt by the athlete at the timeof injury. The prevalence of an ACL tearin a pediatric athlete with a traumaticknee hemarthrosis is about 65%.67 Thepatient with a chronic ACL tear typicallypresents with recurrent effusions andthe sense that the knee gives way oris unstable with attempts at cutting,twisting, or jumping sports.

Physical Examination

In a pediatric athlete with an acutetraumatic knee effusion, the Lachmantest, anterior drawer test, and pivot

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shift test are clinical examinations thataid in making the diagnosis of an ACLtear.

The Lachman test is performed withthe patient supine (Fig 6). The injuredknee is flexed to 30 degrees. The ex-aminer places 1 hand behind the tibiawith the examiners thumb on thetibial tubercle and the other hand onthe patients lower thigh. The tibia ispulled anteriorly. Examinations of bothknees are compared. Increased ante-rior movement of the tibia relative tothe femur without a firm end pointcompared with the examination of theuninjured knee suggests a torn ACL.

The anterior drawer test also is per-formed with the patient supine butwith the knee flexed to 90 degrees(Fig 7). The examiner grasps the tibiajust below the knee joint, with theexaminers thumbs placed on eitherside of the patellar tendon. The tibia ispulled forward. An increased amountof anterior tibial translation com-pared with the opposite leg or a lackof a firm end point suggests a tornACL.69 Both the Lachman and anteriordrawer tests require a relaxed patientwithout hamstring guarding.

The pivot shift test is performed withthe patient supine and the knee ex-tended (Fig 8). The examiner stresses

the lateral side of the knee whilegradually flexing the patients knee. Aclunk sensation occurs when thepartly subluxated tibia relocates inrelation to the femur, indicating thatthe ACL is torn. The pivot shift test isoften difficult to perform in the pedi-atric athlete with an acute knee injurybecause of pain and guarding.

The Lachman test is considered themost accurate of the 3 commonlyperformed clinical tests for an acuteACL tear, showing a pooled sensitivityof 85% (95% confidence interval [CI]8387) and a pooled specificity of94% (95% CI 9295). The pivot shifttest is very specific, namely 98% (95%CI 9699), but has a poor sensitivity of24% (95% CI 2127).68,69 Last, the kneearthrometer is an objective, accurate,and validated tool that measures, inmillimeters, the amount of tibialtranslation relative to the femur whileperforming a Lachman test and, thus,augments the clinical examinationwhen examining a patient with an ACLtear.70,71

Imaging

For the pediatric athlete who presentswith a traumatic knee effusion, plainradiographs should be obtained to ruleout fracture, dislocation, osteochondral

injury, or physeal injury in addition to,or instead of, an ACL tear. MRI is usuallynot necessary to make the diagnosis ofan ACL tear, as a positive Lachman testresult is sufficient. However, in thepediatric patient whose physical ex-amination is difficult to perform be-cause of pain, swelling, and/or lack ofcooperation or if there is concern forassociated injuries or subtle physealfracture, MRI may be a valuable ancil-lary tool.7276 MRI also can be useful forsurgical planning. Sensitivity andspecificity of MRI for detecting ACLtears in children has been reported tobe 95% and 88%, respectively.76 Formeniscal tears in children, MRI hasbeen reported to be 100% sensitiveand 89% specific.72 One study foundthat the sensitivity, specificity, positivepredictive value, and accuracy of MRIfor identifying all categories of patho-logic changes were lower for pediatric(ages 414 years) versus adolescent(ages 1517 years) patients.75

TREATMENT

The treatment of ACL tears in the pe-diatric athlete is challenging and con-troversial. An ACL tear in a child is nota surgical emergency. Multiple timelydiscussions with the parents and thechild about the appropriate manage-ment options and understanding theirgoals and expectations are very im-portant.73 Surgery is not absolute. Thegeneral indications for surgery includethe patients inability to participate inhis or her chosen sport, instability thataffects activities of daily living, and anassociated repairable meniscal tear or aknee injury with multiple torn ligaments.

Treatment of ACL injuries in the skele-tally immature patient remains con-troversial, because standard ACLreconstructions involve the use of drillholes that cross the open physes andmay potentially cause growth distur-bance, such as shortening or angulationof the childs leg.8 A meta-analysis of 55

FIGURE 6Lachman test. (Reproduced with permission from Harris SS, Anderson SJ, eds. Care of the YoungAthlete. 2nd ed. Elk Grove Village, IL: American Academy of Pediatrics and American Academy ofOrthopedic Surgeons; 2009:413.)

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studies suggested that the risk of leglength difference or angular leg devia-tions was approximately 2% after ACLreconstruction in children and adoles-cents.77 The authors recommendedrandomized controlled trials to clarifythis risk more accurately. Ideally, sur-gical treatment of an ACL tear ina skeletally immature athlete would bepostponed until skeletal maturity, and

the athlete would not develop meniscaltears during that waiting time. In thepast, delay in surgical treatment wasvery common. Orthopedic surgeonsrecommended nonoperative treatment,including a brace, rehabilitation, andsports restriction for many monthsuntil skeletal maturity occurred andtraditional ACL surgery could be per-formed safely.73,78,79 For some pediatric

athletes and parents, conservative man-agement still may be a reasonabletreatment option. However, many pe-diatric athletes and their parents areless inclined to agree to restrict theathletes activity. In such cases, an ACLtear in the pediatric athlete treatedconservatively can lead to additional in-stability episodes, meniscal tears, artic-ular cartilage damage, and early-onsetarthritis.8084 Therefore, most recentliterature now supports early surgeryfor pediatric athletes with an ACL-deficient knee and recurrent episodesof instability.82,8587 Overall, ACL surgeryis about 90% successful in restoringknee stability and patient satisfaction.88

No consensus exists on the best methodto treat an ACL tear in a pediatric athlete.Safe and effective surgical techniquescontinue to evolve.78 However, the cur-rent literature suggests reasonable,evidenced-based management optionsthat minimize the risks of iatrogenicgrowth plate injury.89 For example, ACLsurgery in a pediatric athlete is oftenperformed via a physeal-sparing tech-nique or a transphyseal technique.86,9092

