Knotless Soft Tissue Augments for Improving Arthroscopic Rotator Cuff Repair Biomechanics Load sharing and reinforcing soft tissue with knotless suture augments present a disruptive andinnovative technology to managing the surgical care of rotator cuff injuries and prospectively other injurieswhere suture pull-through can have catastrophic effects. This phase I SBIR proposal endeavors to develop anew field of study and redefine clinical practice via innovative soft tissue augment (STA) implants to improvesuture load distribution and tissue healing in rotator cuff repair (RCR) and related surgeries. The significance ofthis project is medical engineering of strong, reinforcing, resorbable polymeric implants that will allow forstudying joint repair stability, understanding the causes/mechanisms of RCR failure, and ultimately preventingthese failures via a commercial product. Central to the NIAMS mission, tendon re-tear following surgical RCRoccurs in as high as 20-45% or more of primary repairs. This failure rate is an unacceptable fact, given that800,000 RCR procedures are performed annually in the U.S. alone. In addition, rotator cuff injuries do not healwell on their own, cause limited mobility, persistent pain, and impact return to activity. Current RCR surgical strategies involve extensive use of sutures passed arthroscopically to providetissue approximation. Unfortunately, suture-only repair commonly fails and instead leads to mechanically weakscar tissue formation, prone to subsequent failure, pain, and disability. The tendon-to-suture interface isbelieved to be the most common RCR failure mode. It is hypothesized that RCR failure occurs via gapformation at the enthesis, primarily due to elongation or suture cut-through at the suture-tendon interface. STAswe are engineering will distribute and share the mechanical load and prevent suture-to-tendon failure as aninnovative approach to significantly improve RCR. Hypothesis: If Soft Tissue Augments (STAs) improve tissuerepair biomechanics by reinforcing standard suture-based rotator cuff repair, then type 2 retears will besignificantly reduced. Aim 1: To determine and optimize soft tissue augment biomechanical properties. Approach: 3Dprinted tendon augments implants will be produced from PDO and UHMWPE from the two STA designs(round and tab shaped) for surgeon assessment and simulated use. The tendon suture augments will be tested incadavers for validating arthroscopic delivery. In addition, STAs surgically placed on the repaired tendons willbe tested for biomechanical performance in pull-to-failure and cyclic testing relative to repair with only sutures(the standard of care). Aim 2: To determine soft tissue augment stability and biocompatibility. Approach: STA will alsobe assessed for biocompatibility per ISO 10993-6. The STA implant stability will also be assessed per ASTM1635-16 standard testing to determine the resorption rate of the soft tissue augments.
Public Health Relevance Statement: Knotless Soft Tissue Anchors for Improving Arthroscopic Rotator Cuff Repair Biomechanics
Around 25% of the over 1.5 million surgeries performed annually for rotator cuff tendon, hernia,
and related soft tissue repairs fail due to the suture cutting through and pulling out of the soft tissue.
In the short term, this research will contribute to fundamental knowledge about the nature and
behavior of how the suture-tissue failure occurs and how this interface can prospectively be
reinforced by biopolymer augments that share and distribute the load to improve surgical repair
success rates. In the long term, this knowledge will be developed into cost-effective, rapidly deployed,
knotless, and simplified augment products that will improve human health and make surgeons' jobs
easier and more successful for rotator cuff, hernia, and other soft tissue repairs.
Project Terms:
