osseointegrated

Osseointegrated is an adjective used to describe implants that have formed a direct, stable interface with living bone, with minimal or no intervening fibrous tissue. This state results from osseointegration, a process in which bone remodels at the implant surface to create direct bone-to-implant contact and allow functional load transfer between the prosthesis and the skeleton.

Materials and surface technology play a key role in achieving osseointegration. Titanium and its alloys are the most common implant materials, though zirconia and other biocompatible options are used in some applications. Surface roughening, microtopography, and coatings such as hydroxyapatite promote bone apposition and secure fixation. Implants may be threaded or porous to enhance mechanical interlock. The healing and integration phase typically spans several months and depends on bone quality, loading conditions, and surgical technique.

Applications are most widely seen in dental implants, where endosseous implants replace missing teeth, and in osseointegrated prostheses for limb amputation, which provide direct skeletal attachment for a prosthetic limb. The concept originated with research by Per-Ingvar Brånemark in the mid-20th century and has since expanded into orthopedics and maxillofacial reconstruction.

Advantages of osseointegrated implants include stable fixation, improved load distribution, and, for limb prostheses, potential reductions in socket-related discomfort and enhanced proprioception. Risks and limitations include infection, peri-implantitis, implant loosening or fracture, failure to achieve osseointegration, and the need for adequate bone stock and surgical expertise. Ongoing research seeks to broaden indications, reduce healing times, and refine surface designs.