The physeal-sparing technique avoidsinjury to the growth plate, but it placesthe graft in a nonanatomic position. Anaccurate understanding of the athletesphysical maturity by determining skele-tal age and Tanner stage helps to identifywhich treatment is best for a specificpatient.73,86,87,9298 The most commonmethod of measuring the patients skel-etal age is to compare an anteropos-terior radiograph of the patients lefthand and wrist to an age-specific ra-diograph in the Greulich and Pyle at-las.94 Tanner stage can be determinedby self-assessment, which has beenshown to be valid and reliable.99

Patients with open physes at Tannerstage III and skeletal age of less than 14in girls and less than 16 in boys can beoffered the option of activity modifi-cation, functional bracing, rehabilita-tion, and careful follow-up. Surgery is

FIGURE 7Anterior drawer test. (Reproduced with permission from Sarwark JF, ed. Essentials of Musculo-skeletal Care. 4th ed. Rosemont, IL: American Academy of Orthopedic Surgeons; 2010:638.)

FIGURE 8Pivot shift test. (Reproduced with permission from Sarwark JF, ed. Essentials of MusculoskeletalCare. 4th ed. Rosemont, IL: American Academy of Orthopedic Surgeons; 2010:637.)

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indicated in skeletally immature patientswith a torn ACL and an additional re-pairable meniscal injury and in patientswho failed conservative care. In addi-tion, ACL surgery can be elected bypatients unwilling to comply with ac-tivity restrictions and bracing. Parentsand patients who request surgery be-fore maturation of the growth platesshould be counseled about the risk ofangular or longitudinal growth injuryand the possible need for additionalsurgery.16,100103

Most orthopedic surgeons select asurgical treatment option based onthe patients skeletal and physiologicage. For example, in the high-risk, mostskeletally immature athlete (skeletalage less than 11 in girls and less than13 in boys, and Tanner stage I or II) anextraphyseal procedure using a bandof the iliotibial tendon or a hamstringtendon graft passed over the top of thelateral femoral condyle and througha groove in the anterior tibia is a rea-sonable surgical option.15,103106 Bothof these extraphyseal proceduresavoid the growth plate to prevent therisk of growth disturbance. A thirdoption for the completely immaturepediatric athlete is a more techni-cally demanding all-epiphyseal pro-cedure using hamstring tendon grafts.Some authors have used intraopera-tive 3-dimensional computed tomog-raphy to confirm the precise tunnellocation and minimize risk of physealinjury.89

In the intermediate-risk mid-age child(skeletal age 11 to 14 in girls and 13 to16 in boys, and Tanner stage III or IV), theprevious physeal-sparing methods maybe selected; however, many of theseintermediate-maturity patients are safelyand more appropriately treated withtransphyseal reconstruction using small7- to 8-mm centrally placed drill holesand a soft tissue graft, such as thehamstring tendons or an allograft.106109

Physeal injury can be minimized by us-

ing a small drill hole and soft tissuegrafts and by placing the fixation awayfrom the physis. Patients and parentsshould be counseled that there remainsa small risk of physeal injury and apossibility of additional surgery forangular or growth disturbance.

Last, adolescents who are approachingskeletal maturity (skeletal age olderthan 14 in girls and older than 16 in boys,Tanner stage V) can undergo anatomicACL surgery with tibial and femoral drillholes and the surgeons graft of choicewith minimal risk of physeal injury.82,110,111

Autografts and allografts are bothreasonable graft choices dependingon the patient and surgeon prefer-ences. Autografts have a lower graftfailure rate in 2 studies.112,113

Rehabilitation after ACL surgery mayneed to be modified for the individualpatient and the particular surgicalprocedure. In general, a graduated re-habilitation program emphasizing fullextension; immediate weight bearing;active range of motion; and strength-ening of the quadriceps, hamstrings, hip,and core can be started in the first fewweeks after surgery. Progressive re-habilitation during the first 3 monthsafter surgery includes range-of-motionexercises, patellar mobilization, pro-prioceptive exercises, endurance train-ing, and closed-chain strengtheningexercises. Straight-line jogging, plyo-metric exercises, and sport-specificexercises are added after 4 to 6months. Return to play typically occurs 7to 9 months after surgery.

Return to Sport

Studies of competitive athletes, mostof whom were older than 18 years, ina variety of sports have demonstratedthat 78% to 91% returned to sportsparticipation after ACL reconstruc-tion.114 However, only 44% to 62%returned to their previous level ofathletic performance.114119 Femaleathletes were less likely than male

athletes to return to sports after ACLinjury or ACL reconstruction.19,119,120

ACL INJURY PREVENTION

Bracing

It is unlikely that prophylactic bracingcan decrease the risk of ACL injury. Therelative effects of 6 different bracedesigns on anterior tibial translationand neuromuscular function were stud-ied in chronically unstable ACL-deficientpatients.121 Bracing decreased ante-rior tibial translation in the range of30% to 40% without the stabilizingcontractions of the hamstrings, quad-riceps, or gastrocnemius muscles. Withmuscle activation and bracing, anteriortibial translation was decreased be-tween 70% and 85%. However, thebraces slowed hamstring muscle re-action times. A brace with a 5-degreeextension stop decreased extensionon landing.122

Functional bracing after ACL re-construction has been studied usingrandomized controlled cohorts placedinto braced or nonbraced groups.123 Thebraced group was instructed to weara functional knee brace for all cutting,pivoting, or jumping activities for thefirst year after ACL reconstruction.There were no differences betweengroups in knee stability, functionaltesting, subjective knee scores, andrange of motion or strength testing,and the investigators concluded thatpostoperative bracing did not changeoutcomes. Data are insufficient at thistime to determine whether functionalbracing decreases the risk of ACL injuryor reinjury. Knee bracing does not im-prove functional performance of sub-jects after ACL reconstruction and mayactually reduce running and turningspeed.124

Neuromuscular Training Programs

Although ACL injuries occur too quick-ly for reflexive muscular activation,

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athletes can adopt or preprogramsafer movement patterns that reduceinjury risk during landing, pivoting, orunexpected loads or perturbationsduring sports movements.54,60 Withsufficient neuromuscular control ofknee position to avoid dynamic valgus,knee stability may be improved duringcompetitive sport and the risk of ACLinjury can be significantly reduced. Acollection of prospective cohort studiesand randomized controlled trials haveexamined the effect of neuromusculartraining programs on ACL, knee, andother lower-extremity injuries in soc-cer, basketball, volleyball, and handball(Fig 9).22,125137 Some studies used only1 or 2 types of exercises, such asplyometric exercises and/or balanceexercises, and others applied a morecomprehensive approach by includingplyometrics (repetitive jumping exer-cises designed to build lower-extremitystrength and power), strengthening,stretching, and balance training.

