Post-Market, Long-Term Follow Up of Mobi-C® Cervical Disc for One and Two Level Treatment of Cervical Disc Disease

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