Recycling of Cervical Artificial Disc for the Symptomatic Adjacent Segment Disorder Combined with Instability on Total Disc Replacement Area: A Case Report

ABSTRACT

The authors describe the revision case of a 58-year-old man who presented with pain in the neck and both shoulders after C4-5 cervical total disc replacement (C-TDR) and C5-6 anterior cervical discectomy and fusion (ACDF), and in whom there was evidence of instability with sagittal translation at the C4-5 TDR level and of a herniated cervical disc (HCD) at the left side of C3-4. The revision surgery was performed as follows previous plate removal at the C5-6 level, artificial disc removal and ACDF at the C4-5 level with cage and previous plate insertion, and TDR at the C3-4 level using the previously implanted C4/5 artificial disc. If instability develops at the level of an artificial disc, we perform additional posterior fusion or anterior removal of the artificial disc and fusion. However, if we encounter combined adjacent segment disc disease, we may reuse the unstable segment artificial disc at the adjacent segment and perform salvage anterior fusion on the unstable segment. This is the first report issued on the management of instability after previous C-TDR involving a switch to ACDF and the use of new TDR at the adjacent level. Furthermore, we conceptually recommend a solution to an emerging problem of adjacent segment disease due to the heterotopic ossification(HO) after C-TDR.