Balancing Stability and Recovery: Impact of Spinal Fusion Length on Surgical Site Infections and Functional Outcomes in Traumatic Thoracic and Thoracolumbar Spinal Cord Injuries

Background Spinal surgeries after traumatic thoracic or thoracolumbar spinal cord injuries (SCI) often involve extensive instrumentation, leading to an increased risk of surgical site infections (SSIs) and complications. This study investigates whether the number of spinal levels fused impacts functional recovery and the frequency of SSIs in individuals with vertebral fractures in the thoracic and/or lumbar spine and SCI. Methods In this retrospective analysis of 282 patients with traumatic thoracic or thoracolumbar SCI, data across two periods (2005–2009 vs. 2018–2022) were compared, including variables such as demographics, setting of the initial surgery (specialized SCI center or general trauma center), SCI severity, number of levels fused, fracture classification, the need for revision surgery, the presence of polytrauma and/or traumatic brain injury (TBI), and the occurrence of SSIs during hospitalization. Functional independence was assessed using the Spinal Cord Independence Measure (SCIM III). Unbiased recursive partitioning (URP-CTREE) was used to identify predictors of SSIs and functional outcomes. Results Patients undergoing longer fusions had a significantly higher rate of SSIs (median fusion length: 5 vs. 3 levels, p = 0.02). Revision surgery and age over 57 were identified as key predictors of SSIs. Shorter fusions (two spinal segments or less) were associated with better functional recovery, particularly in more severe SCI (AIS A, B, or C). Conclusion Longer fusion lengths increase the risk of SSIs and are linked to poorer functional outcomes in patients with thoracic and thoracolumbar SCI. Minimizing fusion length might optimize surgical outcomes and reduce complications. Future research should refine surgical strategies to balance stability with functional recovery.