Biomechanical Analysis of Cervical and Thoracolumbar Spine Motion in Intact and Partially and Completely Unstable Cadaver Spine Models With Kinetic Bed Therapy or Traditional Log Roll

Best Practices and Current Care Concepts in Prehospital Care of the Spine-Injured Athlete in American Tackle Football March 2-3, 2019; Atlanta, GA

Sport-related spine injury can be devastating and have long-lasting effects on athletes and their families. Providing evidence-based care for patients with spine injury is essential for optimizing postinjury outcomes. When caring for an injured athlete in American tackle football, clinicians must make decisions that involve unique challenges related to protective equipment (eg, helmet and shoulder pads). The Spine Injury in Sport Group (SISG) met in Atlanta, Georgia, March 2-3, 2019, and involved 25 health care professionals with expertise in emergency medicine, sports medicine, neurologic surgery, orthopaedic surgery, neurology, physiatry, athletic training, and research to review the current literature and discuss evidence-based medicine, best practices, and care options available for the prehospital treatment of athletes with suspected cervical spine injuries.1,2 That meeting and the subsequent Mills et al publication delineate the quality and quantity of published evidence regarding many aspects of prehospital care for the athlete with a suspected cervical spine injury. This paper offers a practical treatment guide based on the experience of those who attended the Atlanta meeting as well as the evidence presented in the Mills et al article. Ongoing research will help to further advance clinical treatment recommendations.

Spinal Immobilization in the Trauma Room - a Survey-Based Analysis at German Level I Trauma Centers

BACKGROUND

Spinal immobilization is a standard procedure in daily out-of-hospital emergency care. Homogenous recommendations concerning the immobilization of trauma patients during the first therapy in the emergency department do not exist. The aim of the current study was the analysis of the existing strategies concerning spinal immobilization in German level I trauma centers by an internet-based survey.

MATERIALS AND METHODS

The current study is a survey-based analysis of the current strategies concerning spinal immobilization in all 107 level I trauma centers in Germany. The internet-based survey consists of 6 items asking about immobilization in the emergency department.

RESULTS

The return rate was 47.7%. In 14 (28.6%) level I trauma centers the patients remained immobilized on the immobilization tool used by the professional emergency care providers. In 19 (38.8%) level I trauma centers the patients were transferred to a stretcher with a soft positioning mattress on it. Patient transfer to a spineboard or to a TraumaMattress was performed in 11 (22.4%) and 7 (14.3%) level I trauma centers, respectively. Trauma patients were never transferred to a vacuum mattress. Cervical spine protection was most of the time performed by a cervical collar (n = 48; 98.0%). In general, the survey's participants were mainly satisfied (mean = 84/100) with the current strategy of spinal immobilization. The satisfaction was best if the spineboard is used.

DISCUSSION

Patient positioning during initial emergency therapy in the emergency department of German level I trauma centers is highly heterogenous. Besides complete full body immobilization, also the lack of any immobilization was reported by the survey's participants.

Traumatic hyperextension-distraction injuries of the thoracolumbar spine: a technical note on surgical positioning

PURPOSE

Hyperextension-distraction type injury of the thoracolumbar spine is an unstable fracture pattern that generally necessitates surgical stabilization by posterior instrumentation. Care must be taken when positioning these patients from supine to prone due to the unstable nature of their injury. The study objectives were (1) to describe a novel modification of the Jackson table turn technique, which may be safer and more effective than the conventional log-roll method and traditional Jackson table technique for positioning patients with hyperextension-distraction injuries of the thoracolumbar spine from supine to prone in the operating room and (2) to present two cases in which this technique was successfully performed.

METHODS

Two patients were carefully positioned from supine to prone by our modification of the Jackson table turn technique, which utilizes a Wilson frame sandwiched between two flat-top Jackson frames. Case 1: a 65-year-old female presented status-post motor vehicle collision with a T9-T10 extension-distraction injury, requiring T7-T12 posterior spinal instrumented fusion (PSIF). Case 2: a 72-year-old female presented status-post motor vehicle collision with a T9-T10 extension-distraction injury and an unstable L1 burst fracture, requiring T7-L2 PSIF.

