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ACL Injuries in Women<br />Management and Prevention<br />Dr. Connie Lebrun MDCM, MPE, CCFP, <br />Dip. Sport Med, FACSM<b...
Figure 1<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaul...
TABLE.<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaulie...
Figure 2<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaul...
Figure 3<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaul...
Figure 4<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaul...
Figure 5<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaul...
UWO Mustangs<br />
Are Women More at Risk?<br />
Anatomy of ACL<br />Origin from lateral femoral condyle<br />Insertion to tibial plateau medial to anterior horn of latera...
ACL Injury<br />“Commonest cause of the ex-athlete”<br />1 in 10 female athletes (N.C.A.A.)<br />2-6 times higher incidenc...
NATIONAL COLLEGIATEATHLETIC ASSOCIATION<br />INJURY SURVEILLANCE SYSTEM (ISS)<br />
SportYear ISSBegan<br />Soccer (/)	1984/83<br />Softball	1984<br />Ice Hockey ()	1984<br />Field Hockey ()	1984<br />B...
SOCCERACL Injury Rate, 1989-98<br />0.32<br />2.8 X<br />0.13<br />
BASKETBALLACL Injury Rate, 1989-98<br />0.29<br />3.5X<br />0.09<br />
Mechanism of ACL Injury<br />Non-contact mechanism (80%)<br />Rapid but awkward stop<br />The position of “no return”<br /...
Risk Factors:<br /><ul><li>Environmental
Anatomic
Hormonal
Biomechanical</li></ul>Gender  Differences?<br />
Anterior Cruciate Ligament Injury in the Female Athlete<br />Intrinsic factors:<br />Alignment<br />Hyperextension<br />Ph...
Anterior Cruciate Ligament Injury in the Female Athlete<br />Extrinsic factors:<br />Strength<br />Conditioning<br />Shoes...
Anterior Cruciate Ligament Injury in the Female Athlete<br />Combined (partially controllable):<br />Proprioception (posit...
Gender Differences?<br />
Non-Contact Anterior Cruciate Ligament Injuries:  Risk Factors and Prevention Strategies<br />A Consensus Conference held ...
Hunt Valley Consensus ConferenceJune 1999<br />Reviewed research to date:<br /> Anatomic risk factors<br /> Hormonal risk ...
Hunt Valley Consensus ConferenceJune 1999<br /><ul><li>GOALS:
 to increase awareness of “at risk” population
 to stimulate increased research efforts</li></li></ul><li>Hunt Valley Consensus Conference: June 1999  HORMONAL RISK FACT...
Existence of Hormone Receptors in Ligaments<br />Model: human ACL, 5  & 5<br />	    cell culture<br />Relaxin receptor s...
NOT found in male ACL</li></ul>Degroo et al.,Trans Ortho Res Soc, 2001<br />
Effects of Hormones - Cellular Mechanisms<br />Model: <br />Sheep ACL fibroblasts<br />Cyclic estrus function<br />Estroge...
Effects of Hormones-Mechanical Properties of Ligaments<br />Model: <br /><ul><li>mouse knee joint
mechanically quantified drawer test</li></ul>ligament stiffness<br />Estrogen + Relaxin<br />Levine et al.,Ortho Trans, 19...
Effects of Hormones-Mechanical Properties of Ligaments<br />Model: sheep<br /><ul><li>38 animals (38 ACL/10MCL)
6 months
ligament failure test</li></ul>No effect of estrogen level on<br />mechanical properties of ACL or MCL<br />Strickland et ...
Effects of Hormones-Mechanical Properties of Ligaments<br />Model: primate<br /><ul><li>26 animals (26 ACL/26 PT)
2 years
ligament failure test</li></ul>No correlation between ACL or Patellar tendon material properties and estrogen levels.<br /...
Effects of Hormones-Mechanical Properties of Ligaments<br />Estrogen and progesterone receptor sites have been reported in...
Hormone Levels and ACL Injuries<br />Estrogen<br />Progesterone<br />
Hormone Levels and ACL Injuries<br />Population : 17 Norwegian females (8 on BCP)<br />	team handball players<br />	menstr...
Hormone Levels and ACL Injuries<br /><ul><li>Fewer injuries occurred during mid-cycle.
