Intermediate clinical and radiological results of cervical TDR (Mobi-C®) with up to 2 years of follow-up

Abstract

The interest in cervical total disc replacement (TDR) as an alternative to the so-far gold standard in the surgical treatment of degenerative disc disease (DDD), e.g anterior cervical discectomy and fusion (ACDF), is growing very rapidly. Many authors have established the fact that ACDF may result in progressive degeneration in adjacent segments. On the contrary, but still theoretically, preservation of motion with TDR at the surgically treated level may potentially reduce the occurrence of adjacent-level degeneration (ALD). The authors report the intermediate results of an undergoing multicentre prospective study of TDR with Mobi-C prosthesis. The aim of the study was to assess the safety and efficacy of the device in the treatment of DDD and secondary to evaluate the radiological status of adjacent levels and the occurrence of ossifications, at 2-year follow-up (FU). 76 patients have performed their 2-year FU visit and have been analyzed clinically and radiologically. Clinical outcomes (NDI, VAS, SF-36) and ROM measurements were analyzed pre-operatively and at the different post-operative time-points. Complications and re-operations were also assessed. Occurrences of heterotopic ossifications (HOs) and of adjacent disc degeneration radiographic changes have been analyzed from 2-year FU X-rays. The mean NDI and VAS scores for arm and neck are reduced significantly at each post-operative time-point compared to pre-operative condition. Motion is preserved over the time at index levels (mean ROM = 9 degrees at 2 years) and 85.5% of the segments are mobile at 2 years. HOs are responsible for the fusion of 6/76 levels at 2 years. However, presence of HO does not alter the clinical outcomes. The occurrence rate of radiological signs of ALD is very low at 2 years (9.1%). There has been no subsidence, no expulsion and no sub-luxation of the implant. Finally, after 2 years, 91% of the patients assume that they would undergo the procedure again. These intermediate results of TDR with Mobi-C are very encouraging and seem to confirm the efficacy and the safety of the device. Regarding the preservation of the status of the adjacent levels, the results of this unconstrained device are encouraging, but longer FU studies are needed to prove it.

Clinical results and development of heterotopic ossification in total cervical disc replacement during a 4-year follow-up

“…The frequency of significant HO (grade III and IV) in our cohort of CTDR patients appears higher than we would expect from published series with a 2-year follow-up [3,22,23].…”

Sagittal alignment and kinematics at instrumented and adjacent levels after total disc replacement in the cervical spine

“…Concerning clinical outcomes, we noted that our results were concordant with those of most randomized studies carried out in the US [13,17,[21][22][23].…”

Cervical arthroplasty with Discover prosthesis: clinical outcomes and analysis of factors that may influence postoperative range of motion

“…We would like to suggest an increase in the area of TPS and HA layers at each endplate of the Discover disc. HO was found in ten cases of Grade I or II (18.2 %) at the last follow-up, and its incidence was obviously less than in other studies [20][21][22]. Because the contribution of sagittal balance to operative and adjacent segmental longevity is likely to be more important than preservation of ROM [15], artificial cervical Fig.…”