Traumatic fracture-dislocation of C5 on C6 through a previously solid multilevel anterior cervical discectomy and fusion: a case report and review of the literature.

ABSTRACT

BACKGROUND CONTEXT Due to the underlying pathology and altered biomechanics, traumatic cervical fractures have been reported in patients with ankylosing spondylitis (AS), diffuse idiopathic skeletal hyperostosis (DISH), ossification of the posterior longitudinal ligament (OPLL), and combination of DISH and OPLL. However, incidence of a fracture-dislocation through a solid multilevel anterior cervical discectomy and fusion (ACDF) construct with no associated underlying pathology of AS, DISH, or OPLL but severe osteopenia has not, to the best knowledge of the authors, been reported in the medical literature. PURPOSE: To report the development of an unstable cervical spine fracture that occurred through a previous multilevel anterior cervical fusion and the challenges associated with the diagnosis and surgical management of these uncommon lesions. STUDY DESIGN/SETTING: A case report and review of the literature. METHODS: A case report entailing the clinical history, operative management, and postoperative course of a 72-year-old male patient with no known AS, DISH, or OPLL who suffered a cervical spine fracture-dislocation, secondary to a motor vehicle accident, through a previous solid three-level ACDF that was performed 20 years earlier. RESULTS: The patient underwent emergent reduction and realignment of the cervical fracture-dislocation, eventual posterior spinal fusion and stabilization with rigid segmental internal fixation, and application of external halo immobilization. At recent follow-up, he has radiographic evidence of fusion and maintenance of sagittal alignment without loss of reduction. CONCLUSIONS: Multilevel cervical fusion constructs are susceptible to traumatic injuries. Many of the same challenges in the management of the previously fused ACDF patient, who sustains a fracture-dislocation, are similar to those found in the patient with mass-inflammatory conditions or metabolic disorders, such as AS, DISH, or OPLL. In many cases, this includes severe osteopenia, long unstable fusion segments, and difficulties associated with prolonged halo vest immobilization. As a result, preoperative surgical planning should take into consideration the difficulties in achieving fracture reduction, decompression, and proper stabilization.