BEUDAMED
    FDA Adverse Event Injury Summary report: N

    LAG SCREW

    MDR report key: 1821429 · Received August 31, 2010

    Report

    Report Number
    1020279-2010-00245
    Event Type
    Injury
    Date Received
    August 31, 2010
    Date of Event
    August 5, 2010
    Report Date
    October 12, 2010
    Manufacturer
    SMITH-NEPHEW INC.
    Product Code
    HWC
    Adverse Event
    Yes
    Report Source
    Manufacturer report
    Reporter Occupation
    OTHER

    Narratives

    Additional Manufacturer Narrative · 1

    FROM THE ANALYSES CONDUCTED DURING THIS INVESTIGATION, IT WAS CONCLUDED THAT THE INTRAMEDULLARY HIP SCREW CP LAG SCREW FRACTURED BY METAL FATIGUE CRACKING. THE CRACK PROPAGATED BY FATIGUE UNTIL THE COMPONENT COULD NO LONGER WITHSTAND THE APPLIED LOADING AND FRACTURED IN TORSION. FATIGUE CRACKING IS CAUSED BY THE LAG SCREW BEARING CYCLIC (I.E. REPEATED) STRESSES IN EXCESS OF THE MATERIAL ENDURANCE LIMIT FOR AN EXTENDED PERIOD OF TIME. THESE EXCESSIVE CYCLIC STRESSES MAY BE CAUSED BY ANY NUMBER OF CONDITIONS, INCLUDING BUT NOT LIMITED TO (I) MALPOSITIONING OF THE DEVICE, (II) EXCESSIVE PATIENT ACTIVITY LEVELS PRIOR TO FULL BONE UNION, (III) POOR BONE DENSITY, AND (IV) CHRONIC NON/UNION OR MAL/UNION OF THE BONE FRACTURE. THE FATIGUE CRACKING INITIATED AT THE FLAT REGION OF THE FRACTURE SURFACE, ADJACENT TO THE FLAT EXTERIOR SURFACE OF THE LAG SCREW. THIS SUGGESTS THAT LOADING OCCURRED WITH THE FLAT EXTERIOR SURFACE OF THE LAG SCREW ORIENTED SUPERIOR/INFERIOR. THESE FINDINGS SUGGEST THAT THE LAG SCREW WAS POSITIONED DIFFERENTLY FROM THE NORMAL POSITION. NO MATERIALS OR MANUFACTURING FLAWS WERE FOUND IN THIS INVESTIGATION.

    Description of Event or Problem · 1

    BOSTON SCIENTIFIC CRM RECEIVED INFORMATION THAT THIS PRODUCT WAS EXPLANTED DUE TO POCKET EROSION. THERE WAS NO REPORT OF ADVERSE PATIENT EFFECTS, DUE TO THE EXPLANT PROCEDURE.

    Description of Event or Problem · 1

    IT WAS REPORTED THAT A REVISION SURGERY WAS PERFORMED DUE TO A BROKEN LAG SCREW.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    1 LAG SCREW HWC SMITH-NEPHEW INC. 09AT28150

    Patients

    Seq Age Sex Outcome Treatment
    1 91 YR Hospitalization| R (B)(4)