BEUDAMED
    FDA Adverse Event Injury Summary report: N

    LAG SCREW, TI GAMMA3 Ø10.5X95MM

    MDR report key: 3200846 · Received July 2, 2013

    Report

    Report Number
    0009610622-2013-00362
    Event Type
    Injury
    Date Received
    July 2, 2013
    Date of Event
    June 7, 2013
    Report Date
    June 7, 2013
    Manufacturer
    STRYKER TRAUMA KIEL
    Product Code
    HSB
    PMA / PMN Number
    K032244
    Adverse Event
    Yes
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    FL, US
    Reporter Occupation
    PHYSICIAN

    Narratives

    Additional Manufacturer Narrative · 1

    EVALUATION SUMMARY: REFERRING TO THE EVENT DESCRIPTION THE LAG SCREW WAS STATED TO BE THE PRIMARY PRODUCT. IT WAS REPORTED THAT THE LAG SCREW WAS THE ONLY IMPLANT EXCHANGED. THE NAIL STAYED IMPLANTED. INFORMATION ABOUT FURTHER ASSOCIATED DEVICES WAS NOT PROVIDED. IN THIS CASE A LATERALIZATION OF THE IMPLANT WAS REPORTED AFTER AN IMPLANTATION PERIOD OF APPROX. 12 MONTHS. EXAMINATION OF THE AFFECTED DEVICE WAS NOT POSSIBLE AS IT WAS NOT RETURNED FOR INVESTIGATION (KEPT DUE TO HOSPITAL POLICY). THE REVIEW OF THE MANUFACTURING DOCUMENTS REVEALED NO DISCREPANCIES. AS TO OUTSTANDING PRODUCT AND AS TO MISSING INFORMATION SUCH AS X-RAYS A FURTHER STATEMENT IS NOT POSSIBLE. GENERAL ASPECTS: THE BASICS OF THE GAMMA3-SYSTEM ARE THE INTERACTION OF NAIL KIT INCLUDING A SET SCREW AND THE LAG SCREW IN THE PROXIMAL AREA. THE INTENTION IS TO ALLOW THE FRACTURE SITE TO SUBSIDE (IF THE FRACTURE GAP IS TOO BIG) IN ORDER TO SUPPORT BONE UNION. THIS REQUIRES MOTION IN A RELATIVELY RIGID CONSTRUCTION AND IS SOLVED BY LATERALIZATION OF THE LAG SCREW (SEE EXCERPT FROM SURGICAL TECHNIQUE FIG. 4 ¿LAG SCREW STABILIZATION SYSTEM¿). GAMMA3 LAG SCREWS ARE DESIGNED TO TRANSFER THE LOAD OF THE FEMORAL HEAD INTO THE NAIL SHAFT BY BRIDGING THE FRACTURE LINE TO ALLOW FASTER AND MORE SECURE FRACTURE HEALING. THE SET SCREW IS DESIGNED TO FIT INTO ONE OF THE FOUR GROOVES OF THE SHAFT OF THE LAG SCREW WITH ASCENDING SHAPES AT BOTH MEDIAL AND LATERAL. THIS PREVENTS BOTH ROTATION AND COMPLETE MIGRATION OF THE LAG SCREW BUT ALLOWS SLIDING IN A LIMITED AND DEFINED RANGE. (THE SET SCREW HAS A SAFETY FEATURE ¿ A PLASTIC RING ¿ WHICH PREVENTS POTENTIAL LOOSENING DURING THE IMPLANTATION PERIOD.) THE NAIL ALLOWS SLIDING OF THE LAG SCREW FOR DYNAMIC BONE COMPRESSION AT THE FRACTURE SIGHT TO ENHANCE FRACTURE HEALING. THERE ARE SEVERAL POSSIBLE SCENARIOS THAT COULD HAVE LED TO THE REPORTED EVENT: IN ONE SCENARIO THE LAG SCREW HAD BEEN PLACED IN CORRECT POSITION, THE SET SCREW HAD ¿ INITIALLY ¿ BEEN PLACED IN THE GROUND OF THE CORRESPONDING SLIDING FLUTE. IF IN SUCH SITUATION THE SET SCREW IS UNSCREWED MORE THAN ¼ OF A TURN (AS REQUIRED IN THE OPERATION TECHNIQUE) THE INTENDED FUNCTION GETS LOST. THE SPACE BETWEEN LAG SCREW FLUTE AND TIP OF SET SCREW IS TOO BIG TO ENSURE A LIMITED, CONTROLLED SLIDING. AN UNCONTROLLED SLIDING OF THE LAG SCREW EITHER IN LATERAL OR MEDIAL DIRECTION IS THE OUTCOME. IN ANOTHER SCENARIO THE LAG SCREW HAD NOT BEEN IN THE INTENDED POSITION WHILE THE USER SCREWED THE SET SCREW DOWN. THE TIP OF THE SET SCREW LOCKED THE LAG SCREW AND HINDERED THE LAG SCREW FROM TURN FOR TEST REASONS. FOLLOWING THE INSTRUCTION OF UNSCREWING THE SET SCREW FOR ¼ OF A TURN NOW RESULTED IN NO CONTACT BETWEEN LAG SCREW AND SET SCREW. IF THE USER DOES NOT CHECK THE CORRECT LOCKING FUNCTION OF THE SET SCREW BY SLIGHT CLOCKWISE AND COUNTER-CLOCKWISE TURNING OF THE LAG SCREW ¿ WHICH IS DESCRIBED AS A MANDATORY STEP IN THE OPERATIVE TECHNIQUE ¿ THE INSUFFICIENT INSERTION OF THE SET SCREW WILL NOT BE NOTED INTRA-OPERATIVELY. CONSEQUENTLY, THE LAG SCREW WILL NEITHER BE SECURED AGAINST ROTATION NOR AGAINST CONTROLLED SLIDING. HOWEVER, IN BOTH CASES THE LAG SCREW WOULD NOT HAVE BEEN SECURED AS INTENDED. TYPICAL LOAD APPLICATION DURING THE POST IMPLANT PERIOD MAY HAVE CONTRIBUTED TO THE PROGRESS OF LAG SCREW MOTION UNDER UNCONTROLLED CONDITIONS. HOWEVER, A REAL CAUSE OF THE EVENT COULD NOT BE DETERMINED WITHOUT ANY X-RAYS OR THE AFFECTED ITEMS AVAILABLE.