RESULTS

Both patients remained hemodynamically stable and neurologically intact throughout positioning and postoperatively.

CONCLUSIONS

This technique is safe and effective for positioning patients with hyperextension-distraction type injuries of the thoracolumbar spine from supine to prone in the operating room and may be superior to conventional methods. These slides can be retrieved under Electronic Supplementary Material.

Comparison of the Vacuum Mattress versus the Spine Board Alone for Immobilization of the Cervical Spine Injured Patient: A Biomechanical Cadaveric Study

STUDY DESIGN

A biomechanical cadaveric study.

OBJECTIVE

We sought to determine the amount of motion generated in an unstable cervical spine fracture with use of the vacuum mattress versus the spine board alone. Our hypothesis is that the vacuum mattress will better immobilize an unstable cervical fracture.

SUMMARY OF BACKGROUND DATA

Trauma patients in the United States are immobilized on a rigid spine board, whereas in many other places, vacuum mattresses are used with the proposed advantages of improved comfort and better immobilization of the spine.

METHODS

Unstable subaxial cervical injuries were surgically created in five fresh whole human cadavers. The amount of motion at the injured motion segment during testing was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device (Polhemus Inc.). The measurements recorded in this investigation included maximum displacements during application and removal of the device, while tilting to 90°, during a bed transfer, and a lift onto a gurney. Linear and angular displacements were compared using the Generalized Linear Model analysis of variance for repeated measures for each of the six dependent variables (three planes of angulations and three axes of displacement).

RESULTS

There was more motion in all six planes of motion during the application process with use of the spine board alone, and this was statistically significant for axial rotation (P = 0.011), axial distraction (P = 0.035), medial-lateral translation (P = 0.027), and anteroposterior translation (P = 0.026). During tilting, there was more motion with just the spine board, but this was only statistically significant for anteroposterior translation (P = 0.033). With lifting onto the gurney, there was more motion with the spine board in all planes with statistical significance, except lateral bending. During the removal process, there was more motion with the spine board alone, and this was statistically significant for axial rotation (P = 0.035), lateral bending (P = 0.044), and axial distraction (P = 0.023).

CONCLUSION

There was more motion when using a spine board alone during typical maneuvers performed during early management of the spine injured patient than the vacuum mattress. There may be benefit of use of the vacuum mattress versus the spine board alone in preventing motion at an unstable, subaxial cervical spine injury.

LEVEL OF EVIDENCE

2.

Integrity of Damage Control Posterior Spinal Fusion Constructs for Patients With Polytrauma: A Biomechanical Investigation

STUDY DESIGN

Biomechanical.

OBJECTIVE

Evaluate spinal stability achieved with different levels of posterior percutaneous fixation (postPerc) for thoracolumbar fractures in cadavers subjected to ICU activities.

SUMMARY OF BACKGROUND DATA

"Spine damage control" involves postPerc performed within 24 hours of injury and staged, elective, definitive stabilization. Amount of instrumentation needed to initially achieve adequate spinal stability, minimize morbidity, and accommodate ICU care needs between stages are not defined.

METHODS

In full-unembalmed cadavers motion-tracking sensors were placed at T11 and L1. A T12 corpectomy with PLC injury was stabilized with 1, 2, and 3 levels of PostPerc above/below the injury. Motions between T11 and L1 were measured during Log-Roll and Sit-Up on an ICU bed. After in situ testing, anatomic spinal motion ranges were determined under pure moment loads.

