1. Anterior Cruciate Ligament in the Female Athlete
Dr. Rocco Simmerano
Athletic Trainers Meeting
June 3, 2006

2. Overview Epidemiology Relevant Anatomy Mechanisms of Injury
Risk Factors
Physical Exam
Diagnostic Imaging
Treatment Options

3. ACL Injury Approximately 80,000 tears/year in the US
50,000 reconstructions/year ($1 billion)
15-25 years old
70 % sports related
Absolute numbers show males > females
However, in sports where both men and women compete, women are 2-8 times more likely to tear their ACL

4. Anatomy
Musculature
Bones
Ligaments
Tendons
Cartilage

5. Musculature Quadriceps Hamstrings Gastroc-soleus complex
Rectus Femoris
Vastus Lateralis
Vastus Medialis
Vastus Intermedius
Hamstrings
Biceps Femoris
Semimembranosis
Semtitendinosis
Gracilis
Gastroc-soleus complex

6. Ligaments Medial (tibial) collateral ligament
Lateral (fibular) collateral ligament
Function in side to side control

7. Ligaments Anterior cruciate ligament Posterior Cruciate Ligament
Function in front to back control of the knee

8. Tendons Patellar tendon Part of the extensor mechanism
Continuation of the quadriceps

9. Cartilage
Menisci
Secondary stabilizers
Load transmission

10. Functions of the ACL
Prevents anterior movement of the tibia on the femur
Checks lateral rotation of the tibia in flexion
Checks extension/hyperextension of trhe knee

11. Mechanism of ACL Injury
Contact
Non-contact
Change of direction with foot planted
Deceleration
Awkward landing
“Out of control”

12. Risk Factors for ACL Injury
Environmental
Equipment, Landscape, Shoes
Anatomic
Lower extremity alignment, laxity, notch size
Hormonal
Biomechanical
Muscular strength, neuromuscular control

13. Environmental Risk Factors
Bracing
No evidence that prophylactic bracing prevents injury
Shoe-Surface Interaction
Multifactoral, higher friction associated with higher risk of injury

14. Anatomic Risk Factors Alignment Q Angle
FEMALE
MALE
Alignment
Women have higher Q angles, more femoral anteversion, excessive tibial torsion, higher foot pronation
Q Angle

15. Anatomic Risk Factors Laxity Notch Size More common in women than men
Role in injury still unclear
Notch Size
9 of 15 studies support narrow notch width as a contributing factor
In general, notch width is more narrow in women

16. Hormonal Risk Factors
Estrogen and Progesterone receptors found on the ACL
They can influence the mechanical properties of the ACL
Higher estrogen levels reduces the tensile strength of rabbit ACL

17. Hormonal Risk Factors
Studies attempting to link ACL injury with menstrual cycle are conflicting
Survery of 103 ACL injuries in NCAA womens basketball players from showed injury most commonly occurred in the peri-menstrual peroid (just before or just after)
Role of oral contraceptives is still unknown

18. Biomechanical Risk Factors
Proprioception and neuromuscular control
Hamstring and Quad balance
Women tend to have less hamstring activation than men
Eccentric quad contraction
Hip extensor strength
Women tend to have weaker hamstrings and glutei which leads to more upright landings after jumps
More valgus knee angle in women increases stress on the ACL

19. Physical Exam
Swelling
Instability
Lachman
Anterior drawer
Pivot shift

20. Magnetic Resonance Imaging

21. Immediate Care RICE Crutches Knee Immobilizer Referral to Orthopaedist
Rest, Ice, Compression and Elevation
Crutches
Knee Immobilizer
Quadriceps inhibition
Referral to Orthopaedist

22. Treatment Options Age of patient Activity level Associated injuries
Meniscus
Cartilage
Other ligaments
Surgery vs. bracing/activity modification

23. Surgery Timing—”pre”-hab Graft choices Risks of arthrofibrosis
Bone-patellar tendon-bone autograft
Hamstrings autograft
Allograft
Prepubescent reconstruction?

25. Rehabilitation Phase I—pre-op Phase II—0-2 weeks Phase III—3-5 weeks
Regain quad control, optomize ROM
Phase II—0-2 weeks
Wound healing, full extension, 90 deg flexion
Phase III—3-5 weeks
Full ROM
Phase IV—6 weeks +
Strength

26. Injury Prevention Neuromuscular Training
Altering pivot/cut activities
Landing on bent rather than straight knee
Unpublished data showed an 89% decrease in ACl injuries in Division 1 female athletes over 2 years
Prophylactic proprioceptive training
10 fold decrease in injuries over 3 years but a poorly matched control group

27. Questions?
Thank You!!!