###### Abstract  
Vertebroplasty (VP), balloon kyphoplasty (BKP), and vertebral stent (VS) are usually used for treating osteoporoptic compression fractures. However, these procedures may pose risks of secondary adjacent level fractures. This study simulates finite element models of osteoporoptic compression fractures treated with VP, BKP, and VS Vertebral resection method was used to simulate vertebra fracture with [PERSON]'s modulus set at 70 MPa to replicate osteoporosis. A follower load of (1175 N for flexion, and 500 N for all others) was applied in between vertebral bodies to simulate the muscle force. Moment loadings of 7.5 N-m in flexion, extension, lateral bending, axial rotation were applied respectively. The VS model had the highest von Mises stresses on the bone cement under all different loading conditions (flexion/5.91 MPa; extension/3.74 MPa; lateral bending/3.12 MPa; axial rotation/3.54 MPa). The stress distribution and maximum von Mises stresses of the adjacent segments, T11 inferior endplate and L1 superior endplate, showed no significant difference among three surgical models. The postoperative T12 stiffness for VP, BKP, and VS are 2898.48 N/mm, 4123.18 N/mm, and 4690.34 N/mm, respectively. The VS model led to superior surgical vertebra stiffness without significantly increasing the risks of adjacent fracture.  
osteoporosis; compression fracture; vertebplasty; balloon kyphoplasty; vertebral stent system; adjacent fracture +
Footnote †: journal: Applied Sci. 2021, 11, 5764. [[https://doi.org/10.3390/app11135764](https://doi.org/10.3390/app11135764)]([https://doi.org/10.3390/app11135764](https://doi.org/10.3390/app11135764))
the pedicle is localized under fluoroscopic guidance, and then polymethylmethacrylate (PMMA) delivery into the vertebrae body is done to stabilize the fracture and alleviate pain. BKP uses a high-pressure balloon to force the collapsed vertebral body back to its original height by creating a cavity that is subsequently filled with the PMMA. In contrast, vertebrae stent (VS) (SpineJack) utilizes a cranio-caudal expandable implant to increase the body height followed by filling the intravertebral stent with PMMA [5].  
In the past literature, there has been numerous clinical and biomechanical studies that compare the outcomes for both VP and BKP [6; 7; 8; 9; 10; 11]. Though clinical results of both VP and BKP were acceptable, both methods could not prevent the development of adjacent vertebrae fractures. These adjacent fractures are not only due to bone fragility, but also can be caused by the new increased rigidity of the vertebrae filled with bone cement [12; 13]. In the past decade, the vertebrae stent has become a novel surgical method for vertebral compression fracture surgery, as it has also been clinically proven to be effective for vertebral compression fracture treatment [14; 15]. The design concept of the vertebral stent is to increase the stability through the complex of bone cement and stent, to prevent the deflating effect of balloons, and to provide more correction of local alignment [16]. Theoretically, a vertebral stent makes the vertebral body more evenly stressed, and is expected to reduce the complications at both the fractured vertebrae and the adjacent vertebrae. To our knowledge, comparative studies using finite element analysis for the VP, BKP and VS procedures are scarce and limited. The aim of this study was to simulate a finite element model of an osteoporotic compression fracture at the thoracolumbar region treated with these three surgical methods (VP, BKP, and VS). Stress distribution and stiffness of the treated vertebrae and the adjacent vertebral segments were simulated under compressive loading simulation to evaluate the possibility of developing secondary fractures. The findings of this study may guide future treatment decisions for surgeons to provide the most appropriate intervention.