RESULTS

5 cadavers were evaluated. For Log-Roll, 2 and 3 levels above/below restored stability to intact, whereas 1 level above/below did not for axial rotation. For translation, all instrumentation restored stability to intact. During Sit-Up, a linear increase in flexion was observed. At 45° Sit-Up, 2 and 3 levels above/below were similar to intact for flexion; 1 level above/below had significantly more flexion. All instrumentations restored translation to intact for Sit-Up; significantly more axial collapse occurred for instrumentation compared with intact. During ex situ testing, 2 and 3 levels above/below were similar; 1 level above/below had significantly greater laxity in flexion, extension, and axial rotation.

CONCLUSION

Posterior instrumentation 2 or 3 levels above/below a severe thoracolumbar fracture model can restore spinal stability back to its intact condition. 2 levels of fixation above/below this "worst-case scenario" is minimum fixation sufficient to provide absolute spinal stability in the ICU setting as a "Damage Control" technique in patients with polytrauma. In less severe injury models, 1 level of fixation above/below may provide adequate spinal stability; although this should be confirmed in future investigations.

LEVEL OF EVIDENCE

N/A.

Controlled Laboratory Comparison Study of Motion With Football Equipment in a Destabilized Cervical Spine: Three Spine-Board Transfer Techniques

Background

Numerous studies have shown that there are better alternatives to log rolling patients with unstable spinal injuries, although this method is still commonly used for placing patients onto a spine board. No previous studies have examined transfer maneuvers involving an injured football player with equipment in place onto a spine board.

Purpose

To test 3 different transfer maneuvers of an injured football player onto a spine board to determine which method most effectively minimizes spinal motion in an injured cervical spine model.

Study Design

Controlled laboratory study.

Methods

Five whole, lightly embalmed cadavers were fitted with shoulder pads and helmets and tested both before and after global instability was surgically created at C5-C6. An electromagnetic motion analysis device was used to assess the amount of angular and linear motion with sensors placed above and below the injured segment during transfer. Spine-boarding techniques evaluated were the log roll, the lift and slide, and the 8-person lift.

Results

The 8-person lift technique resulted in the least amount of angular and linear motion for all planes tested as compared with the lift-and-slide and log-roll techniques. This reached statistical significance for lateral bending (P = .031) and medial-lateral translation (P = .030) when compared with the log-roll maneuver. The lift-and-slide technique was significantly more effective at reducing motion than the log roll for axial rotation (P = .029) and lateral bending (P = .006).

Conclusion

The log roll resulted in the most motion at an unstable cervical injury as compared with the other 2 spine-boarding techniques examined. The 8-person lift and lift-and-slide techniques may both be more effective than the log roll at reducing unwanted cervical spine motion when spine boarding an injured football player. Reduction of such motion is critical in the prevention of iatrogenic injury.

The Effect of Cricoid Pressure on the Unstable Cervical Spine

BACKGROUND

It has been proposed that cricoid pressure can exacerbate an unstable cervical injury and lead to neurologic deterioration.

OBJECTIVE

We sought to examine the amount of motion cricoid pressure could cause at an unstable subaxial cervical spine injury, and whether posterior manual support is of any benefit.

METHODS

Five fresh, whole cadavers had complete segmental instability at C5-C6 surgically created by a fellowship-trained spine surgeon. Cricoid pressure was applied to the anterior cricoid by an attending anesthesiologist. In addition, the effect of posterior cervical support was tested during the trials. The amount of angular and linear motion between C5 and C6 was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device (Polhemus Inc., Colchester, VT).

RESULTS

When cricoid pressure is applied, the largest angular motion was 3 degrees and occurred in flexion-extension at C5-C6. The largest linear displacement was 1.36 mm and was in anterior-posterior displacement of C5-C6. When manual posterior cervical support was applied, the flexion-extension was improved to less than half this value (1.43 degrees), and this reached statistical significance (p = 0.001). No other differences were observed to be significant in the other planes of motion with the applications of support.

CONCLUSIONS

Based on the evidence presented, we believe that the application of cricoid pressure to a patient with a globally unstable subaxial cervical spine injury causes small displacements. There may be some benefit to the use of manual posterior cervical spine support for reducing motion at such an injured segment.

