Effect of strain rate and bone mineral on the structural properties of the human anterior longitudinal ligament.

The effect of strain rate and bone mineral content on the biomechanical properties of the human lumbar anterior longitudinal ligament-bone complex was studied. Tensile structural properties were determined for 54 such preparations subjected to distraction rates ranging from 0.1-230 mm/sec. The ultimate load as well as the stiffness of the bone-ligament complex increased more than 50% over this strain rate range. A high correlation between bone mineral and structural properties of the ligament-bone complex was also noted. These findings suggest that, in development and construction of spine models for prediction of injury risks, one should consider the effect of different loading rates as well as the inherent properties (i.e., bone mineral content) of the biological material.