Posterior Lumbar Facet Replacement and Arthroplasty.

There is an ongoing desire for the development of motion-preserving facet replacement devices as an alternative to rigid fixation in hopes of better preserving the natural kinematics of the lumbar spine. Theoretically, such a construct would simultaneously address pain associated with spinal instability and prevent abnormal load distribution and adjacent segment degeneration. Several such devices have been developed including the Anatomic Facet Replacement System, the Total Facet Arthroplasty System, and the Total Posterior Arthroplasty System. Of these devices, none have yet proven to be more efficacious than rigid fixation for lumbar spinal stenosis, and studies are ongoing.