Mechanisms and Mitigation of Head and Spinal Injuries Due to Motor Vehicle Crashes

Traumatic cervical spine fracture patterns on CT: a retrospective analysis at a level 1 trauma center

PURPOSE

The purpose of our study was to determine common acute traumatic cervical spine fracture patterns on CT cervical spine (CTCS).

METHODS

We retrospectively reviewed 1091 CTCS positive for traumatic fractures performed over a 10-year period at a level 1 trauma center. Fractures were classified by vertebral level, laterality, and anatomic location (anterior/posterior arch, body, odontoid, pedicle, facet, lateral mass, lamina, spinous process, transverse foramina, and transverse processes).

RESULTS

C2 was the most commonly fractured vertebra (38% of all studies), followed by C7 (32.4%). 48.7% of studies had upper cervical spine (C1 and/or C2) fractures. 39.7% of positive studies involved > 1 vertebral level. Conditioned on fractures at one cervical level, the probability of fracture was greatest at adjacent levels with a 50% chance of sustaining a C7 fracture with C6 fracture. However, 31.3% (136) of studies with multi-level fractures had non-contiguous fractures. The most common isolated vertebral process fracture was of the transverse process, seen in 89 (8.2%) studies at a single level, 27 (2.5%) studies at multiple levels. Subaxial spine vertebral process fractures outnumbered body fractures with progressive dominance of vertebral process fracture down the spine.

CONCLUSION

C2 was the most commonly fractured vertebral level. Multi-level traumatic cervical spine fractures constituted 40% of our cohort, most commonly at C6/C7 and C1/C2. Although the conditional probability of concurrent fracture in studies with multi-level fractures was greatest in contiguous levels, nearly one-third of multi-level fractures involved non-contiguous fractures.

Head-Neck Motion in Prehospital Trauma Patients under Spinal Motion Restriction: A Pilot Study

BACKGROUND

Spinal precautions are intended to limit motion of potentially unstable spinal segments. The efficacy of various treatment approaches for motion restriction in the cervical spine has been rigorously investigated using healthy volunteers and, to a lesser extent, cadaver samples. No previous studies have objectively measured this motion in trauma patients with potential spine injuries during prehospital care. Objective: The purpose of this study was to characterize head-neck (H-N) kinematics in a sample of trauma patients receiving spinal precautions in the field. Methods: This was a prospective observational study of trauma patients in the prehospital setting. Trauma patients meeting criteria for spinal precautions were eligible for inclusion. Participants received usual care, consisting of either a long backboard, cervical collar, and head blocks (BC) or a cervical collar only (CO), and behavior was categorized as compliant (C) or non-compliant (N). Three inertial measurement units (IMUs), placed on each participant's forehead, sternum, and stretcher, yielded data on H-N motion. Outcomes were described in terms of H-N displacement and acceleration, including single- and multi-planar values, root mean square (RMS), and bouts of continuous motion above pre-determined thresholds. Data were analyzed to compare H-N motion by phase of prehospital care, as well as treatment type and patient behavior.

RESULTS

Substantial single- and multi-plane H-N motion was observed among all participants. Maximum single-plane displacements were between 11.3 ± 3.0 degrees (rotation) and 19.0 ± 16.6 degrees (flexion-extension). Maximum multi-plane displacements averaged 31.2 ± 7.2 degrees (range: 7.2 to 82.1 degrees). Maximum multi-plane acceleration averaged 5.8 ± 1.4 m/s² (range: 1.2 to 19.9 m/s²). There were no significant differences among participants between prehospital phase and treatment type. Non-compliant participants showed significantly more motion than compliant participants. Conclusion: Among actual patients, movement appears to be greater than previously recorded in simulation studies, and to be associated with patient behavior. Miniature IMUs are a feasible approach to field-based measurement of H-N kinematics in trauma patients. Future research should evaluate the effects of patient compliance, treatment, and phase of care using larger samples. Key words: spinal immobilization; cervical spine; cervical collar; long backboard.

Seat belt use among patients in motor vehicle collisions: Clinical and demographic factors

OBJECTIVE

Proper use of automobile seat belt in a motor vehicle crash is associated with reduced morbidity and mortality, shorter hospital stays, reduced resource utilization, and fewer missed work days. Seatbelt compliance nationwide is 86%. This study was undertaken to identify factors associated with noncompliance with seatbelt use among admitted patients following a motor vehicle crash.

METHODS

This study was a retrospective analysis of motor vehicle crashes at an Urban Level 1 Trauma Center. Eligible subjects included patients age 18 and over, who were admitted by the Trauma Service following a motor vehicle crash from January to December 2017.

RESULTS

Among 766 participants, the overall rate of seatbelt noncompliance was 32% (N = 245). Some participants met the legal limit of intoxication (80 mg/dl) (N = 119 patients; 22%). Drug use was high among this population, including THC (30%), opiates (29%), benzodiazepines (24%), cocaine (10%), and methamphetamine (10%). Patients who did not wear seat belts were more likely to be male (62.4% no seat belt vs. 51.8% seat belt), intoxicated (30.5% vs. 17.0%), screen positive for cocaine (18.2% vs. 4.7%), THC (37.7% vs. 24.2%), and methamphetamine (15.6% vs. 5.9%). We did not detect significant differences by seat belt use with respect to ethnicity, mode of arrival, day of week, opiate use, or benzodiazepine use.

