Spinal Canal Narrowing During Simulated Whiplash

Ito, Shigeki; Panjabi, Manohar M.; Ivancic, Paul C.; Pearson, Adam M.

doi:10.1097/01.brs.0000127186.81814.4a

Cited by 32 publications

(31 citation statements)

References 53 publications

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“…Continued experimental research with greater sample sizes would be needed to conclusively determine whether or not significant differences exist in cervical neural space kinematics between WHIPS, AHR, and NHR. Peak cervical canal and foramen narrowing of the present study with NHR (Table 1) are contrasted by previously reported data from simulated rear crashes of a human head-neck model [14,15]. Present peak foraminal width narrowing of 1.9 mm at C4/5 compares favorably with 1.7 mm, previously reported at C5/6.…”

Section: Discussioncontrasting

confidence: 57%

“…Using custom transducers to determine spinal canal and foraminal area narrowing, the greatest foraminal area reductions occurred at C5/6 and C6/7, but were of insufficient magnitude to cause injury [13]. Another study found that spinal cord injury during rear impact was unlikely in subjects with normal cervical canal diameters; however, those with severe cervical spinal canal stenosis may be at risk [14]. Nonphysiologic foraminal width narrowing was observed at the lower cervical spine, which indicated potential ganglia compression injury [15].…”

Section: Introductionmentioning

confidence: 99%

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Cervical neural space narrowing during simulated rear crashes with anti-whiplash systems

Ivancic

2012

Eur Spine J

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Purpose Chronic radicular symptoms have been documented in whiplash patients, potentially caused by cervical neural tissue compression during an automobile rear crash. Our goals were to determine neural space narrowing of the lower cervical spine during simulated rear crashes with whiplash protection system (WHIPS) and active head restraint (AHR) and to compare these data to those obtained with no head restraint (NHR). We extrapolated our results to determine the potential for cord, ganglion, and nerve root compression. Methods Our model, consisting of a human neck specimen within a BioRID II crash dummy, was subjected to simulated rear crashes in a WHIPS seat (n = 6, peak 12.0 g and DV 11.4 kph) or AHR seat and subsequently with NHR (n = 6, peak 11.0 g and DV 10.2 kph with AHR; peak 11.5 g and DV 10.7 kph with NHR). Cervical canal and foraminal narrowing were computed and average peak values statistically compared (P \ 0.05) between WHIPS, AHR, and NHR. Results Average peak canal and foramen narrowing could not be statistically differentiated between WHIPS, AHR, or NHR. Peak narrowing with WHIPS or AHR was 2.7 mm for canal diameter and 1.6 mm, 2.7 mm, and 5.9 mm 2 for foraminal width, height and area, respectively. Conclusions While lower cervical spine cord compression during a rear crash is unlikely in those with normal canal diameters, our results demonstrated foraminal kinematics sufficient to compress spinal ganglia and nerve roots. Future anti-whiplash systems designed to reduce cervical neural space narrowing may lead to reduced radicular symptoms in whiplash patients.

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Section: Discussioncontrasting

confidence: 57%

Section: Introductionmentioning

confidence: 99%

Cervical neural space narrowing during simulated rear crashes with anti-whiplash systems

Ivancic

2012

Eur Spine J

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“…Despite this, fracture-dislocation is relatively understudied injury mechanism in experimental SCI research. The geometric variable most relevant to AP cervical dislocation is CPD, and changes in this variable have been assessed during simulated frontal and rear impacts (Ito et al, 2004;Ivancic et al, 2006). Using 3-month old Sprague-Dawley rats, Choo et al (2009) classified a 2.6-mm dislocation as moderate-to-severe with a mortality rate of 10%.…”

Section: Discussionmentioning

confidence: 99%

“…Second, despite our best efforts, we were unable to remove all of the vertebral column extension in our specimens. The importance of this issue is highlighted by findings that spine flexion/extension induced by dynamic front and rear impacts can result in a narrowing of CPD in the cervical spine (Ito et al, 2004;Ivancic et al, 2006). However, we feel this will have a limited influence on our findings as we used a standard mounting technique across all specimens, and pilot results from a single specimen (see ''Tissue specimens'' section) indicated that vertebral column extension during our static fixation had minimal influence on our microCT geometry measures.…”

Section: Discussionmentioning

confidence: 99%

Effects of Advanced Age on the Morphometry and Degenerative State of the Cervical Spine in a Rat Model

