BEUDAMED
    FDA Adverse Event Malfunction Summary report: N

    DHS®/DCS® COUPLING SCREW

    MDR report key: 4151541 · Received October 8, 2014

    Report

    Report Number
    3003875359-2014-10303
    Event Type
    Malfunction
    Date Received
    October 8, 2014
    Date of Event
    September 6, 2014
    Report Date
    September 12, 2014
    Manufacturer
    SYNTHES HAGENDORF
    Product Code
    HWB
    PMA / PMN Number
    PEXEMPT
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    US
    Reporter Occupation
    HEALTH PROFESSIONAL

    Narratives

    Additional Manufacturer Narrative · 1

    DEVICE WAS USED FOR TREATMENT, NOT DIAGNOSIS. ADDITIONAL NARRATIVE: AN EVALUATION WAS PERFORMED ON THE RETURNED DEVICE. AS PER RECEIVED CONDITION OF DEVICE; OUTSIDE THREAD ON ONE SIDE OF THE CONNECTING SCREW BROKE OFF. OUTSIDE THREAD OF THE CONNECTION SCREW IS COMPLETELY ABRUPT. THE BROKEN PART STUCK IN THE INSIDE THREAD OF THE DYNAMIC HIP SCREW (DHS). CORE DIAMETER OF THE OUTSIDE THREAD FROM THE CONNECTING SCREW IS NO LONGER MEASURABLE. RAW MATERIAL FROM CONNECTING SCREW IS NOT HEAT TREATED. DUE TO THE MISSING THREAD FURTHER INVESTIGATION COULD NOT PERFORMED, THE INVESTIGATION WAS UNABLE TO DETERMINE THE CAUSE OF THE BREAKAGE. IF INFORMATION IS OBTAINED THAT WAS NOT AVAILABLE FOR THE INITIAL MEDWATCH, A FOLLOW-UP MEDWATCH WILL BE FILED AS APPROPRIATE.

    Additional Manufacturer Narrative · 1

    DEVICE WAS USED FOR TREATMENT, NOT DIAGNOSIS. ADDITIONAL NARRATIVE: AN EVALUATION WAS PERFORMED ON THE RETURNED DEVICE. AS PER RECEIVED CONDITION OF DEVICE; THE THREADED PART OF THE CONNECTION SCREW IS BROKEN OFF. THE CHEMICAL COMPOSITION OF THE SCREWS WAS TESTED. THE SCREWS WERE FOUND TO BE MADE OF STAINLESS STEEL AND CAN BE COMPARED WITH THE MATERIAL (B)(4). THIS STEEL USED FOR SURGICAL INSTRUMENTS IS AN AUSTENITIC STAINLESS STEEL. THE DIMENSIONS OF THE INVESTIGATED SCREWS WERE CHECKED USING A DIGITAL SLIDING CALLIPER AND FOUND TO BE IN COMPLIANCE WITH THE TECHNICAL DRAWING OF THE PRODUCER. THE THREAD DIAMETER OF THE SCREWS WAS 3.93 MM AT THE SHAFT AND THE DIAMETER OF THE CANNULATIONS WAS 2.58 MM. WHEN EXAMINING THE TWO FRACTURE SURFACES OF THE SCREWS (SCREW 1 / SCREW 2), THE INITIAL FRACTURE AREA AND THE FRACTURE BEHAVIOR WAS IDENTIFIED. IN EACH CASE, THE CRACK STARTED AT THE CIRCUMFERENCE OF THE CORE DIAMETER OF THE SCREW AND RAN INTO THE MATERIAL. AT HIGHER MAGNIFICATION, DIMPLES WERE OBSERVED AT THE CRACK PROPAGATION ZONES. SHEAR DIMPLES WERE DETECTED FOR THE REMAINING FRACTURE SURFACE OF BOTH SCREWS. THE DIRECTION OF THE SHEAR DIMPLES OF SCREW 1 INDICATE, THAT THE FAILURE OCCURRED DURING LOOSENING (COUNTERCLOCKWISE ROTATION) OF THE INSTRUMENT. ON THE OTHER HAND, THE DIRECTION OF THE SHEAR DIMPLES OF SCREW 2 SHOWED THAT THE INSTRUMENT BROKE DURING TIGHTENING (CLOCKWISE ROTATION). OBSERVATIONS AND FINDINGS SHOWED THAT THE SCREW FAILURES WERE CAUSED BY TORSIONAL OVERLOADS. BASED ON THE TOPOGRAPHY OF THE FRACTURE SURFACES, IT CAN BE CONCLUDED THAT THE SCREWS WERE SUBJECTED TO HIGH TORSIONAL LOADS. THESE TORSIONAL LOADS LED TO THE FORCED FRACTURE OF THE SCREWS. THE SCREWS COULD NOT RESIST THE APPLIED FORCE WHICH FINALLY LED TO THE MATERIAL OVERLOAD. THERE IS NO EVIDENCE OF MATERIAL OR MANUFACTURING DEFECTS. IF INFORMATION IS OBTAINED THAT WAS NOT AVAILABLE FOR THE INITIAL MEDWATCH, A FOLLOW-UP MEDWATCH WILL BE FILED AS APPROPRIATE.

