Comparison of tissue-interface pressure in healthy subjects lying on two trauma splinting devices: The vacuum mattress splint and long spine board

Biomechanical design optimization and experimental verification of Bezier curve based two-sectional cervical pillow with variable-density cellular structure

The fundamental function of an optimal cervical pillow is to provide sufficient support to maintain normal spinal alignment and minimize biological stress on the contact surface throughout sleep. The recent advancements in cervical pillows have mainly focused on the subjective and objective evaluations of support comfort, as well as the relationship between pillow height and cervical vertebrae posture. However, only a few studies have addressed shape design guidelines and mechanical performances of the pillows themselves. In this study, a two-sectional contour cervical pillow comprising an arc and a Bezier curve is designed to support the head and neck. The design of the arc-shaped neck section incorporates the Cobb's angle and Borden value from healthy individuals to reflect the consistency of normal cervical anatomical features. The Bezier curve-based head section takes the head length and neck depth into account as significant individual differences. Static analysis and lattice optimization are performed in ANSYS Workbench to develop a variable-density cellular structure, aimed at improving air permeability and reducing the risk of pressure ulcers associated with the cervical pillow. The rapid prototyping technique fused deposition modeling (FDM) and thermoplastic material polylactic acid (PLA) are employed for fabricating different cellular structures. The results demonstrate that the neck section experiences less stress and greater deformation in comparison to the head section, indicating good comfort and support provided by the designed cervical pillow. Additionally, the compressive, bending, and cushion properties of the 3D-printed cervical pillow with variable-density cellular structure are experimentally validated, further confirming its effectiveness.

Evaluation of external stabilization of type II odontoid fractures in geriatric patients-An experimental study on a newly developed cadaveric trauma model

Background

Along with the growing geriatric population, the number of odontoid fractures is steadily increasing. However, the effectiveness of immobilizing geriatric odontoid fractures using a cervical collar has been questioned. The aim of the present study is to analyze the physiological and pathological motion in odontoid fractures and to assess limitation of motion in the cervical spine when applying a cervical collar.

Methods

Motion analysis was performed with wireless motion tracker on unfixed geriatric human cadavers. First, a new geriatric type II odontoid fracture model was developed. In this model, the type II odontoid fracture is operated via a transoral approach. The physiological and pathological flexion and lateral bending of the cervical spine resulting from this procedure was measured. The resulting motion after external stabilization using a cervical collar was analyzed.

Results

The new geriatric type II odontoid fracture model was successfully established using seven unfixed human cadavers. The pathological flexion of the cervical spine was significantly increased compared to the physiological flexion (p = 0.027). Furthermore, the flexion was significantly reduced when a cervical collar was applied. In case of flexion the mean remaining motion was significantly reduced (p = 0.0017) from 41° to 14°. For lateral bending the mean remaining motion was significantly reduced (p = 0.0137) from 48° to 18°.

Conclusions

In case of type II odontoid fracture, flexion and lateral bending of the cervical spine are increased due to spinal instability. Thus, if an odontoid fracture is suspected in geriatric patients, the application of a cervical collar should always be considered since external stabilization can significantly reduce flexion and lateral bending.

Analysis of remaining motion using one innovative upper airway opening cervical collar and two traditional cervical collars

The aim of this study was to compare the remaining motion of an immobilized cervical spine using an innovative cervical collar as well as two traditional cervical collars. The study was performed on eight fresh human cadavers. The cervical spine was immobilized with one innovative (Lubo Airway Collar) and two traditional cervical collars (Stifneck and Perfit ACE). The flexion and lateral bending of the cervical spine were measured using a wireless motion tracker (Xsens). With the Weinman Lubo Airway Collar attached, the mean remaining flexion was 20.0 ± 9.0°. The mean remaining flexion was lowest with the Laerdal Stifneck (13.1 ± 6.6°) or Ambu Perfit ACE (10.8 ± 5.8°) applied. Compared to that of the innovative Weinmann Lubo Airway Collar, the remaining cervical spine flexion was significantly decreased with the Ambu Perfit ACE. There was no significant difference in lateral bending between the three examined collars. The most effective immobilization of the cervical spine was achieved when traditional cervical collars were implemented. However, all tested cervical collars showed remaining motion of the cervical spine. Thus, alternative immobilization techniques should be considered.

[The position of the head during treatment in the emergency room-an explorative analysis of immobilization of the cervical spine]

BACKGROUND

Immobilization of the cervical spine is a standard procedure in emergency medicine mostly achieved via a cervical collar. In the emergency room other forms of immobilization are utilized as cervical collars have certain drawbacks. The present study aimed to provide preliminary data on the efficiency of immobilization in the emergency room by analyzing the residual spinal motion of the patient's head on different kinds of head rests.

