Percutaneous Screw Distraction for Anatomic Restoration

Introduction: Percutaneous pedicle screw fixation and distraction for treating traumatic thoracolumbar burst fractures may provide reduced morbidity but has substantial limitations. We sought to measure the results of distraction across fixed-angle screws for improved anatomical restoration after traumatic thoracolumbar burst fractures, with specific emphasis on post-distraction vertebral body height restoration and spinal canal fragment reduction.

Methods: A patient cohort was assembled using common procedural technology codes and case-by-case reviews. Demographic and relevant clinical characteristics were captured. Pertinent radiographic measurements were collected, as available, at predistraction, postdistraction, and long-term follow-up time points. Paired t-tests, student’s t-tests, Mann-Whitney tests, and chi-square were used in assessing data per normality distribution and variable type.

Results: The cohort included 23 patients, 78.3% male, with a mean age of 42 years. 8.7% of patients had Hounsfield density consistent with osteopenia at the time of injury, while 0% had osteoporosis. Sporting injuries and motor vehicle accidents were the most common modes of injury (both 30.4%), and most injuries occurred at T12 (13.0%) or L1 (47.8%). Upon long-term follow-up, the mean predistraction cross-sectional area improved from 2.1 cm2 to 2.9 cm2 (p < 0.01). In relation to the super-adjacent level, the injured vertebra cross-sectional canal area improved by 34.9% (p < 0.01). Vertebral body index likewise improved significantly (16.5° mean change, p< 0.01). The mean bisegmental Cobb angle lessened by a significant 6.2° (p=0.01), and injured vertebral body compression likewise decreased by 17.8% (p < 0.01). 21.7% of patients underwent posterior decompression for persistent narrowing at the fractured level. To date, ten patients have elected for hardware removal to facilitate restoration of movement, as well as avoid late hardware fracture and adjacent level degeneration.

Conclusion : Distraction across fixed–angle percutaneous screw instrumentation systems provides an efficacious surgical approach to stabilize traumatic thoracolumbar burst fractures and reduce stenosing crushed fragments. Distraction may be sufficient to avoid laminectomy and fusion.