The Bridged Enhanced ACL Repair (BEAR) implant is the first medical advancement to enable your body to heal its own torn anterior cruciate ligament (ACL). That’s a big deal because until now your ACL would have been replaced with either another tendon from your body or a tendon from a deceased donor.
Evolution of ACL Repairs
ACL repairs failed in the past as the normal synovial fluid in the joint would prevent the healing of this ACL. This process is called resorption, where your body slowly breaks down and absorbs the repair over time.
So surgeons began searching for a way to encourage your body to accept the repair and enable it to heal on its own. The first major breakthrough in this area was the development of the autograft, which uses a tendon from another part of your body to replace your ACL.
While this method was an improvement, it still had its limitations as the new tendon was not always as strong as the original. Additionally, there was still the risk of resorption, albeit to a lesser extent.
The use of an allograft uses a tendon from a deceased donor. This method eliminates the need to harvest a tendon from another part of your body, but there is still the risk of resorption as your body may reject the allograft. In addition, allografts are not as strong as autografts and have a higher failure rate, especially in younger patients.
What is the BEAR ACL repair?
The BEAR implant is different because it works with your own blood to help heal the torn ends of the ACL ends back together. The BEAR implant is designed to hold and protect your blood in the gap between the ACL ends to allow the formation of a clot, which is necessary for healing. This is done using the BEAR implant to protect the repair. The BEAR Implant is a decellularized, bovine-derived, type I collagen implant that resorbs in 8 weeks. The BEAR implant prevents the synovial fluid from infiltrating this area and breaking down the normal healing factors.
How is the BEAR implant different from reconstruction?
ACL tears are often treated with surgery called ACL reconstruction. During ACL reconstruction, an orthopedic surgeon removes your torn ACL and replaces it with a graft from another part of your leg (called an autograft) or a deceased donor (called an allograft). Although ACL reconstruction is effective, the procedure has drawbacks; the normal anatomy is not restored. Some people are unable to return to the same level of daily activities or sports after ACL reconstruction.
The BEAR implant is a simpler procedure than an ACL reconstruction to repair. The remaining ACL tissue is preserved and your ACL is restored. Additionally, postoperative care for the BEAR implant is less intensive than postoperative care for ACL reconstruction.
The BEAR implant was cleared by the U.S. Food & Drug Administration and is indicated for skeletally mature patients at least 14 years of age with a complete rupture of the ACL, as confirmed by MRI. Patients must have an ACL stump attached to the tibia to construct the repair. The device must be implanted within 50 days of injury. If your ACL remnants are not intact, you may require an ACL reconstruction.
The benefits of the BEAR implant include:
- Superior in return to sports
- Improved hamstring/quad ratio
- Increased hamstring strength
- Improved pain outcomes
- Helps your own ACL heal
- No need for grafts
- No autograft wound site that needs to heal
- No worries about donor graft quality or risk of disease
- Restores torn ACL quality and size similar to your non-injured ACL
- Faster recovery of muscle strength
- Simple outpatient procedure
- Higher patient satisfaction with being ready to return to sports
- Potential for more normal joint mechanics
- Potential for decreased post-traumatic osteoarthritis (demonstrated only in animals)
- Revisions are easier than a revised ACLR
- Early research shows a trend toward better outcomes with a revision after the BEAR Implant
- Effective across a broad range of tear types
How is BEAR Procedure performed?
The combination of autologous whole blood and the BEAR Implant creates a clot that acts as a bridge between the torn ends of the ACL. This protects the clot from further damage in the synovial environment. Without protection of the repair, there is a high risk of graft failure.
The BEAR Implant helps the body’s natural recovery mechanism by assisting cell migration and proliferation using the patient’s own blood.
At the end of eight weeks, the implant is resorbed and replaced with natural cells, collagen, and blood vessels. Over time, the new tissue continues to remodel and strengthen.
The BEAR Implant specific rehabilitation protocol has been designed to help the ACL heal during the healing process. Return to sports typically occurs at 9 months to 1 year after surgery.