In order to obtain the geometry and size of bone implants that match the patient's original bone from this study, the patient femur knee bone is reconstructed into a 3D femur implant model using an X-Ray data scanner during Reverse Engineering (RE) process. In the process of RE, the femur knee bone was initially reconstructed by scanning its front and side view into a photo using the digital radiography system. For building a 3D model of the femur implant, the front and side view of the knee bones are sketched according to the dimensions and shape of the scanned femur knee bones. Then, one of the sketches is defined as the sketch profile of the femur knee bone, while the other is the trajectory profile. 3D modeling of the femur implant was constructed by using the sweep method in 3D design software. The results of this knee reconstruction obtained a 3D model of the femoral knee bone implant that is following the patient's bone shape.