Biodegradable bone implants in orthopedic applications: a review

Abstract A biologically - validated biodegradable material must comfortably stay in the physiological environment it is placed in, before finally disappearing over the intended period of time with adequate rates of degradation. The primary objective and utility of such a material is to eliminate the requirement of secondary surgery in applications involving bone implants. In recent decades, biodegradable alloys have exhibited enhanced biocompatibility, and improved mechanical and biodegradation properties. This has generated renewed interest in the design of bone implants made up of such materials that can successfully support fractured bone till the culmination of the healing process. However, striking a balance between two seemingly conflicting requirements, namely - sustaining the strength of the implant till the bone acquires the desired strength of its own, and allowing the implant to keep losing strength with its gradual degradation – may be rather complex. To manage this, different healing phases and the associated bone - biodegradable implant interface mechanobiology needs to be focused upon. An adequate and/or optimal design of the implant is based on mechanical properties, degradation rates of implant and bone-biodegradable implant interface interactivity. This review mainly focuses on bone - biodegradable implant interface with due consideration accorded to the mechanical properties, degradation rates and healing process in a standard duration.