532 - Retrieval Analysis of a Titanium Ceramic Composite Cervical Total Disc...

General Session: Arthroplasty - Hall F

Presented by: R. Siskey

Author(s):

R. Siskey(1,2), L. Ciccarelli(1), S. Kurtz(1,2), V. Singh(3), J. Toth(4)

(1) Exponent, Biomedical Engineering, Philadelphia, PA, United States
(2) Drexel University, Biomedical Engineering, Philadelphia, PA, United States
(3) Medtronic, Memphis, PA, United States
(4) The Medical College of Wisconsin, Milwaukee, WI, United States

Abstract

The Prestige LP™ ("Low Profile") cervical total disc replacement (TDR) is fabricated from a titanium ceramic composite consisting of a titanium carbide (TiC) ceramic phase within a titanium alloy (Ti6Al4V) matrix. The Prestige LP was approved for single-level use by the U.S. FDA in 2014, but has been available outside the United States since 2004. In the study that compared the Prestige LP Cervical Disc to cervical fusion, the observed overall success rate of the investigational group was 78.6% compared to 62.7% for the control group at 84 months. A collection of 18 explanted Prestige LP TDRs from 18 patients, after an average implantation time of 2.1 years (1 day - 8.0 years), were subjected to retrieval analysis using ASTM F561, Standard Practice for Retrieval and Analysis of Medical Devices, and Associated Tissues and Fluids as a guide. The Prestige LP wear consists of scratching patterns localized to the articulating surfaces of the device. Based on SEM, the wear patterns were caused by microabrasion with some evidence of third body wear created when the harder TiC ceramic phase detaches from the softer titanium alloy metal matrix and articulates between the bearing surfaces. Evidence of impingement was observed in 39% (7/18) of the cases. The typical host response found in adjacent periprosthetic tissue samples is characterized as a mononuclear chronic inflammatory response. Some tissue samples showed focal metallosis but a uniform discoloration was not typically observed. The titanium ceramic composite used in the manufacture of Prestige LP is without precedent as a biomaterial to achieve a ceramic metal articulation. Although wear on the explants and wear products in periprosthetic tissues was observed, at present, no adverse local tissue reactions like those reported with CoCr bearing surfaces have been found for the Ti-TiC Prestige LP.