Epidemiology Anterior cruciate ligament tear

Epidemiology Anterior cruciate ligament tear

Anterior cruciate ligament tear  
Incidence Incidence of 36.9 injuries per 100,000 person-years.2

80,000 to 100,000 ACL repairs performed each year in the United States.3,4

Function The ACL is the primary stabilizing structure of the knee. The ACL is the primary restraint to anterior translation of the tibia, as well as tibial internal rotation.
Sex 1.4 – 9.5 times increased risk of ACL tear in women than men6,7,234
Age ACL injuries generally occur beginning in late adolescence. Younger athletes usually sustain growth plate injuries (avulsion fractures) rather than ligamentous injuries because of the relative weakness of the cartilage at the epiphyseal plate compared with the ACL.5
Pain location Knee joint / intra capsulair
Pain sensation / Symptoms Patients who sustain ACL injuries classically describe a popping sound, followed by immediate pain and swelling of the knee. The feeling of instability or giving-way episodes typically limit the ability to participate in activities.
History of injury Contact injuries account for only about 30 percent of ACL injuries.11

70 percent of ACL tears are noncontact injuries occurring primarily during deceleration of the lower extremity, with the quadriceps maximally contracted and the knee at or near full extension.15 ACL tears occur mostly in dynamic tasks including landing, deceleration after running or changing stance.1

intensity of play is a factor, with a three to five times greater risk of ACL injuries occurring during games compared with practices.19,20

Approximately 60 to 75 percent of ACL injuries are associated with meniscal tears, up to 46 percent have collateral ligament injuries, and 5 to 24 percent are associated with complete tear of a collateral ligament.25

Risk factors – Narrow intercondylar notch on the distal femur gives a higher risk. (McClay Davis I. et al. 2003)13

– Chance on ACL tear is 2 times higher in family history of ACL tears. (1th,2th,3th grade. (Flynn R.K.et al. 2005)8

– Orchard et al. stated that weather had influence on ACL tears. Warm weather with little to no rain is a risk factor for ACL tear in sports. (McClay Davis I. et al. 2003)13

– Women are a risk factor for ACL tears, hormons, anatomic difference, bone density and laxity of the tissue.(Kim S.-G et al. 2005)14 

– Women injure a reconstucted knee more often than men, 3:1 Female > Men. (McClay Davis I. et al. 2003)13

– Difference in neuromusculair control with less activation of the hamstrings in landing after a jump with less hip- and knee flexion is an important diffrence between female and males and is stated to be a risk factor. (Brukner P.D. et al. 2006)10

– Deie et al. stated that the anterior drawer test shows a difference in females in different parts of the menstruation cycles. (Kim S.-G et al. 2005)14

– Other risk factors:

Increased Q-angle (greater than 14 degrees in men and greater than 17 degrees in women)11,12

Hamstring strength9

Quadriceps dominance (more quadriceps- and decreased hamstring strength)17

Small ACL size16,18

  1. Pollard C.D., Sigward S.M., Susuma S.P.T, et al. 2006. “The influence of inseason prevention training on lower-extremity kinematics during landing in female soccer players.” Clin. J Sport Med. 16(3): 223-227
  2. Gianotti  SM, Marshall  SW, Hume  PA, Bunt  L.  Incidence of anterior cruciate ligament injury and other knee ligament injuries: a national population-based study.  J Sci Med Sport.  2009;12(6):622–627.
  3. Griffin  LY, Agel  J, Albohm  MJ, et al.  Noncontact anterior cruciate ligament injuries: risk factors and prevention strategies.  J Am Acad Orthop Surg.  2000;8(3):141–150.
  4. Grindstaff  TL, et al.  Neuromuscular control training programs and noncontact anterior cruciate ligament injury rates in female athletes: a numbers-needed-to-treat analysis.  J Athl Train.  2006;41(4):450–456.
  5. McCarroll  JR, et al.  Anterior cruciate ligament injuries in the young athlete with open physes.  Am J Sports Med.  1988;16(1):44–47.
  6. Stevenson  H, et al.  Gender differences in knee injury epidemiology among competitive alpine ski racers.  Iowa Orthop J.  1998;18:64–66.
  7. Gwinn  DE, Wilckens  JH, McDevitt  ER, Ross  G, Kao  TC.  The relative incidence of anterior cruciate ligament injury in men and women at the United States Naval Academy.  Am J Sports Med.  2000;28(1):98–102.
  8. Flynn R.K.et al: The Familial Predisposition Toward Tearing the Anterior Cruciate Ligament . A

Case Control Study. In: The American Journal of Sports Medicine, Vol.33, No.1 2005.

