In cervical multi-level degenerative pathology, considering the morbidity of the extensive fusion techniques, some authors advocate for the multilevel disc replacement. This study compared the safety and efficacy of disc replacement with an unconstrained prosthesis in multi- versus single-level patients. A total of 231 patients with cervical degenerative disc disease (DDD) who were treated with cervical disc replacement and completed their 24 months follow-up were analyzed prospectively: 175 were treated at one level, 56 at 2 levels or more. Comparison between both groups was based on usual clinical and radiological outcomes [Neck Disability Index (NDI), Visual Analog Scale (VAS), Range of Motion, satisfaction]. Safety assessments, including complication and subsequent surgeries, were also documented and compared. Mean NDI and VAS scores for neck and arm pain were improved in both groups similarly. Improvement of mobility at treated segments was also similar. Nevertheless, in the multi-level group, analgesic use was significantly higher and occurrence of Heterotopic Ossification significantly lower than in the single-level group. Subject satisfaction was nearly equal, as 94.2% of single-level group patients would undergo the surgery again versus 94.5% in the multi-level group. The overall success rate did not differ significantly. Multi-level DDD is a challenging indication in the cervical spine. This study showed no major significant clinical difference between the two groups. We need further studies to know more about the impact of multi-level arthroplasty, especially on the adjacent segments, but these results demonstrate initial safety and effectiveness in this patient sample.

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.

Percutaneous stabilization plus balloon kyphoplasty seems to be a safe and effective technique to manage thoraco-lumbar fractures without neurological impairment.

With a high rate of proven fusion, restoration of disc height and spinal alignment in most cases, and absence of subsidence or migration, our radiological results with MC+® at more than 1 year of follow-up show the implanted device to be safe and effective for use in treating degenerative conditions of the cervical spine.

IV - Multicenter retrospective study.