A method for 3D printing a patient-specific bone implant having variable density, in various aspects, comprises: (1) providing a thermoplastic polymer composition comprising: (A) between about 20% and about 50% bioactive agent by weight; (B) between about 0.5% and about 10% chemical foaming agent by weight; and (C) balance structural polymer by weight; (2) receiving, by computing hardware, a scan of a bone, the scan comprising at least a 3D image of the bone and radiodensity data for the bone; and (3) causing, by the computing hardware, a 3D printer to form the patient-specific bone implant from the 3D image using the thermoplastic polymer by modifying a 3D printing temperature of the 3D printer during printing of the patient-specific bone implant such that each portion of the patient-specific bone implant is produced at a temperature that corresponds to a desired density defined by the radiodensity data for the bone.