Minor traumatic brain injury: a primer for the orthopaedic surgeon

Is delayed fixation worthwhile in patients with long bone fracture concomitant with mild traumatic brain injury? A propensity score-matched study

INTRODUCTION

Early definite treatment for orthopedic patients is strongly advocated. However, a consensus has not been reached on the optimal timing of long bone fracture fixation for patients with associated mild traumatic brain injury (TBI). Surgeons lack evidence on the basis on which they should decide on the operation timing.

METHODS

We retrospectively reviewed the data of patients with mild TBI and lower extremity long bone fractures from 2010 to 2020. The patients receiving internal fixation within and after 24 h were defined as the early- and delayed-fixation groups. We compared the discharge Glasgow Coma Scale (GCS) scores, lengths of stay, and in-hospital complications. Propensity score matching (PSM) with multiple adjusted variables and a 1:1 matching ratio was applied to reduce selection bias.

RESULTS

In total, 181 patients were enrolled; 78 (43.1%) and 103 (56.9%) patients received early and delayed fracture fixation, respectively. After matching, each group had 61 participants and were statistically identical. The delayed group did not have better discharge GCS scores (early vs. delayed: 15.0 ± 0 vs. 15.0 ± 0.1; p = 0.158). The groups did not differ in their lengths of hospital stay (15.3 ± 10.6 vs. 14.8 ± 7.9; p = 0.789), intensive care unit stay (2.7 ± 4.3 vs. 2.7 ± 3.8; p = 0.947), or incidence of complications (23.0% vs. 16.4%; p = 0.494).

CONCLUSIONS

Delayed fixation for patients with lower extremity long bone fractures concurrent with mild TBI does not result in fewer complications or improved neurologic outcomes compared with early fixation. Delaying fixation may not be necessary to prevent the second hit phenomenon and has not demonstrated any clear benefits.

Eletromagnetic Detection of Mild Brain Injury: A Novel Imaging Approach to Post Concussive Syndrome

INTRODUCTION

Mild traumatic brain injury (mTBI) is a common injury, with nearly 3 - 4 million cases annually in the United States alone. Neuroimaging in patients with mTBI provides little benefit, and is usually not indicated as the diagnosis is primarily clinical. It is theorized that microvascular trauma to the brain may be present in mTBI, that may not be captured by routine MRI and CT scans. Electromagnetic (EM) waves may provide a more sensitive medical imaging modality to provide objective data in the diagnosis of mTBI.

METHODS

COMSOL simulation software was utilized to mimic the anatomy of the human skull including skin, cranium, cerebrospinal fluid (CSF), gray-matter tissue of the brain, and microvasculature within the neural tissue. The effects of penetrating EM waves were simulated using the finite element analysis software and results were generated to identify feasibility and efficacy. Frequency ranges from 7 GHz to 15 GHz were considered, with 0.6 and 1 W power applied.

RESULTS

Variations between the differing frequency levels generated different energy levels within the neural tissue-particularly when comparing normal microvasculature versus hemorrhage from microvasculature. This difference within the neural tissue was subsequently identified, via simulation, serving as a potential imaging modality for future work.

CONCLUSION

The use of electromagnetic imaging of the brain after concussive events may play a role in future mTBI diagnosis. Utilizing the proper depth frequency and wavelength, neural tissue and microvascular trauma may be identified utilizing finite element analysis.

Inhibiting α5 Subunit-Containing γ-Aminobutyric Acid Type A Receptors Attenuates Cognitive Deficits After Traumatic Brain Injury

OBJECTIVES

Cognitive deficits after traumatic brain injury are a leading cause of disability worldwide, yet no effective pharmacologic treatments exist to improve cognition. Traumatic brain injury increases proinflammatory cytokines, which trigger excess function of α5 subunit-containing γ-aminobutyric acid type A receptors. In several models of brain injury, drugs that inhibit α5 subunit-containing γ-aminobutyric acid type A receptor function improve cognitive performance. Thus, we postulated that inhibiting α5 subunit-containing γ-aminobutyric acid type A receptors would improve cognitive performance after traumatic brain injury. In addition, because traumatic brain injury reduces long-term potentiation in the hippocampus, a cellular correlate of memory, we studied whether inhibition of α5 subunit-containing γ-aminobutyric acid type A receptors attenuated deficits in long-term potentiation after traumatic brain injury.

