Official Journal of the Italian Society of Orthopaedics and Traumatology
Table 1 Reported failures of the set/screw locking mechanism of TFNa in the FDA’s MAUDE database from 2015 to 2019, and the mechanism of failure in the observed cases of set screw fracture
From: Bent or broken: analysis of set screw fracture in the TFNa implant
| Â | Reported failures |
|---|---|
Total reported set screw failures in the MAUDE database | 67 |
 Reported failures with helical blade insertion | 48 |
 Reported failures with lag screw insertion | 19 |
 Failure to lock helical blade/lag screw after fully deployed | 13 |
 Lock prong obstructed helical blade/lag screw insertion | 11 |
 Fractured lock prong remained as retained foreign body | 3 |
 Damage to locking mechanism associated with non-union | 9 |
 Uncontrolled collapse and early loss of reduction | 8 |
 Medial migration of the helical blade/lag screw | 8 |
 Damage to locking mechanism associated with cut out | 4 |
Total observed cases of fractured lock prong | 4 |
 Medial migration of lag screw | 1 |
 Early loss of reduction, uncontrolled collapse | 1 |
 Fractured during removal resulting in retained foreign body | 1 |
 Non-union | 1 |