Description of Event or Problem · 0
A REVISION CASE WAS PERFORMED ON L3-S1 FUSION WITH THE XVS SYSTEM. ALL 8 SCREWS WERE REMOVED PRIOR TO THE NAVIGATION. THE PATIENT WAS LEFT WITH 3 INTERBODY CAGES. DURING THE PROCEDURE START AND FOLLOWING, THE PROCEDURE SURGEON DISCUSSED MOVEMENT WITH PERC PIN SECONDARY TO THE PATIENT'S POOR BONE QUALITY. THE SURGEON NAVIGATED L3-S1 PEDICLE SCREWS DURING THE PROCEDURE. UPON COMPLETION OF NAVIGATION OF SCREWS, THE SURGEON TOOK A/P AND LATERAL X-RAY SHOTS AND NOTED L4 SCREWS WERE LOW ON A/P. THE SURGEON REVISED THE SCREWS USING FLUOROSCOPY IN THE PROCEDURE AND COMPLETED THE CASE. THE SURGEON NOTIFIED OF NEURAL DAMAGE, REFERRING TO THE PATIENT DEMONSTRATING MYELOPATHY OF L4 DERMATOMAL PATTERN AND STRENGTH THAT HAS NOT RETURNED SINCE SURGERY. NO FURTHER SIDE EFFECTS WERE SPECIFIED. TWO WEEKS FOLLOWING THIS REPORT, THE SURGEON NOTIFIED THAT THE PAIN AND WEAKNESS THE PATIENT SUFFERED FROM WERE ALL GONE AND THAT HE IS DOING MUCH BETTER. WHILE INVESTIGATING THIS CASE, 2 RELEVANT POINTS WERE RAISED: MOVEMENT OF THE PERC PIN - FROM THE PRE-OP CT IT CAN BE ASSUMED THAT THE PERC PIN WAS NOT LOCATED ON THE PSIS AS INDICATED BUT WAS LOCATED ON SACRO ILIAC JUNCTION. THE SURGEON COMPLAINED ABOUT THE MOVEMENT OF THE PERC PIN THAT MAY HAVE CAUSED FOR THE INACCURATE SCREW PLACEMENT IN LEFT AND RIGHT L4. HOWEVER, THE ORDER OF INSTRUMENTED SCREWS WAS: LEFT L3 DOWN TO S1 AND THEN RIGHT L3 DOWN TO S1. IF THE PERC PIN MOVED AT SOME POINT, THEN ALL SCREWS THAT WERE INSTRUMENTED AFTER THIS MOVEMENT SHOULD HAVE BEEN INACCURATE, WHEREAS THE SURGEON COMPLAINED ONLY ON LEFT AND RIGHT L4 INACCURATE PLACEMENT. THEREFORE, THE PERC PIN MOVEMENT AS A CAUSE FOR INACCURATE PLACEMENT WAS EXCLUDED. PATIENT BODY STRUCTURE - IN THIS REVISION CASE, ALL PREVIOUSLY INSTRUMENTED SCREWS WERE REMOVED PRIOR TO REGISTRATION. ANALYZING THE SCAN THAT WAS TAKEN BEFORE USING THE XVS FOR NAVIGATING THE SCREWS, CLEARLY DEMONSTRATES THE TRACKS OF THE REMOVED SCREWS. THE PREVIOUS SCREWS TRACK MAY GUIDE THE NEW SCREW WRONGLY. ADDITIONALLY, IT WAS NOTED BY THE SURGEON THAT THE PATIENT HAD POOR BONE QUALITY THE INVESTIGATION CONCLUDED THAT ALTHOUGH THE ROOT CAUSE CANNOT BE CONCLUDED CONCLUSIVELY, IT IS REASONABLE TO ASSUME THAT THE COMBINATION OF POOR BONE QUALITY AND TRACKS OF PREVIOUS SCREWS MAY HAVE CAUSED THE LOW PLACEMENT OF THE NEW SCREWS.