Finite element analysis of absorbable screws in Bernese periacetabular osteotomy
10.3760/cma.j.cn121113-20231225-00423
- VernacularTitle:可吸收螺钉应用于伯尔尼髋臼周围截骨术的有限元分析
- Author:
Hui CHENG
1
;
Xiaoying MA
;
Ningtao REN
;
Zhendong ZHANG
;
Haigang JIA
;
Yong LI
;
Jianli ZHANG
;
Dianzhong LUO
;
Hong ZHANG
;
Wei CHAI
Author Information
1. 中国人民解放军总医院第四医学中心骨科医学部关节外科（国家骨科与运动康复临床医学研究中心），北京 100048
- Keywords:
Osteotomy;
Absorbable implants;
Finite element analysis;
Stress, mechanical
- From:
Chinese Journal of Orthopaedics
2024;44(6):419-426
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the stability and feasibility of using absorbable screws during Bernese periacetabular osteotomy.Methods:A retrospective analysis was conducted on a 36 year-old woman diagnosed with developmental dysplasia of the hip, who had undergone Bernese periacetabular osteotomy. Finite element analysis was used to simulate the stability of the acetabulum under loads of 10%, 20%, 50%, and 100% of the patient's weight. The structural stiffness of the pelvis and the maximum equivalent stress on the absorbable screws were observed under different conditions, including whether the acetabular bone block and the ilium were in contact, whether 3 or 4 screws were used, and whether a graft (including fibular cortical bone and PEEK grafts) was used.Results:The structural stiffness of the pelvis fixed with four screws increased by 67%-94% compared to that with three screws. After using a graft, the structural stiffness of the pelvis increased by 50%-83%. As the load increased, the maximum equivalent stress on the screws also increased. When the acetabular bone block and the ilium had no contact, no graft was used, and only three screws were used for fixation, the maximum equivalent stress could reach 518.9 MPa, while this value dropped to 61% when four screws were used (318.7 MPa). When the acetabular bone block and the ilium were in contact, the maximum equivalent stress was about 12% of that when there was no contact, regardless of the number of screws used. When a cortical bone graft or a PEEK graft was used, the maximum equivalent stress could drop to 21%-26% of that without a graft. When the screw strength was 130 MPa, a load of 20% of body weight was applied, and only three screws were used without a graft, the equivalent stress could exceed the strength of the screw; if four screws were used, the equivalent stress was slightly higher than the strength of the screw when a load of 50% of body weight was applied. However, when a graft was used (either cortical bone or PEEK), even when a load of 100% of body weight was applied, the equivalent stress was slightly lower than the strength of the screw.Conclusion:Absorbable screws can provide sufficient stability for Bernese periacetabular osteotomy. The contact between the acetabular bone block and the ilium, an increase in the number of screws, and the use of grafts (cortical bone and PEEK grafts) can further improve stability. Therefore, absorbable screws have broad application prospects in Bernese periacetabular osteotomy.
