Page 28 - ISAKOS 2019 Newsletter Volume 1

CURRENT CONCEPTS
Quick Report: Anterior Cruciate Ligament Rupture in Females
While the reasons for this second peak were not entirely clear, this finding suggests that females are remaining active longer and emphasizes the importance of recognizing that ACL injury is still a risk for the active adult female population.
Table I Risk Factors for ACL Injuries in Females Extrinsic Risk Factors
Epidemiology
• Increased female sports participation • Parental history of ACL injury
Introduction
• •
• •
Increased estradiol
Follicular and pre-ovulatory phases of menstrual cycle
Increased relaxin
Decreased testosterone
• Increased peak knee abduction angles during landing
• Increased quadriceps to hamstrings activity
• Increased lateral trunk displacement leading to increased knee valgus
• Altered trunk and hip flexion angles; increased ranges of trunk motion
• Weakness or poor neuromuscular control in hip external rotators
• Increased hip adduction and internal rotation leading to increased knee abduction moments
• Decreased trunk and hip flexion on landing leading to increased ground- reaction forces on lower extremity
Meghan E. Bishop, MD
The Rothman Orthopaedic Institute New York, NY UNITED STATES
Anthony Romeo, MD
The Rothman Orthopaedic Institute New York, NY UNITED STATES
Anatomic
• Increased Q-angle
• Decreased femoral notch width
• Decreased ACL size
• Increased tibial slope
• Increased ligamentous laxity
• Increased BMI
• Increased incongruent medial
and lateral compartments
Intrinsic Risk Factors
Hormonal Neuromuscular
The elevated risk of anterior cruciate ligament (ACL) tears in female athletes has been well documented, with females being shown to have a 2 to 8 times higher risk of tearing the ACL than their male counterparts1. Numerous studies have investigated this finding and have demonstrated sport- specific risks, with one meta-analysis showing female- male ACL tear incidence ratios of 3.5 in basketball, 2.67 in soccer, and 1.18 in lacrosse1. Anatomical, hormonal, and neuromuscular sex-specific factors have all been associated with an increased risk of ACL injury. Understanding the multifactorial elements that contribute to a higher incidence of ACL injuries in female athletes is important for optimizing treatment and prevention strategies and providing the best care for these individuals. This report will provide a review of the most up-to-date literature regarding the extrinsic and intrinsic risk factors unique to females, prevention strategies, and treatment outcomes.
Risk Factors (Table I)
Extrinsic Risk Factors
With the rise of female participation in youth sports, the number of ACL injuries has increased, with a 2017 study by Beck et al. showing that the number of ACL tears per 100,000 person-years increased by 2.5% per year in females 6 to 18 years of age (compared with 2.2% in males) over a 20-year period. While the peak incidence of ACL tears appears to be in athletes in their late teens and early 20s, particularly in females after puberty1, Nicholls et al., in a 2017 Icelandic nationwide database study of knee MRIs, found a second peak of ACL tears in women in their early 40s.
26 ISAKOS NEWSLETTER 2019: VOLUME I