[Application of three-dimensional printed total scapula for reverse shoulder arthroplasty in treatment of scapular tumors].

Objective:To investigate the effectiveness of three-dimensional (3D) printed total scapula for reverse shoulder arthroplasty in the treatment of scapular tumors. Methods:Between November 2017 and December 2021, 5 patients with scapular tumors were treated by reverse shoulder arthroplasty with 3D printed total scapula. There was 1 male and 4 females. The age ranged from 44 to 59 years, with an average of 50.4 years. There were 2 cases of chondro sarcoma, 1 case of high-grade osteosarcoma, 1 case of lung cancer with scapular metastasis, and 1 case of ligamentoid fibromatosis recurrence. The disease duration was 4-8 months, with an average of 5.8 months. According to the Musculoskeletal Tumor Society (MSTS) scapular girdle classification criteria, 4 cases of tumors involved both S1 and S2 zones, and 1 case involved S2 zone. The tumor diameters ranged from 4.2 to 11.2 cm, with an average of 6.1 cm. The operation time, intraoperative blood loss, and blood transfusion were recorded. During follow-up, the MSTS score was used to evaluate the recovery of limb function of the patients. The sink depth of the affected shoulder, complications, and oncological outcomes were observed. The position of the prosthesis was reviewed by imaging. Results:The operation time ranged from 155 to 230 minutes, with an average of 189 minutes. The intraoperative blood loss was 100-1 500 mL, with a median of 600 mL. Two patients were received blood transfusion of 800 mL and 1 850 mL respectively during operation. All incisions healed by first intention, and no complications such as infection occurred. All patients were followed up 4-22 months, with an average of 13 months. Two patients died at 8 and 15 months after operation respectively due to multiple metastases and organ failure. At last follow-up, the MSTS score of all patients was 73%-83%, with an average of 77.4%. The affected shoulder was 2-4 cm lower than the contralateral side, with an average of 3 cm. Imaging examinations showed that no prosthesis loosening, dislocation, or fracture occurred during follow-up. Conclusion:Reverse shoulder arthroplasty with 3D printed total scapula can obtain good shoulder function and appearance. Patients have high acceptance and satisfaction with this surgical method.