## 3 Specific Devices  
### SpineJack(r)  
The SpineJack(r) is a mechanical kyphoplasty device made of titanium, designed for restoring vertebral body height in osteopororotic vertebral fractures, bone tumors (primary or secondary), and some traumatic fractures [9]. It is inserted through a bilateral transpedicular approach from T10 to L5 and gradually expanded, reducing the fracture by distracting the verteb, particularly affecting the anterior longitudinal ligament. Once the verteb is restored and stabilized in 3D, PMMA is injected to secure the reduction and support axial compression [10]. The use of two devices symmetrically positioned within the vertebral body ensures even distribution of PMMA, reducing the risk of cement leakage [9; 10; 11]. The device's expansion directs the flow of PMMA in a controlled manner, and the interlocking of the cement creates a broad contact area that provides stability to the vertebral body. This system also lowers the risk of leakage into the intervertebral disk space, decreasing the chances of fractures in adjacent vertebrae. Additionally, the device is equipped with a self-locking mechanism that halts further expansion under excessive load forces, significantly reducing the risk of vertebral endplate fractures [10; 11]. By allowing for controlled reduction of the superior endplate, the system enhances the functional recovery of the injured disk. Studies have shown that the SpineJack(r) is a safe and effective method for treating vertebral fractures. The SpineJack(r) is not only effective for treating osteoporortic vertebral fractures, but also for addressing traumatic fractures and primary or secondary bone tumors. The system generates substantial elevation force, making it suitable for reducing older vertebral fractures, known as inveterate collapses, where bone marrow edema is still visible on MRI scans. The SpineJack(r) stands out as the only third-generation PVAS device capable of treating such fractures. In conclusion, this device provides a safer and more efficient restoration of vertebral body height compared to conventional balloon kyphoplasty [8; 10]. In the case shown in Figures 1-3, a patient with collapse of the L1 vertebral body due to suspected metastasis in a case of non-Hodgkin lymphoma, with no evidence of peripheral neurological deficits, is presented (Figure 1). The patient was subsequently subjected to a vertebral biopsy, which did not show any disease localization. The patient then underwent a vertebral reconstruction procedure of the L1 vertebral body with the placement of a SpineJack, followed by vertebplasty of the D12 vertebral body. Following a bi-pedicular approach to L1, and after a preliminary needle biopsy, the procedure began with the preparation of bone tunnels for pre-implantation, followed by the implantation of 5 mm SpineJack devices. This allowed for partial recovery of the height of the collapsed superior endplate and realignment of the posterior wall displacement. The procedure was completed with vertebplasty of the D12 vertebral body via a left-sided monopedicular approach (Figure 2). At follow-up imaging approximately two weeks after the procedure, MRI and X-ray confirmed the successful outcome of the recent treatment, showing stability of the treated vertebral segments, partial recovery of vertebral height, and realignment of the posterior wall at L1. No cement leakage was detected on the final CBCT scan. The postoperative course was smooth, with the patient reporting a good recovery of functionality (Figure 3). Figure 1: Patient with non-metastatic collapse of the L1 vertebral body in a case of non-Hodgkin lymphoma, with no evidence of peripheral neurological deficits. Image showing TSE sequences obtained with a 1.5 Tesla magnet in the sagittal plane of the lumbosacral spine of the patient, before treatment: (**A**) T2-weighted sequence, (**B**) T1-weighted sequence, and (**C**) Short Tau Inversion Recovery sequence.