BEUDAMED
    FDA Adverse Event Injury Summary report: N

    STEALTHSTATION S7 SYSTEM

    MDR report key: 3746820 · Received April 11, 2014

    Report

    Report Number
    1723170-2014-00374
    Event Type
    Injury
    Date Received
    April 11, 2014
    Date of Event
    November 1, 2011
    Report Date
    March 12, 2014
    Manufacturer
    MEDTRONIC NAVIGATION, INC.
    Product Code
    HAW
    PMA / PMN Number
    K050438
    Adverse Event
    Yes
    Product Problem
    Yes
    Report Source
    Manufacturer report
    Reporter Location
    CA
    Reporter Occupation
    PHYSICIAN

    Narratives

    Additional Manufacturer Narrative · 1

    THE SOFTWARE INVESTIGATION FOUND THAT THE ROOT CAUSE WAS UNABLE TO BE DETERMINED WITHOUT FURTHER INFORMATION SINCE THE ON-GOING INVESTIGATION PROVED TO BE INCONCLUSIVE BASED ON THE INFORMATION PROVIDED.

    Additional Manufacturer Narrative · 1

    NO PATIENT INFORMATION IS AVAILABLE. JOURNAL ARTICLE: GOULET, BENOIT; MOK, KELVIN; MATHEW, JACOB E. (2013). PEDICLE VIOLATION AND NAVIGATIONAL ERRORS IN PEDICLE SCREW INSERTION USING THE INTRAOPERATIVE O-ARM: A PRELIMINARY REPORT. INTERNATIONAL JOURNAL OF SPINE SURGERY (7), E88-E94. PER THE SURGEON'S ANALYSIS PROVIDED IN THE ARTICLE: ALTHOUGH NAVIGATION-GUIDED PEDICLE SCREW INSERTION IS MORE PRECISE, NO GUIDANCE SYSTEM IS 100% ACCURATE. THERE ARE MULTIPLE SOURCES OF ERROR IN IMAGE GUIDANCE SYSTEMS. THEY INCLUDE IMAGING ERRORS, REGISTRATION ERRORS, TRACKING ERRORS, DISTANCE OF NAVIGATION PROBE FROM THE DRA (DYNAMIC REFERENCE ARRAY), MOVEMENT OF THE DRA AFTER REGISTRATION, AND SURGEON ERROR. ANOTHER SOURCE OF ERROR COULD BE THE POSSIBLE TOGGLE AT THE POLYAXIAL SCREW JOINTS. HOWEVER, IN COMPARISON WITH THE PAIRED POINT REGISTRATION OR SURFACE MATCHING,OR BOTH, USING PREOPERATIVE CT SCAN, THE O-ARM ELIMINATES SURFACE MODEL REGISTRATION ERRORS AND IMAGING DATA INACCURACY OWING TO CHANGES IN POSITION OF PATIENT. THE IMAGES WERE ANALYZED BY THE PRIMARY AUTHOR AND THE SENIOR AUTHOR AND HENCE THIS MAY INTRODUCE SOME BIAS IN THE INTERPRETATION OF IMAGES. CALCULATION OF THE SAGITTAL AND AXIAL ANGLES IS NOT AN ACCURATE SCIENCE BECAUSE OF THE VARIATIONS IN ANATOMY OF THE VERTEBRAL BODIES. INTRAOBSERVER AND INTEROBSERVER ERRORS ARE POSSIBLE, AND THIS METHOD HAS NOT BEEN VALIDATED. THE NAVIGATED PEDICLE FINDER AND THE NAVIGATED SCREWDRIVER WERE NOT USED. THIS COULD HAVE CONTRIBUTED TO SOME OF THE ERRORS. THERE WAS A POSITIVE CORRELATION BETWEEN THE EXTENT OF AXIAL ERROR AND PRESENCE OF A PERFORATION. THOUGH THE L5 PEDICLE IS THE MOST ANGULATED AND HAS THE MOST MARGIN FOR ROTATIONAL ERROR, THE AUTHORS FOUND ANATOMICAL CONSTRAINT TO BE A SIGNIFICANT FACTOR FOR ERROR. THEY THEORIZE THAT THE MAJOR LIMITATION FOR OBTAINING AN L5 SCREW ANGLE CLOSE TO THE ANATOMICAL PEDICLE ANGLE IS THE CONSTRAINTS OF THE RETRACTION. THEY OBSERVED THAT L5 IS DEEPER IN THE FIELD OWING TO LORDOSIS.

