Abstract: Objective: To investigate the feasiblity of 3D printing technology-assisted pre-operative design in guiding the performance of individualized customization elbow joint prosthesis replacement. Methods: A male patient with comminuted fracture of the right distal humerus after operation was selected,the comminuted fracture of the distal humerus was treated with open reduction and internal fixation 10 years ago. Because of internal fixation fracture,the joint appeared stiffness and pain, and the activity was restricted after treatment; the patient was admitted to hospital for elbow joint function recovery and pain relief, and the patient was given the 3D printing technology-assisted individualized customization elbow joint prosthesis replacement. The computer-assisted design technique combined with 3D printing technology was used to simulate the reconstruted anatomly morphology to confirm the osteotomy range;the personalized elbow prosthesis was designed based on the reconstructed anatomy morphology. During the operation, the osteotomy and elbow joint reconstruction were performed according to the design. Results: The operation was successfully completed,and the intraoperative positioning results showed that the elbow joint prosthesis was in good position and achieved the preoperative design effect.The postoperative follow-up result was satisfactory,the activity of elbow joint could satisfy the daily needs of the patient 6 months after operation. Thirty-six months after operation, the HSS score was increased from 15 points before operation to 90 points after operation. Conclusion: For the patients with internal fixation fracture after complicated distal humerus fracture, the computer-aided design technique combined with 3D printing technology can be used to assist the prosthesis design and preoperative design,and the elbow joint anatomy can be reconstructed and the function can be restored by this method.

Key words: distal humerus fracture, internal fixation fracture, 3D printing technology, individualized customization, elbow joint replacement