Trend toward    in luteal phase</li></ul>Myklebust, et al, Scand Med Science and Sport, 1998<br />
Hormone Levels and ACL Injuries<br /><ul><li>Population : 61 female recreational skiers
Date of injury, cycle length, use of oral contraceptives
Date of next menstrual cycle used to calculate phase of cycle in which injury occurred</li></ul>No correlation between cyc...
Hormone Levels and ACL Injuries<br />Population : 83 College female varsity athletes.<br />(25 on birth control pills)<br ...
Hormone Levels and ACL Injuries<br />Centered moving average<br />Smooth out time dependency of the number of injuries<br ...
Hormone Levels and ACL Injuries<br />Non-linear regression model<br /><ul><li>There is a significant difference in the tim...
Cannot detect exact location ofhigh risk time interval</li></ul>Arendt et al., Journal of Gender Specific Medicine, 2002<b...
Hormone Levels and ACL Injuries<br />Population : 65 females (8 on OCP)<br /><ul><li>Sports related NC-ACL injury
Menstrual phase at time of injury
Urine specimens within 24 h
First day of next cycle
Urine analysis for total estrogen, progesterone, and lutinizing hormone metabolites</li></ul>Wojtys et al,<br />AOSSM, 200...
LH Levels<br />Progesterone<br />Estrogen<br />Hormone Levels and ACL Injuries<br />Poor correlation between urine metabol...
Hormone Levels and ACL Injuries<br />Population : 35 females <br />(25 College / 12 H.S.)<br /><ul><li>Sports related NC-A...
Saliva sample within 48 hours of injury</li></ul>26/37 (70%) injured ACL in follicular phase<br />.<br />Slaughterbeck et ...
Hormones and Tissue Laxity<br />Population: 26 high school female athletes<br />Normal menstrual cycle<br />Prospective si...
Hormone Research<br />Criticisms:<br />One or two measurements not enough to capture female physiology<br />Normative stan...
Conclusion<br />Menstrual cycle phase & musculoskeletal injury<br />Inconclusive data<br />Neuromuscular          mechanis...
Consensus Statements: 1999 Anatomic Risk Factors<br />No consensus on role of the intracondylar notch<br />No consensus on...
Consensus Statements: 1999Anatomic Risk Factors<br />No consensus on role of anatomic alignment<br />
 Anatomic Risk Factor ACL Size<br />Size of ACL: less force is required to rupture a smaller ligament<br />
Anatomic Risk FactorsACL Size<br />Cadaver knees ( N =16 )<br />Direct measurement technique<br />Smaller ACL (cross-secti...
Anatomic Risk Factor ACL Size<br />Measured ACL width on MRI<br />Males ACL (6.1mm) > females ACL (5.2mm) 	<br />Did not c...
Anatomic Risk Factor ACL Size<br />Measured ACL (cross-section) on CT scan<br />Male ACL (47.1mm) > female ACL (35.1mm) <b...
Anatomic Risk Factors ACL Size<br />Measured ACL cross-section on MRI <br />Case control study:matched for gender, age, an...
THE FAMILIAL PREDISPOSITION TOWARDS TEARING THE ACL: A CASE-CONTROL STUDY<br />K. Flynn BSc <br />C. Pedersen MSc<br />A. ...
Anatomic Risk FactorsACL Size<br />Based on data to date it appears that the increased rate of ACL tears seen in patients ...
Anatomic Risk Factor Tibial Slope<br />Tibial Slope: in the “quads active” mechanism of ACL injury, the tibia is planted &...
 Anatomic Risk Factor Tibial Slope<br />There is a 6 mm increase in anterior tibial translation for every 10 degree increa...
 Tibial Slope ACL Deficient Knees<br />
 Anatomic Risk Factor Tibial Slope<br />Tibial slope measured on CT scan<br />No difference in males (8.3 degrees) vs. fem...
 Anatomic Risk Factor Tibial Slope<br />XR measurement<br />case control study: 50 ACL deficient knees to age matched PF k...
 Anatomic Risk Factor Tibial Slope<br />Absolute measurement not contributory (?)<br />Slope plus muscle contractioncombin...
Prevention Strategies for  Anatomic Risk Factors<br />Anatomic risk factors are difficult to alter<br />Little agreement r...
