Safety and efficacy of short percutaneous fixation in AO3 and AO4 lumbar fractures: a single-centre experience of 35 cases

Introduction. Spinal fractures with subsequent bone fragment dislocation are among the injuries most feared by patients and physicians. The surgical strategy is tailored to the individual patient's characteristics and often consists of pedicle instrumentation with rod-screw systems. Short instrumentation has been associated with worse spinal correction and increased complications. However, recent studies have suggested similar results in terms of kyphosis correction and the maintenance of sagittal alignment compared to longer instrumentation. Material and methods. This single-center retrospective study was conducted between January 2018 and April 2021. We included 35 single lumbar burst fractures AO Spine grade A3 or A4 with evidence of intra-canal fragments. Patients underwent minimally invasive percutaneous posterior lumbar instrumentation with pedicle screws. Patients received short segmental fixation involving only one level above and below the fractured vertebra. Results. An immediate postoperative computed tomography (CT) scan demonstrated a significant reduction in vertebral kyphotic deformation (11.7 degrees +/- 1.6 vs 16.7 degrees +/- 5, p<0.001) and sagittal Cobb angle (9.8 degrees +/- 1.3 vs 11.7 degrees +/- 1.5, p < 0.001). The correction was slightly reduced but remained significant at 12 months for both kyphotic (12.3 degrees +/- 1.4, p = 0.03) and sagittal Cobb (10.3 degrees +/- +/- 0.9, p = 0.04). Upper lumbar vertebrae showed even larger correction indices compared to lower lumbar segments. No implant failure or screws pullout was seen at the last follow-up. Conclusions. Short spinal fixation is a safe and effective treatment of complete and incomplete burst fractures with posterior bone fragment dislocation. All included patients fared well and achieved good kyphotic correction with no perioperative or long-term complications.