    Additional Manufacturer Narrative · 1

    DEVICE WILL NOT BE RETURNED FOR EVALUATION. IF ADDITIONAL INFORMATION IS RECEIVED IT WILL BE REPORTED ON A SUPPLEMENTAL REPORT.

    Description of Event or Problem · 1

    IT WAS REPORTED THAT THE PATIENT IS COMPLAINING OF PAIN ON THE LATERAL SIDE OF THE HIP WHERE THE GAMMA NAIL PROTRUDED OUT. SURGEON REPLACED LAG SCREW WITH A SHORTER SCREW. IT WAS REPORTED THAT "95 LAG SCREW WAS TAKEN OUT AND REPLACED WITH 85 LAG SCREW."

    Description of Event or Problem · 1

    IT WAS REPORTED THAT THE PATIENT IS COMPLAINING OF PAIN ON THE LATERAL SIDE OF THE HIP WHERE THE GAMMA NAIL PROTRUDED OUT. SURGEON REPLACED LAG SCREW WITH A SHORTER SCREW. IT WAS REPORTED THAT "95 LAG SCREW WAS TAKEN OUT AND REPLACED WITH 85 LAG SCREW."

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    303207 LAG SCREW, TI GAMMA3 Ø10.5X95MM IMPLANT HSB STRYKER TRAUMA KIEL

    Patients

    Seq Age Sex Outcome Treatment
    1 68 YR Required Intervention