AARHUS SCREW
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
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.
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 |