The purpose of this study is to evaluate clinical and patient-reported outcomes at 10 years following surgery for a cohort of Mobi-C subjects treated on the IDE/Post Approval studies

This is a prospective, multi-center, consecutive cohort study. Subjects invited to participate in this study will have completed the Mobi-C IDE study (G050212). In this study, five hundred and seventy-five subjects were randomized to either the Mobi-C prosthesis or the control treatment - conventional anterior cervical discectomy and fusion (ACDF) with anterior cervical plating. The study was randomized in a 2 to 1 ratio (two Mobi-C subjects for every one subject receiving ACDF with anterior cervical plate). The subject retention rate for Mobi-C subjects was 80.1% (1 level)-84.4% (2 level) at 7 years.

As non-inferiority (1-level) and superiority (2-level) have been well established through 7 years, the design of this study will focus on the long-term outcomes of a cohort of the Mobi-C arm of the study and evaluate the durability of outcomes at 10 years. Study sites invited to participate will be those that enrolled at least 10 subjects, and also had the highest retention rates at 7 years (≥70%). All subjects at these sites will be contacted to participate in an additional 10 year follow up visit. It is estimated that up to 250 subjects will be enrolled at 9-12 study sites.

Certain endpoints are better assessed in comparison to the control ACDF arm, such as adjacent segment degeneration and subsequent surgery. This study has been amended to include a subset of sites that will also enroll control subjects. Up to 3 sites and 50 subjects will be included in this control cohort.

Inclusion Criteria:

1. Prior enrollment in LDR-001 Pivotal Study (IDE G050212);
2. Written informed consent provided by subject or subject's legally authorized representative

Exclusion Criteria:

1. Documented withdrawal of consent from prior Mobi-C study;
2. Documented non-compliance (including unwillingness to return to the site for follow-up visits)
3. Reported pregnancy at time of enrollment, or with plans to become pregnant prior to completing study X-Rays

Mobi-C and control subjects treated on the IDE/Post Approval studies, with one or two level disc replacement