Does turning trauma patients with an unstable spinal injury from the supine to a lateral position increase the risk of neurological deterioration?--A systematic review

Background

Airway protection and spinal precautions are competing concerns in the treatment of unconscious trauma patients. The placement of such patients in a lateral position may facilitate the acquisition of an adequate airway. However, trauma dogma dictates that patients should be transported in the supine position to minimize spinal movement. In this systematic review, we sought to answer the following question: Given an existing spinal injury, will changing a patient’s position from supine to lateral increase the risk of neurological deterioration?

Methods

The review protocol was published in the PROSPERO database (Reg. no. CRD42012001190). We performed literature searches in PubMed, Medline, EMBASE, the Cochrane Library, CINAHL and the British Nursing Index and included studies of traumatic spinal injury, lateral positioning and neurological deterioration. The search was updated prior to submission. Two researchers independently completed each step in the review process.

Results

We identified 1,164 publications. However, none of these publications reported mortality or neurological deterioration with lateral positioning as an outcome measure. Twelve studies used movement of the injured spine with lateral positioning as an outcome measure; eleven of these investigations were cadaver studies. All of these cadaver studies reported spinal movement during lateral positioning. The only identified human study included eighteen patients with thoracic or lumbar spinal fractures; according to the study authors, the logrolling technique did not result in any neurological deterioration among these patients.

Conclusions

We identified no clinical studies demonstrating that rotating trauma patients from the supine position to a lateral position affects mortality or causes neurological deterioration. However, in various cadaver models, this type of rotation did produce statistically significant displacements of the injured spine. The clinical significance of these cadaver-based observations remains unclear. The present evidence for harm in rotating trauma patients from the supine position to a lateral position, including the logroll maneuver, is inconclusive.

Electronic supplementary material

The online version of this article (doi:10.1186/s13049-015-0143-x) contains supplementary material, which is available to authorized users.

Is it safe to use a kinetic therapy bed for care of patients with cervical spine injuries?

INTRODUCTION

Bedrest is often used for temporary management, as well as definitive treatment, for many spinal injuries. Under such circumstances patients cannot remain flat for extended periods due to possible skin breakdown, blood clots, or pulmonary complications. Kinetic therapy beds are often used in the critical care setting, although this is felt to be unsafe for turning patients with spine fractures. We sought to evaluate whether a kinetic therapy bed would cause as much spinal motion at an unstable cervical injury as occurs during manual log-rolling on a standard intensive care unit bed.

METHODS

Unstable C5-C6 ligamentous injuries were surgically created in 15 fresh, whole cadavers. Sensors were affixed to C5 and C6 posteriorly and electromagnetic motion tracking analysis performed. In all cases a cervical collar was applied by an orthotist after creation of the injury. The amount of angular motion and linear displacement that occurred at this injured level was measured during manual log-rolling and patient turning using a kinetic therapy bed. For statistical analysis, the range of motion for angles about each axis and displacement in each direction was analyzed by multivariate analysis of variance with repeated measures.

RESULTS

When comparing manual log-rolling and kinetic bed therapy, significantly more angular motion was created by the log-roll manoeuvre in flexion-extension (p=0.03) and lateral bending (p=0.01). There was no significant difference in axial rotation between the two methods (p=0.80). There were no significant differences demonstrated in medial-lateral and anterior-posterior translation. There was almost two times the axial displacement between manual log-rolling and the kinetic therapy bed and this reached statistical significance (p=0.05).

CONCLUSION

There is less motion at an unstable cervical injury in flexion-extension, lateral bending, and axial displacement when turning a patient using a kinetic therapy bed as opposed to traditional manual log-rolling. It may be preferable to use a kinetic therapy bed rather than manual log-rolling for patients with cervical spine injuries to decrease unwanted spinal motion. In addition, it may be easier and less physically demanding on nursing staff that must regularly turn the patient if manual log-rolling is implemented.

