BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    7.0MM TI MATRIX POLYAXIAL SCREW 50MM THREAD LENGTH

    MDR report key: 3041720 · Received April 8, 2013

    Report

    Report Number
    2530088-2013-10399
    Event Type
    Malfunction
    Date Received
    April 8, 2013
    Date of Event
    July 27, 2011
    Report Date
    July 27, 2011
    Manufacturer
    SYNTHES BRANDYWINE
    Product Code
    NKB
    PMA / PMN Number
    K100952
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    NC, US
    Reporter Occupation
    NURSE

    Narratives

    Additional Manufacturer Narrative · 1

    SYNTHES IS SUBMITTING THIS REPORT AS A RESULT OF REMEDIATION ACTIVITIES RELATED TO FDA WARNING LETTER DATED FEBRUARY 2012. DEVICE(S) LISTED IN THIS REPORT IS (ARE) USED FOR TREATMENT, NOT DIAGNOSIS. ANY ADDITIONAL INFORMATION RECEIVED REGARDING THIS EVENT AFTER FILING THIS REPORT SHALL BE FILED ON A SUPPLEMENTAL MDR. A REVIEW OF THE DEVICE HISTORY RECORDS WAS PERFORMED AND NO COMPLAINT RELATED ISSUES WERE FOUND. THE PRODUCT DEVELOPMENT EVALUATION REVEALED THAT THE SCORING PATTERN DISPLAYED ON THE POLY-AXIAL HEAD WAS A RESULT OF CONTACT BETWEEN THE IMPLANT AND BONY ANATOMY, AND SUBSEQUENT DRAG EXPERIENCED DURING PEDICLE SCREW INSERTION. THE DRAG IMPOSED ON THE POLY-AXIAL HEAD CAUSED THE COLLET TO REMAIN IN THE POP-OFF POSITION, ALLOWING THE HEAD TO PARTIALLY DISENGAGE THE BONE-SCREW. THE FAILURE MECHANISM DISPLAYED BY THE DAMAGED BONE-SCREW CAN ONLY BE ACHIEVED THROUGH AN APPLIED TENSILE LOAD. THE CONDITION OF THE SCREW INDICATES THAT THE ENGAGED HOLDING SLEEVE ATTACHMENT WAS PARTIALLY UNTHREADED FROM THE IMPLANT INTERFACE, AT WHICH POINT A CANTILEVER LOAD WAS APPLIED TO ASSEMBLY BY MEANS OF A DISTRACTOR RACK. THIS INCOMPLETE ENGAGEMENT ALLOWED THE CANTILEVER FORCE TO CONCENTRATE ON ONE SECTION OF THE IDENTIFIED THREADS, EXCEEDING THE DESIGNS TENSILE LIMITS. AFTER FAILURE OF THE BONE-SCREW THREADED INTERFACE, THE DISTRACTOR TIP WAS PERMITTED TO TRANSLATE AND EFFECTIVELY TRANSFER ITS CANTILEVER LOAD TO THE POLY-AXIAL HEAD AND COMPLETE THE PARTIAL DISENGAGEMENT FROM THE BONE-SCREW. UPON FAILURE, IT IS LIKELY THAT THESE EVENTS SEEMED TO TRANSPIRE SIMULTANEOUSLY. AN INTERNAL CORRECTIVE ACTION HAS BEEN OPENED TO ADDRESS THIS ISSUE. BENCH TESTING SUPPORTS THE EVALUATION, RESULTS SHOWING HEAD POP-OFF LOADS IN EXCESS OF 9,000N. AS A MATERIAL BONE IS PHYSICALLY INCAPABLE OF WITHSTANDING SUCH FORCES AND IN THIS SCENARIO WOULD HAVE FAILED MUCH EARLIER THAN THE POLY-AXIAL HEAD RETENTION MECHANISM. THE MATRIX TECHNIQUE GUIDE AS WELL AS OTHER PRODUCT SUPPORT INFORMATION FULLY ILLUSTRATES THE PROPER METHOD OF LOADING AND UNLOADING SCREWS FROM A DETACHABLE HOLDING SLEEVE. HOWEVER, SINCE THE ASSEMBLY CONFIGURATION OF THE DISTRACTOR RACK AND TIP CANNOT BE VERIFIED, THE COMPLAINT MUST BE RENDERED INDETERMINATE. THE MANUFACTURING EVALUATION SHOWED THAT THE PRODUCT WAS RECEIVED IN THE UNASSEMBLED CONDITION AND THE ID THREADS OF THE SCREW ARE SHEARED/ BROKEN FROM THE SCREW HEAD. THERE ARE MARKS IN THE STAR DRIVE NOT CONSISTENT WITH MANUFACTURING. DUE TO THE RECEIVED CONDITION OF THE PART, THE FEATURES PERTAINING TO THE AREA OF THE COMPLAINT COULD NOT BE MEASURED; THEREFORE, THE COMPLAINT IS CONSIDERED INDETERMINATE.

    Additional Manufacturer Narrative · 1

    SYNTHES IS SUBMITTING THIS REPORT AS A RESULT OF REMEDIATION ACTIVITIES RELATED TO FDA WARNING LETTER DATED FEBRUARY 2012. DEVICE(S) LISTED IN THIS REPORT IS (ARE) USED FOR TREATMENT, NOT DIAGNOSIS. ANY ADDITIONAL INFORMATION RECEIVED REGARDING THIS EVENT AFTER FILING THIS REPORT SHALL BE FILED ON A SUPPLEMENTAL MDR.(B)(4)

    Description of Event or Problem · 1

    IT WAS REPORTED THAT DURING A PROCEDURE, THE HEAD BROKE OFF OF A MATRIX SCREW USING A DISTRACTOR RACK. ANOTHER SCREW WAS USED INSTEAD AND THERE WAS NO HARM TO THE PATIENT.

    Description of Event or Problem · 1

    THIS IS REPORT 1 OF 1 FOR THIS COMPLAINT (B)(4).

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    143336 7.0MM TI MATRIX POLYAXIAL SCREW 50MM THREAD LENGTH NKB SYNTHES BRANDYWINE 6538762

    Patients

    Seq Age Sex Outcome Treatment
    1