Accessory articulation of the cervical vertebrae transverse processes simulating a fracture: Incidental findings of an uncommon anatomical variant.

Accessory articulation of the transverse processes of the cervical vertebrae is an extremely rare congenital anomaly. We present two cases of accessory articulation of the transverse processes of the left C5/C6 and C6/C7 cervical vertebrae. The articulation at C5/C6 was found in a 34-year-old male following a mob assault, the C6/C7 accessory articulation occurred in a 28-year-old female involved in a high velocity motor-vehicle accident. Cervical spine fractures were suspected in both cases. Recognition of this variant anatomy and differentiation from a fracture is important especially in an acute trauma setting to prevent unnecessary immobilization and inappropriate specialist referral of these patients. Our search revealed only five previously reported cases in the literature mostly occurring at the C5/C6 level. This is only the second case ever described at the C6/C7 level.