In January 2005, the oversight responsibility of the Post-Approval Studies Program was transferred to the Division of Epidemiology (DEPI) of the Office of Surveillance and Biometrics (OSB)/Center for Devices and Radiological Health (CDRH).
The CDRH Post-Approval Studies Program encompasses design, tracking, oversight, and review responsibilities for studies mandated as a condition of approval of a premarket approval (PMA) application, protocol development product (PDP) application, or humanitarian device exemption (HDE) application. The program helps ensure that well-designed post-approval studies (PAS) are conducted effectively and efficiently and in the least burdensome manner.
CDRH has established an automated, internal tracking system that efficiently identifies the reporting status of active PAS studies ordered since January 1, 2005 based on study timelines incorporated in study protocols and agreed upon by the CDRH and applicants. This system represents CDRH's effort to ensure that all PAS commitments are fulfilled in a timely manner.
In addition, CDRH launched this publicly available webpage to keep all stakeholders informed of the progress of each PAS. The webpage displays general information regarding each PAS, as well as the overall study status (based on protocol-driven timelines and the adequacy of the data) and the applicant's reporting status for each submission due.
The study population is comprised of patients who received the device during the IDE or
controls that underwent Anterior Cervical Decompression and Fusion (ACDF) during the IDE
A total of 191 coflex and 104 fusion patients comprise the sample size.
The following criteria will be used to evaluate CCS at each post year 2 follow-up
point including at year 5. These are the same as used for the two year study only modified to accommodate the longer-term follow-up. For the year 5 endpoint, these are:
Improvement of at least 15 points in the Oswestry Low Back Pain Disability Index (ODI) at 5 years compared to baseline;
No reoperations, revisions, removals, or supplemental fixation;
No major device-related complications, including but not limited to permanent new or increasing sensory or motor deficit at 5 years; and
No epidural steroid injections in the lumbar spine.
In addition to the principal endpoint of survivorship, information on the following efficacy outcomes will be assessed:
Oswestry Disability Index (ODI)
Zurich Claudication Questionnaire (ZCQ)
Leg (right, left) Pain Visual Analog Scale
(VAS) (100mm scale)
Back Pain Visual Analog Scale (VAS) (100mm scale)
Quality of Life (SF-12)
In addition, each component of the composite clinical success will be used to evaluate coflex® device performance in absolute terms and relative to fusion control, including overall device survival.
The anterior/posterior and lateral radiographs will be assessed for evidence of:
Range of motion and translation in flexion/extension, at the implanted and adjacent level(s) as measured on lateral standing flexion/extension films.
Adjacent level breakdown
Radiographic Observations: Fractures, Heterotopic Ossification, etc.
Patients with an unresolved spinous process fracture at 24 months, observed via independent radiographic assessment, will be subjected to a CT scan at 5 years to determine if the spinous process has healed, pending patient and IRB approval.
Followup Visits and Length of Followup
Patients in the long-term follow-up study will be asked to
return for follow-up evaluations annually
(± 4month) at 36,
48 months, and 60 60 months post-surgery. The follow-up evaluations will include assessment of complications, administration of the Oswestry Disability Index (ODI), Leg (right, left, max) and Back Pain
VAS, Zurich Claudication Questionnaire (ZCQ), and SF-12, and radiographic evaluation.