Hunt Valley Consensus ConferenceVideos of ACL Injuries<br />54 videos of ACL injuries were collected in preparation for co...
ACL Injured on Landing<br />Knee slightly flexed<br />Knee in valgus, external rotation<br />
ACL Injured on Landing<br />Knee slightly flexed<br />Knee in valgus, external rotation<br />
Videos of ACL InjuriesConclusions<br />Most common positions at injury were landing from a jump, jump stop, sudden deceler...
Research Needs:  Non-Contact ACL Injuries<br />What is the mechanism of injury in non-contact injuries to the ACL?<br />Vi...
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ACL Injuries in Women Athletes 2011

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Female athletes are six times as liable as male athletes to be injured playing sport. One of the most common of those is the ACL or anterior cruciate ligament. Dr. Connie Lebrun, MD, sports medicine physician at the Glen Sather Sports Medicine Clinic at the University of Alberta discusses causes and treatment of the injury.

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  1. 1. ACL Injuries in Women<br />Management and Prevention<br />Dr. Connie Lebrun MDCM, MPE, CCFP, <br />Dip. Sport Med, FACSM<br />Clinical Director Glen Sather Sports Medicine Clinic<br />University of Alberta, Edmonton, Alberta, CANADA<br />
  2. 2. Figure 1<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaulieu, Melanie<br />Exercise & Sport Sciences Reviews. 38(4):192-200, October 2010.<br />DOI: 10.1097/JES.0b013e3181f450b4<br />Figure 1 . Combined effects of fatigue and decision making on key knee joint biomechanical parameters during a high-impact single leg landing task. As fatigue progressed, statistically significant (P Med Sci Sports Exerc. 2009; 41(8):1661-72. Copyright (C) 2009 Lippincott Williams & Wilkins. Used with permission.]<br />©2010The Amercian College of Sports Medicine. Published by Lippincott Williams & Wilkins, Inc.<br />2<br />
  3. 3. TABLE.<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaulieu, Melanie<br />Exercise & Sport Sciences Reviews. 38(4):192-200, October 2010.<br />DOI: 10.1097/JES.0b013e3181f450b4<br />TABLE. Research studies investigating explicit links between morphological and knee joint biomechanical factors associated with anterior cruciate ligament (ACL) injury risk.<br />©2010The Amercian College of Sports Medicine. Published by Lippincott Williams & Wilkins, Inc.<br />3<br />
  4. 4. Figure 2<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaulieu, Melanie<br />Exercise & Sport Sciences Reviews. 38(4):192-200, October 2010.<br />DOI: 10.1097/JES.0b013e3181f450b4<br />Figure 2 . A custom designed manual loading device was used to apply combined 3D loads to male and female cadaveric knee specimens (A). Using these and resultant ligament strain data, specimen-specific regression models were developed that could predict peak anterior cruciate ligament (ACL) strain magnitudes to within 0.51% +/- 0.01% and 0.52% +/- 0.06% of measured data, and within 0.61% +/- 0.11% and 0.57% +/- 0.05% of validation data (not used in model development) respectively (B). Application of combined valgus (45 Nm), internal rotation (20 Nm) and compressive (300 N) loads at a fixed knee flexion angle (40 deg) and three discrete anterior tibial shear load magnitudes (50 N, 100 N and 150 N) resulted in predicted peak female ACL strains that were significantly greater than male ACL strain values (C). [Adapted from Mizuno K, Andrish JT, van den Bogert AJ, McLean SG. Gender dimorphic ACL strain in response to combined dynamic 3D knee joint loading: implications for ACL injury risk. Knee. 2009; 16(6):432-40. Copyright (C) 2009 Elsevier. Used with permission.]<br />©2010The Amercian College of Sports Medicine. Published by Lippincott Williams & Wilkins, Inc.<br />4<br />
