The Bridge-Enhanced® ACL Repair (BEAR®) Implant is a proprietary bio-engineered bridging scaffold to facilitate healing of the torn ACL.
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.
Listen to this podcast to hear about the development of the BEAR Implant and clinical trial results.
BEAR Clinical Trials
Several clinical trials are underway to study the BEAR implant and its safety and efficacy.
- BEAR I: This single-center, non-randomized, two-arm study compared 10 patients treated with the BEAR Implant to 10 patients treated with hamstring autograft ACL reconstruction. In this small, first-in-human study, the BEAR Implant produced similar outcomes to ACLR with a hamstring autograft.
- 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: Multi-center, prospective cohort clinical study designed to evaluate patient outcomes with the use of Miach's bridge-enhanced ACL repair technology for ACL ruptures.
- BEAR MOON: This randomized, controlled trial being conducted by Cleveland Clinic at five centers of excellence will enroll 200 patients. 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
Clinical Study Results
Higher Physiologic Platelet Counts in Whole Blood Are Not Associated With Improved ACL Cross-sectional Area or Signal Intensity 6 Months After Bridge-Enhanced ACL Repair
Orthopaedic Journal of Sports Medicine, July 2020
- This study assessed whether concentrations of various blood cell types placed into the BEAR Implant at the time of ACL repair would have a significant effect on the healing ligament cross-sectional area or tissue organization (as measured by signal intensity). In 61 patients who underwent MRI at 6 months as part of the BEAR II trial, older age, male gender, and monocyte concentration in female patients were associated with greater healing ligament cross-sectional area; however, signal intensity of the healing ligament was independent of these factors. Physiologic platelet concentration did not have any significant effect on cross-sectional area or signal intensity of the healing ACL.
Females Have Earlier Muscle Strength and Functional Recovery After Bridge-Enhanced Anterior Cruciate Ligament Repair
Tissue Engineering Part A, June 25, 2020 (Ahead of Print)
- The first study comparing gender-specific outcomes for the BEAR Implant found no significant difference between males and females on patient-reported outcomes and objective anteroposterior (AP) laxity testing up to two years postoperatively, despite the fact that females had better hamstring and quadriceps strength indices at 6 months than males as well as better hop test results at 6 and 12 months.
Bridge-Enhanced Anterior Cruciate Ligament Repair Is Not Inferior to Autograft Anterior Cruciate Ligament Reconstruction at 2 Years: Results of a Prospective Randomized Clinical Trial
American Journal of Sports Medicine, May 2020
- The study compared 65 patients treated with the BEAR Implant to 35 treated with autograft anterior cruciate ligament reconstruction (ACLR). The BEAR Implant resulted in non-inferior patient-reported outcomes and anteroposterior (AP) knee laxity, as well as superior hamstring strength, compared to ACLR in a young and active cohort at two-year follow-up.
Changes in Cross-sectional Area and Signal Intensity of Healing Anterior Cruciate Ligaments and Grafts in the First 2 Years After Surgery
American Journal of Sports Medicine, June 2019
- The study compared 10 patients treated with the BEAR Implant to 10 treated with traditional hamstring autografts, using the contralateral ACL as reference. Based on MRI imaging, ACLs treated with the BEAR implant had a cross-sectional area (quantity), signal intensity (quality) and sagittal orientation that were similar to the contralateral ACL at 12 months, whereas hamstring autografts were significantly larger and more vertically oriented than the native ACL at 24 months.
Predictors of Healing Ligament Size and Magnetic Resonance Signal Intensity at 6 Months After Bridge-Enhanced Anterior Cruciate Ligament Repair
American Journal of Sports Medicine, April 2019
- The study evaluated 62 patients treated with the BEAR Implant using MRI imaging at six months. Modifiable factors, including surgical notchplasty and slower recovery of quadriceps strength at three months, were associated with a larger cross-sectional area and improved signal intensity of the healing ACL. Further studies are needed to determine the optimal size of the notchplasty and the most effective postoperative rehabilitation strategy after ACL repair.
Bridge-Enhanced Anterior Cruciate Ligament Repair: Two-Year Results of a First-in-Human Study
Orthopedic Journal of Sports Medicine, March 2019
- First-in-human study assessed the safety and early efficacy of the BEAR Implant to repair an ACL and compared 10 patients treated with the BEAR Implant to 10 treated with traditional hamstring autografts at 24 months. The BEAR Implant resulted in similar clinical, functional and patient-reported outcomes compared to patients undergoing autograft ACL reconstruction. In addition, the BEAR Implant did not result in any patients having an infection or a severe inflammatory reaction, arthrofibrosis or a reaction that required implant removal.
Bench-to-Bedside: Bridge-Enhanced Anterior Cruciate Ligament Repair
Journal of Orthopaedic Research, July 2017
- Review paper detailing the pathway of how a tissue engineering strategy can be used to improve the healing of the ACL in preclinical studies and then translated to patients in an FDA‐approved clinical study. Outlines clinical importance of ACL injuries, history of primary repair, pathology behind failure of the ACL to heal, pre‐clinical studies, FDA approval process, and preliminary results of the first‐in‐human study.
The Bridge-Enhanced Anterior Cruciate Ligament Repair (BEAR) Procedure: An Early Feasibility Cohort Study
Orthopedic Journal of Sports Medicine, November 2016
- First-in-human study compared 10 patients treated with the BEAR Implant to 10 treated with traditional hamstring autografts at three months. The BEAR Implant was tolerated by the synovial environment of the knee, with no deep infections or serious inflammatory reactions noted in the early postoperative period during which the implant is resorbed.
Preclinical Study Results
Use of a Bioactive Scaffold to Stimulate Anterior Cruciate Ligament Healing Also Minimizes Posttraumatic Osteoarthritis After Surgery
American Journal of Sports Medicine, August 2013
- Pre-clinical study using a porcine model. The BEAR Implant produced a ligament that was biomechanically similar to an ACL graft and provides chondroprotection to the joint after ACL surgery.