P21. Revision cervical disc arthroplasty without fusion: a novel “leverage” technique for artificial disc removal

Abstract

BACKGROUND CONTEXT

Cervical disc arthroplasty (CDA) is an established motion-preserving procedure for cervical degenerative disc disease. However, revision CDA is challenging and often requires fusion or posterior decompression techniques.

PURPOSE

We present a case of revision CDA performed without fusion due to previous incomplete decompression of the uncovertebral joints. This report details a novel “leverage” technique used during revision CDA, providing a comprehensive step-by-step description of the procedure. To our knowledge, this is the first report documenting the entire process of revision CDA without fusion.

STUDY DESIGN/SETTING

N/A

PATIENT SAMPLE

A 54-year-old female, with no significant medical history, underwent primary CDA at C5/6 and C6/7 for neck pain radiating to the right upper limb, attributed to herniated intervertebral discs (HIVD) at these levels. Despite the procedure, her symptoms persisted for one year. Follow-up cervical spine computed tomography (CT) revealed bilateral foraminal stenosis due to incomplete decompression of the uncovertebral joints at C5/6 and C6/7, which was the indication of revision CDA.

OUTCOME MEASURES

N/A

METHODS

The patient underwent revision CDA over C5/6 and C6/7 using the Synthes Prodisc-C Vivo prosthesis. After adequate exposure, the anterior aspect of the previously implanted artificial disc was excised using a high-speed diamond burr (Medtronic Legend® Metal Cutter MC30, 3 mm). The anterior gap was sufficiently widened to facilitate the removal of the core from its socket. Following core extraction, a Freer elevator was employed to disengage the remaining metal components using “leverage” technique, preserving the endplates for the placement of a new artificial disc after thorough decompression of the uncovertebral joints. Postoperatively, the patient experienced significant symptomatic relief while maintaining cervical motion. At the two-year follow-up, cervical spine radiographs confirmed stable prosthesis positioning without evidence of neurological deterioration, subsidence, or malalignment.

RESULTS

Standard revision strategies for failed CDA typically involve prosthesis removal followed by fusion, posterior foraminotomy, or laminectomy with fixation. In this case, we performed a revision CDA by “disrupting” the previous artificial disc rather than sacrificing the endplates, allowing for optimal preservation of bony structures. This technique minimizes bone loss and reduces the risk of postoperative subsidence. However, the applicability of the “leverage” technique depends on specific factors, including the reason for revision and the type of the previously implanted disc. This approach is particularly suited for cases involving heterotopic ossification or incomplete initial decompression. Additionally, artificial discs with minimal keel design and limited endplate preparation appear to be the most suitable candidates for this revisional technique.

CONCLUSIONS

We successfully performed a revision CDA without fusion using a novel “leverage” technique, which maximized endplate preservation and maintained cervical mobility. This approach demonstrated sustained clinical efficacy and radiographic stability over a two-year follow-up period, offering a viable alternative to fusion-based revision strategies.

FDA Device/Drug Status

Prodisc C Vivo (Approved for this indication).