Fixation of Vancouver type B1 periprosthetic femur fractures with a self-developed crossed-hug locking plate system: a biomechanical study
10.3760/cma.j.cn115530-20231116-00203
- VernacularTitle:环抱锁定接骨板系统固定Vancouver B1型股骨假体周围骨折的生物力学实验研究
- Author:
Xiaobing CHU
1
;
Minwei JIN
;
Rui DONG
Author Information
1. 浙江中医药大学附属第一医院（浙江省中医院）骨科,杭州 310006
- Keywords:
Femoral fractures;
Internal fixator;
Biomechanics;
Periprosthetic fractures;
Crossed-hug locking plate
- From:
Chinese Journal of Orthopaedic Trauma
2024;26(6):533-537
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the biomechanical properties of a self-developed crossed-hug locking plate system in fixation of Vancouver type B1 periprosthetic femur fractures.Methods:Vancouver type B1 periprosthetic femur fractures in clinic were simulated in 3 samples of artificial adult femur produced by Sawbone corporation in USA, including 2 of model 3403 and 1 of model 3447. The fractures were then fixed with our self-developed crossed-hug locking plate system. After the load state of the human body in the upright stance was simulated on an experimental machine, compression tests (with a loading force of 50 to 500 N, and a displacement controlled acceleration of 5 mm/min), compression fatigue tests (with a loading condition of 50 to 500 N sine wave force value, a frequency of 5 Hz, and cyclic loading of 250 times), torsion tests (torque loaded at an torque angle acceleration of 1°/min to 15°/min in clockwise rotation), and torsion failure tests were conducted in sequence.Results:The axial compression tests showed that the displacements in the 3 samples were 0.83 mm, 0.45 mm and 0.41 mm, respectively, leading to no abnormal changes in the crossed-hug locking plate system in all samples. The compressive fatigue tests showed that the displacements in the 3 samples were (0.70±0.05) mm, (0.44±0.01) mm, and (0.42±0.02) mm, respectively, with the maximum displacement change less than 0.13 mm, leading to no abnormal changes in the crossed-hug locking plate system in all samples. The torsion within 4° in the torsion test showed that the maximum torque was 4.73 N·m in sample 1, 7.82 N·m in sample 2, and 7.37 N·m in sample 3. In the torsion failure tests, sample 1 was fractured at the first screw in the distal femoral bone plate, with an ultimate torque of 28.18 N·m. In sample 2, the torque at which the hook started to slide was 16.00 N·m, and the ultimate torque at which the hook broke to cause internal fixation failure was 18.74 N·m. The torque at which the hook started to slide in sample 3 was 20.49 N·m, and the ultimate torque at which the hook broke to cause internal fixation failure was 24.82 N·m.Conclusion:Our self-developed crossed-hug locking plate for Vancouver type B1 periprosthetic femur fractures has achieved the mechanical strengths required in the mechanical tests which simulate human upright load with Sawbone biomechanical test materials.