Motion generated in the unstable upper cervical spine during head tilt-chin lift and jaw thrust maneuvers

BACKGROUND CONTEXT

Although it is essential to maintain a secure airway in a trauma patient, it is also critical to protect the potentially injured cervical spine. It has previously been suggested that the jaw thrust maneuver be used in place of the head tilt-chin lift in the suspected spine-injured patient.

PURPOSE

We sought to examine whether the jaw thrust was in fact safer to use in the setting of an unstable upper cervical spine injury.

METHODS

Unstable, dissociative C1-C2 injuries were surgically created in nine fresh, lightly embalmed human cadaver specimens. An electromagnetic motion analysis device was used to assess the amount of angular and linear motion with sensors placed above and below the injured segment. Measurements were recorded during execution of the two airway maneuvers. Trials were performed both with and without a cervical immobilization collar in place.

RESULTS

There was almost twice as much angular motion in all planes when performing a head tilt-chin lift as compared with the jaw thrust, and this was statistically significant (p<.013). In addition, there was more displacement at the injured level with a head tilt-chin lift as compared with the jaw thrust. This was statistically significant for axial displacement and anteroposterior translation (p=.003 for both), and approached significance for mediolateral translation (p=.056).

CONCLUSIONS

The jaw thrust maneuver results in less motion at an unstable C1-C2 injury as compared with the head tilt-chin lift maneuver. We therefore recommend the use of the jaw thrust to improve airway patency in the trauma patient with suspected cervical spine injury.

Comparison of circumferential pelvic sheeting versus the T-POD on unstable pelvic injuries: A cadaveric study of stability

OBJECTIVES

Commercially available binder devices are commonly used in the acute treatment of pelvic fractures, while many advocate simply placing a circumferential sheet for initial stabilization of such injuries. We sought to determine whether or not the T-POD would provide more stability to an unstable pelvic injury as compared to circumferential pelvic sheeting.

METHODS

Unstable pelvic injuries (OTA type 61-C-1) were surgically created in five fresh, lightly embalmed whole human cadavers. Electromagnetic sensors were placed on each hemi-pelvis. The amount of angular motion during testing was measured using a Fastrak, three-dimensional, electromagnetic motion analysis device (Polhemus Inc., Colchester, VT). Either a T-POD or circumferential sheet was applied in random order for testing. The measurements recorded in this investigation included maximum displacements for sagittal, coronal, and axial rotation during application of the device, bed transfer, log-rolling, and head of bed elevation.

RESULTS

There were no differences in motion of the injured hemi-pelvis during application of either the T-POD or circumferential sheet. During the bed transfer, log-rolling, and head of bed elevation, there were no significant differences in displacements observed when the pelvis was immobilized with either a sheet or pelvic binder (T-POD).

CONCLUSIONS

A circumferential pelvic sheet is more readily available, costs less, is more versatile, and is equally as efficacious at immobilizing the unstable pelvis as compared to the T-POD. We advocate the use of circumferential sheeting for temporary stabilization of unstable pelvic injuries.

Motion in the unstable cervical spine when transferring a patient positioned prone to a spine board

CONTEXT

Two methods have been proposed to transfer an individual in the prone position to a spine board. Researchers do not know which method provides the best immobilization.

OBJECTIVE

To determine if motion produced in the unstable cervical spine differs between 2 prone logrolling techniques and to evaluate the effect of equipment on the motion produced during prone logrolling.

DESIGN

Crossover study.

SETTING

Laboratory.

PATIENTS OR OTHER PARTICIPANTS

Tests were performed on 5 fresh cadavers (3 men, 2 women; age = 83 ± 8 years, mass = 61.2 ± 14.1 kg).

