**1. Introduction**

514 Recent Advances in Arthroplasty

[41] Yi S, Kim KN, Yang MS, et al. (2010) Difference in occurrence of Heterotopic

*Spine,* 35(16):1556-1561

ossification according to prosthesis type in the cervical artificial disc replacement.

Lumbar spinal arthroplasty was first reported in clinical settings more than 10 years ago by Griffith et al 1. This early experience was acquired with the first lumbar artificial disc, the CHARITÉ I, in patients with degenerative disc disease. Since that time, a randomized controlled trial comparing arthroplasty with the CHARITÉ Artificial Disc vs. anterior lumbar interbody fusion with the BAK Cage and iliac crest bone was completed. Multiple other lumbar arthroplasty devices have been developed subsequent to the CHARITÉ and are undergoing or completing clinical trials.

Unlike other spinal medical devices, lumbar discs are required by the Food and Drug Administration to complete randomized controlled trials (RCT) prior to market approval in the United States. As a result, lumbar arthroplasty devices have undergone more scrutiny and clinical evaluation than any other spinal medical devices. Specifically, a new device, the ProDisc-L, was granted FDA approval in 2006 and was described in a recent peer-review publication2. In addition, the Maverick Total Disc Arthroplasty System (Medtronic Sofamor Danek), Kineflex Lumbar Disc (SpinalMotion), and FlexiCore Intervertebral Disc (SpineCore/Stryker) lumbar discs have both completed their randomized enrollments and are currently in continued access (non-randomized) mode.

All these ongoing and completed randomized clinical trials have generated a large body of evidence on the safety and efficacy of arthroplasty for lumbar spine in clinical applications and, in many cases, in Level-1 publications.

The safety and efficacy of arthroplasty are not the only parameters discussed in the >60 clinical papers published over the last 6 years. In fact, significant insights were developed in the impact of arthroplasty on sagittal alignment and motion, possible adverse events and reoperation, as well as optimal patient selection and indication. Surgical technique and health economics papers have also been generated in an effort to fully understand the clinical and societal impact of this new technology. This review paper is aimed at providing an overview of all the existing clinical data related to spinal arthroplasty.