    Additional Manufacturer Narrative · 1

    DEVICE IS AN INSTRUMENT AND IS NOT IMPLANTED/EXPLANTED. THE DEVICE WAS RECEIVED, THE INVESTIGATION COULD NOT BE COMPLETED, AND NO CONCLUSION COULD BE DRAWN, AS PRODUCT IS ENTERING THE COMPLAINT SYSTEM. NO NON-CONFORMANCE REPORTS WERE GENERATED DURING PRODUCTION. REVIEW OF THE DEVICE HISTORY RECORD SHOWED THAT THERE WERE NO ISSUES DURING THE MANUFACTURE OF THE PRODUCT THAT WOULD CONTRIBUTE TO THIS COMPLAINT CONDITION. DEVICE WAS USED FOR TREATMENT, NOT DIAGNOSIS. IF INFORMATION IS OBTAINED THAT WAS NOT AVAILABLE FOR THE INITIAL MEDWATCH, A FOLLOW-UP MEDWATCH WILL BE FILED AS APPROPRIATE.

    Additional Manufacturer Narrative · 1

    ADDITIONAL NARRATIVE: A PRODUCT DEVELOPMENT EVALUATION WAS COMPLETED: THE INSTRUMENTS WERE RECEIVED VISUALLY CLEAN BUT BROKEN. ACCORDING TO THE COMPLAINT REPORT THE INSERTION OF THE DYNAMIC HIP SCREW (DHS) WAS PERFORMED WITHOUT THE CENTERING SLEEVE (ARTICLE 338.320) WHEREAS THE SURGICAL TECHNIQUE GUIDE INCLUDES THE CENTERING SLEEVE. THE CENTERING SLEEVE PROVIDES MORE STABILITY BETWEEN THE WRENCH AND THE DHS SCREW AND COULD REDUCE THE RISK OF BREAKAGE OF THE CONNECTION SCREW. NEVERTHELESS, BASED ON THE PROVIDED INFORMATION, THE MATERIAL AND THE LOW OCCURRENCE RATE A DESIGN RELATED ISSUE CAN BE EXCLUDED. DEVICE WAS USED FOR TREATMENT, NOT DIAGNOSIS. IF INFORMATION IS OBTAINED THAT WAS NOT AVAILABLE FOR THE INITIAL MEDWATCH, A FOLLOW-UP MEDWATCH WILL BE FILED AS APPROPRIATE.

    Description of Event or Problem · 1

    DEVICE REPORT FROM SYNTHES (B)(4) REPORTS AN EVENT IN (B)(6) AS FOLLOWS: IT WAS REPORTED THAT THE HANDLE AND CONNECTION SCREW BROKE DURING THE INSERTION OF THE SCREW WITH THE PLATE FOR A FEMUR FRACTURE CASE. IT WAS REPORTED THAT THE BONE QUALITY OF THE PATIENT WAS GOOD. DURING THE LAST TURN OF THE HANDLE WHILE GETTING IT HORIZONTAL, THE THREADED PIN OF THE CONNECTION SCREW BROKE AND THE WHOLE THING FELL APART. THE CONNECTION SCREW WAS TAKEN OUT AND THE HANDLE WAS PUT BACK IN WITH THE PLATE IN AN ATTEMPT TO INSERT THE PLATE; HOWEVER THE ALIGNMENT WASN¿T CORRECT, SO THE SURGEON DECIDED TO REMOVE THE SCREW USING ONLY THE HANDLE (NO CONNECTION SCREW). WHILE REMOVING THE SCREW, THE HANDLE FRACTURED BETWEEN THE WELD AND ALSO THE THREAD AS WELL. THE HANDLE HAD COME APART IN A PREVIOUS CASE, BUT IT WAS ABLE TO BE PUT BACK TOGETHER THEN BECAUSE THE THREADS COULD STILL BE CONNECTED. HOWEVER, IN THIS PROCEDURE, THE WHOLE THREAD HAD BROKEN OFF AS WELL. THIS IS REPORT 1 OF 2 FOR (B)(4).

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    633492 DHS®/DCS® COUPLING SCREW EXTRACTOR HWB SYNTHES HAGENDORF 8331356

    Patients

    Seq Age Sex Outcome Treatment
    1 32 YR