The spine remains the most complex series of joints within the body, and research into the basic biomechanics and flexibility is still widespread. Multi-axial and complex simulation of spinal segments in six degrees-of-freedom is the challenge of many researchers as they attempt to understand how the spine behaves under different loading conditions.
There are many different spinal devices and spinal implants on the market and their performance and quality needs validating in a laboratory before they can be used in a clinical situation. Types of spinal device include rods, pedicle screws, hooks, plates, cages, constructs, intervertebral fusion devices, nucleus replacements, and intervertebral disc prostheses. Mechanical testing of spinal implants and testing of spinal devices is normally carried out following ASTM or ISO standards. Testing can include axial compression, torsional, flexion-extension, lateral bending, lateral shearing, and anterior-posterior shear. Examples of mechanical tests of spinal implants are found below.