Abstract: BACKGROUND: Currently, the verification of the precision of personalized bone models is usually performed by methods such as paired t-tests or intraclass correlation coefficient, but such methods often require the production of large batches of models, which do not satisfy the need for immediate use of personalized models.
OBJECTIVE: To study the feasibility of establishing the equivalent model to verify the precision of the personalized bone model rapidly.
METHODS: Bone CT images of three adults were randomly obtained for reconstruction. 3D printing was used to create personalized bone models, and then the personalized bone models were scanned using CT and reconstructed. Mimics was used to compare the reconstructed models of bone CT images with the bone CT images. Geomagic Studio was used to analyze the fitting deviation between the reconstruction model of personalized bone model CT image and the reconstruction model of skeletal CT image. The 3D-printed personalized bone model was measured against the measurement positions and dimensions marked on the reconstruction model of skeletal CT image, and the error was calculated.
RESULTS AND CONCLUSION: (1) By comparing the reconstructed bone CT image model with the bone CT scan image, the two were compatible in terms of anatomical structure and morphology, and the contours almost overlapped. (2) By fitting bias analysis, the standard bias was 0.176, 0.226, and 0.143 mm in order, and all the results were < 0.25 mm. (3) By measuring and calculating the model, the mean relative errors were 0.44%, 0.21%, and 0.13%, and all the results were within 5% error. (4) The constructed equivalent model was in line with the basic conditions for making personalized bone models. The established equivalent model met the clinical needs and design requirements, and it was feasible to use the method of the equivalent model to verify the precision of the personalized bone model quickly. (5) This method could provide a targeted and rapid way to verify the precision of personalized bone models. It could achieve the goal of providing immediate clinical use without the need to produce large batches of models compared to conventional methods such as paired t-tests or intraclass correlation coefficient. 

Key words: equivalent model, 3D printing, personalized bone model, fused deposition modeling, polylactic acid, medical-industrial interaction, precision medicine