MAIN OUTCOME MEASURE(S)

Three-dimensional motions were recorded during 2 prone logroll protocols (pull, push) in cadavers with an unstable cervical spine. Three equipment conditions were evaluated: football shoulder pads and helmet, rigid cervical collar, and no equipment. The mean range of motion was calculated for each test condition.

RESULTS

The pull technique produced 16% more motion than the push technique in the lateral-bending angulation direction (F1,4 = 19.922, P = .01, η(2) = 0.833). Whereas the collar-only condition and, to a lesser extent, the football-shoulder-pads-and-helmet condition demonstrated trends toward providing more stability than the no-equipment condition, we found no differences among equipment conditions. We noted an interaction between technique and equipment, with the pull maneuver performed without equipment producing more anteroposterior motion than the push maneuver in any of the equipment conditions.

CONCLUSIONS

We saw a slight difference in the motion measured during the 2 prone logrolling techniques tested, with less lateral-bending and anteroposterior motion produced with the logroll push than the pull technique. Therefore, we recommend adopting the push technique as the preferred spine-boarding maneuver when a patient is found in the prone position. Researchers should continue to seek improved methods for performing prone spine-board transfers to further decrease the motion produced in the unstable spine.

Eliminating log rolling as a spine trauma order

BACKGROUND

Currently, up to 25% of patients with spinal cord injuries may experience neurologic deterioration during the initial management of their injuries. Therefore, more effective procedures need to be established for the transportation and care of these to reduce the risk of secondary neurologic damage. Here, we present more acceptable methods to minimize motion in the unstable spine during the management of patients with traumatic spine injuries.

METHODS

This review summarizes more than a decade of research aimed at evaluating different methods of caring for patients with spine trauma.

RESULTS

The most commonly utilized technique to transport spinal cord injured patients, the log rolling maneuver, produced more motion than placing a patient on a spine board, removing a spine board, performing continuous lateral therapy, and positioning a patient prone for surgery. Alternative maneuvers that produced less motion included the straddle lift and slide, 6 + lift and slide, scoop stretcher, mechanical kinetic therapy, mechanical transfers, and the use of the operating table to rotate the patient to the prone position for surgical stabilization.

CONCLUSIONS

The log roll maneuver should be removed from the trauma response guidelines for patients with suspected spine injuries, as it creates significantly more motion in the unstable spine than the readily available alternatives. The only exception is the patient who is found prone, in which case the patient should then be log rolled directly on to the spine board utilizing a push technique.

Total motion generated in the unstable thoracolumbar spine during management of the typical trauma patient: a comparison of methods in a cadaver model

OBJECT

The proper prehospital and inpatient management of patients with unstable spinal injuries is critical for prevention of secondary neurological compromise. The authors sought to analyze the amount of motion generated in the unstable thoracolumbar spine during various maneuvers and transfers that a trauma patient would typically be subjected to prior to definitive fixation.

METHODS

Five fresh cadavers with surgically created unstable L-1 burst fractures were tested. The amount of angular motion between the T-12 and L-2 vertebral segments was measured using a 3D electromagnetic motion analysis device. A complete sequence of maneuvers and transfers was then performed that a patient would be expected to go through from the time of injury until surgical fixation. These maneuvers and transfers included spine board placement and removal, bed transfers, lateral therapy, and turning the patient prone onto the operating table. During each of these, the authors performed what they believed to be the most commonly used versus the best techniques for preventing undesirable motion at the injury level.

RESULTS

When placing a spine board there was more motion in all 3 planes with the log-roll technique, and this difference reached statistical significance for axial rotation (p = 0.018) and lateral bending (p = 0.003). Using logrolling for spine board removal resulted in increased motion again, and this was statistically significant for flexion-extension (p = 0.014). During the bed transfer and lateral therapy, the log-roll technique resulted in more motion in all 3 planes (p ≤ 0.05). When turning the cadavers prone for surgery there was statistically more angular motion in each plane for manually turning the patient versus the Jackson table turn (p ≤ 0.01). The total motion was decreased by almost 50% in each plane when using an alternative to the log-roll techniques during the complete sequence (p ≤ 0.007).