  1. Myer  GD, Ford  KR, Barber Foss  KD, Liu  C, Nick  TG, Hewett  TE.  The relationship of hamstrings and quadriceps strength to anterior cruciate ligament injury in female athletes.  Clin J Sport Med.  2009;19(1):3–8.
  2. Brukner P.D. et al.: Recent advances in sports medicine. In: MJA Practice Essentials- Sports Medicine, Vol. 184, Number 4, 20 February 2006.
  3. Hewett  TE, Myer  GD, Ford  KR.  Anterior cruciate ligament injuries in female athletes: Part 1, mechanisms and risk factors.  Am J Sports Med.  2006;34(2):299–311.
  4. Alentorn-Geli  E, Myer  GD, Silvers  HJ, et al.  Prevention of non-contact anterior cruciate ligament injuries in soccer players. Part 1: Mechanisms of injury and underlying risk factors.  Knee Surg Sports Traumatol Arthrosc.  2009;17(7):705–729.
  5. McClay Davis I. et al.: ACL Injuries- The Gender Bias. ACL Supplement Section: Consensus Statement. In: Journal of Orthopaedic & Sports Physical Therapy, Vol. 33, Number 8, August 2003.
  6. Kim S.-G et al.: Analysis of the risk factors regarding anterior cruciate ligament reconstruction using multiple-looped semitendinosus tendon. In: The Knee, 12, 2005.
  7. Shimokochi  Y, Shultz  SJ.  Mechanisms of noncontact anterior cruciate ligament injury.  J Athl Train.  2008;43(4):396–408.
  8. Chaudhari  AM, et al.  Anterior cruciate ligament-injured subjects have smaller anterior cruciate ligaments than matched controls: a magnetic resonance imaging study.  Am J Sports Med.  2009;37(7):1282–1287.
  9. Huston  LJ, Wojtys  EM.  Neuromuscular performance characteristics in elite female athletes.  Am J Sports Med.  1996;24(4):427–436.
  10. Anderson  AF, Dome  DC, Gautam  S, Awh  MH, Rennirt  GW.  Correlation of anthropometric measurements, strength, anterior cruciate ligament size, and intercondylar notch characteristics to sex differences in anterior cruciate ligament tear rates.  Am J Sports Med.  2001;29(1):58–66.
  11. Bjordal  JM, Arnly  F, Hannestad  B, Strand  T.  Epidemiology of anterior cruciate ligament injuries in soccer.  Am J Sports Med.  1997;25(3):341–345.
  12. Hootman  JM, Dick  R, Agel  J.  Epidemiology of collegiate injuries for 15 sports: summary and recommendations for injury prevention initiatives.  J Athl Train.  2007;42(2):311–319.


 Physical Examination

There are three tests for the anterior cruciate ligament:
  1. The anterior drawer test, phenomenon: forward translation of the head of the tibia at 90º bent knee.

  1. The Lachman test, (an anterior drawer at 20 º flexion, which includes the so-called end point of the movement: hard or soft endpoint). The test of Lachman is the most reliable test in the assessment of an anterior cruciate ligament injury.

  1. The pivot shift, a dynamic test which makes the knee move about at 20º from front to back. During the movement of the lower leg, the knee is held in forced valgus and internal rotation while patient lies on his or her back.


Evidence Based Practice

Lachman’s Test (ACL) Utility 1
Study Sensitivity (show) Specificity (exclude) QUADAS Score 0-14
Cooperman3 77 50 12
Rubinstein5 96 100 9
Bomberg1 86 60 9
Anterior Drawer Test (ACL) Utility 2
Study Sensitivity (show) Specificity (exclude) QUADAS Score 0-14
Braunstein2 91 91 10
Noyes4 25 96 10
Bomberg1 41 100 9
Pivot-shift test(ACL, Anterolateral-, Rotational instability) Utility 2
Study Sensitivity (show) Specificity (exclude) QUADAS Score 0-14
Rubinstein5* 93 89 9
Sandberg6 6 100 10
Bomberg1 9 100 9
* Data collected by 5 orthopedic surgeons.
  1. Bomberg BC, McGinty JB. Acute hemarthorsis of the knee: indications for diagnostic arthroscopy. Arthoscopy. 1990;6:221-225
  2. Braunstein EM. Anterior cruciate ligament injusries: a comparison of arthographic and physical diagnosis. AJR Am J Roentgenol. 1982;138:423-425
  3. Cooperman JM, Riddle DL, Rothstein JM. Reliability and validity of judgments of the integrity of the anterior cruciate ligament of the knee using the Lachman’s test. Phys Ther. 1990;70;225-233
  4. Noyes FR, Paulos L, Mooar LA, Signer B. Knee sprains and acute knee hemarthrosis: misdiagnosis of the anterior cruciate ligament tears. Phys Ther. 1980;60:1596-1601.
  5. Rubinstein RA, Jr.,Shelbourne KD, McCarroll JR, VanMeter CD, Rettig AC. The accuracy of the clinical examination in the setting of posterior cruciate ligament injuries. Am J Sports Med. 1994;22:550-557
  6. Sandberg R, Balkfors B, Henricson A, Westlin N. Stability tests in knee ligament injuries. Arch Orthop Trauma Surg. 1986;106:5-7

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