Comparative Analysis of Pedicle Screw Fixation and Interspinous Devices in Lumbar Spinal Fusion: Clinical and Surgical Outcomes in Degenerative Spine Conditions

<b>Background/Objectives</b>: Degenerative lumbar spine conditions are a major cause of disability, particularly in elderly patients or those with comorbidities. Surgical treatment often combines decompression and stabilization to address pain and instability. Pedicle screws are the gold standard for stabilization but pose challenges in patients with compromised bone quality. Interspinous devices have emerged as a less invasive alternative, but comparative studies are limited. This study aimed to compare clinical and surgical outcomes of lumbar decompression with stabilization using pedicle screws versus interspinous devices. <b>Methods</b>: A retrospective cohort study was conducted on patients who underwent lumbar decompression with either pedicle screw fixation or interspinous device stabilization at Mater Olbia Hospital between February 2020 and February 2023. Outcomes were evaluated using VAS for back and leg pain, SF-36 for quality of life, EQ-5D, and SCL-90 for psychological factors. Statistical analysis included paired <i>t</i>-tests, chi-square tests, and multivariate regression. <b>Results</b>: A total of 728 patients were included. The interspinous device group consisted of older patients with higher comorbidity burdens (mean age: 68.4 vs. 59.2 years, <i>p</i> < 0.001). Surgical time and incision size were significantly shorter in the interspinous group (<i>p</i> < 0.001), and no postoperative complications were reported, compared to 3.5% in the pedicle screws group (<i>p</i> < 0.05). Both groups demonstrated significant improvements in pain (VAS), quality of life (SF-36, EQ-5D), and psychological outcomes (SCL-90). Somatization and paranoid ideation were significant predictors of worse postoperative pain, particularly in the pedicle screws group. No significant differences in quality-of-life improvements were observed between the groups. <b>Conclusions</b>: Both stabilization techniques are effective for lumbar spine surgery, with interspinous devices offering a safer and less invasive option for high-risk patients. Psychological factors significantly influence pain outcomes, underscoring the need for a comprehensive approach addressing both physical and psychological aspects to optimize patient recovery.