A Tissue-Saving Alternative to ACL Surgery Is Changing How Doctors Treat Young Athletes

When a young athlete tears their anterior cruciate ligament (ACL)—one of the key stabilizing structures in the knee—surgery has long been considered inevitable. But a groundbreaking approach called bridge-enhanced ACL repair (BEAR) is offering a fundamentally different path forward. Instead of replacing the torn ligament with tissue harvested from elsewhere in the body, BEAR allows surgeons to repair the original ACL in place, potentially sparing athletes from the side effects that come with traditional reconstruction.

Why ACL Reconstruction Became the Standard Treatment

For decades, ACL reconstruction has been the gold standard for young athletes with torn ACLs. The procedure involves taking healthy tissue—called a graft—from somewhere else in the patient's body to replace the damaged ligament. Surgeons have three main graft options to choose from, each with different trade-offs.

• Patellar Tendon Graft: Tissue taken from the area connecting the kneecap to the shinbone, traditionally considered the gold standard for large athletes like football players
• Quadriceps Tendon Graft: Tissue from the area connecting the thigh muscle to the kneecap, often chosen based on the athlete's body size and activity demands
• Hamstring Tendon Graft: Tissue from the back of the knee, sometimes preferred for athletes with a history of front-knee pain

The reason reconstruction became standard is straightforward: when surgeons tried simple repairs decades ago, the failure rate was unacceptably high. The ACL sits inside the knee joint, where synovial fluid—the lubricating liquid inside the joint—breaks down blood clots that would normally help the ligament heal. Without that protective blood clot, the repair would fail. Reconstruction solved this problem by replacing the damaged tissue entirely, but it came with a cost: taking tissue from one part of the body always causes some weakness or side effects at the donor site.

How BEAR Changes the Game for ACL Injuries

BEAR technology, developed by Dr. Martha Murray at Boston Children's Hospital, finally solved the healing problem that made simple repairs fail for so long. The FDA approved BEAR for patient use in 2020, though Dr. Murray had been researching the concept since 1989. The innovation is elegantly simple: a collagen-based implant that looks somewhat like a marshmallow is placed into the knee joint after the torn ACL is repaired. This implant acts as a protective bridge, keeping the blood clot in place and shielding it from the synovial fluid that would otherwise break it down. After about six weeks, the implant dissolves naturally, leaving behind a healed ligament.

"What if we could come up with a material that would bridge that gap and keep the blood clot there, protect the blood clot from the synovial fluid, breaking it down and allow the ACL to repair," explains Dr. Sean Waldron, describing the thinking behind BEAR's development. This tissue-preserving approach eliminates the need to harvest grafts from other parts of the body, avoiding the weakness and complications that can follow traditional reconstruction.

When Should Young Athletes Consider BEAR Over Traditional Reconstruction?

BEAR isn't necessarily right for every young athlete with an ACL tear. Surgeons still need to evaluate whether surgery is needed at all—some young people who don't participate in cutting and pivoting sports may manage without surgery through careful rehabilitation and activity modification. For those who do need surgery, the choice between BEAR and traditional reconstruction depends on several factors, including the athlete's age, activity level, and specific injury characteristics.

One important consideration is the risk of developing patellofemoral syndrome—pain in the front of the knee—after surgery. Dr. Jennifer Weiss, an orthopedic surgeon with 23 years of experience performing ACL procedures, notes that some young athletes, particularly female athletes, have a predisposition to this type of pain. For these patients, avoiding the patellar tendon graft becomes important, which is one scenario where BEAR's tissue-sparing approach offers a meaningful advantage.

The key limitation of BEAR is that it's still a newer technique, and long-term outcome data continues to accumulate. Traditional reconstruction has decades of proven results, while BEAR's track record spans only a few years. However, the elimination of graft-site morbidity—the weakness and complications that come from harvesting tissue—represents a significant potential advantage for young athletes who want to return to their sport with minimal collateral damage to their bodies.