RESUMO
OBJECTIVE@#To study the influence of the number and position of anchor nails on the Bankart repair by the finite element analysis.@*METHODS@#The 3D CT data of shoulder joints including normal adult volunteers were imported into Mimics 10.0 and Geomagic 2012 software to reconstruct the related tissues, and then meshed in Hypermesh 13.0 software to give material attributes. The position and number of MPC constraints were adjusted in Abaqus 6.14 to establish finite element model of shoulder joint under 6 working conditions including A model(normal control model), B model (Bankart damage control model), C model (1 anchor), D model (2 anchors), E model (3 anchors), F model (4 anchors). The humerus external rotation and forward load were added to simulate the fear test of the shoulder joint forward instability.@*RESULTS@#(1)Normally, the inferior glenohumeral ligament complex accompanied by the external rotation of the humerus head has a wrinkle and a significant stress concentration around its anterior and posterior bundle terminations.(2)The stress of the anterior bundle and posterior bundle of the inferior glenohumeral ligament were increased by 52.33% and 45.67% respectively after Bankart's injury.(3)In each model of anchor repair, the stress concentration was obvious at the anchor site, and the stress of anterior and posterior bundle ligaments could be reduced; there were no obvious differences between C, D models and B model(>0.05), and there were significant differences between E, F models and B model(<0.05).@*CONCLUSIONS@#One or two anchors can reduce the stress of the anterior and posterior bundles of the inferior glenohumeral ligament in the repair of Bankart's injury, but when the angle of rotation is large, the stress concentration in the anchor position increases significantly, leading to the increases of the risk of failure. The application of three or four anchors can enhance the constraints on the inferior glenohumeral ligament and reduce the stress of the anchor itself through the "load sharing" effect between anchors, so as to ensure the stability of the shoulder joint and provide a mechanical environment for the early rehabilitation of patients.
Assuntos
Humanos , Fenômenos Biomecânicos , Cadáver , Análise de Elementos Finitos , Instabilidade Articular , Luxação do Ombro , Articulação do OmbroRESUMO
OBJECTIVE@#To analyze the conventional application of using comprehensive hemostatic methods during the perioperative period, and the effect of autologous blood transfusion (ABT) device compared with non-negative pressure drainage on preventing blood loss and allogenic blood transfusion after primary total knee arthroplasty (TKA).@*METHODS@#A total of 131 patients (131 knees) with severe knee osteoarthritis who underwent unilateral primary TKA by the same surgeon in Peking University Third Hospital from June 2014 to June 2015 were enrolled in this study. The patients were divided into ABT group (64 patients) and control group (67 patients). ABT devices were used for drainage and blood transfusion in the ABT group while the control group used the non-negative pressure drainage only. The results of the drainage fluid volume, the decrease of hemoglobin, the total blood loss, the hidden blood loss and blood transfusion after TKA were compared between the two groups.@*RESULTS@#The drainage fluid volume in ABT group was significantly higher than that in control group [515 mL (80-1 610 mL) vs. 260 mL (40-670 mL), P<0.001]. The autologous blood transfusion in ABT group was 245 mL (60-1 070 mL). There were no significant differences between the two groups in the value of hemoglobin decrease 1 day after surgery (P=0.340) and 3 days after surgery (P=0.524). There were no significant differences in the total blood loss (P=0.101) and the hidden blood loss (P=0.062) between the two groups either. There were 9 patients in the 131 patients who received allogeneic blood transfusion, of whom 5 in the ABT group (5/64, the blood transfusion rate was 7.8%) and 4 in the control group (4/67, the blood transfusion rate was 6.0%), and no significant differences in the blood transfusion rate between the two groups (P=0.943).@*CONCLUSION@#With the conventional application of using comprehensive hemostatic methods during perioperative period, the ABT device did not show the effective result of controlling postoperative blood loss and failed to reduce the rate of allogeneic blood transfusion in patients with unilateral primary TKA. However, the ABT device could increase the drainage fluid volume and improve the patient's hospitalization expenses. Therefore, there is no need for routine application of ABT device in unilateral primary TKA.
