BEUDAMED
    FDA Adverse Event Injury Summary report: N

    CD HORIZON SPINAL SYSTEM

    MDR report key: 2096969 · Received May 20, 2011

    Report

    Report Number
    1030489-2011-00588
    Event Type
    Injury
    Date Received
    May 20, 2011
    Date of Event
    March 30, 2011
    Report Date
    December 6, 2011
    Manufacturer
    MSD BARTLETT MFG
    Product Code
    KWP
    PMA / PMN Number
    UNK
    Adverse Event
    Yes
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    OR, US
    Reporter Occupation
    PHYSICIAN

    Narratives

    Additional Manufacturer Narrative · 1

    HOOKS, SCREWS, RODS. (B)(4). NEITHER THE DEVICE NOR APPLICABLE IMAGING FILMS WERE RETURNED TO THE MANUFACTURER FOR EVALUATION, THEREFORE, THE CAUSE OF THE EVENT CANNOT BE DETERMINED.

    Additional Manufacturer Narrative · 1

    MICROSCOPIC AND SEM EXAMINATION OF THE SET SCREWS, MAS, FAS, RODS, AND CROSSLINK REVEALED A SIGNIFICANT AMOUNT OF PITTING PRESENT ON THE SET SCREWS WHERE THEY INTERFACE WITH THE MAS THREADS, AS WELL AS AT THE BASE OF THE SET SCREW WHERE IT INTERFACES WITH THE ROD. THE PITTING/CORRODED LOCATIONS ARE COMPONENT INTERFACE POINTS, SPECIFICALLY THE MAS/FAS HEAD AND SET SCREW THREADS AND THE SET SCREW BOTTOM FACE AND THE SPINAL ROD. THE CORRODED AREAS SEEN UNDER SEM EXAMINATION APPEARED TO HAVE A STRIATED GRANULAR APPEARANCE WITH CUBICAL VOIDS. THESE VOIDS ARE INDICATIVE OF CHEMICAL ATTACK. THE PITTING SEEN AT THESE CONSTRUCT INTERFACE POINTS, WHEN ASSEMBLED, WOULD PROVIDE CREVICES WHICH CAN PROMOTE IN VIVO CORROSION. BOTH THE MAS HEADS AND THE SET SCREW ARE MADE FROM ASTM F2229 (BIODUR 108) STAINLESS STEEL; THE FAS IMPLANTS AND RODS ARE MADE FROM ASTM F138 STAINLESS STEEL. ONLY THE SET SCREWS WERE EXAMINED UNDER HIGH MAGNIFICATION VIA SEM, DUE TO SEM CHAMBER SIZE CONSTRAINTS. HIGHER MAGNIFICATION SEM WOULD PROVIDE ADDITIONAL INFORMATION REGARDING MICROMOTION AT THE MAS/FAS HEAD/SET SCREW AND MAS/FAS HEAD TO ROD INTERFACES, HOWEVER DUE TO SEM CHAMBER CONSTRAINTS SEM ANALYSIS COULD NOT BE COMPLETED. IN ORDER TO PERFORM SUCH AN ANALYSIS, RETURNED COMPONENTS WOULD HAVE TO BE CUT IN ORDER TO FIT INTO THE SEM SAMPLE CHAMBER. THE APPROVAL FOR ANY DESTRUCTIVE ANALYSIS WAS NOT RECEIVED. SEM MICROSCOPY IDENTIFIED CUBOIDAL PITTING /VOIDS SEEN ON MULTIPLE SET SCREW ROD INTERFACE SURFACES; SAMPLES APPEAR CONSISTENT IN LOCATION AND CORRODED SURFACE MORPHOLOGY TO CREVICE CORROSION. ADDITIONAL MICROSCOPIC EXAMINATION OF BOTH FAS AND MAS HEADS IDENTIFIED CRYSTALLOGRAPHIC PITTING IN THE ROD SADDLE / MAS HEAD, CONSISTENT IN LOCATION AND SURFACE MORPHOLOGY WITH CREVICE CORROSION. STAINLESS STEEL CORROSION RESISTANCE IS OBTAINED FROM A PASSIVE FILM WHICH FORMS IN AN OXYGEN RICH ENVIRONMENT; THE PRESENCE OF LARGE AMOUNTS OF BIOLOGICAL MATERIAL MAY HAVE GENERATED AN OXYGEN DEFICIENT REGION, RESULTING ANODIC CELL DEVELOPMENT, WHICH WOULD RESULT IN THE LOSS OF THE PASSIVE FILM AND EVENTUAL CORROSION OF THE MATERIAL. ADDITIONALLY, MICRO-MOTION OF THE COMPONENTS MAY HAVE ALSO CONTRIBUTED BY MECHANICALLY REMOVING THE PASSIVE FILM FORMED ON THE STAINLESS STEEL. BASED ON LITERATURE SEARCHES, CRYSTALLOGRAPHIC PITTING IN A CREVICE-TYPE SITUATION TENDS TO INITIATE AT THE CREVICE IN THE CENTER OF THE GRAINS, RATHER THAN AT GRAIN BOUNDARIES. THE PITS GROW, MOST LIKELY ALONG PREFERENTIAL CRYSTALLOGRAPHIC PLANES, TOWARD THE GRAIN BOUNDARIES. THE GROWTH ALONG COMMON PLANES WOULD EXPLAIN THE CONSISTENT ORIENTATION OF ADJACENT CUBICAL VOIDS. AS THESE VOIDS GROW, THE WALLS FROM ADJACENT VOIDS INTERSECT. THE RIDGES LEFT MOST LIKELY FORM THE STRIATIONS OBSERVED ON THE FIELD RETURNED COMPONENTS. NO OTHER MATERIAL SIGNS OF WEAR, CORROSION, CRACKING, FRACTURE, BREAKAGE, OR EXCESSIVE WERE IDENTIFIED. THE NATURE, LOCATION, AND CORRODED SURFACE MORPHOLOGY OF THE RETURNED IMPLANTS ARE CONSISTENT WITH ANTICIPATED IN-VIVO WEAR DUE TO CREVICE CORROSION.

    Description of Event or Problem · 1

    IT WAS REPORTED THAT THE PATIENT UNDERWENT A POSTERIOR SPINAL DEFORMITY SURGICAL PROCEDURE. IT WAS REPORTED THAT THE PATIENT DEVELOPED AN INFECTION SOME TIME POST-OP. THE PATIENT UNDERWENT A REVISION SURGERY TO HAVE THE HARDWARE REMOVED SINCE FUSION OCCURRED. THE REMOVED HARDWARE SHOWED SIGNS OF CORROSION. NO ADDITIONAL PATIENT COMPLICATIONS WERE REPORTED.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    1 CD HORIZON SPINAL SYSTEM APPLIANCE, FIXATION, SPINAL INTERLAMINAL KWP MSD BARTLETT MFG 7563430 H07B1194

    Patients

    Seq Age Sex Outcome Treatment
    1 Required Intervention RODS, SCREWS