Introduction: Complete spinal cord lesions and quadriplegia occur in 50-84% of patients with bilateral facet dislocation. We present a patient who suffered both bilateral facet dislocation and bilateral pedicle fractures while remaining neurologically intact. Based on this case and a literature review, we hypothesize that bilateral facet dislocations without neurological deficit are accompanied by significant associated fractures that necessitate the maintenance of cervical spine canal patency.

Methods: After falling down stairs, an 86-year-old woman presented complaining of neck pain and was found to be neurologically intact on examination. Computed tomography (CT) of her neck demonstrated bilateral C5-C6 facet dislocation with corresponding bilateral C6 pedicle fractures (figures 1-2). MRI demonstrated no spinal cord compression, edema, or hemorrhage. The patient underwent a C6-C7 anterior cervical decompression and fusion and a C5-T1 anterior cervical plate with screw fixation. During the operation, the C5-C6 and C7-T1 disc spaces were observed to be auto-fused, thus eliminating the need to fuse these segments and facilitating the acquisition of a substantial moment arm length without requiring another operation. She remained neurologically intact upon follow-up.

Results: Numerous case reports have been presented with bilateral facet dislocation with significant neurological deficits in the literature, however, only three cases were found in which no neurological deficits were present. In all three of these cases, the bilateral facet dislocation was associated with significant vertebral fractures which maintained canal patency.

Conclusions: Bilateral pedicle fractures, in addition to bilateral facet dislocation, enlarge the spinal canal, which minimizes the risk of spinal cord compression and therefore neurological injury. Due to the rarity of this injury, the most appropriate surgical intervention is not evident. We believe an ACDF with plating is usually the best initial choice. This should usually be accompanied by a dorsal fixation and fusion – as was originally planned in our case.

Patient Care: Increase awareness that bilateral facet dislocations are less likely to cause devastating neurological outcomes when the injury is associated with bilateral pedicle fractures.

Learning Objectives: After reviewing this case report and review of the literature, participants should be able to: 1) Describe the importance of bilateral pedicle fractures in addition to bilateral facet dislocations to prevent devastating neurological injury and 2) Discuss, in small groups, what alternative methods could have been used for treatment.

References: 1. Hadley MN, Fitzpatrick BC, Sonntag VK, Browner CM: Facet fracture-dislocation injuries of the cervical spine. Neurosurgery 30:661-666, 1992 2. Kim SW, Ciccarelli JM, Fedder IL: Bilateral cervical facet dislocation without neurological injury. Orthopedics 27:1297-1298, 2004 3. Ivancic PC, Pearson AM, Tominaga Y, Simpson AK, Yue JJ, Panjabi MM: Mechanism of cervical spinal cord injury during bilateral facet dislocation. Spine (Phila Pa 1976) 32:2467-2473, 2007 4. Baker RP, Grubb RL, Jr.: Complete fracture-dislocation of cervical spine without permanent neurological sequelae. Case report. J Neurosurg 58:760-762, 1983 5. Razack N, Green BA, Levi AD: The management of traumatic cervical bilateral facet fracture-dislocations with unicortical anterior plates. J Spinal Disord 13:374-381, 2000 6. Song K-J, Lee K-B: Posterior Reduction/Fusion Followed by Anterior Decompression/Fusion of Unreduced Bilateral Facet Fracture-Dislocation in the Lower Cervical Trauma. Neurosurgery Quarterly 18:109-114 110.1097/WNQ.1090b1013e31815ca31816da, 200 7. Menku A, Kurtsoy A, Tucer B, Oktem IS, Akdemir H: The surgical management of traumatic C6 - C7 spondyloptosis in a patient without neurological deficits. Minim Invasive Neurosurg 47:242-244, 2004 8. Kang JD: Unilateral and bilateral facet fractures and dislocations of the subaxial spine. Current Opinion in Orthopaedics 8:33-40, 1997