Abstract:[Objective] To introduce the method and short-term clinical effect of 3D printing polyetheretherketone (PEEK) prosthesis for reconstruction of bone defect after resection of clavicular tumor. [Methods]Five patients with malignant tumors of the clavicle were treated with "segment resection of the clavicle tumor+3D printing PEEK pseudoweight reconstruction". The lesions involved the lateral segment of the clavicle in 3 cases, the medial segment in 2 cases, and pathological fracture in 2 cases. After computer modeling with reference to the shape of the patient's healthy side clavicle, 3D printing is used to prepare personalized prosthesis and osteotomy guide plate. During the operation, the sternoclavicular ligament or acromioclavicular ligament is cut off according to the tumor site, and the other side uses osteotomy guide plate to assist osteotomy, and the tumor body and surrounding normal muscle tissue are removed simultaneously. The personalized prosthesis prepared by 3D printing is placed and the normal clavicle at the reserved end is tightly connected and fixed with the prosthesis using the clavicle plate, The severed sternoclavicular ligament or acromioclavicular ligament was reconstructed with titanium alloy suture rivets. [Results]The incisions of 5 patients were all healed in the first stage after operation. The patients were followed up for 2 to 26 months after operation. The shape and function of the shoulder recovered well. No local tumor recurrence, obvious rejection, infection and other complications were found during the follow-up period. [Conclusion]Segmental resection of clavicular tumor+3D printing PEEK pseudo-weight reconstruction is feasible for the treatment of malignant tumors of clavicle, and the short-term effect is satisfactory.