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| General |
| Study Status |
Completed |
Application Number /
Requirement Number |
P100012 / PAS002 |
| Date Original Protocol Accepted |
10/26/2012
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| Date Current Protocol Accepted |
02/06/2013
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| Study Name |
PCM Cervical Long Term
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| Device Name |
NUVASIVE PCM CERVICAL DISC SYSTEM
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| General Study Protocol Parameters |
| Study Design |
Randomized Clinical Trial
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| Data Source |
New Data Collection
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| Comparison Group |
Concurrent Control
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| Analysis Type |
Analytical
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| Study Population |
Adult: >21
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| Detailed Study Protocol Parameters |
| Study Objectives |
Multi-center randomized clinical trial
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| Study Population |
The study population is comprised of patients who received the device during the IDE or controls that underwent ACDF during the IDE.
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| Sample Size |
The sample size is comprised of 142 PCM cervical disc patients and
110 controls that underwent ACDF.
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| Key Study Endpoints |
The primary endpoint will be individual subject success at the 7 year visit. ¿Success¿ is defined as:
Improvement of at least 20% on the Neck Disability Index (NDI) at 7 years compared to baseline;
No device failures (at the index level) requiring revision, re-operation, removal, or supplemental fixation;
No major complications such as vascular or neurological injury;
Radiographic success
Secondary endpoints include neurological assessment, Neck and Arm Pain Visual Analog Scale, and Short-Form-36 Health Survey Questionnaire.
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| Follow-up Visits and Length of Follow-up |
7 years.
Patients will undergo follow-up assessments at 5, 6, and 7 post-operative years..
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| Interim or Final Data Summary |
| Actual Number of Patients Enrolled |
205 investigational and 172 control subjects (per protocol – withdrawals).
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| Actual Number of Sites Enrolled |
18
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| Patient Follow-up Rate |
At 84 months, the follow-up rate (for the Primary Endpoint) was 86.0% (166/193) for the investigational group and 75.0% (117/156) for the control group.
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| Final Safety Findings |
Based on the data available, the rate of implant related serious adverse events was 4.1% in the investigational group and 3.8% in the control group. The overall (84-month) rate of secondary surgical intervention (SSSI) device removals was 13.2% (for training group subjects), 7.3% (for the PCM investigational group) and 8.8% (for training and investigational groups combined). For SSSI device removals, it is unknown whether clinically acceptable fusion occurs or if fusion after PCM removal is deleteriously impacted.
For the additional individual radiographic safety endpoints (e.g., migration, radiolucency, heterotopic ossification, adjacent level degeneration), no serious safety concerns were evident, though the radiographic data availability was low (49%-73%).
A possible association between radiolucency and failure of the device (i.e., device migration) that may require a secondary surgical intervention (SSSI) cannot be ruled out based on the data available.
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| Final Effect Findings |
Based on the data available, the study met its primary objective by demonstrating that for the primary endpoint (clinical composite success defined as 20% NDI improvement, no reoperations, removals or revisions, and no major complications*), PCM is non-inferior to ACDF at 84 Months. Statistical superiority of the primary endpoint was achieved.
The primary endpoint at 84 months, using the 20% NDI definition of success, was 67.5% (112/166) for the investigational group compared to 50.8% (60/118) for the control group. The primary endpoint at 84 months, using the alternative 15-point NDI definition, was 64.53% (107/166) for the investigational group compared to 50.0% (59/118) for the control group.
These results are based on data availability rates of 87% for the PCM group and 75% for the control group at 84 months.
For additional, individual effectivness endpoints (e.g., NDI, VAS, SF36, Dysphagia, and Patient Satisfaction, time to recovery, radiographic effectiveness measures), based on the data available, the PCM group tended to reveal better performance than the control group.
However, these data are based on low data availability rates and/or highly discrepant data availability rates between PCM and control groups.
*Complications: Defined as major vessel injury, neurological damage, or nerve injury; Maintenance or improvement in all components of neurologic status; and Radiographic success (for PCM patients, defined as lack of evidence of continuous bridging bone between the adjacent endplates of the involved motion segment or >2° of segmental movement on lateral flexion/extension radiographs; for ACDF patients defined as evidence of continuous bridging bone between the adjacent endplates of the involved motion segment, radiolucent lines at =50% of the graft-vertebral interfaces, and less than or equal to 2° of segmental movement on lateral flexion/extension radiographs).
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| Study Strengths & Weaknesses |
This long term (7 year) extended follow-up study was able to demonstrate comparable safety and effectiveness outcomes (non-inferiority) between the PCM device and anterior cervical discectomy and fusion (ACDF). The study retained 91.5% of investigational subjects, and 89.6% of the control subjects from the original IDE study. The data are limited however to the subjects in the IDE study, which may not be necessarily be representative of real world use. There was a low rate of data availability for many endpoints and substantially different rates between the PCM and control group; as such, the data for additional measures (including patient satisfaction and radiographic measures) cannot be heavily interpreted. There was no requirement or prespecified methodology for investigator- performed radiographic assessments so the data regarding migration or HO as indication for SSSI may not be accurate. Also, fusion outcomes on those subjects undergoing removal SSSI were not captured during the study and so the study does not permit a conclusion regarding possible deleterious effect on fusion if performed after device removal.
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| Recommendations for Labeling Changes |
The labeling should be updated to include the long-term follow-up data generated in this Post-Approval study.
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