STUDY DESIGN: This is a retrospective cohort study. OBJECTIVE: To evaluate the combined modified percutaneous short-segment posterior instrumentation technique by reducing and fixating the thoracolumbar burst fracture and checking the efficacy of indirect spinal decompression using intraoperative CT. This study aims to (1) demonstrate that using modified percutaneous short-segment posterior instrumentation is enough to rebuild spinal stability and decompress the spinal stenosis for thoracolumbar burst fracture and (2) prove the effects of spinal canal decompression by intraoperative portable CT with the surgical technique. SUMMARY OF BACKGROUND DATA: Various posterior instrumentation methods have been used to treat thoracolumbar burst fractures and decompress retropulsed bony fragments through ligamentotaxis, but no studies have assessed the efficacy of combining percutaneous short-segment posterior instrumentation with intraoperative CT. METHODS: Using modified percutaneous short-segment posterior instrumentation to rebuild the spinal stability and ligamentotaxis effect to indirect decompression of the spinal stenosis without laminectomy and check parameters immediately after surgery by real-time intraoperative portable CT. RESULTS: Fifty-seven patients with thoracolumbar burst fractures underwent modified percutaneous short-segment posterior instrumentation from 2018 to 2023 at a single medical center. Mean injured vertebral canal dimension increased from 90.8±26.3 to 122.1±30.3 mm2 (P<
0.05) and mean canal encroachment index decreased from 44.8±9.5% to 25.6±4.8% (P<
0.05), the anterior body height increased from 13.9±3.8 to 25.9±3.9 mm (P<
0.01) and kyphotic angle decreased from 27.3±3.2 to 8.6±2.1 degrees (P<
0.01). Neurological function was improved by at least 1 Frankel grade in neurological deficit patients. No significant difference in kyphotic angle between post-op and 6-month follow-up. CONCLUSIONS: Indirect decompression of the spinal canal with modified percutaneous short-segment fixation without laminectomy was an effective treatment for thoracolumbar burst fracture, even in selected incomplete neurological deficits patients.