Description of Event or Problem · 0
IN THIS CASE, THE FELLOW PLACED 2 SCREWS ON THE LEFT L4&L5, PERCUTANEOUSLY. WHEN THE RESIDENT BEGAN RIGHT SIDE, HE REPORTED HIS HEADSET SCREEN WAS BLANK, AM TROUBLESHOOT AND THEN OPTED TO SWITCH TO A DIFFERENT HEADSET. THE RESIDENT STARTED TO LANDMARK CHECK THE RIGHT SIDE. AM, FELLOW, AND RESIDENT ALL NOTED THAT THE BURR APPEARED TO BE IN THE PEDICLE WHEN IT SHOULD HAVE BEEN ON THE NEAR CORTEX. AM SUGGESTED ABORTING THE NAVIGATION TO RE-SPIN. FLUORO WAS POSITIONED AND UPON TAKING A/P AND LATERAL SHOTS IT WAS NOTED THAT THE LEFT L4&L5 SCREWS WERE INACCURATE AND IN THE DISC SPACE. LEFT L4&L5 SCREWS WERE REMOVED AND PLACED UNDER FLUORO. NEUROMONITORING REPORTED NO CHANGE IN SIGNAL. UPON REVIEWING THE SCAN, AM NOTED THAT THE PIN WAS PLACED IN THE SACRUM, NOT PSIS. THE PATIENT ALSO HAS A HIGH BMI WITH POSTERIOR TISSUE THICKNESS AND SKINFOLDS. XLINK WAS PLACED OVER A SKIN FOLD. THE RESIDENT AND FELLOW MAY HAVE EXPERIENCED TISSUE DRIFT FROM THE PATIENT. THE PROBABLE CAUSE FOR THE INACCURACY WAS EITHER A PLATFORM SHIFT AFTER REGISTRATION OR A MOVEMENT OF THE PATIENT MARKER OR X MARKER DURING THE REGISTRATION PROCESS. THIS EVENT SEEMS TO BE CAUSED BY A USER ERROR, RELATED TO PERFORMING A LANDMARK CHECK AT THE SKIN LEVEL, WHICH DIDN'T ENABLE DETECTING THE MOVEMENT OF THE REFERENCE FRAME FOLLOWING REGISTRATION. HOWEVER, SINCE THE INVESTIGATION TEAM CANNOT BE CERTAIN THAT A USER ERROR IS THE ROOT CAUSE, AND DUE TO THE FACT THAT SCREWS WERE REDIRECTED, IT WAS DECIDED TO REPORT THIS EVENT.