[Variants of congenital fusion of the cranio-vertebral portion of the osteoarticular apparatus, adjacent cervical segments and their pathogenetic significance].

The report contains some results of a clinicoroentgenological study of 1208 individuals where in 107 (8.8%) cases there was a fusion of the cranio-vertebral area and adjacent segments. This pathology was expressed in the form of concrescence in 66 cases (61.6%) and in the form of assimilation--in 41 cases (38.3%). The fusion was mainly in the form of concrescense in the segment C2--C3 (in 62 cases). Less frequent was a fusion of the atlant with the occipital bone in the form of assimilation, (in 27 cases), concrescense (in 4 cases), and significantly less frequent a fusion of the atlant with the axis (in 3 cases in the form of assimilation, in 1 case in the form of concrescence). A fusion of the fragments of the atlant arc and axis was seen in 3 cases, a fusion of the type of the Clippel--Feil syndrome in 8 examined individuals. Concrescence irrespective of localization rarely creates a pathological neurological situation. Assimilation on the contrary was quite frequently accompanied by severe neurological disturbances and led to stable working incapacity.