Anterior Cruciate Ligament in the Female Athlete

Dr. Rocco Simmerano

Athletic Trainers Meeting

June 3, 2006

Overview

EpidemiologyRelevant AnatomyMechanisms of InjuryRisk FactorsPhysical ExamDiagnostic ImagingTreatment Options

ACL Injury

Approximately 80,000 tears/year in the US50,000 reconstructions/year ($1 billion) 15-25 years old70 % sports relatedAbsolute 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 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

ContactNon-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

HormonalBiomechanical

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 Women have higher Q

angles, more femoral anteversion, excessive tibial torsion, higher foot pronation

FEMALE MALE

Q Angle

Anatomic Risk Factors

Laxity 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 Rest, Ice, Compression and Elevation

CrutchesKnee Immobilizer

Quadriceps inhibition

Referral to Orthopaedist

Treatment Options

Age of patientActivity levelAssociated injuries

Meniscus Cartilage Other ligaments

Surgery vs. bracing/activity modification

Surgery

Timing—”pre”-hab Risks of arthrofibrosis

Graft choices Bone-patellar tendon-bone autograft Hamstrings autograft Allograft Prepubescent reconstruction?

Rehabilitation

Phase I—pre-op 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!!!