[Status quo of facet joint replacement]

This review, regarding facet joint replacement, includes the presentation of six different implant systems from five US firms and one Swiss company. The implant systems are introduced for motion retaining replacement of the lumbar facet joints. Biomechanical and clinical results are included as far as they have been available from an Internet search, publications,oral and poster presentations, and from companies directly. At the beginning anatomical, biomechanical, and clinical data of the natural facet joints are presented. Basic principles of the high morbidity in that topographical region and at the same time for an artificial replacement of the facet joints are derived from the data. An implant classification and the available results of these implants are the basis for this article, which presents the actual situation of the treatment method for motion retaining replacements of facet joints, which have been in general clinical use since 2005. Clinical studies are not yet finalized and there are not enough clinical data; therefore, no binding recommendations for treatment with artificial facet joints are possible.