Abstract
Background: Type II odontoid fractures are the commonest upper cervical spine injury in the elderly, following minor falls. Structural heterogeneity within the axis with deficiency of bone mass in the base of the odontoid process has been attributed for these fractures.
Aims: To analyse whether osteoporosis at the dens-body junction is directly related to the occurrence of odontoid fractures in the elderly.
Material and Methods: We studied the reformatted CT scan images of 36 patients over the age of 70 years who had cervical spine injuries following minor trauma. In all these patients the severity of osteoporosis at the dens-body junction, and in the peg and body of axis were evaluated. The severity was graded into none, mild, moderate and severe, depending on the cortical thickness, trabecular pattern, and the size of holes (absence of trabeculae) using sagittal, coronal and transverse sections of CT scan pictures. The osteoporosis was graded into none, mild, moderate and severe. Statistical analysis was performed using Pearsons Chi-square test to find the significance of osteoporosis at the dens-body junction in producing Type II odontoid fractures in the elderly.
Results: Type II odontoid fractures was seen in 21 patients. Eleven of the 21 patients with Type II fractures and eight of the 15 patients with no Type II odontoid fractures had significant osteoporosis at the dens-body junction. Five patients with Type II fracture and eight patients with no Type II fractures had significant osteoporosis at the dens and body of axis. Statistical analysis showed that the osteoporosis at the dens-body junction was not significant in patients with Type II odontoid fracture compared to those with no Type II odontoid fracture (Chi-square value = 1.1; df = 3, p = 0.78).
Conclusions: Eventhough osteoporosis is one of the factors that increase the incidence of Type II fractures of the odontoid process in the elderly, it is not a direct aetiological factor.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