Systematic examination of the dataextracted from these studies leads toa few potentially valuable general-izations.138140 Plyometric training com-bined with technique training andfeedback to athletes regarding properform were the common components ofprograms that effectively reduced ACLinjury rates. Balance training alone maynot be sufficient to reduce ACL injuryrisk. Although some of the effectiveprograms did not include strengthtraining, those that did were among themost effective at decreasing ACL injuryrates. ACL injury reduction was greatestfor soccer athletes, and combined pre-and in-season training was more ef-fective than pre- or in-season trainingalone. With respect to age, the greatestreduction in injury risk was demon-strated for female athletes in their mid-teens (1418 years) compared withthose in their late teens (1820 years)and adults (>20 years), with 72% riskreduction for those

the pediatric athlete whose phys-ical examination is difficult to per-form because of pain, swelling,and lack of cooperation.

8. An ACL tear in a youth athlete isnot a surgical emergency. Multiplediscussions with the athlete and par-ents may be needed to understandthe athletes goals and parental ex-pectations and to educate the fam-ily about possible treatment options.

9. The patients skeletal age, measuredby an anteroposterior radiograph ofthe left hand and wrist, and Tannerstage are helpful for the physicianin deciding the most appropriatetreatment of an ACL tear in a skele-tally immature athlete.

10. Pediatricians and orthopedic sur-geons treating young people withACL injuries should advise themthat regardless of treatment choice,they are at increased risk of early-onset osteoarthritis in the injuredknee. Such discussions should beappropriately documented in thepatients medical record.

11. Musculoskeletal changes that de-crease dynamic joint stability inhigh-risk female athletes and po-tentially lead to higher injury ratesin this population could be modifiedif neuromuscular training interven-tions are instituted in early-middleadolescence, when the neuromus-cular risk factors for ACL injurystart to develop.

12. Neuromuscular training appears toreduce the risk of injury in adoles-

cent female athletes by 72%. Pre-vention training that incorporatesplyometric and strengthening exer-cises, combined with feedback toathletes on proper technique, ap-pears to be most effective.

13. Pediatricians and orthopedic sur-geons should direct patients athighest risk of ACL injuries (eg, ad-olescent female athletes, patientswith previous ACL injury, general-ized ligamentous laxity, or familyhistory of ACL injury) to appropri-ate resources to reduce their injuryrisk (http://www.aap.org/cosmf).Such discussions also should beappropriately documented in thepatients medical record.

14. Pediatricians and orthopedic sur-geons who work with schools andsports organizations are encour-aged to educate athletes, parents,coaches, and sports administra-tors about the benefits of neuro-muscular training in reducing ACLinjuries and direct them to appro-priate resources (http://www.aap.org/cosmf).

LEAD AUTHORSCynthia R. LaBella, MD, FAAPWilliam Hennrikus, MD, FAAPTimothy E. Hewett, PhD, FACSM

COUNCIL ON SPORTS MEDICINE ANDFITNESS EXECUTIVE COMMITTEE,20122013Joel S. Brenner, MD, MPH, FAAP, ChairpersonAlison Brooks, MD, MPH, FAAPRebecca A. Demorest, MD, FAAPMark E. Halstead, MD, FAAP

Amanda K. Weiss Kelly, MD, FAAPChris G. Koutures, MD, FAAPCynthia R. LaBella, MD, FAAPMichele LaBotz, MD, FAAPKeith J. Loud, MDCM, MSc, FAAPStephanie S. Martin, MD, FAAPKody A. Moffatt, MD, FAAP

PAST COUNCIL EXECUTIVECOMMITTEE MEMBERSHolly J. Benjamin, MD, FAAPCharles T. Cappetta, MD, FAAPTeri McCambridge, MD, FAAP

LIAISONSAndrew J. M. Gregory, MD, FAAP AmericanCollege of Sports MedicineLisa K. Kluchurosky, MEd, ATC National AthleticTrainers AssociationJohn F. Philpot, MD, FAAP Canadian PediatricSocietyKevin D. Walter, MD, FAAP National Federationof State High School Associations

CONSULTANTTimothy Hewett, PhD

STAFFAnjie Emanuel, MPH

SECTION ON ORTHOPEDICS EXECUTIVECOMMITTEE, 20122013Richard M. Schwend, MD, FAAP, ChairpersonJ. Eric Gordon, MD, FAAPNorman Y. Otsuka, MD, FAAPEllen M. Raney, MD, FAAPBrian A. Shaw, MDBrian G. Smith, MDLawrence Wells, MD

PAST SECTION EXECUTIVE COMMITTEEMEMBERWilliam L. Hennrikus, MD, FAAP, Immediate PastChairperson

STAFFS. Niccole Alexander, MPP

REFERENCES

1. Micheli LJ, Metzl JD, Di Canzio J, ZurakowskiD. Anterior cruciate ligament reconstructivesurgery in adolescent soccer and basketballplayers. Clin J Sport Med. 1999;9(3):138141

2. Hootman JM, Dick R, Agel J. Epidemiologyof collegiate injuries for 15 sports: sum-

mary and recommendations for injuryprevention initiatives. J Athl Train. 2007;42(2):311319

3. Caine D, Caine C, Maffulli N. Incidence anddistribution of pediatric sport-related inju-ries. Clin J Sport Med. 2006;16(6):500513