    Description of Event or Problem · 1

    UPON JOURNAL ARTICLE REVIEW PERFORMED BY A MEDTRONIC NAVIGATION, INC. CLINICAL MDR/VIGILANCE EXPERT, IT WAS FOUND THAT TWENTY-SIX CONSECUTIVE PATIENTS WITH DEGENERATIVE SPONDYLOLISTHESIS UNDERWENT L4-5 INSTRUMENTED FUSION FROM (B)(6) 2011 TO (B)(6) 2012. O-ARM IMAGING AND STEALTHSTATION NAVIGATION WAS USED TO INSERT THE PEDICLE SCREWS. POSTOPERATIVE COMPUTED TOMOGRAPHY IMAGES WERE ACQUIRED AND ASSESSED FOR PEDICLE BREACH AND ANTERIOR CORTICAL PERFORATION. PLANNED TRAJECTORIES OF EACH SCREW WERE COMPARED WITH THE ACTUAL TRAJECTORIES IN THE POSTOPERATIVE IMAGES TO ASSESS NAVIGATIONAL ACCURACY IN BOTH AXIAL AND SAGITTAL PLANES. A TOTAL OF 104 SCREWS WERE INSERTED IN 26 PATIENTS. NONE OF THE PATIENTS HAD COMPLICATIONS FROM HARDWARE MISPLACEMENT. THERE WERE NO NEW POSTOPERATIVE RADICULOPATHY OR VASCULAR INJURIES. A SINGLE(1/104;1%) PEDICLE BREACH OCCURRED AT RIGHT L5 GRADE 1 (LATERAL BREACH OF 1MM). NO CLINICAL EFFECT WAS SEEN. THERE WAS A TOTAL OF 7 OF 104 (6.7%) ANTEROLATERAL PERFORATIONS (MEAN:2.2MM AND RANGE:1-4 MM). ALL THESE PERFORATIONS WERE AT THE L5 LEVEL. MOST PERFORATIONS WERE 2MM OR LESS, EXCEPT ONE CASE WHICH HAD A 4-MM PERFORATION. NONE OF THEM WAS NEAR BLOOD VESSELS OR VISCERAL ORGANS. ANTEROLATERAL PERFORATIONS ARE NOT ROUTINELY MENTIONED IN THE PEDICLE SCREW LITERATURE PRESUMABLY BECAUSE IT IS VERY RARELY ASSOCIATED WITH ANY CLINICAL EVENTS. USE OF O-ARM-GUIDED PEDICLE SCREW INSERTION WAS ASSOCIATED WITH LOW INCIDENCE OF PEDICLE BREACH(1%) AND A LOW RANGE OF NAVIGATIONAL ERROR IN BOTH SAGITTAL AND AXIAL PLANES. ANTEROLATERAL VERTEBRAL BODY PERFORATION WAS HIGHER AT L5 WITHOUT ANY NEGATIVE CLINICAL EVENTS. DESPITE THE HIGH NEED FOR TECHNICAL SUPPORT, THE AUTHORS (SURGEONS) FOUND THAT O-ARM WAS A VERY EFFICIENT TOOL FOR ACCURATE PEDICLE SCREW INSERTION.

    Devices

    Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
    221104 STEALTHSTATION S7 SYSTEM NEUROLOGICAL STEREOTAXIC INSTRUMENT HAW MEDTRONIC NAVIGATION, INC. S7

    Patients

    Seq Age Sex Outcome Treatment
    1 Other| S O-ARM 1000