Crosslink augmentation in posterior fixation of unstable thoracic and thoracolumbar fractures: A comparative cohort study of mechanical failure and sagittal alignment.

BACKGROUND: The value of crosslink augmentation in posterior thoracolumbar instrumentation for traumatic fractures remains uncertain. Although biomechanical studies suggest improved rotational stability, clinical evidence is limited. OBJECTIVE: To compare mechanical failure and sagittal alignment in posterior pedicle-screw constructs with and without crosslink augmentation for traumatic thoracic, thoracolumbar, and lumbar fractures. METHODS: A retrospective single-center comparative cohort study included patients treated between January 2018 and March 2026 for traumatic thoracic, thoracolumbar, or lumbar fractures. Patients were grouped according to crosslink use. The primary outcome was construct-related mechanical failure, including rod fracture, screw loosening, implant disconnection, crosslink failure, progressive loss of correction, or revision for deformity. Local kyphosis was measured preoperatively, postoperatively, and at final follow-up. RESULTS: Twenty-eight patients were analyzed: 13 with crosslink augmentation and 15 without crosslinks. Crosslink constructs were longer, with more instrumented levels (4.9 vs. 3.9; P = 0.008) and screws (8.2 vs. 6.7; P = 0.013). Index-level screw omission was more frequent with crosslinks (61.5% vs. 20.0%; P = 0.051), as was neurological deficit (84.6% vs. 0%; P < 0.001). AO type B/C morphology and confirmed or suspected posterior ligamentous complex injury were similarly distributed. No mechanical failures occurred in the crosslink group, whereas one noncrosslink patient developed screw loosening associated with chronic infection/fistula. Sagittal differences were not statistically significant, although final kyphosis and late kyphotic progression numerically favored crosslink augmentation. CONCLUSION: Crosslink-augmented constructs showed no mechanical failures despite greater baseline complexity. These findings suggest potential mechanical benefit, but larger studies are required.