Background and Objectives: Osteoporotic fractures in the thoracic/lumbar spine pose significant challenges in surgical management, with high risks of complications. This study investigates the role of preoperative CT scans and Hounsfield Units (HUs) in predicting postoperative outcomes. Materials and Methods: A retrospective study was conducted from November 2015 to January 2018. Sixty-one patients over 60 years of age with unstable osteoporotic thoracolumbar spine fractures (OF: 3–4) were included. Preoperative CT scans were performed to measure HU values. Postoperative standing X-rays were taken at 3–12 months to assess signs of loosening, adjacent fractures, or screw dislodgement. HU was divided into quartiles: Q1 (87.59). Results: Out of the 61 patients, 14 (23%) exhibited signs of screw loosening, adjacent fractures, or screw dislodgement within 3 to 12 months postoperatively. The mean HU value measured was 65.21, with a range from 21.43 to 140.7. Notably, all patients with observed loosening or dislodgement had HU values below 68. HU significantly predicted mortality, with the second quartile showing a markedly increased risk (adjusted odds ratio [aOR] = 8.12; p = 0.044). However, HU quartiles were not significant predictors of other outcomes. Other factors (fracture level and ASA classification) also influenced clinical outcomes, particularly mortality. Conclusions: HU values from preoperative CT scans are crucial in predicting the risk of screw loosening, dislodgement, and adjacent fractures in osteoporotic spinal fractures. Integrating HU assessment into clinical practice can improve preoperative planning, allowing for more targeted surgical interventions and better clinical outcomes.