METHODS

In the present study biomechanical motion data of the cervical spine of a test subject were analyzed. The test subject was placed in a supine position on a mobile stretcher (Stryker M1 Roll-In System, Kalamazoo, MI, USA) wearing a cervical collar (Perfit ACE, Ballerup, Denmark). Three different head rests were tested: standard pillow, concave pillow and cavity pillow. The test subject carried out a predetermined motion protocol: right side inclination, left side inclination, flexion and extension. The residual spinal motion was recorded with wireless motion trackers (inertial measurement unit, Xsens Technologies, Enschede, The Netherlands). The first measurement was performed without a cervical collar or positioning on the pillows to measure the physiological baseline motion. Subsequently, three measurements were taken with the cervical collar applied and the pillows in place. From these measurements, a motion score was calculated that can represent the motion of the cervical spine.

RESULTS

When the test subject's head was positioned on a standard pillow the physiological motion score was reduced from 69 to 40. When the test subject's head was placed on concave pillow the motion score was further reduced from 69 to 35. When the test subject's head was placed on cavity pillow the motion score was reduced from 69 to 59. The observed differences in the overall motion score of the cervical spine are mainly due to reduced flexion and extension rather than rotation or lateral inclination.

CONCLUSION

The motion score of the cervical spine using motion sensors can provide important information for future analyses. The results of the present study suggest that trauma patients can be immobilized in the early trauma phase with a cervical collar and a head rest. The application of a cervical collar and the positioning on the concave pillow may achieve a good immobilization of the cervical spine in trauma patients in the early trauma phase.

Evidence for the use of spinal collars in stabilising spinal injuries in the pre-hospital setting in trauma patients: a systematic review

Purpose

Spinal collars were introduced in 1967 into the management of spinal trauma care as it was thought that this technique of immobilisation would prevent any further neurological or spinal damage in high-risk patients. The aim of this systematic review was to determine whether the use of spinal collars in the pre-hospital trauma patient was recommended by published literature.

Methods

A systematic search of the literature was conducted between 1990 and 2020, screening PubMed, Medline, Science Direct and Google Scholar. The consequent findings were then qualitatively synthesised with the aim of effectively evaluating the evidence to resolve the discrepancy between current practice and literature.

Results

Of the nine eligible studies, six deemed that spinal collars should not be used in pre-hospital trauma patients with the remaining three reporting uncertainty if spinal collars were best practice. Our results suggest that there is a discrepancy between current guidance and practice in that although the guidelines recommend the use of spinal collars in the pre-hospital setting the majority of the studies were against the use of spinal collars. Importantly, none of the studies reported any benefits of spinal collars.

Conclusion

Our study shows a disparity between current guidelines and the published literature and warrants further direct research to obtain a more comprehensive view of the use of spinal collars in a pre-hospital setting.

An Experimental Intervention Study Assessing the Impact of a Thin Silicone Gel Surface Overlay on Interface Pressure

Introduction

The incidence of pressure ulcers (PUs) presents a substantial threat to patients, especially geriatric patients, those with restricted mobility, and patients suffering from chronic diseases such as cancer. PUs creates a huge financial burden on healthcare authorities and patients, costing billions to treat and manage. Radiography and radiotherapy patients may experience medical device related (MDR) PUs and studies have shown that high interface pressure (IP) values exist for the head when placed on an X-ray table without a mattress. These high IP values pose a PU risk to patients, especially those accessing prolonged radiography/radiology and radiotherapy procedures. The current study assessed the impact on IP values for the head from using a thin silicone gel surface overlay during radiographic procedures and identified whether this reduced the risk of PUs.

Materials and Methods

A calibrated XSENSOR pressure mat was used to measure IP for the head on an X-ray table with and without a thin silicone gel surface overlay. Prior to pressure mapping, the silicone gel surface overlay was assessed for its impact on radiation attenuation and image quality.

Results

Study participants were 14 males (70%) and six females (30%), with an age range of 25-53 years (mean = 34.4 ± 7.0). Paired-samples t-test results indicated that there was a statistically significant decrease in the mean IP for the head on the X-ray table without the silicone gel surface overlay (mean = 83.9 ± 8.2 in mmHg) and the X-ray table with the gel surface overlay (mean = 62.4 ± 6.1 in mmHg), p ≤ 0.001. Paired-samples t-test results indicated that there was a statistically significant decrease in the mean peak pressure index (PPI) for the head on the X-ray table without the silicone gel surface overlay (mean = 205.1 ± 28.2 in mmHg) and the X-ray table with the gel surface overlay (mean = 159.8 ± 26.8 in mmHg), p ≤ 0.001.

