Unstable conditions of the craniocervical junction such as atlanto-occipital dislocation (AOD) or atlanto-axial instability (AAI) are severe injuries with a high risk of tetraplegia or death. Immobilization by a cervical collar to protect the patient from secondary damage is a standard procedure in trauma patients. If the application of a cervical collar to a patient with an unstable craniocervical condition may cause segmental motion and secondary injury to the spinal cord is unknown. The aim of the current study is (i) to analyze compression on the dural sac and (ii) to determine relative motion of the cervical spine during the procedure of applying a cervical collar in case of ligamentous unstable craniocervical junction. Ligamentous AOD as well as AOD combined with ligamentous AAI was simulated in two newly developed cadaveric trauma models. Compression of the dural sac and segmental angulation in the upper cervical spine were measured on video fluoroscopy after myelography during the application of a cervical collar. Furthermore, overall three-dimensional motion of the cervical spine was measured by a motion tracking system. In six cadavers each, the two new trauma models on AOD and AOD combined with AAI could be implemented. Mean dural sac compression was significantly increased to -1.1 mm (-1.3 to -0.7 mm) in case of AOD and -1.2 mm (-1.6 to -0.6 mm) in the combined model of AOD and AAI. Furthermore, there is a significant increased angulation at the C0/C1 level in the AOD model. Immense three-dimensional movement up to 22.9° of cervical spine flexion was documented during the procedure. The current study pointed out that applying a cervical collar in general will cause immense three-dimensional movement. In case of unstable craniocervical junction, this leads to a dural sac compression and thus to possible damage to the spinal cord.

Purpose: This study aimed to identify the prevalence and predictors of spinal injuries that are suitable for immobilization. Methods: Retrospective cohort study drawing from the multi-center database of the TraumaRegister DGU^®, spinal injury patients ≥ 16 years of age who scored ≥ 3 on the Abbreviated Injury Scale (AIS) between 2009 and 2016 were enrolled. Results: The mean age of the 145,833 patients enrolled was 52.7 ± 21.1 years. The hospital mortality rate was 13.9%, and the mean injury severity score (ISS) was 21.8 ± 11.8. Seventy percent of patients had no spine injury, 25.9% scored 2–3 on the AIS, and 4.1% scored 4–6 on the AIS. Among patients with isolated traumatic brain injury (TBI), 26.8% had spinal injuries with an AIS score of 4–6. Among patients with multi-system trauma and TBI, 44.7% had spinal injuries that scored 4–6 on the AIS. Regression analysis predicted a serious spine injury (SI; AIS 3–6) with a prevalence of 10.6% and cervical spine injury (CSI; AIS 3–6) with a prevalence of 5.1%. Blunt trauma was a predictor for SI and CSI (OR 4.066 and OR 3.640, respectively; both p < 0.001) and fall > 3 m for SI (OR 2.243; p < 0.001) but not CSI (OR 0.636; p < 0.001). Pre-hospital shock was predictive for SI and CSI (OR 1.87 and OR 2.342, respectively; both p < 0.001), and diminished or absent motor response was also predictive for SI (OR 3.171) and CSI (OR 7.462; both p < 0.001). Patients over 65 years of age were more frequently affected by CSI. Conclusions: In addition to the clinical symptoms of pain, we identify ‘4S’ [spill (fall) > 3 m, seniority (age > 65 years), seriously injured, skull/traumatic brain injury] as an indication for increased attention for CSIs or indication for spinal motion restriction.

The extrication of patients following a road traffic collision is among the basic procedures in emergency medicine. Thus, extrication is a frequently performed procedure by most of the emergency medical services worldwide. The appropriate extrication procedure depends on the patient's current condition and accompanying injuries. A rapid extrication should be performed within a few minutes, and the cervical spine (at least) should be immobilized. To our knowledge, the scientific literature and current guidelines do not offer detailed recommendations on the extrication of injured patients. Thus, the aim of the current study is to compare the effectiveness of spinal stabilization during various out-of-hospital extrication procedures. This is an explorative, biomechanical analysis of spine motion during different extrication procedures on an example patient. Movement of the cervical spine was measured using a wireless human motion tracker. Movement of the thoracic and lumbar spine was quantified with 12 strain gauge sensors, which were positioned paravertebrally on both sites along the thoracic and lumbar spine. To interpret angular movement, a motionscore was developed based on newly defined axioms on the biomechanics of the injured spine. Self-extrication showed the least spinal movement (overall motionscore sum = 667). Movement in the cervical spine could further be reduced by applying a cervical collar. The extrication by a rescue boa showed comparable results in overall spinal movement compared to the traditional extrication via spineboard (overall motionscore sum = 1862vs. 1743). Especially in the cervical spine, the spinal movement was reduced (motionscore sum = 339 vs. 595). However, the thoracic spine movement was increased (motionscore sum = 812 vs. 432). In case of a suspected cervical spine injury, guided self-extrication seems to be the best option. If the patient is not able to perform self-extrication, using a rescue boa might reduce cervical spinal movement compared to the traditional extrication procedure. Since promising results are shown in the case of extrication using a patient transfer sheet that has already been placed below the driver, future developments should focus on novel vehicle seats that already include an extrication device.