The proximal tibia metaphysis is a potential alternative donor site for a sufficient amount of cancellous bone, associated with low morbidity and complication rate. We performed an observational computed tomography imaging study to determine the volume of cancellous bone that can be harvested from the proximal tibia compared to the anterior iliac crest, based on an advanced three-dimensional medical imaging model. Results of this study support the findings that a sufficient amount of cancellous bone can be harvested from the proximal tibia compared to the anterior iliac crest. By using a computed tomography imaging technique, the volume of cancellous bone can be precisely determined. However, this study does not show how much bone is safe to remove before increasing the tibial fracture risk.