DESIGN

Experimental animal study.

SETTING

Research laboratory.

SUBJECTS

Adult male mice and hippocampal brain slices.

INTERVENTIONS

Anesthetized mice were subjected to traumatic brain injury with a closed-head, free-weight drop method. One week later, the mice were treated with L-655,708 (0.5 mg/kg), an inhibitor that is selective for α5 subunit-containing γ-aminobutyric acid type A receptors, 30 minutes before undergoing behavioral testing. Problem-solving abilities were assessed using the puzzle box assay, and memory performance was studied with novel object recognition and object place recognition assays. In addition, hippocampal slices were prepared 1 week after traumatic brain injury, and long-term potentiation was studied using field recordings in the cornu Ammonis 1 region of slices that were perfused with L-655,708 (100 nM).

MEASUREMENTS AND MAIN RESULTS

Traumatic brain injury increased the time required to solve difficult but not simple tasks in the puzzle box assay and impaired memory in the novel object recognition and object place recognition assays. L-655,708 improved both problem solving and memory in the traumatic brain injury mice. Traumatic brain injury reduced long-term potentiation in the hippocampal slices, and L-655,708 attenuated this reduction.

CONCLUSIONS

Pharmacologic inhibition of α5 subunit-containing γ-aminobutyric acid type A receptors attenuated cognitive deficits after traumatic brain injury and enhanced synaptic plasticity in hippocampal slices. Collectively, these results suggest that α5 subunit-containing γ-aminobutyric acid type A receptors are novel targets for pharmacologic treatment of traumatic brain injury-induced persistent cognitive deficits.

A Scoping Review of Pain in Children after Traumatic Brain Injury: Is There More Than Headache?

Headache is a common source of pain in children after traumatic brain injury (TBI); however, relatively little is known about nonheadache pain in this pediatric population. The present review seeks to map the extant literature to determine the prevalence, characteristics, and impact of nonheadache pain in children post-TBI of all severities. We found that of 109 studies published on pain in children after a TBI, 95 (87%) were focused exclusively on headache pain and only 14 (13%) reported on nonheadache pain or overall pain, with half (n = 7) in the form of case studies. Overall, the level of evidence was low, with only three level 1 high-quality prospective studies. In one study, over half (57.1%) of adolescents who experienced persistent pain post-TBI reported pain in multiple body sites (e.g., back, lower limb, and neck).¹ For each additional noncephalic pain site, the risk for developing chronic migraine is also increased. Nevertheless, pain in body regions other than the head is often not assessed systematically in pediatric TBI research. Findings of the current review suggest that pain assessment in children post-TBI needs improvement, given that pain is linked to worse recovery, poorer quality of life, and can be long-lasting. More rigorous examination of nonheadache pain and its role in impeding recovery in children post-TBI is imperative and has the potential to improve the care and management of children with TBI. We conclude with recommendations for pain assessment, discuss gaps in the literature, and highlight directions for future research.

Prospective Evaluation of Posttraumatic Stress Disorder and Depression in Orthopaedic Injury Patients With and Without Concomitant Traumatic Brain Injury

OBJECTIVES

Psychological morbidities after injury [eg, posttraumatic stress disorder (PTSD) and depression] are increasingly recognized as a significant determinant of overall outcome. Traumatic brain injury (TBI) negatively impacts outcomes of patients with orthopaedic injury, but the association of concurrent TBI, orthopaedic injury, and symptoms of PTSD and depression has not been examined. This study's objective was to examine symptoms of PTSD and depression in patients with orthopaedic trauma with and without TBI.

DESIGN

Longitudinal prospective cohort study.

SETTING

Urban Level I Trauma Center in the Southwest United States.

PATIENTS/PARTICIPANTS

Orthopaedic trauma patients older than 18 years admitted for ≥24 hours.

MAIN OUTCOME MEASUREMENTS

Questionnaires examining demographics, injury-related variables, PTSD, and depression were administered during hospitalization and 3, 6, and 12 months later. Orthopaedic injury and TBI were determined based on ICD-9 codes. Generalized linear models determined whether PTSD and depression at follow-up were associated with TBI.

RESULTS

Of the total sample (N = 214), 44 (21%) sustained a TBI. Those with TBI had higher rates of PTSD symptoms, 12 months postinjury (P = 0.04). The TBI group also had higher rates of depressive symptoms, 6 months postinjury (P = 0.038).

