title: Effect of amplitude of micromotion on bone ingrowth into titanium chambers implanted in the rabbit tibia.
abstract: The micromotion chamber for implantation in the rabbit tibia consists of two titanium components that have a 1 mm contiguous pore for bone ingrowth. The fixed, outer cylinder of the chamber contains a movable inner core that can be manually rotated. The model is unique because specific, discrete, daily periods of motion of a predetermined amplitude and frequency can be delivered to the ingrowing tissue. In the present study, we compared the histological and scintigraphic results of bone ingrowth into chambers having a congruently shaped interface that was moved 20 cycles/d with an amplitude of either 0.5 or 0.75 mm. Histological sections from both amplitude groups contained extensive new woven and trabecular bone, embedded in a fibrovascular network. However, the chambers with a larger amplitude of motion yielded less bone ingrowth than those with a smaller amplitude. These studies suggest that short, discrete periods of motion can stimulate the formation of fibrous tissue rather than bone using the parameters chosen in this model.
authors: Stanford University School of Medicine, Division of Orthopaedic Surgery, CA 94305-5326.
authors: S
authors: S
authors: Goodman
authors: P
authors: P
authors: Aspenberg
mesh_terms: D000818:Animals; D001846:Bone Development; D009068:Movement; D019736:Prostheses and Implants; D011817:Rabbits; D014025:Titanium
chemical_list: D014025:Titanium