319 - Long-Term Serum Metal Concentrations Up to 84 Months after Surgery in...

General Session: Cervical-1

Presented by: J.K. Burkus - View Audio/Video Presentation (Members Only)

Author(s):

J.K. Burkus(1), V. Singh(2), A. Skipor(3), J. Jacobs(4)

(1) The Hughston Clinic, Spine Surgery, Columbus, GA, United States
(2) Medtronic Spinal and Biologics, Memphis, TN, United States
(3) Rush University Medical Center, Chicago, IL, United States
(4) Midwest Orthopaedics at RUSH, LLC, Chicago, IL, United States

Abstract

Purpose: Cervical disc arthroplasty (CDA) has been established as an effective motion-preserving alternative to fusion for the treatment of degenerative cervical disc disease.1 The articulating components of the CDA have a tendency to generate particulate wear debris and soluble metal ions. Our study was a prospective, longitudinal study examining the serum chromium (Cr) and nickel (Ni) concentrations in patients implanted with a stainless steel based PRESTIGE® cervical disc (Medtronic, Inc., Memphis, TN). The articulating components of this disc have ball-in-trough design.

Methods: Twenty-five patients were enrolled in the study following strict exclusion criteria (e.g., no previous permanent metal implants and no professional exposure to metal particles). Blood serum Cr and Ni concentrations were determined using high-resolution, inductively coupled, plasma-mass spectrometry preoperatively and at 3, 6, 12, 24, 36, 60, and 84 months postoperatively. The detection limit for Cr and Ni were 0.015 ng/mL and 0.17 ng/mL, respectively, and values below the detection limit were assigned a value of half the detection limit (0.008 ng/mL and 0.085 ng/mL for Cr and Ni, respectively). Longitudinal statistical comparisons were made using the Friedman test.

Results: Table shows median serum Cr and Ni concentrations before surgery and after surgery. The serum levels at all postoperative time points were statistically higher than preoperative levels for Cr (Friedman < 0.01). The median values of both Cr and Ni concentrations appeared to peak at 36 months, slightly less than 4 times the mean preoperative values. Discussion and

Conclusions: When compared with preoperative levels, higher serum Cr levels were detected at all postoperative time points. The detected serum Cr and Ni levels were order of magnitude lower than concentrations reported for the stainless-steel-based posterior instrumentation without any sign of corrosion.2 1. Gao, Y, Liu, M, Li, T, Huang, F, Tang, T, Xiang, Z. A Meta-Analysis comparing the results of cervical disc arthroplasty with anterior cervical discectomy and fusion (ACDF) for the treatment of symptomatic cervical disc disease. J Bone Joint Surg Am. 2013;95:555-61. 2. del Rio J, Beguiristain J, Duart J. Metal levels in corrosion of spinal implants. Eur Spine J 2007;16:1055-1061.