Congenital Agenesis of the C6 Pedicle Leading to Misdiagnosis of a Traumatically Jumped Facet: A Case Report.

This case report discusses the rare issue of an atrophic cervical pedicle at the C6 level in a patient found unconscious with a jumped facet and an unknown mechanism of injury. A means to discern between traumatic jumped facets versus congenital anomalies is addressed, including missing pedicles, which is encountered at the C6 level in this case. A literature review revealed that the most common level where this occurs is at the C6 level. The structural anatomic pathologies and the variants relative to congenital facet atrophy are identified, including the location and the surrounding vasculature; more specifically, the vertebral arteries. This information is helpful to assist clinicians when discerning between a traumatic subluxation injury that requires instrumentation and reduction versus a congenital anomaly that can usually be managed conservatively.