166 



Nachdruck verboten. 



On a Case of Fusion of the Atlas and Axis. 



By G. Elliot Smith, Cairo. 

 With 3 Figures. 



Ankylosis of adjoining vertebrae has been frequently found in 

 every region of the spinal column. But a fusion of the axis and 

 atlas not caused by disease has not hitherto been recorded, so far as 

 I am aware. In the opinion of Professor Macalister, who has de- 

 voted special attention to the study of the atlas and its variations, 

 "atlanto-axial ankylosis is always the result of disease" ^). 



Among the large collections of human skeletons, which are con- 

 stantly coming under my notice in Egypt, I have seen a very great 

 number of fused vertebrae from every region of the spinal column, 

 and in one case (an ancient Egyptian) I have met with a fused atlas 

 and axis, which not only exhibits no trace of any pathological process 



"Wy^yf 'S? 





Fig. 1. The anterior aspect of the fused atlas and axis. 



to explain the ankylosis, but is clearly an instance of developmental 

 eccentricity. Fusion of the odontoid process of the axis to the atlas, 

 of which it is morphologically the centrum, is not unknown; but in 

 all the recorded instances of this form of ankylosis the odontoid had 

 become separated from the body of the axis. 



In the case that I am now placing on record the ankylosis has 



1) A. Macalistek, Notes on the development and variations of the 

 atlas. Journ. of Anat. and Physiol, Vol. 27, 1893, p. 542. 



