Clinical Trials in the Spotlight Main Page

The National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) supports a range of clinical trials studying new and existing interventions for prevention and treatment of arthritis, musculoskeletal, and skin diseases.  Investigators supported by the NIAMS need your help finding individuals to participate in clinical trials.  Participating in clinical trials allows you to play an active role as a volunteer in research and contribute to generating new knowledge about the disease/condition, and potentially future treatments.  The information below is designed to help you quickly learn about actively recruiting research studies for which you or someone you know may be eligible. 

Study Description

Tissues which live within joints, including the anterior cruciate ligament, rotator cuff tendon, meniscus and labrum fail to heal spontaneously after injury and have high failure rates of surgical repair. The ACL represents a good model to study the problem of intra-articular healing as there are validated preclinical models and clinical outcome measures that make it possible to critically evaluate the success or failure of strategies to enhance tissue healing. The current standard of care for ACL injuries is ACL reconstruction, which is good at stabilizing the knee but requires compromising other uninjured structures around the knee to obtain a graft that is subsequently used to replace the ACL. Further the early posttraumatic OA is not mitigated despite ACL reconstruction. The preclinical studies on ACL repair called BEAR (Bridge-Enhanced ACL Repair) demonstrated a prevention of posttraumatic OA and achieved knee stability. The positive preclinical findings of BEAR compared to ACL reconstruction provided the foundation for two FDA approved preliminary clinical trials: 1) the first-in-human cohort study (“BEAR I”), and 2) a small, single-center randomized control trial (“BEAR II”). The statistical analysis of our pilot data shows a 200 patient trial will be required to demonstrate non-inferiority of BEAR (a novel paradigm changing technology) when compared to ACL reconstruction (current gold standard) for the key outcomes of anterior-posterior (AP) knee laxity and a validated patient reported outcome for knee surgery. Therefore, the study team proposes the BEAR-MOON (Bridge-Enhanced ACL Repair) multi-center randomized non-inferiority clinical trial for co-primary outcomes AP (anterior-posterior) knee laxity and International Knee Documentation Committee (IKDC) validated patient reported outcome measure.

The subjects will be between 18 and 40 years of age with a complete ACL tear and randomized to either 1) ACL Reconstruction with patellar tendon autograft (ACLR) or 2) Bridge-Enhanced ACL Repair (BEAR). The study team will follow subjects at 6 months, 1 and 2 years after surgery. While achieving these aims has the potential to change the clinical practice of ACL surgery, the impact is potentially far greater, as the availability of an FDA- approved carrier that can be used to deliver complex biologic therapies to tissues within joints could enable the clinical translation of the preclinical studies being conducted in multiple areas of regenerative medicine by providing a delivery vehicle for these therapies.


Ages Eligible for Study:           18 Years to 40 Years   (Adult)

Sexes Eligible for Study:          All

Accepts Healthy Volunteers:  No

Inclusion Criteria:

  • 18-40 years of age
  • Complete ACL tear as confirmed by MRI
  • Selected surgical treatment of ACL injury
  • Believed to be a surgical candidate for ACL reconstruction by treating physician
  • Time from injury to surgery is ≤50 days
  • Stated willingness to comply with all study procedures for the duration of the study, including lifestyle, activity, and sports restrictions
  • Provision of signed and dated informed consent form


Exclusion Criteria:

  • Any prior surgery on affected or unaffected knee
  • Confirmed or suspected contralateral ACL tear
  • ACL tear found to be only partial and the treating physician feels it does not require surgery because it is "stable"
  • Diagnosis of posterolateral corner injury (complete lateral collateral ligament tear, biceps femoris tendon avulsion, arcuate ligament tear, popliteus ligament tear) that requires concurrent or staged surgical treatment
  • Diagnosis of Grade 3 medial collateral injury that requires concurrent or staged surgery
  • Insufficient ACL tissue on MRI
  • Diagnosis of complete patellar dislocation
  • Diagnosis of complete patellar tendon or quadriceps tear
  • Obesity with a BMI ≥35
  • Does not speak or understand English
  • History of regular tobacco or nicotine use in any form
  • History of drug or alcohol abuse
  • Inability to take oral medications
  • Use of intra-articular corticosteroids in the affected knee within last 6 months
  • Chronic use of oral corticosteroids (e.g., to treat lupus, rheumatoid arthritis, asthma, etc.)
  • History of prior infection in knee
  • History of chemotherapy treatment
  • History of sickle cell disease
  • History of anaphylaxis
  • Any condition that, in the opinion of the investigator, could affect healing (e.g., diabetes, inflammatory arthritis, etc.)
  • Pregnancy or lactation
  • Known allergic reactions to meat products or collagen
  • Known allergy to bovine collagen, bovine gelatin, or other bovine products
  • Known adverse reaction to any bovine product
  • Febrile illness within 7 days
  • Treatment with another investigational drug or other intervention, either concurrently or previously, that would interfere with surgical healing


  • Time from injury to surgery has exceeded 50 days
  • No ACL tear found upon arthroscopic inspection
  • ACL tear found to be only partial, with normal pivot shift and endpoint, and does not require surgery
  • Displaced bucket handle meniscal injury requiring repair
  • Diagnosis of full-thickness chondral injury of Grade 3 or 4, or that requires more than microfracture (i.e., osteochondral autograft transplant), on either condyle
  • Unrecognized lateral or medial sided Grade 3 ligamentous injury that requires concurrent or staged surgery
  • Tibial stump length is < 1cm
  • Tibial footprint attachment is < 50% intact
  • Any other reason the ACL stump should be deemed irreparable (e.g., tissue quality too poor to hold suture)


Study Design:

Allocation: Randomized

Intervention Model: Parallel Assignment

Masking: Triple (Participant, Care Provider, Outcomes Assessor)

Primary Purpose: Treatment

Study Location(s):

Washington University St. Louis, Saint Louis, Missouri, United States, 63110

Cleveland Clinic, Cleveland, Ohio, United States, 44195

Ohio State University, Columbus, Ohio, United States, 43202

Brown University/Rhode Island Hospital, Providence, Rhode Island, United States, 02906

Vanderbilt University, Nashville, Tennessee, United States, 37232

Study Website:


Last Updated: August 2019