Efficacy of MeniscoFix for Sub-Total Meniscal Replacement: A Comprehensive Approach in Cadaver Knees and an Ovine Surgical Model

Meniscal injuries represent one of the most common intra-articular knee injuries, resulting in over 750,000 surgical procedures in the United States annually. Removal of the torn tissue, known as meniscectomy, typically provides short-term relief from pain, discomfort, and instability, but alters the joint’s mechanics, leaving the patient susceptible to post-meniscectomy syndrome and in the long-term, post-traumatic osteoarthritis. We are developing a load-bearing meniscal replacement implant, MeniscoFixTM, capable of being slowly absorbed while remodeling into functional, chondroprotective neo-meniscal tissue. The goal of this Phase II SBIR project is to determine the efficacy of MeniscoFix™ in a subtotal meniscectomy model, addressing anatomical, biomechanical, and functional requirements in human cadaver knees in situ and a long-term large animal (ovine) surgical model. Aim #1: Investigate the combined effects of MeniscoFix™ implantation and surgical fixation techniques on contact stresses and meniscal displacement in a subtotal meniscectomy model. These parameters will be quantified during cyclic loading of cadaver knees with MeniscoFix™ implants after subtotal meniscectomy. Surgical fixation techniques include interference screws in bone tunnels, suture to the meniscal rim, and suture anchors in the tibia to ‘reconstruct’ the medial meniscotibial ligament. Aim #2: Determine long-term efficacy of MeniscoFix™ in the sheep subtotal meniscectomy model. Incorporating design changes based on Phase I SBIR studies and utilizing surgical fixation techniques optimized in Aim #1, MeniscoFix™ will be used to replace meniscal tissue removed via subtotal meniscectomy in skeletally mature sheep for periods of 6 and 12 months. A subtotal meniscectomy without an implant will serve as a clinically relevant control. Aim #3: Demonstrate that MeniscoFix™ meets requirements for a “first-in-human” evaluation. Verify that the MeniscoFix™ design and ex vivo performance satisfies requirements for meniscal replacement after subtotal meniscectomy. Reliability of packaging and labeling, sterility validation, and shelf-life testing will be conducted vs. our pre-established acceptance criteria. This requisite testing will reduce risks associated with translation from pre-clinical to clinical use and ensure patient safety by satisfying appropriate FDA, ISO, and ASTM standards. Long-Term Impact: Completion of this Phase II study will facilitate submission of an IDE to the FDA for a first- in-human clinical trial, specifically, an Early Feasibility Study. Our long-term goal is to offer surgeons a novel, safe, and effective treatment to improve the quality of life for patients undergoing subtotal meniscectomy or experiencing post-meniscectomy syndrome, potentially delaying or eliminating the need for knee replacement surgery in patients at high risk of developing PTOA following severe meniscal compromise.