New Imaging Protocol Urged for Young Athletes After ACL Surgery

ORLANDO, FL – May 12, 2026 – Landmark research presented at the Pediatric Orthopedic Society of North America (POSNA) annual meeting is calling for a significant shift in how young athletes are monitored after anterior cruciate ligament (ACL) surgery. Two new studies from the renowned Hospital for Special Surgery (HSS) in New York reveal that a substantial percentage of growing children develop subtle leg alignment issues post-surgery, a risk that researchers argue can be managed and corrected with routine pre- and post-operative imaging.

The findings challenge the current standard of care and advocate for a more proactive approach to protect the long-term musculoskeletal health of an increasingly vulnerable population of young athletes.

The Growing Problem of Youth ACL Injuries

Once considered an adult injury, ACL tears have become alarmingly common in children and adolescents. The past two decades have seen a dramatic rise in pediatric ACL injuries, a trend experts link to increased youth participation in high-level, competitive sports and a move towards early, year-round specialization in a single sport. This intense focus places repetitive stress on developing bodies, making them more susceptible to significant joint injuries.

For children and teens whose bones are still growing, an ACL tear presents a unique surgical dilemma. The growth plates—areas of developing cartilage at the ends of long bones—are fragile and essential for a child’s limbs to grow to their proper length and alignment. In adults, standard ACL reconstruction involves drilling tunnels through the exact areas where these growth plates are located in children, posing a risk of stunting or deforming bone growth.

In response, orthopedic surgeons have developed specialized “physeal-sparing” techniques designed to reconstruct the torn ligament while avoiding or minimizing damage to the growth plates. While these advanced procedures have allowed for earlier and safer surgical intervention, the new HSS research indicates that the risk of growth disturbances has not been entirely eliminated.

HSS Research Reveals Hidden Risks

Led by Dr. Peter D. Fabricant, a pediatric orthopedic surgeon at HSS, the multi-center studies evaluated outcomes for children who underwent two common types of growth-plate-sparing ACL reconstruction. The results highlight a previously underappreciated risk.

One study focused on pre-pubertal patients—girls younger than 12 and boys younger than 14—who have the most significant growth remaining and are therefore most vulnerable. Among 112 patients, researchers found that approximately 25% developed subtle but significant postoperative changes, such as leg length discrepancies or angular deformities, within a year of their surgery.

“If you injure the growth plate in a younger child who has many years to grow, there’s a lot of time during which that growth plate can grow abnormally,” explains Dr. Fabricant. “It’s important to make people aware that even though these procedures are safe overall and designed to respect the growth plates, there is still a risk of kids experiencing alignment issues afterward.”

A second study examined adolescent patients who had less than two years of growth remaining. Even in this less vulnerable group, researchers found that 15% to 30% developed changes in leg alignment following a transphyseal ACL reconstruction, a technique that more closely resembles the adult procedure.

The critical insight from both studies is that these alignment changes are often too subtle to be detected through a standard physical examination. Only through comparative X-ray imaging of both the surgical and uninjured leg, taken before and after the procedure, can these potentially troublesome deviations be accurately identified and tracked.

A Call for a New Standard of Care

The HSS research team argues that these findings provide compelling evidence to make routine imaging a new standard of care for all growing children undergoing ACL reconstruction. This proactive monitoring is crucial because it opens a critical, time-sensitive window for early and minimally invasive intervention.

“This study gives evidence to support the use of imaging to routinely check a patient’s alignment before surgery, check it after surgery, and monitor these kids for growth disturbances,” Dr. Fabricant states. He notes that relying on subjective concerns to trigger imaging may lead to “missed opportunities for early intervention.”

When alignment issues are caught early in a growing child, they can often be corrected with a minimally invasive procedure called implant-mediated guided growth. This technique involves placing small implants around the growth plate to gently guide the bone to grow back into correct alignment. It is a minor operation with a quick recovery.

However, this option is only available while the growth plates are still active. “If you aren’t routinely imaging to monitor alignment and you don’t realize it in time, then you’re beyond that window of being able to do that minimally invasive surgery,” Dr. Fabricant warns. The alternative for a patient who has stopped growing is a major corrective surgery known as an osteotomy, which involves cutting and realigning the bone—a procedure with a far more extensive recovery and higher risk.

Protecting the Future of Young Athletes

Beyond just preventing complex surgeries, proactively managing leg alignment has profound implications for an athlete’s future. Proper alignment is a vital factor in joint health and athletic performance. Even subtle malalignment can alter biomechanics, increasing the risk of re-injury to the ACL graft, injury to the other knee, and the early onset of osteoarthritis later in life.

The research also underscores the importance of preoperative imaging. By identifying a patient's baseline alignment before surgery, surgeons can make more informed decisions. For a patient with a borderline alignment issue, a surgeon might opt to perform a guided growth procedure at the same time as the ACL reconstruction, addressing a potential problem before it worsens.

While implementing routine imaging would add an upfront cost to care, the long-term benefits in preventing re-injuries and major corrective surgeries present a strong case for its value and cost-effectiveness. By shifting from a reactive to a proactive mindset, the medical community can better protect the long-term health and athletic careers of young people.

“We know that leg alignment is a vital factor in predicting injury, reinjury, and surgical failure,” says Dr. Fabricant. “The logical next step is to strongly consider intervening on alignment problems when necessary in order to prevent reinjury.”