Three-dimensional printing technology in reverse shoulder arthroplasty after resection of proximal humeral tumors / 中华骨科杂志

Objective:To analyze the efficacy of the reconstruction of the proximal humerus by reverse shoulder arthroplasty with three-dimensional (3D) printing technology after tumor rescetion.Methods:A retrospective analysis was conducted on the data of eight patients undergoing semi-constrained reverse shoulder arthroplasty with 3D printing technology after the resection of bone tumors in proximal humeri at the Affiliated Wuxi People's Hospital of Nanjing Medical University from December 2017 to January 2021. There were four males and four females with an average age of 55.1 (range, 31-73) years, all of whom had unilateral onset, 2 on the left and 6 on the right. There was one case of leiomyosarcoma (Enneking IIB), two cases of chondrosarcomas (one Enneking IA and one Enneking IB), four cases of Campanacci grade 3 giant cell tumor of bone, and one case of bone metastasis of lung adenocarcinoma. Individualized prosthesis and implantation protocol were completed preoperatively in all patients. The glenoid baseplate was manufactured using 3D printing technology. During the surgery, Malawer type I tumor resection and semi-constrained reverse shoulder arthroplasty were performed, with 6 cases simultaneously using allograft-prosthetic composite reconstruction. The follow-up was scheduled, and the patient received X-ray examination of the shoulder. The range of motion of the shoulder was measured, the Constant-Murley score and musculoskeletal tumor society (MSTS) score were recorded.Results:All 8 patients successfully completed the surgery, with a surgical time of 173.8±46.7 min (range, 130-260 min), intraoperative blood loss of 487.5±334.6 ml (range 200-1,200 ml), and proximal humeral resection of 9.9±4.6 cm (range, 4.5-19.0 cm). All patients were followed up for a period of 45.6±12.5 months (range, 24-60 months). At the last follow-up, the abduction ranges of motion of the affected shoulders increased from 27.5°±14.4° pre-operatively to 106.3°±21.8° post-operatively, with a statistically significant difference ( t=11.37, P<0.001). The forward flexion ranges increased from 28.1°±12.8° pre-operatively to 115.6°±24.0° post-operatively, with a statistically significant difference ( t=11.49, P<0.001). The Constant-Murley score was improved from 40.5±14.3 pre-operatively to 79.3±11.2 post-operatively, with a statistically significant difference ( t=9.58, P<0.001). The MSTS score was 25.6±2.2 (range, 23-28), including 6 excellent cases and 2 good cases. At 2 weeks after surgery, one patient experienced joint dislocation that was successfully reduced manually. Up to the final follow-up, all patients had survived without local tumor recurrence, metastasis, prosthesis infection and loosening. Conclusion:3D printing technology assisted shoulder arthroplasty is helpful for effective reconstruction and shoulder joint function recovery after resection of proximal humeral tumors, with satisfactory outcomes in the early and middle stages.

3D-Printed Prosthesis Replacement for Limb Salvage after Radical Resection of an Ameloblastoma in the Tibia with 1 Year of Follow Up: A Case Report

Ameloblastoma in the tibia is rare. Limb reconstruction after tumor resection is challenging in terms of selection of the operative method. Here, we report a case of radical resection of an ameloblastoma in the mid-distal tibia combined with limb salvage using a three-dimensional (3D)-printed prosthesis replacement, with 1-year follow-up results. After receiving local institutional review board approval, a titanium alloy prosthesis was designed using a computer and manufactured with 3D-printing technology. During the operation, the stem of the prosthesis was inserted closely into the proximal tibial medullary cavity. Then, the metal ankle mortise and the talus were compacted closely. Radiographic results at 1-year follow up showed that the prosthesis was well placed, and no loosening was observed. The Musculoskeletal Tumor Society (MSTS) 93 functional score was 26 points, and the functional recovery percentage was 86.7%. Computer-assisted 3D-printing technology allowed for more volume and structural compatibility of the prosthesis, thereby ensuring a smooth operation and initial prosthetic stabilization. During the follow up, the presence of bone ingrowths on the porous surface of some segments of the prosthesis suggested good outcomes for long-term biological integration between the prosthesis and host bone.

Effect of Volatile Chemicals in the Air of Newly Decorated Rooms on O~6-methylguanine-DNA Methyltransferase Expression in Lung,Liver,Kidney and Testicle Tissues of Mice / 环境与健康杂志

Objective To study the effect of volatile chemicals in the air of newly decorated rooms on O6-methylguanine-DNA methyltransferase (MGMT) expression in the lung, liver, kidney and testicle tissues of mice. Methods Forty Kunming mice were randomly divided into four groups and the imitate pollutants mixture of volatile chemicals in the air of newly decorated rooms was used as the exposed toxicants: low-dose exposure group (7.5 mg/m3), moderate-dose exposure group (15 mg/m3), high-dose exposure group (30 mg/m3), the control group (no exposure ). The mice were exposed 4 hours each day, for nine weeks. Streptavidin and biotechnology-peroxidase (SABC) immunohistochemical method was used to determine the MGMT expression in the lung, liver, testicle and kidney tissues. Results The expression of MGMT in the liver, lung, testicle tissues in the high, moderate and low-dose groups reduced significantly compared with the control group (P0.05). Conclusion The higher exposure of volatile chemicals from the air of newly decorated rooms may inhibit the MGMT expression in the liver, lung and testicle tissues of mice.