Conclusions

The use of a thin silicone gel surface overlay could reduce IP risk for the head by approximately 25%. The reduction in IP risk could have a significant impact in reducing the risk of developing a PU. To ensure maximum benefit, the silicone gel surface overlay should be evaluated to address the specific needs within radiography and radiotherapy planning and treatment settings.

Remaining Cervical Spine Movement Under Different Immobilization Techniques

BACKGROUND

Immobilization of the cervical spine by Emergency Medical Services (EMS) personnel is a standard procedure. In most EMS, multiple immobilization tools are available.The aim of this study is the analysis of residual spine motion under different types of cervical spine immobilization.

METHODS

In this explorative biomechanical study, different immobilization techniques were performed on three healthy subjects. The test subjects' heads were then passively moved to cause standardized spinal motion. The primary endpoints were the remaining range of motion for flexion, extension, bending, and rotation measured with a wireless human motion detector.

RESULTS

In the case of immobilization of the test person (TP) on a straight (0°) vacuum mattress, the remaining rotation of the cervical spine could be reduced from 7° to 3° by additional headblocks. Also, the remaining flexion and extension were reduced from 14° to 3° and from 15° to 6°, respectively. The subjects' immobilization was best on a spine board using a headlock system and the Spider Strap belt system (MIH-Medical; Georgsmarienhütte, Germany). However, the remaining cervical spine extension increased from 1° to 9° if a Speedclip belt system was used (Laerdal; Stavanger, Norway). The additional use of a cervical collar was not advantageous in reducing cervical spine movement with a spine board or vacuum mattress.

CONCLUSIONS

The remaining movement of the cervical spine is minimal when the patient is immobilized on a spine board with a headlock system and a Spider Strap harness system or on a vacuum mattress with additional headblocks. The remaining movement of the cervical spine could not be reduced by the additional use of a cervical collar.

Demonstration of pressure reduction in a new proof of concept spine board

Pressure injuries are a significant problem following spinal cord injury (SCI). High interface pressures while lying on a spine board during emergency transport appear to play a major role in their formation. The aim of the present study was to assess the interface pressures and sensing area between the body and the standard spine board (SSB) and a proof of concept spine board prototype (P-5). Twenty-one able-bodied subjects were assessed on each board. Interface pressures and sensing area were recorded every minute over 15 min. The mean peak pressure was higher on the SSB at the head, scapulothoracic (S-T), sacroiliac (S-I), and heels (227.6 mmHg, 148.9 mmHg, 360.3 mmHg, and 179.3 mmHg) compared to P-5 (51.9 mmHg, 60.1 mmHg, 66.8 mmHg, and 60.2 mmHg). The peak pressure index (PPI) at the head, S-T and S-I was higher on the SSB (100.2 mmHg, 101.6 mmHg, and 270.6 mmHg) compared to P-5 (41.6 mmHg, 51.9 mmHg and 58.7 mmHg). An analysis using pairwise comparisons for repeated measures showed that interface pressures (p < .05) and PPI (p < .001) were reduced at all locations. Modifications of a spine board incorporated in P-5 can dramatically reduce interface pressures and reduce pressure injury formation.

New clinical guidelines on the spinal stabilisation of adult trauma patients - consensus and evidence based

Traumatic spinal cord injury is a relatively rare injury in Denmark but may result in serious neurological consequences. For decades, prehospital spinal stabilisation with a rigid cervical collar and a hard backboard has been considered to be the most appropriate procedure to prevent secondary spinal cord injuries during patient transportation. However, the procedure has been questioned in recent years, due to the lack of high-quality studies supporting its efficacy. A national interdisciplinary task force was therefore established to provide updated clinical guidelines on prehospital procedures for spinal stabilisation of adult trauma patients in Denmark. The guidelines are based on a systematic review of the literature and grading of the evidence, in addition to a standardised consensus process.This process yielded five main recommendations:A strong recommendation against spinal stabilisation of patients with isolated penetrating trauma; a weak recommendation against the prehospital use of a rigid cervical collar and a hard backboard for ABCDE-stable patients; and a weak recommendation for the use of a vacuum mattress for patient transportation. Finally, our group recommends the use of our clinical algorithm to ensure good clinical practice.

Severe pressure ulcers requiring surgery impair the functional outcome after acute spinal cord injury

STUDY DESIGN

Retrospective matched cohort study.

OBJECTIVES

Assessing the influence of surgically managed grade 3 and 4 pressure ulcers (PU) in the acute phase after spinal cord injury (SCI) on the neurological and functional outcome after 1 year.

SETTING

Specialized SCI-unit within a level 1 trauma center in Murnau, Germany.

