Onderzoek uit Zweden.

 

 

Hidden Cervical Spine Injuries in Traffic

Accident Victims with Skull Fractures

HalidorJonsson, Jr., Gunilla Bring, Wolfgang Rauschning, and Bo Sahlstedt

Journal of Spinal Disorders vol.4, No.3, pp251-263. 1991 Raven Press.Ltd,

NewYork

 

Summary: We studied 22 cervical spines from traffic accident victims with fatal craniocerebral injuries (19 male victims and three female victims; mean age, 26 years). Two had parietal fractures, 20 had skull base fractures (seven ring fractures),

and 16 had severe polytrauma. The spines with all soft tissues were frozen in situ and removed. Fine-focus specimen radiograms were taken in special views and evaluated by an expert orthopedic radiologist. The specimens were then

cryosectioned, and all injuries were recorded at submillimeterí intervals on high resolution film. Ten radiological fracture diagnoses were incorrect; six were false positive, and four were false negative. In the upper cervical spine, only one of 10

gross ligamentous disruptions was suspected on the radiograms. In the lower cervical spine, 198 lesions were missed on the radiograms: 77 facet joint and ligamentum flavum injuries, 77 uncovertebral, and 22 disc lesions. In two adolescents, eight cartilaginous end-plate avulsions of the discs were found. At

second-look evaluation, only four of the 245 unrecognized bone and discoligamentous lesions were detected on the radiograms. All spines were injured.

Multiple-level soft-tissue injuries were common. Key Words: Cervical spine trauma-Skull and face injuries-Forensic autopsy-Radiography-Discoligamentous lesions-Soft-tissue injuries.

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Discussion A 100% incidence of cervical spinal injuries was found in traffic accident victims with fatal craniocerebral trauma.

Most victims were killed on the site of the accident. Only five survived for a few days, and 16 had severe polytrauma. We

chose the presence of a skull fracture as a criterion for selection of the cases to ensure a reasonable impact force.

During routine autopsies, the spine is virtually never autopsied. Hematomas in the prevertebral tissues are the most common indication of an underlying spinal lesions (21). The absence of prevertebral hematomas does not preclude serious injuries,

because only four of our cases with a 9100% incidence of spine injuries had prevertebral muscle hematomas. Current autopsy techniques are likely to miss the vast majority of cervical spine injuries (21,24,28,92,102). In the upper cervical spine, even major injuries are difficult to detect, because this region is hidden under the skull base and behind the facial skeleton (20,93). In our series, the traumatic events during the accident were not sufficiently clear for a correlation of the impact with the

pathoanatomical lesions. Such studies have been conducted on larger autopsy series in which the details of the accident could be reconstructed (103). Both hyperextension and hyperflexion of the head in combination with frontal impact shearing forces can cause foramen magnum ring fractures (118). All but two of our cases with face injuries also had skull base fractures. Of the 20 skull base fractures, 17 were located in the posterior fossa and seven were classical ring fractures. In addition to the inspection, the stability of the cervical spine was tested

by a physician versed in manual examination of the spine (G.B.). None of the 10 major ruptures of virtually all ligaments at the craniovertebral junction was detected, probably due to the fractures around the foramen magnum, which rendered the skullbases grossly unstable.

Gross autopsy dissection cannot avoid distorting and destructing important topographic relationships or demonstrate smaller lesions. No systematic precision study has been conducted on in vivo traumatized cervical spines.

Even though our cases were limited to 22, the findings became repetitive and predictable halfway into the study. In an ongoing study of skull contusions without fractures, we foud more

severe injuries than in the present series. This may be due to the fact that the skull fractures absorb much of the impact energy, transmitting less force to the cervical spine. Only a few investigators hold the view that the coincidence of head trauma

and cervical spine injuries is overemphasized (77, 101).

Very few of the injuries, including potentially deleterious softtissue ruptures, were detected or even suspected on the specimen radiograms . Contrary to emergency and bedside radiography, the specimen radiograms were taken under

optimum experimental conditions. A large number of radiograms were taken in standardized views without motion artifacts or superimposition of the shoulders or the mandible. In addition, all films were assessed by a radiologist highly versed in

the evaluation of spinal trauma. The vast majority of injuries were not recognized, and the incidence of false positive findings was surprisingly high. Four facet joint fractures and two upper end-plate fractures were incorrectly diagnose on the

specimen radiograms. The transverse process fractures at C4, C5, and C6 were only detected at second look. The superior articular process fracture of C6 was not seen on any of the radiograms, including the 45° oblique experimental articular pillar views, even though the radiologist was aware of the fracture.

All radiograms were rigorously reassessed in view of the pathoanatomical lesions,

yet very few additional lesions were detected. It would seem reasonable to assume that similar injuries may be overlooked in clinical situations and that a 'negative' radiographic examination does not exclude cervical spine injuries.

Plain radiograms cannot detect soft-tissue lesions unless they are associated with vertebral body malalignment or asymmetry or with bone avulsions (59,67,70,74,79,121). In clinical

practice, it is well known that emergency plain radiograms are usually negative after a whiplash-type injury even when the clinical findings are indicative of such lesions

(1, 48, 64).

