The projected number of American amputees is expected to rise to 3.6 million by 2050 (1 in every 144 people). Many of these individuals depend on prosthetic limbs to ambulate and perform routine daily activities which may be cumbersome and uncomfortable for a person with limb loss. Transcutaneous intramedullary osseointegrated prosthetic attachment is a novel surgical technique that allows direct fixation of an implant to the distal end of a residual limb bone, therefore eliminating the need for socket attachment. Although this surgical procedure has been conducted in Europe, the operation requires a prolonged rehabilitation program to allow bone ingrowth to occur before full weight bearing is permitted. This “ingrowth period†may be markedly reduced by expediting skeletal attachment through electrically induced ossification. Controlling osteogenesis at the implant interface will be essential for improving the quantity and quality of bone in patients with amputations. Regulated electrical stimulation has proven effective in augmenting fracture healing and in non-traumatized bone models but has not been investigated for improving and accelerating skeletal fixation in patients with transcutaneous osseointegrated implant (TOI) technology. One advantage of this patient population is that a TOI implant protrudes from the residual limb and while functioning as a mechanical support can also serve as a potential cathode for an external electrical stimulation device. This system may induce osteoblast migration toward the cathode and improve the quality and rate of implant/bone attachment. The first step of validating the novel electrical bone ingrowth stimulator will be determined by computational modeling coupled with a small animal in vivo model. Computer models will be generated from computer tomography (CT) images collected during carcass evaluation and used to map current density and electric field distribution in the proximal femur of adult New Zealand white rabbits. Histological and mechanical testing will be used to evaluate the force required to remove the implant at the time of euthanasia, assessing bone ingrowth, ongrowth and mineral apposition rates when electrical stimulation is applied to the limb/implant circuit.