  5. 5. Figure 3<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaulieu, Melanie<br />Exercise & Sport Sciences Reviews. 38(4):192-200, October 2010.<br />DOI: 10.1097/JES.0b013e3181f450b4<br />Figure 3 . Associations between key knee joint anatomical indices and peak stance phase knee joint biomechanical variables during a single-leg landing task. Specifically, peak anterior knee joint reaction force was significantly positively correlated with lateral posterior tibial slope (LTS) (A). Peak knee joint internal rotation angle was significantly positively correlated with the ratio between medial and lateral posterior tibial slopes (MTS:LTS) (B). Peak knee abduction angle was significantly positively correlated with both MTS:LTS and the ratio between the tibial plateau width and the intercondylar distance (TPW:ICD) (C). [Adapted from McLean SG, Lucey SM, Rohrer S, Brandon C. Knee joint anatomy predicts extreme in vivo knee joint mechanics during single leg landings. Clin Biomech. 2010;In press. Copyright (C) 2010 Elsevier. Used with permission.]<br />©2010The Amercian College of Sports Medicine. Published by Lippincott Williams & Wilkins, Inc.<br />5<br />
  6. 6. Figure 4<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaulieu, Melanie<br />Exercise & Sport Sciences Reviews. 38(4):192-200, October 2010.<br />DOI: 10.1097/JES.0b013e3181f450b4<br />Figure 4 . Conceptual model depicting integrative morphological and biomechanical contributions to knee joint and anterior cruciate ligament (ACL) loading during high-impact landing maneuvers. Explicit combinations of postural alignment and knee joint anatomical and laxity factors are posited to implicate within the ACL injury risk via the generation of large knee joint and resultant ACL load states. For the associated figure, ABd = abduction; IR = internal rotation; Ant Shear = anterior tibial shear; Fx = force in the x-axis direction; Fy = force in the y-axis direction; Fz = force in the z-axis direction; Mx = moment about the x-axis; My = moment about the y-axis; Mz = moment about the z-axis.<br />©2010The Amercian College of Sports Medicine. Published by Lippincott Williams & Wilkins, Inc.<br />6<br />
  7. 7. Figure 5<br />Complex Integrative Morphological and Mechanical Contributions to ACL Injury Risk.<br />McLean, Scott; Beaulieu, Melanie<br />Exercise & Sport Sciences Reviews. 38(4):192-200, October 2010.<br />DOI: 10.1097/JES.0b013e3181f450b4<br />Figure 5 . Surrogate (integrative forward dynamic and finite element) modeling techniques proposed to successfully investigate anterior cruciate ligament (ACL) causality based on integrative neuromechanical and morphological factors. Systematic and/or random perturbations can be applied at each level of the modeling pipeline, based on quantified variations in each measure, to determine ACL injury risk arising through individual-specific neuromechanical and morphological vulnerabilities.<br />©2010The Amercian College of Sports Medicine. Published by Lippincott Williams & Wilkins, Inc.<br />7<br />
  8. 8.
  9. 9.
  10. 10. UWO Mustangs<br />
  11. 11. Are Women More at Risk?<br />
  12. 12. Anatomy of ACL<br />Origin from lateral femoral condyle<br />Insertion to tibial plateau medial to anterior horn of lateral meniscus<br />
  13. 13. ACL Injury<br />“Commonest cause of the ex-athlete”<br />1 in 10 female athletes (N.C.A.A.)<br />2-6 times higher incidence than males in same sport<br />
  14. 14. NATIONAL COLLEGIATEATHLETIC ASSOCIATION<br />INJURY SURVEILLANCE SYSTEM (ISS)<br />
  15. 15. SportYear ISSBegan<br />Soccer (/) 1984/83<br />Softball 1984<br />Ice Hockey () 1984<br />Field Hockey () 1984<br />Basketball (/) 1986/86<br />Spring Football 1986<br />SportYear ISSBegan<br />Football 1982<br />Volleyball () 1982<br />Gymnastics (/) 1983/84<br />Wrestling 1983<br />Baseball 1983<br />Lacrosse (/) 1984/83<br />Based on exposure rates<br />
  16. 16.
  17. 17. SOCCERACL Injury Rate, 1989-98<br />0.32<br />2.8 X<br />0.13<br />
  18. 18.
  19. 19. BASKETBALLACL Injury Rate, 1989-98<br />0.29<br />3.5X<br />0.09<br />
  20. 20.