CONCLUSIONS

Although it is unknown how much motion in the unstable spine is necessary to cause secondary neurological injury, the accepted tenet is to minimize motion as much as possible. This study has demonstrated the angular motion incurred by the unstable thoracolumbar spine as experienced by the typical trauma patient from the field to positioning in the operating room using the best and most commonly used techniques. As previously reported, using the log-roll technique consistently results in unwanted motion at the injured spinal segment.

Motion in the unstable thoracolumbar spine when spine boarding a prone patient

INTRODUCTION

Previous research has found that the log roll (LR) technique produces significant motion in the spinal column while transferring a supine patient onto a spine board. The purpose of this project was to determine whether log rolling a patient with an unstable spine from prone to supine with a pulling motion provides better thoracolumbar immobilization compared to log rolling with a push technique.

METHODS

A global instability was surgically created at the L1 level in five cadavers. Two spine-boarding protocols were tested (LR Push and LR Pull). Both techniques entailed performing a 180° LR rotation of the prone patient from the ground to the supine position on the spine board. An electromagnetic tracking device registered motion between the T12 and L2 vertebral segments. Six motion parameters were tracked. Repeated-measures statistical analysis was performed to evaluate angular and translational motion.

RESULTS

Less motion was produced during the LR Push compared to the LR Pull for all six motion parameters. The difference was statistically significant for three of the six parameters (flexion-extension, axial translation, and anterior-posterior (A-P) translation).

CONCLUSIONS

Both the LR Push and LR Pull generated significant motion in the thoracolumbar spine during the prone to supine LR. The LR Push technique produced statistically less motion than the LR Pull, and should be considered when a prone patient with a suspected thoracolumbar injury needs to be transferred to a long spine board. More research is needed to identify techniques to further reduce the motion in the unstable spine during prone to supine LR.

Comparison of thoracolumbar motion produced by manual and Jackson-table-turning methods. Study of a cadaveric instability model

BACKGROUND

Patients who have sustained a spinal cord injury remain at risk for further neurologic deterioration until the spine is adequately stabilized. To our knowledge, no study has previously addressed the effects of different bed-to-operating room table transfer techniques on thoracolumbar spinal motion in an instability model. We hypothesized that the conventional logroll technique used to transfer patients from a supine position to a prone position on the operating room table has the potential to confer significantly more motion to the unstable thoracolumbar spine than the Jackson technique.

METHODS

Three-column instability was surgically created at the L1 level in seven cadavers. Two protocols were tested. The manual technique entailed performing a standard logroll of a supine cadaver to a prone position on an operating room Jackson table. The Jackson technique involved sliding the supine cadaver to the Jackson table, securing it to the table, and then rotating it into a prone position. An electromagnetic tracking device measured motion--i.e., angular motion (flexion-extension, lateral bending, and axial rotation) and linear translation (axial, medial-lateral, and anterior-posterior) between T12 and L2.

RESULTS

The logroll technique created significantly more motion than the Jackson technique as measured with all six parameters. Manual logroll transfers produced an average of 13.8 degrees to 18.1 degrees of maximum angular displacement and 16.6 to 28.3 mm of maximum linear translation. The Jackson technique resulted in an average of 3.1 degrees to 5.8 degrees of maximum angular displacement (p < 0.001) and 4.0 to 10.0 mm of maximum linear translation (p < 0.05).

CONCLUSIONS

Compared with the logroll, the Jackson-table transfer method provides superior immobilization of an unstable thoracolumbar spine during transfer of supine cadavers to a prone position on the operating room table.

CLINICAL RELEVANCE

This study addresses in-hospital patient safety. Performing the Jackson turn requires approximately half as many people as required for a manual logroll. This study suggests that the Jackson technique should be considered for supine-to-prone transfer of patients with known or suspected instability of the thoracolumbar spine.