Platelets contain growth factors that are believed to stimulate early fracture repair. Autologous platelets can be sequestered, concentrated, and mixed with thrombin to yield a so-called autologous growth factor gel, which might enhance bone repair or bone graft incorporation. The effect of this platelet concentrate on total tissue and bone ingrowth into porous coralline hydroxyapatite was studied in a bone chamber rat model. Chambers with the platelet concentrate showed a significant increase in bone and total tissue ingrowth distance compared to untreated controls, indicating a platelet concentrate might enhance the clinical performance of porous hydroxyapatite in bone replacement.