  21. 21. Mechanism of ACL Injury<br />Non-contact mechanism (80%)<br />Rapid but awkward stop<br />The position of “no return”<br />ACL tears in 70 ms<br />
  22. 22. Risk Factors:<br /><ul><li>Environmental
  23. 23. Anatomic
  24. 24. Hormonal
  25. 25. Biomechanical</li></ul>Gender Differences?<br />
  26. 26. Anterior Cruciate Ligament Injury in the Female Athlete<br />Intrinsic factors:<br />Alignment<br />Hyperextension<br />Physiological rotatory laxity<br />ACL size<br />Notch size and shape<br />Hormonal influences<br />Inherited skills and coordination<br />
  27. 27. Anterior Cruciate Ligament Injury in the Female Athlete<br />Extrinsic factors:<br />Strength<br />Conditioning<br />Shoes <br />Motivation<br />
  28. 28. Anterior Cruciate Ligament Injury in the Female Athlete<br />Combined (partially controllable):<br />Proprioception (position sense/balance)<br />Neuromuscular activation patterns<br />Sport-specific skills (acquired)<br />
  29. 29. Gender Differences?<br />
  30. 30. Non-Contact Anterior Cruciate Ligament Injuries: Risk Factors and Prevention Strategies<br />A Consensus Conference held at Hunt Valley, Maryland on June 10, 1999<br />Sponsored by AAOS, AOSSM, NCAA, and NATA<br />Organized by Letha Y. Griffin, M.D., Ph.D.<br />Elizabeth A. Arendt, M.D.<br />
  31. 31. Hunt Valley Consensus ConferenceJune 1999<br />Reviewed research to date:<br /> Anatomic risk factors<br /> Hormonal risk factors<br /> Biomechanical/neuromuscular risk factors<br /> Reviewed videos on non-contact ACL injuries<br /> Reviewed existing neuromuscular programs<br />
  32. 32. Hunt Valley Consensus ConferenceJune 1999<br /><ul><li>GOALS:
  33. 33. to increase awareness of “at risk” population
  34. 34. to stimulate increased research efforts</li></li></ul><li>Hunt Valley Consensus Conference: June 1999 HORMONAL RISK FACTORS<br />No consensus that sex specific hormones play a role in increased ACL injuries in females<br />No evidence to recommend modification of sports or hormonal modification for females<br />Remains a “fertile” area for future research<br />
  35. 35. Existence of Hormone Receptors in Ligaments<br />Model: human ACL, 5  & 5<br /> cell culture<br />Relaxin receptor sites :<br /><ul><li>Found in female ACL
  36. 36. NOT found in male ACL</li></ul>Degroo et al.,Trans Ortho Res Soc, 2001<br />
  37. 37. Effects of Hormones - Cellular Mechanisms<br />Model: <br />Sheep ACL fibroblasts<br />Cyclic estrus function<br />Estrogen receptors present in sheep ACL fibroblasts<br />No effect of physiologic levels of estrogen on cell proliferation or collagen synthesis<br />Seneviratne et al.<br />Trans. Ortho. Res. Soc, 2000<br />
  38. 38. Effects of Hormones-Mechanical Properties of Ligaments<br />Model: <br /><ul><li>mouse knee joint
  39. 39. mechanically quantified drawer test</li></ul>ligament stiffness<br />Estrogen + Relaxin<br />Levine et al.,Ortho Trans, 1999<br />
  40. 40. Effects of Hormones-Mechanical Properties of Ligaments<br />Model: sheep<br /><ul><li>38 animals (38 ACL/10MCL)
  41. 41. 6 months
  42. 42. ligament failure test</li></ul>No effect of estrogen level on<br />mechanical properties of ACL or MCL<br />Strickland et al.,Trans of Ortho Res Soc, 2000<br />
  43. 43. Effects of Hormones-Mechanical Properties of Ligaments<br />Model: primate<br /><ul><li>26 animals (26 ACL/26 PT)
  44. 44. 2 years
  45. 45. ligament failure test</li></ul>No correlation between ACL or Patellar tendon material properties and estrogen levels.<br />Arendt et al.,ISAKOS, 2001<br />
  46. 46. Effects of Hormones-Mechanical Properties of Ligaments<br />Estrogen and progesterone receptor sites have been reported in human ACL cells.<br />Relaxin receptor sites have been reported in female ACL cells.<br />The effect of relaxin, or relaxin plus estrogen may merit further investigation.<br />
  47. 47. Hormone Levels and ACL Injuries<br />Estrogen<br />Progesterone<br />
  48. 48. Hormone Levels and ACL Injuries<br />Population : 17 Norwegian females (8 on BCP)<br /> team handball players<br /> menstrual phase at time of N-C ACL injury menstrual history questionnaire<br />Myklebust et al., Scand Med Science and Sport, 1998<br />
  49. 49. Hormone Levels and ACL Injuries<br /><ul><li>Fewer injuries occurred during mid-cycle.
