213 - Replacement of Cervical Total Disc Replacement...

#213 Replacement of Cervical Total Disc Replacement

Cervical ADR

Poster Presented by: S.L. Blumenthal

Author(s):

S.L. Blumenthal (1)
D.D. Ohnmeiss (2)

(1) Texas Back Institute, Plano, TX, United States
(2) Texas Back Institute Research Foundation, Plano, TX, United States

Abstract

Introduction: Clinical outcomes of cervical total disc replacement (TDR) have consistently been found to be at least as good as anterior cervical fusion (ACF), with some evidence to support reduced adjacent segment degeneration. While the results are good, as with any surgical procedure, there are unanticipated events related to factors such as placement and sizing. The more common recommendation for treating these events is to remove the TDR and perform ACF. The purpose of this study was to review our experience with cases of cervical TDR revision or replacement with another TDR.

Methods: During a period of nine years and experience implanting more than 400 cervical TDRs, the authors encountered three cervical cases where a TDR was repositioned or replaced with another TDR. Each of these cases was reviewed in detail to determine the reason for re-operation and the clinical outcome. In each case, the option of TDR vs. anterior cervical fusion was discussed with the patient, who opted for the TDR, if possible.

Results:

Case 1.A 43-year old woman had a Bryan cervical disc implanted at C5-6 (at another clinic) with good results for about six years when she began experiencing neck and bilateral upper extremity pain and paresthesias. She did not improve with non-operative care. CT/myelography showed retrolisthesis at the TDR level. Intra-operatively, it was found that the TDR's inferior endplate was loose. This device was removed and successfully replaced with a ProDisc-C device.

Case 2.In a patient of relatively small stature, during surgery at C5-6, the smallest PCM disc was noted to be positioned a few millimeters anteriorly, although it was positioned as far posteriorly as deemed same. Converting the procedure to ACF was considered. However, the TDR fit was satisfactory and the patient had clearly communicated she wanted to receive this TDR. Ten days later, the patient's pain had increased. X-rays showed that the disc had dislodged. It was opted to replace it with a ProDisc-C, which offered a smaller footprint. Using the previous incision site, the migrated device was removed and the replacement disc implanted. Post-operatively, x-rays showed the device in proper position and mobile. The patient reported improvement in pain.

Case 3.A 58 year old male underwent TDR using a ProDisc-C device at C5-6 for left upper extremity pain. This pain was relieved, but by 6 days post-operative, he had onset of significant right upper extremity pain. Radiographs revealed that the device was off midline to the right. Revision surgery was performed through the same incision as the previous surgery. The device was removed as were posterolateral bony fragments impinging on the C6 nerve root. Bone graft was used to fill the original keel treads and new ones were cut at the midline. The ProDisc-C device was implanted and radiographs confirmed adequate positioning. The patient's C6 weakness resolved by 6-month follow-up and the patient has complete resolution of his neck and arm pain.

Discussion: Fortunately, TDR revision occurs rarely. While standard consensus is to revise such cases to a fusion, we have found cervical disc to disc revision possible, provided that there is no structural limiting factor for TDR.