This Article Full Text (PDF) Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Ammann, M E Articles by Thurnher, S Search for Related Content PubMed PubMed Citation Articles by Ammann, M E Articles by Thurnher, S

Dynamic forces influencing vertebral fracture risk

Department of Radiology, University of Vienna, AKH, Wahringer Gurtel 18–20, A-1090 Vienna, Austria

This excerpt was created in the absence of an abstract.

The risk of fracture of human vertebrae in vivo in relation to densitometric data has been reported (Buchanan et al, 1987; Cullum et al, 1989). Densitometric measurements alone do not, however, correlate well with actual structural failure (McBroom et al, 1985). Compressive strength characteristics and modes of fracture of human vertebrae have been determined with single load cycles in vitro (Kazarian & Graves, 1977).

Bone, however, is subjected to mechanical fatigue. Its apparent strength is reduced by multiple load cycles as opposed to a single load cycle. Static methods do not take into account the cyclic dynamic axial loading of the lumbar spine that occurs during everyday life (Brinckmann et al, 1987). We simulated the effect of these changing forces on isolated lumbar vertebrae and on lumbar motion segments consisting of two adjacent vertebrae with the connective tissue joining them left in place (Schmorl & Junghanns, 1968). Elasticity and deformation behaviour were analysed.

Received for publication May 11, 1992. Revision received September 23, 1992. Accepted for publication November 2, 1992.