The spine is the most frequent location of bone metastases. Local treatment aims at palliation of pain and, given the increased likelihood of long-term cancer survival, at local control. Kyphoplasty and intraoperative radiotherapy (Kypho-IORT) provided instantaneous pain relief in 70% of patients at the first day after the intervention and resulted in local control rates of > 93% at 1 year in a recently conducted phase I/II trial. To assess its clinical value, we designed a phase III trial which tests Kypho-IORT against the most widespread standard-of-care, external beam radiotherapy (EBRT), in patients with painful vertebral metastases. This phase III study includes patients ≥50 years of age with up to 4 vertebral metastases and a pain score of at least 3/10 points on the visual/numeric analogy scale (VAS). Patients randomized into the experimental arm (A) will undergo Kypho-IORT (Kyphoplasty plus IORT with 8 Gy prescribed to 13 mm depth). Patients randomized into the control arm (B) will receive EBRT with either 30 Gy in 10 fractions or 8 Gy as a single dose. The primary end point is pain reduction defined as at least − 3 points on the VAS compared to baseline at day 1. Assuming that 40% of patients in the Kypho-IORT arm and 5% of patients in the control arm will achieve this reduction and 20% will drop out, a total of 54 patients will have to be included to reach a power of 0.817 with a two-sided alpha of 0.05. Secondary endpoints are evaluation of the percentage of patients with a pain reduction of at least 3 points at 2 and 6 weeks, local tumor control, frequency of re-intervention, secondary fractures/sintering, complication rates, skin toxicity/wound healing, progression-free survival (PFS), overall survival (OS) and quality of life. This trial will generate level 1 evidence on the clinical value of a one-stop procedure which may provide instantaneous pain relief, long-term control and shortened intervals to further adjuvant (systemic) therapies in patients with spinal metastases. Registered with ClinicalTrials.gov, number: NCT02773966 (Registration date: 05/16/2016).

Background/Objectives: Cage implantation decompresses neural elements, stabilizes segments, and promotes fusion, with sagittal balance influenced by cage size, geometry, and position. This retrospective study compared the effects of lumbar interbody cages with 10° and 15° lordotic angles on global and segmental lordosis in patients undergoing transforaminal lumbar interbody fusion (TLIF). Methods: Data from 215 patients who underwent 259 TLIF procedures between 2018 and 2022 were analyzed. All the surgeries were performed by a single senior orthopedic spine surgeon, and cages were selected by the surgeon based on patients’ clinical and anatomical factors. Radiographic assessments included measurements of global and segmental lordosis. Results: Patients who received 15° cages demonstrated significantly greater segmental lordosis compared to those who received 10° cages in both bisegmental and monosegmental procedures (p < 0.001). While the global lordosis in the 10°-cage group remained unchanged postoperatively (p = 0.687), bisegmental procedures showed a small but statistically significant increase (p = 0.035). Moreover, global lordosis did not significantly differ between the 10°- and 15°-cage groups. Conclusions: Cage geometry significantly influenced segmental lordosis, with 15° cages achieving overall more superior radiographic results compared to 10° cages. However, global lordosis was unaffected by cage angle, thereby highlighting the multifaceted nature of factors that influence overall spinal alignment. These findings provide valuable insights into lumbar spine surgery, thus emphasizing the need for comprehensive preoperative planning and consideration of individual patient characteristics.

Background and Objectives: Percutaneous iliosacral screw fixation is a standard treatment for posterior pelvic ring instability and sacral insufficiency fractures. However, conventional transsacral S1 screw fixation is associated with notable complication rates, most commonly implant loosening; dysmorphic sacral anatomy increases the risk of iatrogenic L5 or S1 nerve root injury. This study presents a modified S1 trajectory to engage the high-density bone of the anterior and cranial S1 vertebral body (promontory) by transferring preoperative 3D planning to intraoperative 2D fluoroscopy. Materials and Methods: This retrospective study analyzed implant placements for posterior pelvic ring instability, including high-velocity trauma and fragility fractures of the pelvis (FFPs). Preoperative computed tomography (CT) multiplanar reconstruction defined a modified corridor from a posterior-caudal iliac entry point directed cranially and ventrally into the S1 promontory. The 3D trajectory was transferred intraoperatively using standard 2D fluoroscopy (lateral, anteroposterior, inlet, and outlet views) with the patient prone. In cases of reduced bone quality or intended sacroiliac fusion, 3D-printed titanium implants (triangular or cylindrical threaded, 10.0–13.5 mm outer diameter) were selected over 7.5 mm cannulated screws. Results: Overall, 137 implants were placed in 71 patients: 13 cannulated screws in high-velocity pelvic ring trauma, 72 triangular titanium sacroiliac fusion implants (iFuse Implant System^®, SI-Bone), and 52 threaded titanium fusion implants (iFuse TORQ^®, SI-Bone) in patients with FFP. The modified trajectory consistently engaged the anterior and cranial S1 vertebral body. Postoperative 3D CT confirmed accurate placement of all implants. No iatrogenic nerve injuries or revisions for implant malposition occurred. Mean follow-up was 12 ± 9 months. Conclusions: Preoperative 3D CT planning combined with standard 2D fluoroscopy guided a modified S1 trajectory toward the cranial S1 vertebral body. Accurate and safe implant placement was achieved in the prone position without navigation systems, providing a practical alternative when standard transverse trajectories are limited by narrow bony corridors or sacral or pelvic dysmorphy.