Effect of central screw size on stability of the glenoid baseplate in reverse shoulder arthroplasty: a finite element analysis
10.3760/cma.j.cn115530-20250603-00239
- VernacularTitle:中心螺钉尺寸对反肩置换关节盂基座稳定性影响的有限元分析
- Author:
Wanhan SU
1
;
Kai TANG
;
Wencheng YANG
;
Shiwen SHEN
;
Tianpei CHEN
;
Bin CHEN
Author Information
1. 福建医科大学附属龙岩第一医院脊柱外科，龙岩 364000
- Publication Type:Journal Article
- Keywords:
Shoulder joint;
Arthroplasty;
Prosthesis failure;
Finite element analysis;
Central screw;
Fixation stability
- From:
Chinese Journal of Orthopaedic Trauma
2025;27(10):897-903
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To investigate the impact of central screw size on the stability of the glenoid baseplate in reverse shoulder arthroplasty using a finite element analysis.Methods:Four sizes of central screws (length × diameter) were designed: 25.0 mm×5.5 mm (G1), 30.0 mm×5.5 mm (G2), 25.0 mm×6.5 mm (G3), and 30.0 mm×6.5 mm (G4), along with a glenosphere, a baseplate, and peripheral screws. The central screw of group G1 was selected for a biomechanical test along with a set of customized prosthesis. The results were used to validate a finite element model. The validated finite element model was employed to analyze the central screws of 4 different sizes under a vertically downward 490 N load in simulation. After the model calculation was completed, the total displacement of each model, the maximum Von Mises stress on the bone surface at the baseplate-bone contact interface, the maximum Von Mises stress on the bone tissue around the screw-bone interface, the maximum value of the maximum principal strain (tensile strain), the maximum value of the minimum principal strain (compressive strain), the total volume of bone damage, and the volume of bone damage around the central screw were analyzed.Results:Insignificant differences were found in the total displacement and total volume of bone damage across the 4 models. On the bone surface at the baseplate-bone contact interface, the maximum Von Mises stress in G3 and G4 (11.26 MPa and 9.88 MPa, respectively) was slightly higher than that in G1 and G2 (9.11 MPa and 8.90 MPa, respectively). On the bone tissue around the screw-bone interface, G4 exhibited significantly higher maximum stress (15.82 MPa) and significantly higher maximum value of the maximum principal strain (10.09×10 -2) than G1 (8.51 MPa, 3.88×10 -2), G2 (9.45 MPa, 4.29×10 -2), and G3 (9.92 MPa, 3.92×10 -2), while the maximum value of the minimum principal strain in G3 (12.12×10 -2)was significantly higher than that in G1 (8.23×10 -2), G2 (8.10×10 -2), and G4 (8.34×10 -2). The volume of bone damage around the central screw in G3 (11.4 mm 3) was significantly smaller than that in G1 (24.9 mm 3), G2 (28.5 mm 3), and G4 (20.3 mm 3). Conclusions:In reverse shoulder arthroplasty, to a certain extent, increasing the length of a central screw amplifies bone damage volume around the screw. Conversely, increasing only the diameter of a central screw reduces bone damage volume around the screw, consequently lowering the loosening risk of a central screw.