  50. 50. Trend toward in luteal phase</li></ul>Myklebust, et al, Scand Med Science and Sport, 1998<br />
  51. 51. Hormone Levels and ACL Injuries<br /><ul><li>Population : 61 female recreational skiers
  52. 52. Date of injury, cycle length, use of oral contraceptives
  53. 53. Date of next menstrual cycle used to calculate phase of cycle in which injury occurred</li></ul>No correlation between cycle phase & NC-ACL injury<br />Boynton et al.,<br />AOSSM, 2000<br />
  54. 54. Hormone Levels and ACL Injuries<br />Population : 83 College female varsity athletes.<br />(25 on birth control pills)<br /> Menstrual phase at time of N-C ACL<br /> No data on onset of next menses<br />No significant difference in NC-ACL injury & day of menstrual cycle.<br />Trend toward in follicular stage<br />Arendt et al.,Journal of Gender Specific Medicine, 2002<br />
  55. 55. Hormone Levels and ACL Injuries<br />Centered moving average<br />Smooth out time dependency of the number of injuries<br />Arendt et al., Journal of Gender Specific Medicine, 2002<br />
  56. 56. Hormone Levels and ACL Injuries<br />Non-linear regression model<br /><ul><li>There is a significant difference in the time dependency of the number of injuries
  57. 57. Cannot detect exact location ofhigh risk time interval</li></ul>Arendt et al., Journal of Gender Specific Medicine, 2002<br />
  58. 58. Hormone Levels and ACL Injuries<br />Population : 65 females (8 on OCP)<br /><ul><li>Sports related NC-ACL injury
  59. 59. Menstrual phase at time of injury
  60. 60. Urine specimens within 24 h
  61. 61. First day of next cycle
  62. 62. Urine analysis for total estrogen, progesterone, and lutinizing hormone metabolites</li></ul>Wojtys et al,<br />AOSSM, 2001<br />
  63. 63. LH Levels<br />Progesterone<br />Estrogen<br />Hormone Levels and ACL Injuries<br />Poor correlation between urine metabolites and athlete recollection of cycle<br />Higher number of ACL injuries during mid-cycle<br />No data on how metaboliteswere used to define stages of cycle<br />X = ACL injury<br />LH Concentration levels<br />Progesterone levels (ng/ml)<br />Estrogen levels (pg/ml)<br /> X <br /> X X X <br /> X X X X <br /> X X X X X X X <br />X X X X X X X X X X X <br />X X X X X X X X X X X X X X X X X<br />X X X X X X X X X X X X X X X X X X X X X X<br />Wojtys et.al.,<br />AOSSM, 2001<br />
  64. 64. Hormone Levels and ACL Injuries<br />Population : 35 females <br />(25 College / 12 H.S.)<br /><ul><li>Sports related NC-ACL injury
  65. 65. Saliva sample within 48 hours of injury</li></ul>26/37 (70%) injured ACL in follicular phase<br />.<br />Slaughterbeck et al.,NATA, 2001<br />
  66. 66. Hormones and Tissue Laxity<br />Population: 26 high school female athletes<br />Normal menstrual cycle<br />Prospective single blinded 8 week study<br />KT-1000 measurements taken prior to practice<br />Repeated measurement of KT-1000 over 8 weeks<br />Menstrual cycles charted<br />No difference in KT-1000 with phase of the menstrual cycle<br />Karageanes et al.,Clin J Sports Med, 2000<br />
  67. 67. Hormone Research<br />Criticisms:<br />One or two measurements not enough to capture female physiology<br />Normative standards not well defined<br />Small #’s unlikely to capture hormonal variability<br />Most studies have large S.D. bars<br />
  68. 68. Conclusion<br />Menstrual cycle phase & musculoskeletal injury<br />Inconclusive data<br />Neuromuscular mechanism (?)<br />
  69. 69. Consensus Statements: 1999 Anatomic Risk Factors<br />No consensus on role of the intracondylar notch<br />No consensus on role of ligament size<br />
  70. 70. Consensus Statements: 1999Anatomic Risk Factors<br />No consensus on role of anatomic alignment<br />
  71. 71. Anatomic Risk Factor ACL Size<br />Size of ACL: less force is required to rupture a smaller ligament<br />
