Background: After prior spine surgeries, deep-seated infections pose serious clinical problems and frequently call for repeat surgical procedures. Whether, decompression by itself or in conjunction with instrumented fusion is the best surgical strategy is still up for dispute. Aim: This study aimed to evaluate clinical and radiological outcomes of redo surgical interventions in patients with deep-seated spine infections, comparing decompression alone versus decompression with instrumented fusion. Patients and methods: A single-center retrospective cohort study that included 21 patients was conducted at the Neurosurgery Department, Faculty of Medicine, Zagazig University. Patients were divided into two groups: Fusion-assisted decompression and decompression alone. Functional outcomes (Barthel Index), complication rates, and microbiological profiles were analyzed. Results: The fusion group had significantly longer operation durations and higher intraoperative blood loss. Pain showed remarkable improvement in both groups, with the fusion group achieving significantly better results for back and leg pain. Functional outcomes, measured by the Barthel Index, were superior in fusion group with 36.4% achieving independence compared to none in the decompression-alone group. The recovery rate was significantly higher in fusion group compared to decompression-alone group. Staphylococcus aureus and Escherichia coli were the predominant organisms, with a higher rate of no growth in the fusion group versus the decompression-alone group. Conclusion: Adding instrumented fusion to decompression in redo surgeries for deep-seated spine infections resulted in better pain relief, superior functional outcomes, and higher recovery rates compared to decompression alone. Despite longer operative times and increased blood loss, the overall clinical benefits support the inclusion of fusion in appropriate cases.