4. Arnoczky SP. Anatomy of the anteriorcruciate ligament. Clin Orthop Relat Res.1983;(172):1925

5. Amis AA, Dawkins GP. Functional anatomy ofthe anterior cruciate ligament. Fibre bundleactions related to ligament replacements

e1446 FROM THE AMERICAN ACADEMY OF PEDIATRICS by guest on October 13, 2018www.aappublications.org/newsDownloaded from

http://www.aap.org/cosmfhttp://www.aap.org/cosmfhttp://www.aap.org/cosmf

and injuries. J Bone Joint Surg Br. 1991;73(2):260267

6. Jones SJ, Lyons RA, Sibert J, Evans R,Palmer SR. Changes in sports injuries tochildren between 1983 and 1998: com-parison of case series. J Public HealthMed. 2001;23(4):268271

7. Majewski M, Susanne H, Klaus S. Epide-miology of athletic knee injuries: a 10-year study. Knee. 2006;13(3):184188

8. Kocher MS, Saxon JS, Hovis WD, HawkinsRJ. Management and complications ofanterior cruciate ligament injuries inskeletally immature patients: survey ofthe Herodicus Society and The ACL StudyGroup. J Pediatr Orthop. 2002;22(4):452457

9. Granan LP, Forssblad M, Lind M, EngebretsenL. The Scandinavian ACL registries 2004-2007: baseline epidemiology. Acta Orthop.2009;80(5):563567

10. Renstrom P, Ljungqvist A, Arendt E, et al.Non-contact ACL injuries in female ath-letes: an International Olympic Committeecurrent concepts statement. Br J SportsMed. 2008;42(6):394412

11. Comstock R, Collins C, McIlvain N. NationalHigh-School Sports-Related Injury Sur-veillance Study, 2009-2010 School YearSummary. Columbus, OH: The ResearchInstitute at Nationwide Childrens Hospital;2010. Available at: www.nationwidechil-drens.org/cirp-rio-study-reports. AccessedFebruary 28, 2013

12. Shea KG, Pfeiffer R, Wang JH, Curtin M,Apel PJ. Anterior cruciate ligament injuryin pediatric and adolescent soccer play-ers: an analysis of insurance data. JPediatr Orthop. 2004;24(6):623628

13. Clanton TO, DeLee JC, Sanders B, Neidre A.Knee ligament injuries in children. J BoneJoint Surg Am. 1979;61(8):11951201

14. Bradley GW, Shives TC, Samuelson KM.Ligament injuries in the knees of children.J Bone Joint Surg Am. 1979;61(4):588591

15. DeLee JC, Curtis R. Anterior cruciate lig-ament insufficiency in children. ClinOrthop Relat Res. 1983;(172):112118

16. McCarroll JR, Rettig AC, Shelbourne KD.Anterior cruciate ligament injuries in theyoung athlete with open physes. Am JSports Med. 1988;16(1):4447

17. Powell JW, Barber-Foss KD. Sex-relatedinjury patterns among selected highschool sports. Am J Sports Med. 2000;28(3):385391

18. Arendt E, Dick R. Knee injury patternsamong men and women in collegiatebasketball and soccer. NCAA data andreview of literature. Am J Sports Med.1995;23(6):694701

19. Bjordal JM, Arn1y F, Hannestad B, Strand T.Epidemiology of anterior cruciate liga-ment injuries in soccer. Am J Sports Med.1997;25(3):341345

20. Chandy TA, Grana WA. Secondary schoolathletic injury in boys and girls: a three-year comparison. Phys Sportsmed. 1985;13(3):106111

21. Kujala UM, Taimela S, Antti-Poika I, OravaS, Tuominen R, Myllynen P. Acute injuriesin soccer, ice hockey, volleyball, basket-ball, judo, and karate: analysis of nationalregistry data. BMJ. 1995;311(7018):14651468

22. Hewett TE, Lindenfeld TN, Riccobene JV,Noyes FR. The effect of neuromusculartraining on the incidence of knee injury infemale athletes. A prospective study. Am JSports Med. 1999;27(6):699706

23. de Los M, Dahlstedt LJ, Thome R. A 7-year study on risks and costs of kneeinjuries in male and female youth par-ticipants in 12 sports. Scand J Med SciSports. 2000;10(2):9097

24. Freedman KB, Glasgow MT, Glasgow SG,Bernstein J. Anterior cruciate ligamentinjury and reconstruction among univer-sity students. Clin Orthop Relat Res. 1998;(356):208212

25. Trentacosta NE, Vitale MA, Ahmad CS. Theeffects of timing of pediatric knee liga-ment surgery on short-term academicperformance in school-aged athletes. AmJ Sports Med. 2009;37(9):16841691

26. Lohmander LS, Ostenberg A, Englund M,Roos H. High prevalence of knee osteo-arthritis, pain, and functional limitationsin female soccer players twelve yearsafter anterior cruciate ligament injury.Arthritis Rheum. 2004;50(10):31453152

27. Lohmander LS, Englund PM, Dahl LL, RoosEM. The long-term consequence of ante-rior cruciate ligament and meniscusinjuries: osteoarthritis. Am J Sports Med.2007;35(10):17561769

28. Daniel DM, Stone ML, Dobson BE, FithianDC, Rossman DJ, Kaufman KR. Fate of theACL-injured patient. A prospective out-come study. Am J Sports Med. 1994;22(5):632644

29. Boden BP, Dean GS, Feagin JA, Jr, GarrettWE Jr. Mechanisms of anterior cruciateligament injury. Orthopedics. 2000;23(6):573578

30. McNair PJ, Marshall RN, Matheson JA.Important features associated with acuteanterior cruciate ligament injury. N Z MedJ. 1990;103(901):537539

31. Hewett TE, Myer GD, Ford KR. Anteriorcruciate ligament injuries in female ath-letes: part 1, mechanisms and risk fac-

tors. Am J Sports Med. 2006;34(2):299311

32. Hewett TE, Torg JS, Boden BP. Videoanalysis of trunk and knee motion duringnon-contact anterior cruciate ligamentinjury in female athletes: lateral trunkand knee abduction motion are combinedcomponents of the injury mechanism. BrJ Sports Med. 2009;43(6):417422

