BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    CANNULATED SCREW ASNIS III Ø4.0X46MM TL15.5MM

    MDR report key: 3070947 · Received April 22, 2013

    Report

    Report Number
    0008031020-2013-00105
    Event Type
    Malfunction
    Date Received
    April 22, 2013
    Date of Event
    February 21, 2013
    Report Date
    March 24, 2013
    Manufacturer
    STRYKER OSTEOSYNTHESIS-SELZACH
    Product Code
    HWC
    PMA / PMN Number
    K000080
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    AS
    Reporter Occupation
    PHYSICIAN

    Narratives

    Additional Manufacturer Narrative · 1

    DEVICE REMAINS IMPLANTED. IF ADDITIONAL INFORMATION BECOMES AVAILABLE IT WILL BE REPORTED ON A SUPPLEMENTAL REPORT. (B)(4): DEVICE REMAINS IMPLANTED.

    Additional Manufacturer Narrative · 1

    EVALUATION SUMMARY: PROVIDED X-RAYS PERMITTED TO CONFIRM THE EVENT THAT THE SCREW BROKE. IT CAN BE CLEARLY SEEN THAT THE CORTICAL OF THE BONE IS DENSE. A PREVIOUS SIMILAR CASE OF BROKEN THREAD OF ASNIS SCREW WAS REVIEWED ((B)(4)); A CLINICAL ASSESSMENT WAS GIVEN TO OUR CLINICAL EXPERT WHO STATED: DURING INSERTION OF THE ASNIS SCREW THE THREAD HAS TWISTED AND COME UNWOUND INTO THE SURROUNDING SOFT TISSUE. THE TIP OF THE ASNIS-SCREW IS DESIGNED AS A SELF CUTTING AND SELF- TAPPING SCREW ALLOWING FOR PASSING CANCELLOUS BONE STRUCTURE AND ITS RESPECTIVE SMALL COMPACTA. BUT, THE ASNIS SCREW IS DEFINITELY NOT DESIGNED TO PASS DENSE CORTICAL BONE STRUCTURE, AS IT IS CLEARLY VISIBLE IN THE INTRA OPERATIVE FLUOROSCOPY. ESPECIALLY, WHEN THE SCREW IS INSERTED IN AN OBLIQUE DIRECTION IN RELATIONSHIP TO THE BONE SURFACE, THERE IS A HIGH RISK THAT THE SHARP EDGES OF THE ASNIS SCREW TIP SNAG IN THE DENSE BONE RESULTING IN TWISTING OF THE THREAD. FOR SUCH A USE PRE DRILLING WITH THE CANNULATED DRILL 2.7 MM ((B)(4)) AND PRE TAPPING WITH THE CANNULATED TAP ((B)(4)) WOULD BE MANDATORY PRIOR TO INSERTING AN ASNIS SCREW 4.0 MM. EVEN WITH A TAP MADE OF HARDENED INSTRUMENT STEEL AND SPECIALLY SHARPENED CUTTING EDGES IT WOULD BE A CHALLENGE TO PASS THE DENSE CORTEX IN AN OBLIQUE DIRECTION. THEREFORE, UNDER SUCH CONDITIONS IT IS BORDERLINE PROCEDURE TO PASS THE CORTEX WITH A SIMPLE SCREW WITHOUT PRE TAPPING. THE TWISTING OF THE THREAD IN THE DENSE BONE HAS BEEN NEARLY PREDICTABLE IN THE GIVEN CASE. WITHOUT PRE TAPPING, THE SELF DRILLING/TAPPING DESIGN OF THE ASNIS SCREW IS ONLY APPLICABLE IN CANCELLOUS BONE AND IN THIN COMPACTA BUT NEVER IN DENSE SOLID CORTEX BONE." A REVIEW OF THE DEVICE HISTORY FOR THE REPORTED LOT DID NOT INDICATE ANY ABNORMALITIES. NO CORRECTIVE ACTIONS ARE REQUIRED AT THIS TIME. BASED ON PREVIOUS CLINICAL STATEMENT, THIS CASE COULD BE CLASSIFIED AS USER RELATED. INDICATIONS FOR ANY MATERIAL, MANUFACTURING OR DESIGN RELATED PROBLEMS WERE NOT DETERMINED IN THE INVESTIGATION. IF THE DEVICE IS RETURNED OR MORE DETAILED AND RELEVANT INFORMATION BECOMES AVAILABLE THE INVESTIGATION REPORT WILL BE UPDATED. DEVICE NOT RETURNED.

    Description of Event or Problem · 1

    ON X-RAY AT END OF PROCEDURE, METAL WAS NOTED TO HAVE BEEN DISLODGED OFF ASNIS SCREW.

    Description of Event or Problem · 1

    ON X-RAY AT END OF PROCEDURE, METAL WAS NOTED TO HAVE BEEN DISLODGED OFF ASNIS SCREW.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    172863 CANNULATED SCREW ASNIS III Ø4.0X46MM TL15.5MM IMPLANT HWC STRYKER OSTEOSYNTHESIS-SELZACH Z11453

    Patients

    Seq Age Sex Outcome Treatment
    1 7 YR Other