Myelointegration of titanium implants: B lymphopoiesis and hemopoietic cell proliferation in mouse bone marrow exposed to titanium implants

Multinucleated giant cells have been observed at interfaces between bone ma rrow and titanium implants in mouse femurs. This raises concern that macrop hage-derived factors might perturb local lymphohemopoiesis, possibly even p redisposing to neoplasia in the B lymphocyte lineage. It has been found tha t an implant-marrow interface with associated giant cells persists for at l east 1.5 years. Precursor B cells show early increases in number and prolif erative activity. At later intervals, however, they do not differ significa ntly from controls, and there are no perturbations in spatial localization of either B lineage cells or DNA-synthesizing hemopoietic cells. The result s of this investigation in mice demonstrate that, following initial marrow regeneration and fluctuating precursor B cell activity, and despite the pre sence of giant cells, titanium implants apparently become well-tolerated by directly apposed bone marrow cells in a lasting state of "myelointegration ."