RESUMO
STUDY DESIGN: Retrospective case series. OBJECTIVE: Describe the injury characteristics of ballistic fractures involving the atlantoaxial spine. SUMMARY OF BACKGROUND DATA: Civilian gunshot wounds to the spine are an increasingly common injury in the United States. Civilian studies have focused on ballistic injuries to the entire spine as opposed to a region-specific fashion. Only a single 10-patient case series investigating ballistic fractures to the upper cervical spine (C1 and C2) exists, leaving a large gap in the understanding of this injury complex. METHODS: A retrospective chart review was performed. Extracted data included patient demographics, neurological status on presentation, fracture morphology, assessment of stability, other associated injuries, and surgical procedures performed. Proportional analysis was performed to characterize the fractures and their associated neurological injuries. RESULTS: Thirty-six patients were identified, with 86% being male with an average patient age of 30.0 ± 10.36 years (mean ± SD). Fracture morphology was characterized using proportional analysis. Initial neurological exams were either ASIA A or ASIA E, without any incomplete injuries noted. Patients who sustained a transcanal injury did not show any neurological improvement. The initial in-hospital mortality rate was 5.6%, with a 1-year mortality rate of 8.3%. There is a high incidence of associated vascular injury (66%) and mandible fracture (33%). CONCLUSIONS: Ballistic penetrating trauma to the atlantoaxial spine often results in complex injury patterns necessitating multidisciplinary care with high rates of morbidity and mortality. If neurological deficits are present initially, they are often complete. Two thirds of patients sustained an associated vascular injury, which should be screened for with CT angiography.
RESUMO
BACKGROUND CONTEXT: Civilian gunshot wounds to the spine are an increasingly common injury in the USA. A majority of the available research is focused on a military population suffering high energy missile injury. Minimal research has focused on civilian ballistic injuries to the lumbosacral spine as the available studies focus on the entire spine due to limited numbers. PURPOSE: Characterize ballistic injuries to the lumbosacral spine and develop a model to predict the presence of neurological deficit based upon a patients presenting fracture morphology. STUDY DESIGN: Retrospective chart review. PATIENT SAMPLE: One hundred forty-eight consecutive patients that were presented to an urban level 1 trauma center with ballistic injures to the spine involving the levels L1-S2. OUTCOMES MEASURES: Neurological status at presentation and final follow up using the American Spinal Injury Association (ASIA) Impairment Scale. METHODS: IRB approval was obtained, and retrospective chart review was performed. Extracted data included patient demographics, neurological status on presentation and final follow-up, fracture morphology, assessment of stability, other associated injuries, and surgical procedures performed. Proportional analysis was performed to characterize the fractures and their associated neurological injuries. Chi-square testing was done to identify fracture characteristics associated with neurologic injury. A multiple logistical regression was performed using fracture characteristics highly associated with neurological deficit to develop a model to predict neurologic deficit. The model was then validated with a receiver operator curve. RESULTS: Of the 148 patients, 14 patients underwent spinal surgery with the most common indication being decompression and foreign body removal. There was a high incidence of intra-abdominal injury (73.6%). Fractures were characterized by level, affected vertebral component, and spinal canal involvement. Neurological injury was classified using the ASIA scale at presentation and final follow up. Odds-ratios of vertebral fracture characteristics showed neurologic deficit was highly associated with pedicle fractures (OR=9.07 [4.14-21.54] - 95% CI), lamina fractures (OR=6.42 [3.16-13.62] - 95% CI), facet fractures (OR=5.95 [2.90-12.79] - 95% CI), intra-canal bone (OR=12.79 [5.98-29.05] - 95% CI), and an intra-canal trajectory (OR=1078 [4.48-28.98]) - 95% CI. Multiple logistic regression was performed to construct a predictive model of neurologic deficit which showed that intra-canal trajectory, pedicle fracture and facet fracture are associated with neurologic deficit. An ROC curve was made with an area of 0.849 ([0.7853 to 0.9128 - 95% CI], p<.0001) demonstrating a good model fit. CONCLUSIONS: Ballistic injuries to the lumbosacral spine involve complex injury patterns in an often polytraumatized patient. Fractures involving the pedicle, lamina, and facet are highly associated with neurologic injury, as is a trans-canal trajectory. A patients fracture morphology can be used to predict if a neurologic deficit is present.
