In this study, we propose a novel bioresorbable bioactive implant for tibial tuberosity advancement (TTA). The
implant consists of a gradually resorbing load-bearing shell which encompasses rapidly resorbing small casings
loaded with silica-based bioactive glass (BG) particulates which promote bone formation and reduce the risk
of infection. The shell and the casings are manufactured by 3D printing from two medical grade biodegradable
polymers (a polyglycolide/lactide based and a polydioxanone based) that have different degradation rates. The
casings are expected to resorb within days after surgery to expose the BG particulates while the shell would retain the load-bearing properties of the implant for the time required by bone healing. Unlike the currently used
metallic devices, the novel implant is resorbed and excreted from the body once its purpose is fulfilled.This study
presents a logical progression from the in vitro characterisation of the materials and implants to the in vivo investigation of the experimental implants. This included mechanical testing of the materials, finite element analysis
of a preliminary design of the novel TTA implant, assessment of the degradation behaviour of the polymers and
the ion exchange of BG in simulated body fluid, and investigation of the biological response to the novel implants
after implantation in rabbits.The osteointegration of the novel implants was comparable to the osteointegration
of Ti6Al4V implants in the control group; the biological efficacy and safety were confirmed. The biological response was in line with the expectations. The proof of concept for the novel TTA implants was demonstrated.