Biomechanical Research On The Osseointegrated Lower Limb Prosthesis

Background: The osseointegrated lower limb prosthesis is a new type of prosthesis that overcomes many defects of conventional prosthesis. At present, osseointegrated prosthesis has become one trend of lower limb prosthesis development. And it has received increasing interest in the field of basic research and application studies. But the osseointegrated lower limb prosthesis still has lots of problems that need to be solved, so the concerned research is necessary.Objectives: To study osseointegrated lower limb implant, including the study of shape and surface treatment through the animal experiment. To investigate the change of osseointegration status of bone-implant interface along with the change of time. In addition, to analyze the initial stress distribution of bone-implant interface by the finite element method. To comparatively analyze the results of initial stress distribution and the results of histological observation and investigate whether they have some relations.Methods: Sixteen animal models of two months,four months and six months were established respectively. Implants of two different shapes were introduced into the animal models, respectively spindle-shaped and threaded. And also implants of two different surface treatments were introduced into the animal models, respectively HA coating and Al2O3 surface roughening. The bonding intensity of bone-implant interface was studied through the biomechanical pull-out test. Furthermore, the osseointegration status of bone-implant interface was observed by the X-ray photography. A three-dimensional finite element model corresponding to the animal model was established. The initial stress distribution was simulated by the Interference Fit Options in the finite element software.