Modeling the strain fields for an in-vivo bone growth experiment

Osseointegration is critical for implant fixation, and mechanical stimuli play a role in this process. Our long term goal is to investigate the relationship between local mechanical environment and osseointegration. In this paper, as a first step in the study, we constructed an approximate 3D model of the in-vivo test and focused on calculating the strain fields around the implant. We first demonstrated that 3D finite element models gave significant differences compared with 2D models. The 3D model was then used to study strain distributions as gap tissue properties were varied over an experimentally estimated range in the first 7 days post implant. Results for strain concentration in gap tissue around the circumferential ridges and bottom of the implant agreed, on average, with previous 2D studies. Variations of the strain field around the implant were consistent with bone healing and remodeling trends around the implant between post-surgical days 1 and 5, and 6 and 7.