1. Finite element analysis of stability of ulnar coronoid process prosthesis using 2.0 mm and 2.5 mm screws fixation
Yi LU ; Hailong ZHANG ; Kunzhi LIN ; Hongwen WEI
Chinese Journal of Orthopaedics 2020;40(1):46-51
Objective:
To compare difference in stability between two fixation modes in application of three-dimensional (3D) printed coronoid process prosthesis.
Methods:
3D coronoid process prosthesis was reconstructed from computed tomography (CT) scanning acquired from volunteers with normal bony architecture of elbow. The prosthesis fixation was simulated using screws with diameter of 2.0 mm and 2.5 mm separately. Finite element analysis (FEA) was conducted at elbow flexion with different angles and the parameters including the maximum equivalent stress and the maximum displacement were evaluated.
Results:
Compared fixation using screw with the diameter of 2.0 mm and 2.5 mm, the maximum equivalent stress were 56.29 MPa and 39.96 MPa and the maximum displacement were 0.038 0 mm and 0.029 0 mm in 30° flexion of elbow; the maximum equivalent stress were 8.97 MPa and 8.12 MPa and the maximum displacement were 0.006 5 mm and 0.005 8 mm in 90° flexion of elbow; the maximum equivalent stress were 10.03 MPa and 9.32 MPa and the maximum displacement were 0.007 9 mm and 0.006 6 mm in 130° flexion of elbow. The maximum equivalent stress occurs at the junction of head and shaft with in both situations while the value from screw with diameter of 2.5 mm was lower. The displacement was smaller in the screw with diameter of 2.5 mm.
Conclusion
Compared to screws with the diameter of 2 mm, screw with the diameter of 2.5 mm shows superior stability in the fixation of 3D printed coronoid process prosthesis.
2.Incidence of venous thromboembolism in esophageal cancer: a real-world study of 8 458 cases
Kunyi DU ; Xin NIE ; Kexun LI ; Changding LI ; Kun LIU ; Zhiyu LI ; Kunzhi LI ; Simiao LU ; Kunhan NI ; Wenwu HE ; Chenghao WANG ; Jialong LI ; Haojun LI ; Qiang ZHOU ; Kangning WANG ; Guangyuan LIU ; Wenguang XIAO ; Qiang FANG ; Qiuling SHI ; Yongtao HAN ; Lin PENG ; Xuefeng LENG
Chinese Journal of Digestive Surgery 2024;23(1):109-113
Objective:To investigate the incidence of venous thromboembolism (VTE) in patients with esophageal cancer (EC).Methods:The retrospective cohort study was conducted. The clinicopathological data of 8 458 EC patients who were admitted to Sichuan Cancer Hospital from January 2017 to December 2021 were collected. There were 6 923 males and 1 535 females, aged (64±9)years. There were 3 187 patients undergoing surgical treatment, and 5 271 cases undergoing non-surgical treatment. Observation indicators: (1) incidence of VTE in EC patients; (2) treatment and outcomes of patients with VTE. Measurement data with normal distribution were represented as Mean± SD, and comparison between groups was analyzed using the t test. Measurement data with skewed distribution were represented as M(range), and comparison between groups was analyzed using the nonparameter rank sum test. Count data were expressed as absolute numbers or percentages, and comparison between groups was analyzed using the chi-square test or Fisher exact probability. Comparison of ordinal data was analyzed using the nonparameter rank sum test. Results:(1) Incidence of VTE in EC patients. Of 8 458 EC patients, 175 cases developed VTE, with an incidence rate of 2.069%(175/8 458). Among 175 VTE patients, there were 164 cases of deep venous thrombosis (DVT), 4 cases of pulmonary embolism (PE), 7 cases of DVT and PE. There were 59 surgical patients and 116 non-surgical patients. There was no significant difference in thrombus type between surgical and non-surgical EC patients with VTE ( χ2=1.95, P>0.05). Of 3 187 surgical patients, the incidence of VTE was 1.851%(59/3 187), including an incidence of 0.157%(5/3 187) of PE. PE accounted for 8.475%(5/59) of surgical patients with VTE. Of 5 271 non-surgical patients, the incidence of VTE was 2.201%(116/5 271), including an incidence of 0.114%(6/5 271) of PE. PE accounted for 5.172%(6/116) of non-surgical patients with VTE. There was no significant difference in the incidence of VTE or PE between surgical patients and non-surgical patients ( χ2=1.20, 0.05, P>0.05). (2) Treatment and outcomes of patients with VTE. Among 175 EC patients with VTE, 163 cases underwent drug treatment, and 12 cases did not receive treatment. Among 163 cases with drug therapy, 158 cases underwent anticoagulant therapy, 5 cases were treated with thrombolysis. All the 163 patients were improved and discharged from hospital. Conclusions:The incidence of VTE in patients with EC is relatively low, as 2.069%. There is no significant difference in the incidence of VTE or thrombus type between surgical EC patients and non-surgical EC patients.