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

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

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

Anatomy Musculature Bones Ligaments Tendons Cartilage

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

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

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

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

Cartilage Menisci Secondary stabilizers Load transmission

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

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

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

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

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

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

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

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 1998-1999 showed injury most commonly occurred in the peri-menstrual peroid (just before or just after) Role of oral contraceptives is still unknown

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

Physical Exam Swelling Instability Lachman Anterior drawer Pivot shift

Magnetic Resonance Imaging

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

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

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

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

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

Questions? Thank You!!!