腰椎疾患に於ける Ante-position 型 instabiliyty のX線学的検討

抄録

The radiological features of ante-position type instability (AP group), as defined by Knutsson, were studied in 74 cases and compared with 55 cases of degenerative spondylolisthesis (DS group), and 58 cases of lumbar disc lesion (DL group) which excluded the AP group, the DS group, Spondylolysis and Spondylolisthesis. 88% of the AP group and 94% of the DS group were female.
The age distribution was almost the same in both the AP group and the DS group and predominant in those over fifty.
Anterior slips occured at L4 level in 93% of the AP group and 67% of the DS group. Severe facet joint degeneration was more predominant in the DS group (92%) than in the AP group (81%).
The frequency of M type and W type lamina was more predomiant in the DS group (78%) than in the AP group (29%) and DL group (L4:23%), whereas the pedicle-facet angle was almost the same in both the DS group and the AP group.
In conclusion, there are several similar radiological features in both the DS group and the AP group, but there are some differences, too.
Thus, we consider the AP group to be a slight different group from the DS group.