Early recognition of cervical spine injuries is essential for identifying lesions that warrant surgical intervention both to alleviate acute neurovascular compromise and to prevent late disabling sequelae (18, 45, 51, 56, 76, 90, 96, 97, 106, 119). Targeted radiographic examinations in the acute stage are necessary to avoid iatrogenic complications and to detect 'hidden' or 'occult' soft-tissue injuries. These may be

impossible to diagnose in the later course of the disease (25, 26, 49, 59, 89, 121).

Abnormal curvatures, malalignment, and disturbance in the normal pattern of motion in the injured segments on flexion-extension radiograms are indicative of soft-tissue lesions (32, 52, 80, 94).

Major fracture dislocations are not unfrequently overlooked in comatose neurotraumatized patients and iatrogenic impairment; fatalities caused by inappropriate handling of neurointensive care patients have even been reported

(16, 56, 84, 90, 119). Based on our own findings and reports in the literature, we recommend that cervical spine injuries be suspected in all patients with craniocerebral trauma until proven otherwise (4, 9, 15, 21, 28, 73, 98). A firm cervical collar should be applied when possible. In addition to plain radiograms, computed tomography should be done early because

small bone avulsions and subtle asymmetries may be the only sign of serious discoligamentous injuries (74, 80, 105).

Skull fractures are frequently associated with odontoid process and atlas fractures (103). Although patients with these fractures normally survive (56, 105), severe ligamentous ruptures in this region are almost invariably fatal (34, 84, 117). In our

material, all odontoid process fractures were associated with ruptures of the cruciate ligaments and the tectorial membrane, reflecting the severity of these injuries.

Insufficient surgical stabilization and disturbance of the blood circulation account for pseudarthroses in odontoid process fractures (95). In our type B fracture, ruptured ligaments and stripped periosteum were caught in the fracture gap. Such soft-tissue interposition is likely to cause malunion or pseudarthrosis.

The majority of patients injured in automobile accidents develop stiffness , localized neck tenderness, and not infrequently radiating pain. These symptoms may worsen over time, sometimes after an asymptomatic interval, and many of these injuries entail costly insurance litigatons (29, 35, 40, 47, 54, 60, 65, 75, 78, 110, 119, 123). A plethora of diffuse symptoms and signs from seemingly nonrelated organ systems, such as interscapular pain, occipital headache, vertigo, and prolonged symptoms, have been identified as adverse prognostic factors after cervical sprains (8, 41, 65, 75). They have been attributed to tearing of the deep muscles, and traction injuries of the accessory and the sympathetic nerves surrounding the vertebral arteries (13, 14, 30, 45, 55, 61, 67, 68, 69, 72, 81, 99, 107, 114, 121).

Most ruptures of the posterior muscle's were found in close vicinity to the facet joints. Associated facet joint injuries included hemarthroses, and distention and ruptures of the joint capsules, which usually were associated with injuries and

dislocations of the meniscoids. Such joint injuries could explain the stiffness and pain after so-called whiplash lesions. Perineural hematomas in comminuted transverse

process fractures (Fig.7) are likely to cause perineural scarring and radiculopathy.

Disc and discoligamentous lesions have been reported by many authors

(2, 3, 6, 7, 19, 22, 31, 36, 38, 43, 48, 62, 63, 71, 87, 100, 108, 109). In our material, isolated avulsions of the anulus fibrosus from the rim of the vertebral bodies and anulus ruptures extending into the substance of the discs were common in adults. One large

disc herniation in a specimen with multilevel anulus fibrosus ruptures occupied more than half of the spinal canal and compressed the spinal cord posteriorly against the

lamina (Fig.11). This rare case of a true herniated nucleus pulposus (HNP) illustrates the 'recoil' effect that the nucleus can exert on the spinal cord (27). To our surprise, we found as many as 77 uncovertebral injuries. Some of these were associated with

disc ruptures, but the majority were confined to the uncus region. To our knowledge , this lesion has not been demonstrated previously, although injuries of the uncovertebral pseudojoints have been suspected as a cause of the uncovertebral spondylosis changes that not unfrequently are observed after neck injuries. In specimens from two adolescents, we observed partial and complete separations

of the cartilaginous end-plate from the bony end-plates of the vertebral bodies, which resembled epiphysiolysis of the long bones. These occurred at multiple levels and without dislocation of the end-plates. Few illustrations in the literature show this

lesion. In deceleration experiments in monkeys, similar cervical spine distraction injuries have been produced (63, 116). Their significance has not been recognized, nor is it known if and how cartilaginous end-plate avulsions heal (6, 36, 71). In the

cervical spine, these cartilaginous end-plates fuse with the bony end plates by ossification around the age of 24 (58).

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Conclusions

1. Cervical spine injuries are common in traffic accident victims withskull fractures.

2. The majority of lesions are soft-tissue injuries.

3. Plain radiograms fail to show many fractures; they show virtually no soft-tissue lesions.

4. Uncovertebral injuries are common, both with disc ruptures and as isolated lesions.

5. Cartilaginous end-plate avulsions are typical lesions in adolescents.

6. Most cervical spine injuries are not detected during routine autopsies.