Analysis of Ti-6Al-4V implants placed with fibroblast growth factor 1 in rat tibiae

Titanium-aluminum-vanadium (Ti-6Al-4V) implants were placed in the tibiae o f 32 rats (male Sprague-Dawley, 350 g) to examine healing and bone response . Half of the implants were treated with fibroblast growth factor 1 (FGF-1) delivered in an activated fibrinogen matrix. Animals were injected with a radiopharmaceutical imaging agent, technetium-99m-methylene diphosphonate ( Tc-99m-MDP), which concentrates in bone, especially in areas of higher oste oblastic activity. Binding of Tc-99m-MDP to the implant was detected in viv o by Anger gamma camera imaging. Fourteen days after implant surgery, speci mens were recovered and prepared for histomorphometric analysis. Histologic examination revealed that samples treated with FGF-1 demonstrated signific antly greater amounts of bone-to-implant contact (P <.05) compared to contr ols. Also, FGF-1-treated samples showed significantly greater amounts of bo ne (percent volume) adjacent to implants (P <.005). These findings were sup ported by analyses of the non-invasive Tc-99m-MDP images, which demonstrate d significantly greater uptake of Tc-99m-MDP adjacent to FGF-1-treated impl ants (P <.05). Results of the experiments supported the hypothesis that FGF -1 could increase bone production around implants in a rat model.