Evaluation of Outcomes from Pedicle Screw Fixation Before and After Laminectomy : Short title: Outcomes of Pedicle Screw Fixation Before and After Laminectomy.

BACKGROUND

Pedicle screw fixation is a standard technique for spinal stabilization in patients undergoing laminectomy for decompression. This study aims to compare the outcomes of pedicle screw fixation performed before versus after laminectomy, focusing on its effects on spinal stability, recovery outcomes, and complication rates.

MATERIALS AND

METHODS

This retrospective cohort study, conducted from July 2017 to July 2020 at the Neurosurgery Departments of Imam Reza and Shohada Hospitals in Tabriz, Iran, assessed outcomes of two approaches to pedicle screw fixation in 104 patients undergoing laminectomy for degenerative spinal conditions. The patients were equally divided into two groups of 52: one group receiving pedicle screw fixation before laminectomy, and the other following laminectomy. Key intraoperative parameters-such as blood loss, operative time, and screw placement accuracy-were evaluated and compared between groups. Data were analyzed using SPSS software, employing Independent Samples T-Tests and Chi-square tests, with statistical significance defined at P0.05. This retrospective cohort study compares two surgical sequences-pedicle screw fixation before versus after laminectomy-in patients undergoing lumbar decompression, aiming to evaluate intraoperative efficiency and short-term outcomes.

RESULTS

The laminectomy-first group had a lower infection rate (5.76% vs. 9.61%) and required fewer blood transfusions (96.1% vs. 90.3%) than the screw-first group, though these differences were not significant (P0.05). Blood loss and drain output were significantly higher in the laminectomy-first group (P0.05), but surgery duration was shorter (P=0.01), with similar hospital stays between groups. The laminectomy-first approach also required fewer screw path corrections and fluoroscopy uses, indicating greater intraoperative efficiency (P=0.001).

CONCLUSION

This study demonstrates that pedicle screw fixation after laminectomy demonstrated greater intraoperative efficiency with fewer adjustments and reduced fluoroscopy use. However, due to the retrospective nature of the study and lack of systematic documentation of baseline stability and symptom dominance, future prospective or randomized controlled trials are needed to confirm these findings and guide evidence-based surgical decision-making.