FDA Adverse Event Malfunction Summary report: N

AARHUS SCREW

MDR report key: 8055194 · Received November 9, 2018

Report

Report Number
8010099-2018-00003
Event Type
Malfunction
Date Received
November 9, 2018
Report Date
November 9, 2018
Manufacturer
MEDICON E.G.
Product Code
DZE
UDI-DI
04046826385484
PMA / PMN Number
K041527
Adverse Event
Yes
Product Problem
Yes
Report Source
Manufacturer report
Reporter Location
WI, US
Reporter Occupation
OTHER

Narratives

Additional Manufacturer Narrative · 1

THE SCREW WAS SUBJECT TO VISUAL AND MICROSCOPIC INSPECTION. DURING THE INSERTION PROCESS, IT HAD BROKEN AT THE SECOND THREAD CLOSE TO THE SCREW HEAD. DURING INSERTION OF A SCREW INTO BONE, THE TORSIONAL FORCE INCREASES WITH EVERY TURN. THE SCREW FRACTURED AT THE SPOT WHERE THE TORSIONAL FORCE IS TRANSLATED FROM THE TIP OF THE THREAD TO THE SHAFT. WHEN A SCREW IS OVERWOUND IT ALWAYS FRACTURES AT THIS POINT. OVERWINDING OCCURS WHEN THE TORSION FORCE PRODUCED BY THE SCREWDRIVER IS INCREASED ALTHOUGH THE SCREW CANNOT BE INSERTED ANY FURTHER. THE SCREW HAS REACHED ITS POINT OF MAXIMAL FIXATION IN THE BONE, THE USER DOES NOT RECOGNIZE THIS AND CONTINUES TURNING THE SCREW ALTHOUGH THE BONE IS TOO HARD FOR INSERTION OF THE FULL SCREW LENGTH WITHOUT PREDRILLING. TO TEST THIS SCENARIO, THREE SCREWS FROM ANOTHER BATCH WERE SUBJECT TO OVERLOAD TO DETERMINE THE TYPE OF FRACTURE CAUSED BY OVERWINDING. THE FRACTURE MODE OF THE RETURNED SCREW AND OF THE SCREWS SUBJECT TO TESTING TO FAILURE WAS SIMILAR. WE THEREFORE CONCLUDE THAT THE RETURNED SCREW BROKE DUE TO USER ERROR, I.E. BY OVERLOADING THE SCREW DURING INSERTION.

Description of Event or Problem · 1

THE ORTHODONTIC SCREW BROKE AS IT WAS BEING INSERTED INTO THE PATIENT'S JAW. THE BROKEN PIECE WAS REMOVED IMMEDIATELY. NO HARM TO PATIENT.

Devices

Seq Brand Generic Product Code Manufacturer Model Lot UDI-DI
895846 AARHUS SCREW ORTHODONTIC SCREW DZE MEDICON E.G. 094410/180915 04046826385484

Patients

Seq Age Sex Outcome Treatment
1 Required Intervention