CONCLUSIONS

In this study, 32% of patients in motor vehicle crashes were not compliant with seat belt use. Noncompliance with seat belt use was higher among patients who were male, younger age, intoxicated, or who had positive screens for cocaine, THC, or methamphetamine.

Does Overall Cervical Spine Pathology Relate to the Clinical Heterogeneity of Chronic Whiplash?

BACKGROUND AND PURPOSE

There remains limited evidence for the clinical importance of most imaging findings in whiplash. However, it is possible the type and number of findings on Computed Tomography (CT) may contribute to prognostic recovery models. The purpose is to interpret cervical spine pathologies in the context of known factors influencing recovery.

MATERIALS AND METHODS

This is a secondary analysis from a database of 97 acutely injured participants enrolled in a prospective inception cohort study. Thirty-eight participants underwent standard of care cervical spine CT in the emergency medicine department. All 38 participants were assessed at <1-week, 2-weeks, and 3-months post-injury and classified using percentage scores on the Neck Disability Index (recovered/mild (NDI of 0-28%) or moderate/severe (NDI ≥ 30%)). Between-group comparison of categorical variables (gender (male/female), presence of at least one CT finding (yes/no), and presence of ≥3 pathologies on CT (yes/no)) was conducted using 2-tailed Fisher's exact test.

RESULTS

Participants from both groups demonstrated at least one observable pathology. The group with persistent moderate/severe symptoms presented with significantly more pathology at baseline than those who later reported recovery or milder symptoms at 3-months post injury (p = 0.02).

CONCLUSIONS

This preliminary study, which needs replication in a larger cohort, provides foundation that the number of degenerative pathologies seen on initial post MVC CT may be associated with the subsequent clinical course of whiplash.

How Do We Meet the Challenge of Whiplash?

A previous special issue of JOSPT (October 2016) discussed whiplash in terms of the clinical problems and current research surrounding prevention, biomechanics of injury, emergent care, imaging advancements, recovery pathways and prognosis, pathogenesis of posttrauma pain, acute and chronic management, and new predictive clinical tools. While great strides have been made in the field of whiplash and are continuing in earnest, a key group of clinicians and academics have recognized that inconsistent outcomes in published literature hamper our ability to meaningfully synthesize research findings, leading to results of systematic reviews that provide very few concrete clinical recommendations. We are optimistic that improved outcomes for people with whiplash-associated disorder (WAD) are attainable in the near future, as interdisciplinary research efforts continue to align internationally, new mechanisms are identified and explored, and advanced statistical techniques allow complex questions to be answered in clinically meaningful ways. J Orthop Sports Phys Ther 2017;47(7):444-446. doi:10.2519/jospt.2017.0106.

An Integrated Model of Chronic Whiplash-Associated Disorder

Synopsis The development of persistent symptoms following whiplash injury from a motor vehicle collision is common and contributes substantially to societal and personal costs. The popular Quebec Task Force classification system of whiplash-associated disorders (WADs) was meant to function as a prognostic and intervention decision aid, but its usefulness has been questioned. Emerging evidence highlights the heterogeneity of WAD by demonstrating physical and psychological impairments that are unique to those who develop persistent symptoms. These impairments are not recognized in the Quebec Task Force classification system. The purpose of this clinical commentary is to describe an integrated model that focuses on how psychological and neurobiological factors interact with, and are influenced by, existing personal and environmental factors to contribute to the development of chronic WAD. The model has been developed through more than 20 years of work in the field, consultation with experts, in-depth synthesis of existing evidence, and new evidence from the authors' own research programs. A subtheme is that a point of convergence currently exists between the psychological, physiological, and social determinants of health literature that can further explain the complex presentation of WAD. The new model is proposed to orient future research toward more interdisciplinary efforts across nontraditional fields, including data scientists and consumers, to clarify the WAD condition. J Orthop Sports Phys Ther 2017;47(7):462-471. Epub 16 Jun 2017. doi:10.2519/jospt.2017.7455.

Whiplash Continues Its Challenge

There have been many advances in the management of neck pain disorders, but a personal frustration as a clinician and researcher in the field is that the incidence of full recovery following a whiplash injury as a result of a motor vehicle crash has not increased and, subsequently, the rate of transition to chronic neck pain has not lessened. The commentaries in this special issue reflect the multifaceted nature of whiplash-associated disorders and the wide-ranging research in the field. While management of whiplash, especially the challenge of lessening the rate of transition to chronicity, has yet to be achieved, the picture is becoming clearer. This should give great confidence and some hope to individuals with whiplash-associated disorders who have long-term pain and functional disability that after the next decade of research and clinical development, the outcomes following whiplash are likely to be vastly improved. J Orthop Sports Phys Ther 2016;46(10):815-817. doi:10.2519/jospt.2016.0112.