A single fracture in the atlas ring: report of two cases and a review of the literature

Lag screws for reduction of bilateral lateral mass fractures due to spinal trauma

Introduction

Bilateral fracture of the C1 lateral mass is a relatively uncommon type of traumatic lesion. Treatment of this kind of fractures is usually conservative, with either external immobilization or traction.

Research question

Whether surgical management, with placement of lag screws in lateral mass of C1, could represent a first-line treatment.

Material and methods

We describe a case of 67-years old man with bilateral fractures of lateral mass of Atlas due to road accident trauma without ligament lesion but severe gap between bone edges. We performed Computed Tomography and Magnetic Resonance scans for pre-operative imaging, X-Ray and CT scan for follow-up. Medtronic navigation system was used as intraoperative guidance for screw placement.

Results

Radiological and clinical results were good, with optimal bone reduction and patient's early return to daily activities.

Discussion and conclusion

Surgical management remains debateable for isolated C1 lateral mass fractures. Different surgical approaches have been described for atlas fractures, such as transoral anterior C1-ring plate osteosynthesis, posterior osteosynthesis with a lateral mass screw rod, and posterior C1 to C2 fusion and C0 to C2 fusion. Minimally invasive operative treatment with lag screw and reduction of fracture's edges without occiput-C1 or C1-C2 stabilization could be the optimal treatment with good result and decreasing rate of pseudoarthrosis, allowing to avoid Halo-vest discomfort and complications.

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Bilateral fracture of the C1 lateral mass is relatively uncommon type of traumatic lesion.

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When gap among fracture's edges is severe there is high rate of not fusion or pseudoarthrosis.

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Surgical reduction with bilateral lag screw, preserving C1-C2 motion and good results at follow-up imaging.

Unilateral atlanto-axial fractures in near side impact collisions: An under recognized entity in cervical trauma

Objective:

Nearside impact collisions presenting with lateral mass fractures of atlanto-axial vertebrae contralateral to the impact site represents a rare fracture pattern that does not correlate with previously described injury mechanism. We describe our clinical experience with such fractures and propose a novel description of biomechanical forces involved in this unique injury pattern. The findings serve to alert clinicians to potentially serious consequences of associated unrecognized and untreated vertebral artery injury.

Material and Methods:

In addition to describing our clinical experience with three of these fractures, a review of Crash Injury Research and Engineering Network (CIREN) database was conducted to further characterize such fractures. A descriptive analysis of three recent lateral mass fractures of the atlanto-axial segment is coupled with a review of the CIREN database. A total of 4047 collisions were screened for unilateral fractures of atlas or axis. Information was screened for side of impact and data regarding impact velocity, occupant injuries and use of restraints.

Results:

Following screening of unilateral fractures of atlas and axis for direct side impacts, 41 fractures were identified. Cross referencing these cases for occurrence contralateral to side of impact identified four such fractures. Including our recent clinical experience, seven injuries were identified: Five C1 and two C2 fractures. Velocity ranged from 14 to 43 km/h. Two associated vertebral artery injuries were identified.

Conclusions:

Complexity of the atlanto-axial complex is responsible for a sequence of events that define load application in side impacts. This study demonstrates the vulnerability of vertebral artery to injury under unique translational forces and supports the use or routine screening for vascular injury. Diminished sensitivity of plain radiography in identifying these injuries suggests that computerized tomography should be used in all patients wherein a similar pattern of injury is suspected.

Single fracture in the atlas vertebral arch: analysis of an unusual event

STUDY DESIGN

Retrospective study.

OBJECTIVE

The aim of this study is to show that a single traumatic fracture of the atlas is unusual but not rare and requires specific management strategies, which can be highlighted by the study of the junctional ligaments and membranes.

SUMMARY OF BACKGROUND DATA

A single traumatic fracture of the atlas arch is considered a rare event and has been analyzed in few case reports. Ligaments and membranes play a primary role in providing stability to the craniovertebral junction area.

METHODS

Here, we report 10 cases of a single traumatic fracture of the atlas arch: 4 cases were part of our series of spine injuries and were studied by magnetic resonance imaging during the acute phase to assess the junctional ligaments. The remaining 6 cases were obtained from the Literature.

RESULTS

Indirect signs of a traumatic ligamentous injury were found only in 1 patient. However, in all cases, these fractures were considered biomechanically stable and all patients were discharged with a rigid collar. During the follow-up, all patients reported an improvement in their neck pain and tenderness, with radiologic signs of bone healing.

CONCLUSIONS

A single fracture of the atlas arch is an unusual traumatic event that results from slow-force impact. Medical experience in treating this specific fracture subtype is nowadays poor because of the paucity of the literature; thus, this unusual condition may either be underestimated or even overstudied and overtreated. Nowadays, it seems reasonable to assume that the management should be conservative in all cases and that magnetic resonance imaging often plays only a marginal role.

Traumatic injuries to the craniovertebral junction: a review of rare events

The craniovertebral junction is a specific region of the spine with unique anatomical and biomechanical properties that yields a wide variety of injury patterns. Junctional traumatic fractures and/or dislocations are widely reported in clinical practice, but we could identify only a subgroup of upper cervical spine traumatic injuries with very few cases reported in the literature, and for this reason may be considered rare. In some of these cases, the absence of spinal biomechanical instability, in association with moderate clinical symptoms (neck stiffness and pain) and the difficulty in fracture identification through standard cervical radiographs, leads to a high percentage of missed injuries. In other cases, traumatic events have been commonly described only in autopsy series due to the high degree of spinal biomechanical instability. Herein, we have summarized all the relevant literature concerning this issue and also included our cases, with the aim of emphasizing prompt diagnosis and correct management. We provide a guide for correctly identifying "rare" craniovertebral junction traumatic injuries.

A single fracture in the ring of vertebrae below the atlas: report of four cases

A single fracture of the ring of a vertebra is a rare injury of the spine. In this report, we present five single fractures of the posterior ring of the cervical spine below the atlas from four patients after motor vehicle accidents. Initial radiographs failed to show any of these fractures; all were detected by computed tomography. Single ring fractures are stable and none of our patients presented with a neurological deficit. Patients were treated conservatively with a cervical collar or a cervicothoracic brace. They all recovered without any neurological abnormalities.