Laing

Cox

Tetzlaff

et al. 2011

The Anatomical Record

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Aging causes changes in the geometry of the human cervical spine that may influence the tissue response to applied loads. Rat models are often used to study spinal cord injuries (SCI) and have the potential to enhance our understanding of the effect of age on SCI. The goal of this study was to characterize the morphometry and degenerative state of the cervical spine in Fisher 344 rats, and to determine the influence of age on these variables. Fifteen rats were split into three age groups: young adult (3 months of age), aged (12-18 months) and geriatric (30 months). Following tissue harvest we used a lCT scanner to image the cervical and upper thoracic spine from each specimen. Analysis software was used to measure variables including canal pinch diameter (the most rostral point on the dorsal aspect of a vertebral body to the most caudal aspect of the lamina on the immediately rostral vertebra), vertebral canal depth, width, and area, vertebral body height, depth, width, and area, and intervertebral disc thickness. Orthopaedic surgeons used midsagittal images to rate the degenerative state of the intervertebral discs. For all measures except disc thickness there was a significant increase (mean (SD) ¼ 15.0 (9.7)%) for the aged compared to young specimens (P < 0.05). There were significant differences between the aged and geriatric specimens for only vertebral body depth (P ¼ 0.016) and area (P ¼ 0.020). Intervertebral disc degeneration was significantly greater on the ventral aspect of the spinal column (P < 0.001), with a trend toward increased degeneration in the geriatric specimens (P ¼ 0.069). The results suggest that agerelated morphometric differences may need to be accounted for in experimental aging models of SCI in rats. Anat Rec, 294:1326Rec, 294: -1336Rec, 294: , 2011. V V C 2011 Wiley-Liss, Inc.

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“…But the pathogenesis of whiplash complaints is still poorly understood. Injury to longitudinal ligaments [5][6][7], facet joints [7,8], discs [7], spinal cord [9], or muscles [10,11] has been studied as possible sources of chronic pain. However, no detectable findings are significantly different from asymptomatic subjects, and there is no known association between structure damage and symptoms.…”

Section: Introductionmentioning

confidence: 99%

Magnetic resonance imaging signal changes of alar and transverse ligaments not correlated with whiplash-associated disorders

Shen

2012

Eur Spine J

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Purpose Hypothesis that loss of integrity of the membranes in the craniocervical junction might be the cause of neck pain in patients with whiplash-associated disorders (WADs) has been proposed. In recent years, with development of more detailed magnetic resonance imaging (MRI) techniques, morphologic changes of the ligaments and membranes in the craniocervical junction, especially alar and transverse ligaments have been discussed. A metaanalysis was performed to evaluate the relationship of MRI signal changes of alar and transverse ligaments and WADs. Methods A systematic search of EMBASE, PUBMED, and Cochrane Library and references from eligible articles were conducted. Comparative studies reporting on evaluating the relationship between MRI high-signal changes of alar and transverse ligaments and WADs were regarded eligible. A pooled estimate of effect size was produced. Results Alar ligaments: Six studies (total n = 622) were included. MRI signal changes of alar ligaments did not appear to be related with WADs (P = 0.20, OR = 1.54, 95 % CI = 0.80-2.94). Heterogeneity was present (I 2 = 46 %, P = 0.10), which was eliminated upon sensitivity analysis bringing the OR to 1.27 (95 % CI = 0.87-1.86, I 2 = 0 %). Transverse ligaments: Four studies (total n = 489) were included. MRI signal changes of transverse ligament did not appear to be related with WADs (P = 0.51, OR = 1.44, 95 % CI = 0.49-4.21). Heterogeneity was present (I 2 = 77 %, P = 0.005), which was eliminated upon sensitivity analysis bringing the OR to 0.79 (95 % CI = 0.49-1.28, I 2 = 0 %). Conclusion MRI signal changes of alar and transverse ligaments are not supposed to be caused by whiplash injury, and MRI examination of alar and transverse ligaments should not be used as the routine workup of patients with WADs.

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Spinal Canal Narrowing During Simulated Whiplash

Cited by 32 publications

References 53 publications

Cervical neural space narrowing during simulated rear crashes with anti-whiplash systems

Cervical neural space narrowing during simulated rear crashes with anti-whiplash systems

Effects of Advanced Age on the Morphometry and Degenerative State of the Cervical Spine in a Rat Model

Magnetic resonance imaging signal changes of alar and transverse ligaments not correlated with whiplash-associated disorders

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