Anterior cruciate ligament (ACL) tears are among the most common—and most serious—injuries in young athletes. Teenage girls and young women are particularly vulnerable, especially those who play high-impact sports like soccer, basketball and volleyball.
Research shows female athletes are up to eight times more likely than their male counterparts to experience an ACL tear. These injuries often require surgery and a 9-12- month recovery period. For any kind of athlete, that kind of setback can be physically and emotionally devastating. The good news is that with proper training, awareness and early intervention, many of these injuries can be prevented or treated effectively to avoid long-term damage.
The ACL is one of four primary ligaments in the knee. It helps keep the knee stable and protects the meniscus and cartilage when an athlete changes direction, pivots or lands from a jump.
Why are young female athletes more likely to tear this ligament? Several factors are involved.
Anatomically, females tend to have a more “knock-kneed” alignment, which puts greater stress on the ACL, especially during awkward landings or sudden direction changes. On average, females also have less muscle mass around the knee compared to males, which means they have less natural support for the joint.
Hormones, including estrogen and progesterone, may also affect ligament looseness and stability. In adolescent females, hormonal fluctuations during or after puberty may further increase the risk of injury. Research from Cedars-Sinai and other institutions suggests that certain phases of the menstrual cycle, when estrogen levels are high, may be linked to a higher likelihood of ACL injuries.
Sports that require cutting, pivoting and jumping are the most common culprits in knee injuries. These movements can put sudden, intense strain on the ligament, particularly in athletes who haven’t learned proper landing mechanics.
Some ACL injuries are dramatic—athletes may hear a pop, experience immediate swelling and feel their knee give out. Other injuries are more subtle, especially when the tear is the result of a non-contact incident. In those cases, the most telling symptom is a persistent sense of instability, particularly when trying to cut or pivot.
Diagnosis involves a clinical exam and is confirmed with imaging, usually an MRI. In most young, active patients, surgery to reconstruct the ligament is the best option. We typically use a tendon graft from the same leg to replace the torn ACL. While walking and basic activities often feel normal within a few weeks, returning to sport takes much longer—as much as a year for the graft to integrate and strengthen.
Prevention, however, is where we can make the biggest impact. ACL prevention programs—incorporating strength training, neuromuscular control drills and jump-landing instruction—are essential. These can be as simple as bodyweight squats, hamstring-strengthening movements and plyometric drills that teach athletes to land with knees aligned and under control. When done consistently, often as part of a warmup, these programs significantly reduce injury rates.
For athletes returning from ACL surgery, my advice is always the same: be patient. The knee may feel strong after a few months, but the biology takes time. Returning too soon risks reinjury, which can be heartbreaking after months of rehab.
Once an athlete has torn one ACL, their risk of tearing the other is about four times higher. Not only does the athlete carry the same anatomic risk factors in the healthy knee, the individual also is likely to overcompensate. Imbalances in knee strength and the nervous system effectively make the healthy knee perform overtime, increasing the risk for injury.
All of this is why prevention training is not just a pre-injury strategy—it’s a lifelong habit for any athlete who wants to stay healthy and competitive. And even if reinjury does occur, it’s not the end of a sports career. With proper treatment, revision surgery and dedicated rehabilitation, many athletes successfully return to their sport stronger than ever.
Michael Banffy, M.D., is chief of Sports Medicine at Cedars-Sinai Orthopaedics, specializing in joint preservation, cartilage restoration and advanced hip, shoulder and knee arthroscopy. He serves as a team physician for the Los Angeles Rams, the Los Angeles Dodgers and Loyola Marymount University Athletics.
