ABC SELF-LOCKING CERVICAL SCREW 4.0X16MM

Additional Manufacturer Narrative

MANUFACTURING SITE EVALUATION: INVESTIGATION ON-GOING. ADDITIONAL INFORMATION / INVESTIGATION RESULTS WILL BE PROVIDED IN A SUPPLEMENTAL REPORT.

Description of Event or Problem

IT WAS REPORTED THAT THERE WAS AN ISSUE WITH FJ933T - ABC SELF-LOCKING CERVICAL SCREW 4.0X16MM. ACCORDING TO THE COMPLAINT DESCRIPTION, THE PETALS FROM THE SCREW BROKEN REPEATEDLY. WHEN C4/5 ANTERIOR CERVICAL DISCECTOMY AND FUSION (ACDF) WAS PERFORMED, THE LOCKING PIN OF THE C5 RIGHT SIDE SCREW WAS LIFTED, SO IT WAS TAKE OUT. CHECKING THE SCREW ON THE RIGHT SIDE OF C5, SEVERAL PETALS WERE ALREADY BROKEN, AND THE REST WERE UNSTABLE.TAKE OUT THE BROKEN AND UNSTABLE PETALS FIRST, THEN REINSERT THE LOCKING PIN INTO THE SCREW AND TAKE OUT THE SCREW.SAME FOR THE SCREW ON LEFT PETALS OF C5. THE C4 HAD TWO BROKEN LEFT SCREW PETALS, BUT WAS ABLE TO TAKE OUT ANY PROBLEMS, AND WAS ABLE TO TAKE OUT THE ABC PLATE WITHOUT ANY PROBLEMS. A REVISION SURGERY WAS NECESSARY. THE ADVERSE EVENT IS FILED UNDER AAG REFERENCE (B)(4).

Additional Manufacturer Narrative

INVESTIGATION RESULTS: VISUAL INVESTIGATION: WE RECEIVED THREE DAMAGED ABC SCREWS WITH PARTIALLY BROKEN OFF PETALS AND LOOSENED FIXATION PIN / SPRING. WE MADE A VISUAL INSPECTION OF THE RECEIVED PIECES. AT FIRST, WE COUNTED THE LOOSENED PETALS, SPRINGS AND PINS. WE FOUND 10 BROKEN OFF PETALS, TWO SPRINGS AND TWO FIXATION PINS. THAN WE MADE A VISUAL INSPECTION OF EACH SCREW, HEREINAFTER CALLED "A" ; "B" AND "C". SCREW A SHOWS NO DEFECTS AT ITS THREAD. AT THE HEAD OF SCREW A FOUR OF THE FIVE PETALS AND THE LOCKING PIN AND ITS SPRING ARE MISSING. THE FRACTURE SURFACE SHOWS THE TYPICALLY SIGN OF FORCED FRACTURE. SCREW B SHOWS A PROPER THREAD, AT THE HEAD TWO OF THE FIVE PETALS ARE MISSING. THE LOCKING PIN IS STILL IN ITS POSITION, BUT THE HEXAGON IS DAMAGED/DEFORMED AT ITS UPPER FLANK. THE FRACTURE SURFACE SHOWS THE TYPICALLY SIGN OF FORCED FRACTURE. SCREW C SHOWS NO DEFECTS AT ITS THREAD. AT THE HEAD OF SCREW A FOUR OF THE FIVE PETALS AND THE LOCKING PIN AND ITS SPRING ARE MISSING. THE FRACTURE SURFACE SHOWS THE TYPICALLY SIGN OF FORCED FRACTURE. IN THE NEXT STEP WE INVESTIGATED THE TWO FALLEN OFF LOCKING PINS, HEREINAFTER CALLED PIN "A" AND PIN "B". PIN A SHOWS A HEAVILY DAMAGED/DEFORMED HEXAGON, THE HEXAGON OF PIN B IS IN A PROPER CONDITION. BATCH HISTORY REVIEW: THE DEVICE QUALITY AND MANUFACTURING HISTORY RECORDS HAVE BEEN CHECKED FOR THE AVAILABLE LOT NUMBER AND WERE FOUND TO BE ACCORDING TO OUR SPECIFICATIONS VALID AT THE TIME OF PRODUCTION. REVIEW OF THE COMPLAINT HISTORY REVEALED THAT NO SIMILAR COMPLAINTS HAVE BEEN FILED AGAINST PRODUCTS FROM THIS BATCH NUMBER. THE REVIEW OF RISK ASSESSMENT REVEALED THAT THE OVERALL RISK LEVEL (SEVERITY 6(10) X PROBABILITY 4(10) OF OCCURRENCE) ACCORDING TO DIN EN ISO 14971 IS STILL ACCEPTABLE. CONCLUSION AND MEASURES / PREVENTIVE MEASURES: THE ROOT CAUSE FOR THE DAMAGED HEXAGON IS MOST PROBABLY A NOT CORRECT / NOT FULLY INSERTED HEX KEY DURING THE SCREWING PROCESS. THE REASON FOR THE BROKEN PETALS CANNOT BE CONCLUSIVELY DETERMINED. THE SUM OF THE MISSING PETALS ON THE THREE SCREW HEADS IS 10, THE SUM OF THE ENCLOSED BROKEN OFF PARTS IS ALSO 10. TWO LOCKING PINS AND TWO SPRINGS ARE ENCLOSED SEPARATELY, IN TWO OF THE THREE SCREWS BOTH THE SPRING AND THE LOCKING PIN ARE MISSING. IT CAN THEREFORE BE ASSUMED THAT ALL BROKEN OFF PARTS OF THE SCREWS COMPLAINED ABOUT WERE REMOVED FROM THE PATIENT. BASED UPON THE INVESTIGATIONS RESULTS A CAPA IS NOT NECESSARY.