Implant Breakage of the Proximal Femoral Nail (PFN)Reasons and Case Reports

Case Reports:

In three subtrochanteric femoral fractures (AO classification 31 A.3) treated with a proximal femoral nail (PFN), the implant broke at the level of the hole for the femoral neck screw. All three PFN had been statically interlocked.

Treatment: The broken intramedullary part of the system could be removed in all cases. In two cases refixation was achieved with a dynamic hip screw (DHS) and a long plate, in one case with a 95° AO blade plate.

Reasons for Implant Breakage: Implant failure was caused by delayed fracture healing due to statistic interlocking. This could have been prevented by early dynamization. On the other hand, the implant may have failed due to excessive strain on the load-bearing element, whose load bearing limit probably had been exceeded by the fact of load transmission over a long period of time.