Focal Knee Resurfacing Implant: A Promising Approach in the Management of Osteoarthritis

Osteoarthritis (OA) is a degenerative joint disease that results in pain and impaired mobility. A significant contributing factor in the development of OA is the presence of focal cartilage defects, which are localized areas of articular cartilage damage or loss. These defects often serve as precursors to widespread OA, and, if left untreated, can escalate into full-blown disease. Current biological focal cartilage repair techniques have demonstrated favorable outcomes in younger patients. However, individuals over the age of 40 may experience diminished clinical success and recurring symptoms due to age-related reduced regenerative capacity. Meanwhile, total knee arthroplasty (TKA) as the “gold standard” surgical treatment for end-stage OA, carries a higher lifetime risk of revision surgery in middle-aged patients. This creates a challenging treatment gap for active, middle-aged patients (40–60 years), who are too old for regenerative procedures but too young for arthroplasty. To address this gap, a biomimetic mini-implant called SyCap has been developed. SyCap is a focal knee resurfacing implant (FKRI) composed of non-degradable polycarbonate urethane (PCU) with a top layer featuring a Shore hardness of 80A, which closely mimics the mechanical properties of cartilage. This study aims to evaluate the ability of SyCap to restore the normal joint biomechanics and to compare its performance to metal implants. An ex vivo experiment using human cadaveric knee specimens has been designed to assess tibiofemoral contact mechanics before and after implantation. Contact pressure and contact area during gait cycle under physiological loading conditions generated by a joint simulator will be measure using pressure mapping sensors. Each specimen will be tested under four conditions: native, 15-mm full-thickness chondral defect, 17-mm SyCap implant (Avalanche Medical), and 17-mm metal implant. Preliminary pilot studies have been conducted to establish the experimental protocol and validate the feasibility of measuring tibiofemoral contact mechanics. Data acquisition and analysis from the main experimental phase is expected to be completed prior to the conference, providing insights into the biomechanical performance of the SyCap implant compared to its metal counterpart and untreated defects. This study aims to address a critical treatment gap in middle-aged patients suffering from focal cartilage defect by exploring the performance of the SyCap implant. By restoring joint biomechanics and offering a viable alternative to traditional treatments, SyCap has the potential to improve clinical outcomes in this demographic. Future findings are expected to inform both clinical practice and the development of next-generation FKRIs.