CONCLUSIONS

Having a TBI in addition to orthopaedic injury was associated with significantly higher rates of PTSD at 12 months and depression at 6 months postinjury. This suggests that sustaining a TBI in addition to orthopaedic injury places patients at a higher risk for negative psychological outcomes. The findings of this study may help clinicians to identify patients who are in need for psychological screening and could potentially benefit from intervention.

LEVEL OF EVIDENCE

Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

Head CT for Minor Head Injury Presenting to the Emergency Department in the Era of Choosing Wisely

Introduction

The Choosing Wisely campaign currently recommends avoiding computed tomography (CT) of the head in low-risk emergency department (ED) patients with minor head injury, based on validated decision rules. However, the degree of adherence to this guideline in clinical practice is unknown. The objective of this study was to evaluate adherence to the Choosing Wisely campaign’s recommendations regarding head CT imaging of patients with minor head injury in the ED.

Methods

We conducted a retrospective cohort study of adult ED patients at a Level I trauma center. Patients aged ≥ 18 years who presented to the ED with minor head injury were identified via International Classification of Diseases, 9th Revision, Clinical Modification codes. Medical record abstraction was conducted to determine the presence of clinical symptoms of the NEXUS II criteria, medical resource use, and head CT findings. We used descriptive statistics to characterize the study sample, and proportions were used to quantify guidelines adherence.

Results

A total of 489 subjects met inclusion criteria. ED providers appropriately applied the Choosing Wisely criteria for 75.5% of patients, obtaining head CTs when indicated by the NEXUS II rule (41.5%), and not obtaining head CTs when the NEXUS II criteria were not met (34.0%). However, ED providers obtained non-indicated CTs in 23.1% of patients. Less than 2% of the sample did not receive a head CT when imaging was indicated by NEXUS II.

Conclusion

ED providers in our sample had variable adherence to the Choosing Wisely head-CT recommendation, especially for patients who did not meet the NEXUS II criteria.

Evaluation of a coplanar 6a3ω configuration in the Hybrid III 50th percentile male head

OBJECTIVES

In order to understand the mechanisms of traumatic brain injury (TBI) and develop proper safety measures, it is essential that accurate instrumentation methods are utilized. The brain injury criterion (BrIC) has been developed and validated to predict brain injuries in combination with the head injury criterion (Takhounts et al. 2011, 2013). Because the validated BrIC is heavily dependent on angular motion, the accuracy of any head instrumentation technique should be judged in part by its ability to measure angular motion. The main objective of this study was to evaluate a method of accurately measuring 6-degree-of-freedom (DOF) anthropomorphic test device (ATD) head kinematics using a coplanar 6 accelerometers and 3 angular rate sensors (6a3ω) configuration.

METHODS

A coplanar 6a3ω configuration (c6a3ω) was implemented via a newly designed fixture. The c6a3ω fixture was placed at the center of gravity (CG) of a Hybrid III 50th percentile ATD (HIII 50) head. In addition, a tetrahedron fixture with 9 installed accelerometers (tNAAP) was externally mounted on the posterior surface of the HIII 50 skull cap. The c6a3ω setup also allowed for comparison to the 3a3ω configuration (i3a3ω) by subsequently treating the c6a3ω fixture as an i3a3ω fixture by only using accelerations and angular rates from select sensors. A total of 63 tests were conducted by impacting the head-neck apparatus at various high speeds and directions by a pneumatic ram. Normalized root mean square deviation (NRMSD), peak differences, and uncertainty were used for quantitative evaluation of the 3 configurations (e.g., c6a3ω, i3a3ω, and tNAAP).

RESULTS

The average NRMSD and peak differences between the calculated angular accelerations were less than 5% between the tNAAP and the c6a3ω with 5.6% of uncertainty but greater than 18% for NRMSD and 20% for the peak differences between the tNAAP and i3a3ω with 58.2% uncertainty. Average NRMSD and peak differences between transformed resultant linear accelerations and gold standards (accelerations directly measured by accelerometers at the origin of tNAAP or c6a3ω fixtures) were also calculated. The c6a3ω had both NRMSD and peak differences less than 3% (uncertainty of 2.5%), and i3a3ω had NRMSD, peak values, and uncertainty on the order of 20% and higher. The tNAAP was slightly less accurate than the c6a3ω for transformed accelerations (NRMSD and peak differences <6%, uncertainty of 4.6%) and showed NRMSD and peak differences in the 7-8% range for angular velocity and rotation (uncertainty of 4.3 and 6.7%, respectively).