33. Boden BP, Torg JS, Knowles SB, Hewett TE.Video analysis of anterior cruciate liga-ment injury: abnormalities in hip andankle kinematics. Am J Sports Med. 2009;37(2):252259

34. Hewett TE, Lynch TR, Myer GD, Ford KR,Gwin RC, Heidt RS Jr. Multiple risk factorsrelated to familial predisposition to an-terior cruciate ligament injury: fraternaltwin sisters with anterior cruciate liga-ment ruptures. Br J Sports Med. 2010;44(12):848855

35. Hewett TE. Neuromuscular and hormonalfactors associated with knee injuries infemale athletes. Strategies for in-tervention. Sports Med. 2000;29(5):313327

36. Hewett TE, Zazulak BT, Myer GD. Effects ofthe menstrual cycle on anterior cruciateligament injury risk: a systematic review.Am J Sports Med. 2007;35(4):659668

37. Zazulak BT, Paterno M, Myer GD, RomaniWA, Hewett TE. The effects of the men-strual cycle on anterior knee laxity:a systematic review. Sports Med. 2006;36(10):847862

38. Paterno MV, Rauh MJ, Schmitt LC, Ford KR,Hewett TE. Incidence of contralateral andipsilateral anterior cruciate ligament (ACL)injury after primary ACL reconstructionand return to sport. Clin J Sport Med.2012;22(2):116121

39. Wright RW, Magnussen RA, Dunn WR,Spindler KP. Ipsilateral graft and contra-lateral ACL rupture at five years or morefollowing ACL reconstruction: a systematicreview. J Bone Joint Surg Am. 2011;93(12):11591165

40. Tanner JM, Davies PS. Clinical longitudinalstandards for height and height velocityfor North American children. J Pediatr.1985;107(3):317329

41. Hewett TE, Myer GD, Ford KR. Decrease inneuromuscular control about the kneewith maturation in female athletes. JBone Joint Surg Am. 2004;86-A(8):16011608

42. Uhorchak JM, Scoville CR, Williams GN,Arciero RA, St Pierre P, Taylor DC. Riskfactors associated with noncontact injuryof the anterior cruciate ligament: a pro-spective four-year evaluation of 859 West

PEDIATRICS Volume 133, Number 5, May 2014 e1447

FROM THE AMERICAN ACADEMY OF PEDIATRICS

by guest on October 13, 2018www.aappublications.org/newsDownloaded from

www.nationwidechildrens.org/cirp-rio-study-reportswww.nationwidechildrens.org/cirp-rio-study-reports

Point cadets. Am J Sports Med. 2003;31(6):831842

43. Haycock CE, Gillette JV. Susceptibility ofwomen athletes to injury. Myths vs reality.JAMA. 1976;236(2):163165

44. Zelisko JA, Noble HB, Porter M. A com-parison of mens and womens pro-fessional basketball injuries. Am J SportsMed. 1982;10(5):297299

45. Gray J, Taunton JE, McKenzie DC, ClementDB, McConkey JP, Davidson RG. A survey ofinjuries to the anterior cruciate ligamentof the knee in female basketball players.Int J Sports Med. 1985;6(6):314316

46. Emerson RJ. Basketball knee injuries andthe anterior cruciate ligament. ClinSports Med. 1993;12(2):317328

47. Shelbourne KD, Davis TJ, Klootwyk TE. Therelationship between intercondylar notchwidth of the femur and the incidence ofanterior cruciate ligament tears. A pro-spective study. Am J Sports Med. 1998;26(3):402408

48. LaPrade RF, Burnett QM II. Femoral inter-condylar notch stenosis and correlationto anterior cruciate ligament injuries. Aprospective study. Am J Sports Med. 1994;22(2):198202, discussion 203

49. Anderson AF, Dome DC, Gautam S, AwhMH, Rennirt GW. Correlation of anthropo-metric measurements, strength, anteriorcruciate ligament size, and intercondylarnotch characteristics to sex differences inanterior cruciate ligament tear rates. AmJ Sports Med. 2001;29(1):5866

50. Lombardo S, Sethi PM, Starkey C. Inter-condylar notch stenosis is not a risk fac-tor for anterior cruciate ligament tears inprofessional male basketball players: an11-year prospective study. Am J SportsMed. 2005;33(1):2934

51. Loudon JK, Jenkins W, Loudon KL. The re-lationship between static posture and ACLinjury in female athletes. J Orthop SportsPhys Ther. 1996;24(2):9197

52. Trimble MH, Bishop MD, Buckley BD, FieldsLC, Rozea GD. The relationship betweenclinical measurements of lower extremityposture and tibial translation. Clin Bio-mech (Bristol, Avon). 2002;17(4):286290

53. Sderman K, Alfredson H, Pietil T, WernerS. Risk factors for leg injuries in femalesoccer players: a prospective investigationduring one out-door season. Knee SurgSports Traumatol Arthrosc. 2001;9(5):313321

54. Hewett TE, Myer GD, Ford KR, et al. Bio-mechanical measures of neuromuscularcontrol and valgus loading of the kneepredict anterior cruciate ligament injuryrisk in female athletes: a prospective

study. Am J Sports Med. 2005;33(4):492501

55. McLean SG, Lipfert SW, van den Bogert AJ.Effect of gender and defensive opponenton the biomechanics of sidestep cutting.Med Sci Sports Exerc. 2004;36(6):10081016

56. Pflum MA, Shelburne KB, Torry MR, DeckerMJ, Pandy MG. Model prediction of ante-rior cruciate ligament force during drop-landings. Med Sci Sports Exerc. 2004;36(11):19491958

57. Paterno MV, Schmitt LC, Ford KR, et al.Biomechanical measures during landingand postural stability predict second an-terior cruciate ligament injury after an-terior cruciate ligament reconstructionand return to sport. Am J Sports Med.2010;38(10):19681978

58. Markolf KL, Graff-Radford A, Amstutz HC.In vivo knee stability. A quantitative as-sessment using an instrumented clinicaltesting apparatus. J Bone Joint Surg Am.1978;60(5):664674

