MRI Study Shows Miach Orthopaedics BEAR Implant Restores Torn ACL Quality and Size Similar to Native ACLs

Study of 20 Patients Published in American Journal of Sports Medicine

WESTBOROUGH, Mass.--()--Miach Orthopaedics, Inc., a privately held company dedicated to developing bio-engineered surgical implants for connective tissue repair, today announced results of a study published online in the American Journal of Sports Medicine showing torn anterior cruciate ligaments (ACLs) treated with the Bridge-Enhanced® ACL Repair (BEAR®) implant are similar to the contralateral (native) ACL at 12 months based on MRI imaging.

The study, “Changes in Cross-sectional Area and Signal Intensity of Healing Anterior Cruciate Ligaments and Grafts in the First 2 Years After Surgery,” compared 10 patients treated with the BEAR implant to 10 treated with traditional hamstring autografts, using the contralateral ACL as reference. The study showed 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.

“The results highlight the ability of the BEAR implant to restore the signal intensity and anatomy of the torn ACL to those of the native ACL,” said Martha Murray, M.D., professor of orthopaedic surgery at Harvard Medical School, an orthopaedic surgeon in the Sports Medicine Division at Boston Children’s Hospital and founder of Miach Orthopaedics. “MRIs from these two cohorts were helpful in comparing the changes over a two-year period, as well as the influences of other anatomic features of the knee after surgery. While more study is needed, these results show promise for the regenerative properties of the BEAR implant in restoring more normal knee anatomy.”

Specific study results include:

  • Mean cross-sectional area of the hamstring autografts was 48% to 98% larger than the contralateral intact ACLs at all time points, whereas BEAR ACLs were 23% to 28% greater at 3 and 6 months but similar at 12 and 24 months.
  • BEAR ACLs were similar in sagittal orientation to the contralateral ACLs, while the hamstring autografts were 6.5% more vertical.

“We are encouraged by the results of this study, which add to the growing body of evidence supporting use of the BEAR implant as a potential treatment option for people with torn ACLs,” said Martha Shadan, president and CEO, Miach Orthopaedics. “ACL repair using the BEAR implant is a new approach to an old problem that we think has the potential to improve outcomes for people with torn ACLs.”

About the Study

Patients with a complete, midsubstance ACL tear who were treated with either BEAR (n=10) or ACLR (n=10) underwent MR imaging at 3, 6, 12 & 24 months after surgery. Images were analyzed to determine the average cross-sectional area and signal intensity of the ACL or graft at each time point. ACL orientation, stump length and bony anatomy were also assessed.

About ACL Tears & Reconstruction

Every year, approximately 200,000 ACL injuries occur in the U.S. Without treatment, the ACL does not heal, resulting in ACL reconstruction surgery being one of the most common orthopaedic procedures in the U.S. Traditional ACL reconstruction using an autograft or allograft stabilizes the knee but has drawbacks – primarily that only about 60 percent of patients can return to their sport at the same level, and the ACL re-tear rate can be nearly 30 percent for teens.

About the BEAR® Implant

The proprietary bio-engineered Bridge-Enhanced® ACL Repair (BEAR®) implant is intended to facilitate healing of the torn ACL. It 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 implant 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.

About Miach Orthopaedics, Inc.

Miach Orthopaedics, Inc. is a privately held company located in Westborough, Massachusetts, dedicated to developing bio-engineered surgical implants for connective tissue repair. The company’s initial focus is on the Bridge-Enhanced® ACL Repair (BEAR®) technology as a viable alternative to conventional ACL reconstruction for patients who have sustained an ACL injury. The BEAR technology was pioneered by Martha Murray, M.D., at the Boston Children’s Hospital Department of Orthopaedic Surgery with initial research funding provided by the NFL Players Association, Boston Children’s Hospital and the National Institutes of Health. For more information on Miach Orthopaedics and its products, visit and follow the company on Twitter and LinkedIn.


Joni Ramirez
Merryman Communications

Release Summary

New study results show torn ACLs treated with Miach Orthopaedics’ BEAR® implant are similar to the contralateral (native) ACL at 12 months.


Joni Ramirez
Merryman Communications