  72. 72. Anatomic Risk FactorsACL Size<br />Cadaver knees ( N =16 )<br />Direct measurement technique<br />Smaller ACL (cross-section) in females compared to males<br />Muneta et al.,AJSM, 1997<br />
  73. 73. Anatomic Risk Factor ACL Size<br />Measured ACL width on MRI<br />Males ACL (6.1mm) > females ACL (5.2mm) <br />Did not control for height and weight<br />Staubli etal.,Arthroscopy, 1999<br />
  74. 74. Anatomic Risk Factor ACL Size<br />Measured ACL (cross-section) on CT scan<br />Male ACL (47.1mm) > female ACL (35.1mm) <br />Controlled for height and weight <br />Jackowski et al.,(Thesis, London, Ont.) 2001<br />
  75. 75. Anatomic Risk Factors ACL Size<br />Measured ACL cross-section on MRI <br />Case control study:matched for gender, age, and activity <br />20 F ACL deficient knees: contralateral knee compared to 20 controls<br />ACL deficient group had smaller x-sect (31mm) than controls (42.9mm)<br />Willits et al.,AOSSM, 1999<br />
  76. 76. THE FAMILIAL PREDISPOSITION TOWARDS TEARING THE ACL: A CASE-CONTROL STUDY<br />K. Flynn BSc <br />C. Pedersen MSc<br />A. Kirkley, MD<br />C. Lebrun, MD<br />Peter J. Fowler, MD<br />The University of Western Ontario, London<br />
  77. 77. Anatomic Risk FactorsACL Size<br />Based on data to date it appears that the increased rate of ACL tears seen in patients with narrower notches may simply be a manifestation of a smaller ACL.<br />Is the smaller ACL appropriate for the size / strength of the individual ????<br />If no -- is it due to gender, hormones, training??<br />
  78. 78. Anatomic Risk Factor Tibial Slope<br />Tibial Slope: in the “quads active” mechanism of ACL injury, the tibia is planted & the quadriceps contracts resulting in sufficient force to cause excessive posterior translation of the femur in relation to the tibia, resulting in tearing of the ACL.<br />The greater the tibial slope the easier it is for the femur to “slide” down the slope thus tearing the ACL<br />
  79. 79. Anatomic Risk Factor Tibial Slope<br />There is a 6 mm increase in anterior tibial translation for every 10 degree increase in anterior tibial slope<br />DeJour and Bonnin,JBJS, 1994<br />
  80. 80. Tibial Slope ACL Deficient Knees<br />
  81. 81. Anatomic Risk Factor Tibial Slope<br />Tibial slope measured on CT scan<br />No difference in males (8.3 degrees) vs. female (8.1 degrees) varsity athletes<br />Jackowski et al.,(Thesis, London, Ont.) 2001<br />
  82. 82. Anatomic Risk Factor Tibial Slope<br />XR measurement<br />case control study: 50 ACL deficient knees to age matched PF knees<br />no significant difference in ACL deficient knees (9.7 degrees) to controls (9.9 degrees)<br />Meister et al.,Amer J Knee Surg, 1997<br />
  83. 83. Anatomic Risk Factor Tibial Slope<br />Absolute measurement not contributory (?)<br />Slope plus muscle contractioncombined effect (?) <br />
  84. 84. Prevention Strategies for Anatomic Risk Factors<br />Anatomic risk factors are difficult to alter<br />Little agreement regarding which anatomic factors may be significant, hence no prevention strategies recommended at this time.<br />
  85. 85. Hunt Valley Consensus ConferenceVideos of ACL Injuries<br />54 videos of ACL injuries were collected in preparation for consensus conference<br />22/54 in basketball: 15 women, 5 men, 2 ?<br />Mechanism of injury: jump stop, jump landing, sudden deceleration<br />
  86. 86. ACL Injured on Landing<br />Knee slightly flexed<br />Knee in valgus, external rotation<br />
  87. 87. ACL Injured on Landing<br />Knee slightly flexed<br />Knee in valgus, external rotation<br />
  88. 88. Videos of ACL InjuriesConclusions<br />Most common positions at injury were landing from a jump, jump stop, sudden deceleration<br />Injured leg was usually not extended, but less than 30º flexion<br />
  89. 89. Research Needs: Non-Contact ACL Injuries<br />What is the mechanism of injury in non-contact injuries to the ACL?<br />Video data conflicts with in vitro data concerning ACL failure mechanisms<br />
