OBJECTIVETo evaluate the value of multi-spiral CT thinner scanning and three-dimensional and multi-planar reconstruction in the diagnosis of atlantoaxial fracture and dislocation.

METHODSSixty-nine patients suffered from atlantoaxial injuries included 54 males and 15 females with an average age of 46.5 years ranging from 17 to 73. Roentgenograph, multi-spiral CT thinner scanning, three dimensional reconstruction (3D) and multi-planar reconstruction (MPR) were applied for patients before and after surgery.

RESULTSMulti-spiral CT thinner scanning and reconstruction provided clear images for all subjects. There were 49 odontoid bone fractures (Anderson type II 35, type III 14), 9 cases combined injuries of C1 and C2 (Jeffson's fracture associated with Hangman fracture), 6 of C1 burst fractures and 5 of C2 vertebral body fractures. While only 38 cases (38/69) were correctly diagnosed according to roentgenographs, 23 missed diagnosis, 6 couldn't be diagnosed clearly and 2 misdiagnosis. The position of internal fixation could be seen clearly in CT imaging after surgery. There were two screws perforated the lateral wall of C1 and three perforated the superior wall.

CONCLUSIONThe multi-spiral CT thinner-scanning, three dimensional reconstruction (3D) and multi-planar reconstruction (MPR) provide clear imagings to diagnose the details of atlantoaxial fractures and dislocations, and to select the therapeutic regimen. It can also be used to check the position of the internal fixation after surgeries. So it can be the first eikonic choice for atlantoaxial injuries.