Aim:This study aimed to investigate which pedicle level and wall were most affected by screw malpositions in osteoporotic and non-osteoporotic patients who underwent thoracolumbar stabilization, and whether there was a significant difference between the two groups.Material and Methods:In this retrospective study, we evaluated pedicle screw malpositions and the specific walls involved in various cases of thoracolumbar stabilization performed between 2014 and 2025 using the freehand technique with fluoroscopy guidance by the same surgical team. A total of 972 patients with a T-score ≤ -2.5 (osteoporotic group) and > -2.5 (non-osteoporotic group) who underwent stabilization for traumatic vertebral fracture, spinal stenosis, recurrent disc herniation, spinal tumor, or spondylolisthesis were included. All patients had preoperative MRI, CT, bone mineral densitometry, and X-ray, as well as postoperative CT and X-rays. Acute decompression cases without preoperative densitometry and those treated with vertebroplasty/kyphoplasty were excluded. In cases of malposition, postoperative CT scans were used to evaluate superior, inferior, lateral, medial, and anterior cortical breaches, and comparisons were made between the two groups.Results:Screw malposition rates were significantly higher in osteoporotic patients across all levels, particularly in thoracic vertebrae. The medial pedicle wall was more frequently affected in osteoporotic patients.Conclusion:In osteoporotic patients, transpedicular screw fixation using the freehand technique with fluoroscopy guidance was associated with a higher rate of malpositions, particularly involving the medial pedicle wall. This complication can be minimized with increased surgical experience and careful intraoperative technique.