59. Solomonow M, Baratta R, Zhou BH, ShojiH, Bose W, Beck C, DAmbrosia R. Thesynergistic action of the anterior cruciateligament and thigh muscles in maintain-ing joint stability. Am J Sports Med. 1987;15(3):207213

60. Hewett TE, Stroupe AL, Nance TA, Noyes FR.Plyometric training in female athletes.Decreased impact forces and increasedhamstring torques. Am J Sports Med.1996;24(6):765773

61. Huston LJ, Wojtys EM. Neuromuscularperformance characteristics in elite fe-male athletes. Am J Sports Med. 1996;24(4):427436

62. Markolf KL, Burchfield DM, Shapiro MM,Shepard MF, Finerman GA, Slauterbeck JL.Combined knee loading states that gen-erate high anterior cruciate ligamentforces. J Orthop Res. 1995;13(6):930935

63. Sell TC, Ferris CM, Abt JP, et al. Predictorsof proximal tibia anterior shear forceduring a vertical stop-jump. J Orthop Res.2007;25(12):15891597

64. Ford KR, Myer GD, Hewett TE. Valgus kneemotion during landing in high school fe-male and male basketball players. MedSci Sports Exerc. 2003;35(10):17451750

65. Myer GD, Ford KR, Hewett TE. The effectsof gender on quadriceps muscle activa-tion strategies during a maneuver thatmimics a high ACL injury risk position. JElectromyogr Kinesiol. 2005;15(2):181189

66. Nyland JA, Caborn DN, Shapiro R, JohnsonDL. Fatigue after eccentric quadricepsfemoris work produces earlier gastroc-

nemius and delayed quadriceps femorisactivation during crossover cutting amongnormal athletic women. Knee Surg SportsTraumatol Arthrosc. 1997;5(3):162167

67. Stanitski CL, Harvell JC, Fu F. Observationson acute knee hemarthrosis in childrenand adolescents. J Pediatr Orthop. 1993;13(4):506510

68. Guntler RA, Stine R, Torg JS. Lachman testevaluated. Quantification of a clinical ob-servation. 1987;(216):141150

69. Benjaminse A, Gokeler A, Van der SchansCP. Clinical diagnosis of an anterior cru-ciate ligament rupture: a meta-analysis. JOrthop Sports Phys Ther. 2006;36(5):267288

70. Daniel DM, Stone ML, Sachs R, Malcolm L.Instrumented measurement of anteriorknee laxity in patients with acute ACLdisruption. Am J Sports Med. 1985;12(6):14011407

71. Bach BR, Warren RF, Flynn WM, Kroll M,Wickiewiecz TL. Arthrometric evaluation ofknees with a torn anterior cruciate liga-ment. J Bone Joint Surg Am. 1990;72(9):12991306

72. King SJ, Carty HM, Brady O. Magneticresonance imaging of knee injuries inchildren. Pediatr Radiol. 1996;26(4):287290

73. Stanitski CL. Anterior cruciate ligamentinjury in the skeletally immature patient:diagnosis and treatment. J Am AcadOrthop Surg. 1995;3(3):146158

74. Williams JS, Jr, Abate JA, Fadale PD, TungGA. Meniscal and nonosseous ACL injuriesin children and adolescents. Am J KneeSurg. 1996;9(1):2226

75. McDermott MJ, Bathgate B, Gillingham BL,Hennrikus WL. Correlation of MRI and ar-throscopic diagnosis of knee pathology inchildren and adolescents. J PediatrOrthop. 1998;18(5):675678

76. Lee K, Siegel MJ, Lau DM, Hildebolt CF,Matava MJ. Anterior cruciate ligamenttears: MR imaging-based diagnosis ina pediatric population. Radiology. 1999;213(3):697704

77. Frosch KH, Stengel D, Brodhun T. Out-comes and risks of operative treatment ofrupture of the anterior cruciate ligamentin children and adolescents. Arthroscopy.2010;26(11):15391550

78. Beasley LS, Chudik SC. Anterior cruciateligament injury in children: update ofcurrent treatment options. Curr OpinPediatr. 2003;15(1):4552

79. Woods GW, OConnor DP. Delayed anteriorcruciate ligament reconstruction in ado-lescents with open physes. Am J SportsMed. 2004;32(1):201210

e1448 FROM THE AMERICAN ACADEMY OF PEDIATRICS by guest on October 13, 2018www.aappublications.org/newsDownloaded from

80. Graf BK, Lange RH, Fujisaki CK, Landry GL,Saluja RK. Anterior cruciate ligamenttears in skeletally immature patients:meniscal pathology at presentation andafter attempted conservative treatment.Arthroscopy. 1992;8(2):229233

81. Mizuta H, Kubota K, Shiraishi M, Otsuka Y,Nagamoto N, Takagi K. The conservativetreatment of complete tears of the ante-rior cruciate ligament in skeletally im-mature patients. J Bone Joint Surg Br.1995;77(6):890894

82. Aichroth PM, Patel DV, Zorrilla P. The nat-ural history and treatment of rupture ofthe anterior cruciate ligament in childrenand adolescents. A prospective review. JBone Joint Surg Br. 2002;84(1):3841

83. Millett PJ, Willis AA, Warren RF. Associatedinjuries in pediatric and adolescent an-terior cruciate ligament tears: does a de-lay in treatment increase the risk ofmeniscal tear? Arthroscopy. 2002;18(9):955959

84. Lawrence JT, Argawal N, Ganley TJ. De-generation of the knee joint in skeletallyimmature patients with a diagnosis of ananterior cruciate ligament tear: is thereharm in delay of treatment? Am J SportsMed. 2011;39(12):25822587

85. Anderson AF. Transepiphyseal replace-ment of the anterior cruciate ligamentusing quadruple hamstring grafts inskeletally immature patients. J Bone JointSurg Am. 2004;86-A(pt 2 suppl 1):201209

86. Beynnon BD, Johnson RJ, Abate JA, FlemingBC, Nichols CE. Treatment of anterior cru-ciate ligament injuries, part I. Am J SportsMed. 2005;33(10):15791602

