Anterior column reconstruction with mono-segmental fusion and lag screw fixation of sagittal split for burst-split fracture of the thoracolumbar spine.

Objectives
To present and evaluate the safety and efficacy of our new procedure for treating thoracolumbar burst-split fractures without neurological injury.Methods
Our new surgical technique for the treatment of thoracolumbar burst-split fractures (AO type A4, Magerl classification A3.2.1) involving (1) posterior reduction and bisegmental instrumention, (2) anterior screw fixation of the caudal sagittal split, (3) anterior one-level fusion of the cranial segment, and (4) interval posterior implant removal was presented. In an initial cohort of patients, demographic information, surgical specifics and imaging data were evaluated.Results
Twenty-one patients (mean age 29.5 ± 11.8 years, 38% male, mean follow-up 36 ± 14 months) were included. Anterior column reconstruction involving sagittal split lag screw and monosegmental fusion was performed at a mean of 2.9 ± 2 days after posterior instrumentation. All fractures healed. There were no occurrences of implant failures or migrations. None of the patients required revision surgery. The removal of the temporary posterior instrumentation was performed at a mean of 8.4 ± 1.8 months after the initial surgery. Bisegmental, superior monosegmental, and inferior monosegmental kyphosis angle did not significantly change from six months to 12 months postoperatively after removal of the posterior instrumentation (p > 0.9). No listhesis or change in bisegmental scoliosis angle were observed. The inferior monosegmental angle was significantly greater in flexion (1.2° ± 5.8°) compared to extension (-3.3° ± 6°) at 12 months postoperatively indicating motion in the inferior, non-fused segment after removal of the posterior instrumentation (p = 0.0001). The intervertebral disc height at the temporarily fused segment decreased significantly from six (9.2 ± 2.2) to 12 months postoperatively (8.3 ± 2.2; p < 0.0101).Conclusion
Thoracolumbar burst-split fractures can be safely and successfully treated through a treatment protocol that includes (1) posterior reduction and bisegmental instrumention, (2) anterior screw fixation of the caudal sagittal split, (3) anterior one-level fusion of the cranial segment, and (4) interval posterior implant removal. This new surgical technique promotes reliable fracture healing, kyphosis correction and preserves the physiological motion at the caudal segment.