OBJECTIVETo evaluate the efficacy and safety of transoral plate internal fixation for instability atlas fracture.

METHODSA retrospective study was performed in eight patients with instability atlas fractures, who were treated by a transoral plate internal fixation from July 2007 to June 2011. There were 6 males and 2 females,with an average age of 39.5 years old ranging from 23 to 48 years. Among them, 5 case were falling injury, 3 cases were traffic accident injury. Three patients had bilateral fractures of the anterior arch (prehalf Jefferson fractures, Landells type I), 5 had anterior are fracture associated posterior are fracture (Half-ring Jefferson fractures, Landells type II), and 2 had anterior and posterior are fracture associated with single lateral mass fractures (Landells type III).

RESULTSAll patients were followed up for 6 to 24 months after operation (av- eraged 13 months), and all the patients had the clinical symptoms improved to some extent. Operation time ranged from 80 to 140 min (averaged 98 min); the intra-operative blood loss was 120 to 300 ml (averaged 180 ml); and the average fluoroscopic time was 55 s. No patients happened neurological and vertebral artery injuries-related complications or other complications after operation. The followed-up X-ray and CT manifested osseous fusion in all the 8 patients,no loosening or breakage of the screws.

CONCLUSIONTransoral plate internal fixation for instability atlas fracture is a reliable and safety technique that allows maintenance of rotatory mobility in the C1,2 joint and restoration of congruency in the atlanto-occipital and atlanto-axial joints.