  90. 90. Injury Mechanisms – Body Positions<br />
  91. 91. Knee Biomechanics (in vitro)<br />External loads of valgus and external rotation do not load the ACL between 100 and 300 flexion<br />Quadriceps activation can load the ACL between 100 and 300 flexion; this is increased if no hamstrings activation<br />
  92. 92. Consensus Statements: 1999Biomechanical Risk Factors<br />At this time, neuromuscular factors appear to be the most important reason for the differing ACL injury rates between males and females<br />Strong quadriceps activation during eccentric contraction a major factor in injury to ACL<br />
  93. 93. Neuromuscular Prevention Programs<br />Henning - Griffis Program<br />Caraffa Program<br />Wedderkopp’s Program<br />Cincinnati Program<br />Frappier Program (Fargo, N.D.)<br />Santa Monica Program (PEP)<br />Norwegian Awareness Program<br />
  94. 94. Norwegian Awareness Program<br />Three types of excercises with progression:<br />Floor<br /> Airex balancemat<br /> Balance board<br />5 weeks 2-4 x per week<br />Then 1 x week through the season (Oct-April)<br />
  95. 95. Results After 9900 Season: All 3 Divisions<br />
  96. 96. Conclusion:<br />Only 29% of the teams carried out the program according to the plan<br />Elite teams had the best compliance <br />Exercise quality improved when led by physical therapists <br />Compliance may be improved by:<br />More information<br />Changes in type of excercises<br />Improved info to the coach<br />Sign a contract with the team<br />
  97. 97. New and More Sports RelatedTraining Programs<br />Handball related excercises<br />Fakes <br />Two-leg landing<br />Less static excercises<br />Increased skill-level<br />Increased number of two-persons drills<br />Increased knowledge and motivation for players<br />
  98. 98. Floor Exercises – Progression<br />Run wtake off<br />Jump and two-leg landing<br />Jump-in fake<br />Turn around jump<br />Jump in with two leg landing<br />
  99. 99. Air Mat Progression<br />Receive ball on one leg<br />Jump shot with two leg landing<br />One leg landing<br />Two and one leg ”fight”<br />Jump in with turnround<br />
  100. 100. Baps Board Progression:<br />Two leg passes<br />Knee flex two leg and one leg<br />Passes one leg<br />One leg ball dribling wclosed eyes<br />Two leg and one leg ”fight”<br />
  101. 101. All Divisions<br />1999-00: 5 of 23<br />2000-01: 7 of 17<br />
  102. 102. Elite Division<br />1999-00: 4 of 6<br />2000-01: 3 of 5<br />
  103. 103. Conclusion:<br />An awareness program reduced ACL injuries in Norwegian team handball by 40% overall and 50% at elite level<br />
  104. 104. Conclusions<br />Prevention of ACL injuries is possible:<br />Neuromuscular training<br />Focus on knee position<br />Change the plant and cut and landing technique<br />Possibilities for better results with more control of the training <br />
  105. 105. Research Needs: Non-Contact ACL Injuries<br />What are strategies for preventing non-contact ACL injuries?<br />What do all these programs have in common?<br />
  106. 106. Research Needs: Non-Contact ACL Injuries<br />Proprioception training<br />Identifying at risk motions and positions. <br />Train avoidance techniques when possible<br />Training programs that enhance body control, in particular rotational control of the limb<br />Pelvifemoral muscles (hip extension, hip abduction, abdominals)<br />
  107. 107. Research Needs: Non-Contact ACL Injuries<br />What specific neuromuscular factor accounts for the difference in ACL injury incidence between males and females? - most studied risk factor to date is GENDER<br />
  108. 108. Take “3” to Save the KNEE<br /> Accentuate Balanced Body Motion<br />Control Limb Rotation<br />Land with Bent Knee and Hip<br />
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