METHODS

We performed a retrospective matched cohort study. For every patient with acute SCI and a PU requiring surgery, we identified matched controls within our database in a 1:3 ratio. Matching criteria were: AIS-grade (American Spinal Injury Association Impairment Scale), neurological level and age. The scores of the SCIM-III (Spinal Cord Independence Measure) and the ISNCSCI (International Standards for Neurological Classification of Spinal Cord Injury) as well as the total length of stay (LOS) at the hospital were used as outcome parameters. We applied a stratified analysis using a conditional logistic regression to test for group differences in each outcome parameter of the study.

RESULTS

In a 6-year period (2010-2015) 28 patients required flap surgery due to 3-4° PU in the acute phase after SCI. Of these patients, 15 had complete data sets according to the EMSCI (European Multicenter Study about Spinal Cord Injury) protocol. Patients with severe PUs during the acute SCI phase had a significantly impaired functional outcome. After 1 year the improvement of the SCIM score was significantly lower in the PU group compared to the control group (17.4 versus 30.5; p < 0.006). However, the change in AIS grade after 1 year was not significantly affected. The LOS was prolonged by a mean of 48 days in the PU group (p < 0.006).

CONCLUSIONS

Severe PUs requiring surgery in the acute phase after SCI impair the functional outcome and increase LOS. Preventive measures should be applied to all acute SCI patients. Patients should be transferred to specialized SCI-centers as soon as possible.

Analysis of cervical spine immobilization during patient transport in emergency medical services

PURPOSE

It remains controversial how to immobilize the cervical spine (CS) in trauma patients. Therefore, we analyzed different CS immobilization techniques during prehospital patient transport.

METHODS

In this explorative, biomechanical analysis of immobilization techniques conducted in a standardized setting, we recorded CS motion during patient transport using a wireless human motion tracker on a volunteer. To interpret spinal movement a benchmark called motionscore (MS) was developed based on biomechanics of the injured spine.

RESULTS

We found the best spinal motion restriction using a spine board, head blocks and immobilization straps with and without a cervical collar (CC) (MS 45 vs. 27). Spinal motion restriction on a vacuum mattress with CC and head blocks was superior to no CC or head blocks (MS 103 vs. 152). An inclined vacuum mattress was more effective with head blocks than without (MS 124 vs. 187). Minimal immobilization with an ambulance cot, CC, pillow and tape was slightly superior to a vacuum mattress with CC and head blocks (MS 92 vs. 103). Minimal immobilization without CC showed the lowest spinal motion restriction (MS 517).

CONCLUSIONS

We suggest an immobilization procedure customized to the individual situation. A spine board should be used whenever spinal motion restriction is indicated and the utilization is possible. In some cases, CS immobilization by a vacuum mattress with CC and head blocks could be more beneficial. In an unstable status of the patient, minimal immobilization may be performed using an ambulance cot, pillow, CC and tape to minimize time on scene caused by immobilization.

Maintaining immobilisation devices on trauma patients during CT: a feasibility study

BACKGROUND

To reduce the possibility of secondary deterioration of spinal injuries, it is desirable to maintain the spinal immobilisation that is applied in the prehospital setting throughout computed tomography (CT) scanning. A previous study found that metallic components within the inflation valve of the vacuum mattresses caused CT artefacts. The aim of our study was to investigate the effect of vacuum mattresses with plastic valves on CT artefacts, the radiation dose, and noise compared to a trauma transfer board and the spine boards currently used in our trauma system.

METHODS

We scanned an anthropomorphic whole body phantom with different immobilisation devices on a 128-slice CT scanner using the standard polytrauma CT-protocol at our institution. The phantom was scanned without any immobilisation device and with three different vacuum mattresses, two spine boards, and one trauma transfer board. Two radiologists independently assessed the artefacts. Agreement between the two radiologists was measured using the kappa coefficient. The radiation dose and noise were assessed.

RESULTS

One spine board produced major artefacts due to its metal components. One of the vacuum mattresses resulted in artefacts that impaired clinical judgement. Otherwise, the artefacts predominantly did not impede clinical judgement and were mainly subtle. One of the vacuum mattresses resulted in no artefacts that affected clinical judgement. The overall inter-rater agreement was substantial (0.86, kappa 0.77). We did not observe any artefacts due to plastic valves. The mean CT radiation dose was slightly higher for two of the devices in the head series than that for the trauma transfer board, used as the standard in our system. Only marginal differences were noted for the other devices and series. Small differences in image noise were found between the devices.

CONCLUSIONS

Our results indicate that it is feasible to maintain some vacuum mattresses with plastic valves on trauma patients during CT scanning. The tested mattresses did not result in a considerably increased radiation dose or artefacts that hampered clinical judgement. One of the tested vacuum mattresses produced no artefacts that hampered clinical judgement whatsoever.