ACL Tears & Treatment
Anterior cruciate ligament (ACL) tears are a common sports injury. Every year, approximately 200,000 injuries to the ACL occur in the U.S. The ACL is one of the four primary ligaments that provide stability to the knee joint. Without treatment, the ACL does not heal, resulting in ACL reconstruction surgery being one of the most common orthopaedic procedures in the U.S.
ACL reconstruction stabilizes the knee, but has a number of drawbacks:
- Reconstruction using an autograft involves removing the ACL and replacing it with a graft of tendon harvested from previously healthy parts of the leg, which compromises uninjured structures and requires healing not only the ACL site, but the graft site as well.
- The allograft approach uses a graft from a donor, which has other risks. Moreover, this approach has been reported to have a lower success rate among younger, more active patients.
- Even with surgery for ACL reconstruction, only about 60 percent of patients can return to their sport at the same level.
- The ACL re-tear rate can be as high as 20 percent for teens.
The Bridge-Enhanced® ACL Repair (BEAR®) implant is a proprietary bio-engineered sponge designed as a bridging scaffold to facilitate healing of the torn ACL and is an alternative to the current standard reconstruction treatment for torn ACLs. Use of the BEAR technology does not require a second surgery to harvest the patient's own tissue as required with autograft reconstruction.
The BEAR implant is designed to be surgically placed between the torn ACL ends at the time of repair, and to hold a small amount of the patient’s blood in the wound site. The combination of the BEAR implant and the patient’s blood provides a scaffold that allows the torn ends of the ACL to heal back together.
It is hoped this new technology will restore more normal anatomy and function of the knee, and thus enable a higher percentage of patients to get back to activities they enjoy.
The BEAR implant is an investigational device and is only available in FDA-approved clinical trials.
Watch this video to find out more about how the BEAR implant works.
Watch this video to find out more about ACL tears, the BEAR implant and the first patient to receive it.
BEAR Clinical Trials
Several clinical trials are underway to study the BEAR implant and its safety and efficacy.
- BEAR I: Enrollment is completed in this single-center, non-randomized, two-arm study that compared 10 patients treated with the BEAR implant to 10 patients treated with hamstring autograft ACL reconstruction.
- BEAR II: Enrollment is completed in this single-center, non-randomized, two-arm study that compared 65 patients treated with the BEAR implant to 35 patients treated with autograft ACL reconstruction.
- BEAR III: Enrollment of 250 patients is ongoing in this study taking place at Boston Children's Hospital and Rhode Island Hospital. Patients who may be eligible for the study:
- will be ages 12 to 35
- will be seen within 3 weeks of injury by a Boston Children's Hospital or Rhode Island Hospital participating surgeon
- cannot have a history of prior ACL surgery on the affected knee
- must not use tobacco, corticosteroids, or have a history of diabetes or inflammatory arthritis or any condition that could affect healing
- BMI <35 (will be measured in clinic)
- must not have an allergy to bovine collagen (cow protein)
- To see if you are eligible to participate, email:
- BEAR MOON: Enrollment of 200 patients will begin later in 2019 in this randomized, controlled trial being conducted by Cleveland Clinic at five centers of excellence. The trial will compare patients treated with the BEAR implant to standard autograft patellar tendon reconstruction. The BEAR MOON trial is supported by a $6 million RO1 grant from the National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health. For more information about the trial refer to https://clinicaltrials.gov/ct2/show/NCT03776162?term=BEAR+MOON&rank=1