Mechanical behaviour of two types of vertebral distractors submitted to compression-flexion tests.

The authors submitted two different types of vertebral distractors to compression-flexion tests in order to assess their biomechanical behaviour. By using special devices it was possible to simulate the load to which these methods are subjected after insertion into a tract of the spinal column. The aim was to determine the mechanical resistance and in particular, the yielding load, namely the amount of load beyond which the distractor is deformed, thus losing its initial characteristics. Our study showed that these methods of distraction possess the qualities of stability, strength and elasticity.