Design and R&D of anatomic posterior malleolus locking plate for chinese people and its biomechanical analysis
10.3760/cma.j.cn121113-20231006-00214
- VernacularTitle:国人解剖型后踝锁定钢板的设计、研发及生物力学分析
- Author:
Yongqi LI
1
;
Yi LIAO
;
Jiang XIA
;
Bing LI
;
Haichao ZHOU
;
Youguang ZHAO
;
Yunfeng YANG
Author Information
1. 上海市同济医院骨科（李兵、杨云峰现调入上海交通大学医学院附属瑞金医院骨科），上海 200065
- Keywords:
Ankle fractures;
Models, anatomic;
Internal fixators;
Computer-aided design;
Biomechanical phenomena
- From:
Chinese Journal of Orthopaedics
2024;44(10):692-699
- CountryChina
- Language:Chinese
-
Abstract:
Objective:A novel anatomic posterior malleolus locking plate for Chinese people was designed, researched, developed, and tested biomechanically.Methods:An anatomic parameter database of posterior malleolus of Chinese people was established by collecting CT images of ankle joints from 100 healthy volunteers in Shanghai Tongji hospital from June 2022 to May 2023. Combined with relevant computer-aided technologies, a novel anatomic posterior malleolus locking plate for Chinese people was designed and produced. In addition, model verification and biomechanical test were carried out on vertical displacements under different fixation modes and different axial loads (500, 1 000, and 1 500 N). Failure loads at a displacement of 2 mm and maximum failure loads at the complete failure of internal fixation were also tested and recorded.Results:Based on the imaging anatomic measurement, the width quartile of posterior malleolus was 19.4, 26.6, 35.0 mm. The 3D reconstruction models of ankle joint CT corresponded to small, medium, and large basic posterior malleolus plates. Height of the screw safety zone was 5.5(5.3, 5.7) mm. The tip-back angle was 153.0°(148.5°, 157.5°) and tip-back height was 20.0(19.7, 20.9) mm. The novel anatomic posterior malleolus locking plate based on tibiofibular and ankle joint CT scan and relevant computer-aided technologies fit well with posterior malleolus of tibia, showing anatomic fitting. Based on the associate biomechanical test, the novel plate fixation had smaller vertical displacements of posterior malleolus fragment under axial loads of 500, 1 000, and 1 500 N compared with the control plate, but greater failure loads when the vertical displacement of the posterior malleolus fragment was 2 mm and greater maximum failure loads at complete failure of the internal fixation. At an axial load of 500 N, the vertical displacements of the posterior malleolus fragment after posterior malleolus fixation with a control plate, a 6-hole anatomical locking plate, and a 5-hole anatomical locking plate were 0.60±0.02, 0.45±0.04, and 0.52±0.04 mm, respectively with significant difference ( F=88.287, P<0.001); at an axial load of 1 000 N, the vertical displacements were 2.22±0.03, 1.10±0.03, and 1.15±0.03 mm for the three fixation modes, respectively, and the difference was statistically significant ( F=10 061.890, P<0.001); At an axial load of 1 500 N, the vertical displacements were 2.81±0.04, 1.50±0.03 and 1.67±0.03 mm for the three fixation modes, respectively with significant difference ( F=9 774.019, P<0.001). When the vertical displacement of the posterior malleolus fragment was 2 mm, the failure loads for the three fixation modes were 0.80(0.73, 0.80)、2.00(1.93, 2.00) and 1.70(1.70, 1.70) kN, respectively with significant differences ( H=54.245, P<0.001). The maximum failure loads at complete failure of the internal fixation for the three fixation modes were 1.90(1.90, 1.98)、4.30(4.30, 4.30) and 3.70(3.63, 3.70) kN, respectively with significant differences ( H=53.863, P<0.001). Conclusions:The novel anatomic posterior malleolus locking plate for Chinese people was well matched to the posterior malleolus with high mechanical strength and good stability, showing a promising future for clinical application.
