Aseptic osteolysis is a main cause of loosening of orthopaedic implant failures. The wear debris derived from polymers (UHWMPE) and/or metals of implants (Ti) elicit primary inflammatory and secondary osteolytic responses. In total temporomandibular joint (TMJ) reconstruction with implants, foreign body reactions are reported and are the major cause of failure in the metal-on-metal and Teflon ^® or Proplast ^® -on-metal prosthesis, leading a revision surgery. A new generation of implants replaced Teflon ^® by UHWMPE in the fossa component with acceptable clinical results in long term follow-up (14 years). Furthermore, there are some biomechanics factors for to improve. However, the pathophysiological process of the implant failure is not fully understood.

Purpose: The present work describes osteolytic murine model induced by wear debris particles of more usual polymeric and metallic implants used in total TMJ. These models allow a better understanding of osteolytic process and constitute interesting tools to develop new therapy approaches.

Material and methods: We used calvaria osteolytic model in 12 weeks old C57BL/6 male mice. Particles of UHWMPE (size < 5 μm) and Titanium (size < 4 μm) were subperiosteally implanted for mimic wear debris osteolysis. A microarchitectural (μCTscan), histological and immunohistochemical evaluation have been carried out.

Results: The particles rapidly induced an inflammatory reaction associated with an osteolytic process from day 5 after implantation.

Conclusions: This model identified the key role of bone microenvironment in implant failures by wear debris particles and identified molecular/cellular targets for new therapeutic approaches.

Funding: This work was supported by the ANR2007 INSERM Pathophysiology of Human Diseases, project R07196NS.

Conflict of interest: The main author belongs to the congress scientific commission.