The Functional Positions The Atlantoaxial Relative Rotation Angle Of The Ct Study

[Abstract] Objective To investigate the change of the relative rotation angle of ci on c2 in the functional position using CT. Normal groups and atlantoaxial rotatory fixation(AARF) groups were Compared and analysed.In order to help dignosis of the AARF. Methods 82 normal subjects and 18 Cases of AARF were examined in neutral position, then scanned the head orating 20 to 25 the right or left respectively with CT. The relative rotatio angle of C 1 on C2 in the functional position were measwred, the changes of ADI and Lads were compared as well. Result S There were differences in the relative. Rotation angle of ci on c2 of different age in normal groups. There was statistical significence betweer the case of less 40 years old and be youd 40years old. Compared ARRF groups with all of different age normal groups, there were strongly differences. There were statistical significance in the change of ADI and no significance in the Change of the LADS between ormal groups and AARF groups. Conlusions Mearsuring and Analysing the relative rotation angle of ci on c2 in functional position by CT,and the change of ADI it would be helpful for the diagnosis of ARRF.