87. Kocher MS, Smith JT, Zoric BJ, Lee B,Micheli LJ. Transphyseal anterior cruciateligament reconstruction in skeletally im-mature pubescent adolescents. J BoneJoint Surg Am. 2007;89(12):26322639

88. Freedman KB, DAmato MJ, Nedeff DD,et al. Arthroscopic anterior cruciate liga-ment reconstruction: a metaanalysiscomparing patellar tendon and hamstringgrafts. Am J Sports Med. 2003;31(1):211

89. Lawrence JT, Bowers AL, Belding J, CodySR, Ganley TJ. All-epiphyseal anteriorcruciate ligament reconstruction in skel-etally immature patients. Clin OrthopRelat Res. 2010;468(7):19711977

90. Mohtadi N, Grant J. Managing anteriorcruciate ligament deficiency in the skele-tally immature individual: a systematicreview of the literature. Clin J Sport Med.2006;16(6):457464

91. Micheli LJ. Sports injuries in children andadolescents. Questions and controversies.Clin Sports Med. 1995;14(3):727745

92. Simonian PT, Metcalf MH, Larson RV. An-terior cruciate ligament injuries in theskeletally immature patient. Am J Orthop.1999;28(11):624628

93. Nikolaou P, Kalliakmanis A, Bousgas D,Zourntos S. Intraarticular stabilizationfollowing anterior cruciate ligament in-jury in children and adolescents. KneeSurg Sports Traumatol Arthrosc. 2011;19(5):801805

94. Greulich WW, Pyle SI. Radiographic Atlasof Skeletal Development of the Hand andWrist. Palo Alto, CA: Stanford UniversityPress; 1959

95. Kaeding CC, Flanigan D, Donaldson C.Surgical techniques and outcomes afteranterior cruciate ligament reconstructionin preadolescent patients. Arthroscopy.2010;26(11):15301538

96. Marshall WA, Tanner JM. Variations inpattern of pubertal changes in girls. ArchDis Child. 1969;44(235):291303

97. Marshall WA, Tanner JM. Variations in thepattern of pubertal changes in boys. ArchDis Child. 1970;45(239):1323

98. Tanner JM, Whitehouse RH. Clinical longi-tudinal standards for height, weight,height velocity, weight velocity, and stagesof puberty. Arch Dis Child. 1976;51(3):170179

99. Tanner JM, Whitehouse RH, Marshall WA,Carter BS. Prediction of adult height fromheight, bone age, and occurrence ofmenarche, at ages 4 to 16 with allowancefor midparent height. Arch Dis Child. 1975;50(1):1426

100. Duke PM, Litt IF, Gross RT. Adolescentsself-assessment of sexual maturation.Pediatrics. 1980;66(6):918920

101. Koman JD, Sanders JO. Valgus deformityafter reconstruction of the ACL in theskeletally immature patient. J Bone JointSurg Br. 1999;81(5):711715

102. Lipscomb AB, Anderson AF. Tears of theanterior cruciate ligament in adolescents.J Bone Joint Surg Am. 1986;68(1):1928

103. Kocher MS, Garg S, Micheli LJ. Physealsparing reconstruction of the ACL inskeletally immature prepubescent chil-dren and adolescents. J Bone Joint SurgBr. 2005;87(11):23712379

104. Micheli LJ, Rask B, Gergerg L. Anteriorcruciate ligament reconstruction inpatients who are prepubescent. ClinOrthop Relat Res. 1999;(364):4047

105. Nakhostine M, Bollen SR, Cross MJ. Re-construction of mid-substance ACL rup-ture in adolescents with open physes. JPediatr Orthop. 1995;15(3):286287

106. Guzzanti V, Falciglia F, Stantiski CL.Physeal-sparing intraarticular anterior

cruciate ligament reconstruction in pre-adolescents. Am J Sports Med. 2003;31(6):949953

107. Andrews M, Noyes FR, Barber-Westin SD.Anterior cruciate ligament allograft re-construction in the skeletally immatureathlete. Am J Sports Med. 1994;22(1):4854

108. Bisson LJ, Wickiewicz T, Levinson M, WarrenR. ACL reconstruction in children withopen physes. Orthopedics. 1998;21(6):659663

109. Lo IK, Kirley A, Fowler PJ, et al. The out-come of operatively treated anterior cru-ciate ligament disruption in the skeletallyimmature child. Arthroscopy. 1997;13(5):627634

110. Fuchs R, Wheatley W, Uribe JW, et al. Intra-articular anterior cruciate ligament re-construction using patellar tendon allograftin the skeletally immature patient. Ar-throscopy. 2002;18(8):824828

111. Schachter AK, Rokito AS. ACL injuries inthe skeletally immature patient. Orthope-dics. 2007;30(5):365370, quiz 371372

112. Kaeding CC, Aros B, Pedroza A, et al. Allo-graft versus autograft anterior cruciateligament reconstruction: predictors offailure from a MOON prospective longitu-dinal cohort. Sports Health. 2011;3(1):7381

113. Borchers JR, Pedroza A, Kaeding C. Activitylevel and graft type as risk factors foranterior cruciate ligament graft failure:a case-control study. Am J Sports Med.2009;37(12):23622367

114. Ardern CL, Webster KE, Taylor NF, Feller JA.Return to sport following anterior cruci-ate ligament reconstruction surgery:a systematic review and meta-analysis ofthe state of play. Br J Sports Med. 2011;45(7):596606

115. Reinhardt KR, Hammoud S, Bowers AL,Umunna BP, Cordasco FA. Revision ACLreconstruction in skeletally mature ath-letes younger than 18 years. Clin OrthopRelat Res. 2012;470(3):835842

116. McCullough KA, Phelps KD, Spindler KP,et al; MOON Group. Return to high school-and college-level football after anteriorcruciate ligament reconstruction: a Multi-center Orthopaedic Outcomes Network(MOON) cohort study. Am J Sports Med.2012;40(11):25232529

117. Lee DY, Karim SA, Chang HC. Return tosports after anterior cruciate ligamentreconstructiona review of patients withminimum 5-year follow-up. Ann Acad MedSingapore. 2008;37(4):273278