CONCLUSIONS

The c6a3ω configuration exhibited much better accuracy for calculating angular acceleration and transformed linear acceleration than the i3a3ω configuration. The tNAAP showed slightly less accurate transformed linear acceleration than the c6a3ω and was demonstrated to have less accuracy than c6a3ω and i3a3ω for calculating angular velocity and rotation. The c6a3ω configuration could be a potential alternative to specialized NAAP ATD heads because all kinematics can be measured near the head CG, and 6a3ω instrumentation provides the most comprehensive 6DOF kinematics (i.e., accelerations, velocities, and displacements) with accuracy.

Incidence rate of mild traumatic brain injury among patients who have suffered from an isolated limb fracture: Upper limb fracture patients are more at risk

OBJECTIVES

This study compares the incidence rate of mild traumatic brain injury (mild TBI) detected at follow-up visits (retrospective diagnosis) in patients suffering from an isolated limb trauma, with the incidence rate held by the hospital records (prospective diagnosis) of the sampled cohort. This study also seeks to determine which types of fractures present with the highest incidence of mild TBI.

PATIENTS AND METHODS

Retrospective assessment of mild TBI among orthopaedic monotrauma patients, randomly selected for participation in an Orthopaedic clinic of a Level I Trauma Hospital. Patients in the remission phase of a limb fracture were recruited between August 2014 and May 2015. No intervention was done (observational study).

MAIN OUTCOME MEASUREMENTS

Standardized semi-structured interviews were conducted with all patients to retrospectively assess for mild TBI at the time of the fracture. Emergency room related medical records of all patients were carefully analyzed to determine whether a prospective mild TBI diagnosis was made following the accident.

RESULTS

A total of 251 patients were recruited (54% females, Mean age=49). Study interview revealed a 23.5% incidence rate of mild TBI compared to an incidence rate of 8.8% for prospective diagnosis (χ(2)=78.47; p<0.0001). Patients suffering from an upper limb monotrauma (29.6%; n=42/142) are significantly more at risk of sustaining a mild TBI compared to lower limb fractures (15.6%; n=17/109) (χ(2)=6.70; p=0.010). More specifically, patients with a proximal upper limb injury were significantly more at risk of sustaining concomitant mild TBI (40.6%; 26/64) compared to distal upper limb fractures (20.25%; 16/79) (χ(2)=7.07; p=0.008).

CONCLUSIONS

Results suggest an important concomitance of mild TBI among orthopaedic trauma patients, the majority of which go undetected during acute care. Patients treated for an upper limb fracture are particularly at risk of sustaining concomitant mild TBI.

Clinical indications of computed tomography (CT) of the head in patients with low-energy geriatric hip fractures

OBJECTIVE

To define the role of head computed tomography (CT) scans in the geriatric population with isolated low-energy femur fractures and describe the pertinent clinical variables which are associated with positive CT findings with the objective to decrease the number of unnecessary CT scans performed.

DESIGN

Retrospective review.

SETTING

Level I trauma centre.

PATIENTS

Eleven hundred ninety-two (1192) patients sustaining a femur fracture following a low-energy fall.

MAIN OUTCOME MEASUREMENT

Pertinent clinical variables that were associated with CTs that yielded positive findings.

RESULTS

Two hundred fifty patients (21%) underwent a head CT scan as part of their evaluation. Of these patients, 83% suffered proximal femur fractures, 11% shaft fractures and 6% distal fractures. The majority of the patients were evaluated by the emergency department (ED) with only 18% (44/250) being evaluated by the trauma team. Average patient age was 83 years (range 65-99 years). One hundred seventy-three patients (69%) were on some form of antiplatelet medication or anticoagulation. Of the 250 patients who underwent head CT scan, 16 (6%) patients had acute findings (haemorrhage - 15, infarct - 1), and none of the patients required neurosurgical intervention.

CONCLUSION

None of the patients with a traumatic injury required a neurosurgical invention after sustaining a low energy fall (0/1192). Head CT scans should have a limited role in the work-up of this patient population and should be reserved for patients with a history and physical findings that support head trauma.

LEVEL OF EVIDENCE

Prognostic level III. See instructions for authors for a complete description of levels of evidence.