The Science Behind Wear Testing for Great Toe Implants for Hallux Rigidus

An orthopedic surgeon makes decisions about which implants to use to help his or her patients. Understanding not only the level of clinical evidence supporting the use of the implant, but also the rigor of the material testing both mechanical and histologic, is critical to avoid repeating the failures resulting in bone loss and joint instability, such as that seen with silicone within the foot and ankle. The regulatory system allows for a 510(k) approval for implants as long as they can prove the new implant is "like" the old one in its use and application and therefore no new knowledge is gained and the surgeon has no science to examine clinically, biomechanically or histologically. This PVA hydrogel implant (Cartiva SCI) has provided scientific evidence of clinical effectiveness in a prior study and provides a great example of robust biomechanical and histologic testing for the surgeon to share with his or her patient when considering its use.