| Model Number |
47127 |
| Health Effect - Clinical Code |
No Information (3190)
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| Date of Event |
12/12/2018
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Type of Reportable Event
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Serious Injury
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Additional Manufacturer Narrative
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No evaluation possible at this time.The implants have not been returned nor has the identifying lot number been provided.Upon the receipt of additional information or the product in question, a follow-up report will be submitted.
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Event or Problem Description
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Ct images revealed migration of the set screws at the distal 4-levels of the arsenal spinal fixation construct.During the revision conducted on (b)(6) 2018, seven of eight set screws were found to be loose.All 8 screws at the distal end of the construct were removed and replaced with an alternative system.The remainder of the construct did not show any indication of an issue therefore the two systems were fastened via a rod-rod connector.The arsenal spinal fixation system was originally implanted (b)(6) 2017 in a patient with pseudo arthrosis.
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Additional Manufacturer Narrative
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There were two additional set screws reported to have been loose.They are of the same product part number but contain a separate manufacturing lot number.· 7919703 manufactured 12/20/2016 an investigation of the returned set screws showed that the threads are not deformed which indicates the set screws had not been cross threaded.However, an evaluation of the bottom set screw surface revealed unusual wear marks.The bottom surface is the surface which interacts with the rod to create a stable construct, therefore the wear pattern on this surface may be indicative of the screw performance.The expected set screw bottom surface pattern is as hour glass wear pattern resulting from a fully tightened set screw, normal to rod, with distributed loading of the rod.The explant set screws show wear marks that are unevenly distributed which indicates a non-distributed loading condition.One of the set screw showed wear marks similar to a starburst pattern which indicates partial set screw back out.This starburst pattern being indicative of non-normal loading of the rod under a dynamic loading condition.Based on these findings, the explants indicate that set screw disengagement is a result of a non-distributed loading and non-normalized rod conditions at final lockdown.
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Search Alerts/Recalls
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