118. Laboute E, Savalli L, Puig P, et al. Analysisof return to competition and repeat

PEDIATRICS Volume 133, Number 5, May 2014 e1449

FROM THE AMERICAN ACADEMY OF PEDIATRICS

by guest on October 13, 2018www.aappublications.org/newsDownloaded from

rupture for 298 anterior cruciate ligamentreconstructions with patellar or ham-string tendon autograft in sportspeople.Ann Phys Rehabil Med. 2010;53(10):598614

119. Kvist J. Rehabilitation following anteriorcruciate ligament injury: current recom-mendations for sports participation.Sports Med. 2004;34(4):269280

120. Spindler KP, Huston LJ, Wright RW, et al;MOON Group. The prognosis and pre-dictors of sports function and activity atminimum 6 years after anterior cruciateligament reconstruction: a population co-hort study. Am J Sports Med. 2011;39(2):348359

121. Wojtys EM, Kothari SU, Huston LJ. Anteriorcruciate ligament functional brace use insports. Am J Sports Med. 1996;24(4):539546

122. Yu B, Herman D, Preston J, Lu W, KirkendallDT, Garrett WE. Immediate effects of a kneebrace with a constraint to knee extensionon knee kinematics and ground reactionforces in a stop-jump task. Am J SportsMed. 2004;32(5):11361143

123. McDevitt ER, Taylor DC, Miller MD, et al.Functional bracing after anterior cruciateligament reconstruction: a prospective,randomized, multicenter study. Am JSports Med. 2004;32(8):18871892

124. Wu G, Siegler S, Allard P, et al; Standard-ization and Terminology Committee of theInternational Society of Biomechanics; In-ternational Society of Biomechanics. ISBrecommendation on definitions of jointcoordinate system of various joints forthe reporting of human joint motionpart I: ankle, hip, and spine. J Biomech.2002;35(4):543548

125. Caraffa A, Cerulli G, Projetti M, Aisa G,Rizzo A. Prevention of anterior cruciateligament injuries in soccer. A prospectivecontrolled study of proprioceptive training.Knee Surg Sports Traumatol Arthrosc.1996;4(1):1921

126. Heidt RS, Jr, Sweeterman LM, Carlonas RL,Traub JA, Tekulve FX. Avoidance of soccerinjuries with preseason conditioning. AmJ Sports Med. 2000;28(5):659662

127. Sderman K, Werner S, Pietil T, EngstrmB, Alfredson H. Balance board training:prevention of traumatic injuries of thelower extremities in female soccer players?A prospective randomized intervention study.Knee Surg Sports Traumatol Arthrosc. 2000;8(6):356363

128. Myklebust G, Engebretsen L, Braekken IH,Skjlberg A, Olsen OE, Bahr R. Preventionof anterior cruciate ligament injuries infemale team handball players: a pro-spective intervention study over threeseasons. Clin J Sport Med. 2003;13(2):7178

129. Mandelbaum BR, Silvers HJ, Watanabe DS,et al. Effectiveness of a neuromuscularand proprioceptive training program inpreventing anterior cruciate ligamentinjuries in female athletes: 2-year follow-up. Am J Sports Med. 2005;33(7):10031010

130. Olsen OE, Myklebust G, Engebretsen L,Holme I, Bahr R. Exercises to preventlower limb injuries in youth sports: clus-ter randomised controlled trial. BMJ.2005;330(7489):449

131. Petersen W, Braun C, Bock W, et al. Acontrolled prospective case control studyof a prevention training program in fe-male team handball players: the Germanexperience. Arch Orthop Trauma Surg.2005;125(9):614621

132. Pfeiffer RP, Shea KG, Roberts D, GrandstrandS, Bond L. Lack of effect of a knee ligamentinjury prevention program on the incidenceof noncontact anterior cruciate ligamentinjury. J Bone Joint Surg Am. 2006;88(8):17691774

133. Gilchrist J, Mandelbaum BR, Melancon H,et al. A randomized controlled trial toprevent noncontact anterior cruciate lig-ament injury in female collegiate soccer

players. Am J Sports Med. 2008;36(8):14761483

134. Soligard T, Myklebust G, Steffen K, et al.Comprehensive warm-up program toprevent injuries in young female foot-ballers: cluster randomized controlledtrial. BMJ. 2008;337:a2469

135. Steffen K, Myklebust G, Olsen OE, Holme I,Bahr R. Preventing injuries in femaleyouth footballa cluster-randomizedcontrolled trial. Scand J Med Sci Sports.2008;18(5):605614

136. Kiani A, Hellquist E, Ahlqvist K, Gedeborg R,Michalsson K, Byberg L. Prevention ofsoccer-related knee injuries in teenagedgirls. Arch Intern Med. 2010;170(1):4349

137. LaBella CR, Huxford MR, Grissom J, Kim KY,Peng J, Christoffel KK. Effect of neuro-muscular warm-up on injuries in femalesoccer and basketball athletes in urbanpublic high schools: cluster randomizedcontrolled trial. Arch Pediatr Adolesc Med.2011;165(11):10331040

138. Myer GD, Sugimoto D, Thomas S, HewettTE. The influence of age on the effective-ness of neuromuscular training to reduceanterior cruciate ligament injury in fe-male athletes: a meta-analysis. Am JSports Med. 2013;41(1):203215

139. Hewett TE, Ford KR, Myer GD. Anterior cru-ciate ligament injuries in female athletes:part 2, a meta-analysis of neuromuscularinterventions aimed at injury prevention. AmJ Sports Med. 2006;34(3):490498

140. Yoo JH, Lim BO, Ha M, et al. A meta-analysis of the effect of neuromusculartraining on the prevention of the anteriorcruciate ligament injury in female ath-letes. Knee Surg Sports TraumatolArthrosc. 2010;18(6):824830

141. Ratzlaff CR, Liang MH. New developmentsin osteoarthritis. Prevention of injury-related knee osteoarthritis: opportunitiesfor the primary and secondary preventionof knee osteoarthritis. Arthritis Res Ther.2010;12(4):215

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