Facet Translation Analysis in the Lumbar Spine: An Application in Posterior Dynamic Stabilization

Facet articulation in the human lumbar spine has not been thoroughly characterized with regard to the effects of degeneration or surgical intervention. Kozanek et al. investigated the translation and rotation of the facets in 11 healthy adult subjects during maximal voluntary bending [1]. Li et al. used the same measurement technique on a cohort of 10 patients with degenerative disc disease (DDD) and found some significant differences in facet motion compared to a cohort of healthy patients [2]. Jegapragasan et al. investigated facet translations in intact lumbar spines in vitro and found the technique of facet translation analysis (FTA) to yield significantly different results compared to a similar analysis based on a vertebral body based coordinate system [3]. This abstract describes the application of this FTA technique in evaluating a posterior dynamic stabilization (PDS) system.