BEUDAMED
    FDA Adverse Event Injury Summary report: N

    APEX MODULAR HIP STEM

    MDR report key: 929175 · Received October 16, 2007

    Report

    Report Number
    1226188-2007-00011
    Event Type
    Injury
    Date Received
    October 16, 2007
    Date of Event
    September 21, 2007
    Report Date
    October 16, 2007
    Manufacturer
    OMN LIFE SCIENCE INC
    Product Code
    KWY
    PMA / PMN Number
    K000788
    Adverse Event
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    OK, US
    Reporter Occupation
    OTHER

    Narratives

    Additional Manufacturer Narrative · 1

    OTHER DEVICES USED: CATALOG NUMBER 220410 APEX MODULAR NECK 3X16. DEVICE HISTORY RECORDS FOR THE STEM ARE INTACT AND CONFORMING AND INDICATE MANUFACTURE TO SPECIFICATION. THERE WERE FOUR PIECES AVAILABLE FOR EXAMINATION: THE TITANIUM ALLOY FEMORAL STEM, THE TITANIUM ALLOY MODULAR NECK, THE COBALT CHROME BALL HEAD (ASSEMBLED ON THE NECK), AND THE TITANIUM ALLOY NECK PLUG (ASSEMBLED IN THE NECK). THE ALIGNMENT PIN WAS FRACTURED, WITH THE DISTAL PART REMAINING IN THE STEM AND THE PROXIMAL PART REMAINING IN THE NECK. THE PROXIMAL END OF THE FEMORAL STEM SHOWED MINOR SURFACE DAMAGE SECONDARY TO SURGICAL REMOVAL OF THE STEM. THE COBALT CHROME FEMORAL HEAD SHOWED MINOR SURFACE DISCOLORATION BUT WAS OTHERWISE INTACT. THE COBALT CHROMIUM HEAD WAS FIRMLY SEATED ON THE TRUNNION OF THE NECK. THE NECK PLUG WAS FIRMLY SEATING IN THE NECK AND OTHERWISE UNREMARKABLE. THE FRACTURE SURFACE OF THE COBALT CHROMIUM PIN HAD A MOTTLED APPEARANCE (SEE ATTACHED PHOTO). THERE WERE NO INDICATIONS OF FATIGUE FRACTURE, SUCH AS ELONGATED RIDGES OR STRIATIONS. THE SUPERIOR SURFACE OF THE STEM AND INFERIOR SURFACE OF THE NECK WERE SCORED IN A CIRCULAR PATTERN, INDICATING ROTATION ABOUT THE LONGITUDINAL AXIS OF THE NECK PEG. BURNISHING OF THE NECK PEG WHERE THE PEG ENGAGED THE STEM WAS CONSISTENT WITH ROTATION OF THE NECK ON THE STEM. IN SUMMARY, THESE FINDINGS SUGGEST THAT FAILURE OCCURRED DUE TO SHEAR FRACTURE OF THE ALIGNMENT PIN, FOLLOWED BY ROTATION OF THE NECK ON TOP OF THE STEM WITH SUBSEQUENT SURFACE ABRASION AS DESCRIBED. DIMENSIONAL INSPECTION OF THE MODULAR STEM AND NECK INTERFACES WAS PRECLUDED BY ABRASIVE WEAR SECONDARY TO SHEARING OF THE LOCATING PIN. REVIEW OF THE INSPECTION RECORDS FOR THE SPECIFIC STEM AND NECK LOTS INDICATES THAT THE DIMENSIONS OF THE MODULAR NECK PEG AND MATING HOLE IN THE STEM WERE WITHIN SPEC. THE CERTIFICATE OF COMPLIANCE AND CHEMICAL COMPOSITION FOR THE COBALT CHROME ALIGNMENT PIN INDICATES CONFORMANCE TO ASTM F1537, INCLUDING YIELD STRENGTH (124 KSI), TENSILE STRENGTH (179 KSI), AND ELONGATION (21%). SEE SCANNED PAGES.

    Description of Event or Problem · 1

    LEFT POROUS FEMORAL STEM, MODULAR NECK AND HEAD REVISED 40 MONTHS AFTER PRIMARY TOTAL HIP ARTHROPLASTY.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    1 APEX MODULAR HIP STEM POROUS FEMORAL STEM KWY OMN LIFE SCIENCE INC 6X16MM STEM 271

    Patients

    Seq Age Sex Outcome Treatment
    1 61 YR Required Intervention