Compliant Shape Memory Polymer Device for Meniscal Repair

DESCRIPTION (provided by applicant): The objective of this project is to develop compliant meniscal repair devices based on shape memory polymers. The repair device will be inserted in a less invasive temporary shape and then triggered to expand into its permanent functional shape. Meniscus repair represents an increasingly common and critical soft-tissue based orthopedic procedure. Approximately 900,000 procedures are performed annually in the United States at an estimated cost of over 86 million. Fixation devices, such as sutures, tacks, and hybrid devices, are commonly used in meniscus repair procedures to help facilitate tissue healing. The requirements of minimal invasion and appropriate biomechanical properties are often mutually exclusive with devices comprised of static materials. The most common reported failures of current meniscal repair devices include device misplacement and breakage, compliance mismatch with meniscus tissue, inflammation of joint cavity, and chondral damage. The proposed shapememory meniscal repair device collectively addresses the primary clinical issues associated with both rigid tacks and suture-based devices used in meniscal repair procedures. The device will be inserted in a thin shape to allow for easy insertion and minimal tissue damage. Specific geometric design features will be included on both ends of the device to provide fixation within the torn tissue ends. Using the shape memory characteristics of the device material, the device will be triggered to expand acrossthe tear site AND compress the two torn tissue ends together to provide complete tissue-to-tissue contact for enhanced healing. By tailoring the geometry of the device, the compliance of the device will be more closely aligned to native meniscus tissue such that the biomechanics of the meniscus are not drastically altered. This proposed project will be accomplished through two specific Aims. Aim 1 will involve understanding how device geometry impacts device compliance and shape memory recovery characteristics. Aim 2 will focus on developing prototypes and testing their functional performance in an in vitro benchtop model. The successful completion of the Phase I will demonstrate overall proof of concept for compliant shape memory repair devices as well asprovide the fundamental knowledge needed to develop successful commercial devices. PUBLIC HEALTH RELEVANCE: This project can impact the estimated 900,000 patients who undergo meniscus repair annually in the United States. The goal of this project isto develop compliant shape memory repair devices that will improve the functional outcome for patients with torn menisci by offering a less invasive approach and more reliable healing.