Lateral cortical notching in specific cases of delayed unions or nonunions after intertrochanteric and reversed fractures

Abstract

Background

Stabilization of both intertrochanteric and reversed trochanteric fractures is commonly performed by proximal femoral nailing. However, biomechanics significantly differ between these two fracture types.

Patients and methods

In this study we report on the occurrence of delayed union or nonunion after inter- or reversed trochanteric fractures in eight patients (7 females and 1 male).

Results

Mean age was 73.3 years (range 63–82). The interval between initial operation and first intervention ranged between 4.3 and 15.0 months (mean 8.4 months). Failure of bone healing may cause permanent strain on the implant leading to nail breakage, which we observed in three of these eight cases.

Conclusion

Dynamization is part of the general treatment concept for delayed union and nonunion after intramedullary fracture fixation. Normally it is performed by removal of interlocking screws or by occupying a ‘dynamic’ interlocking hole. We can show, however, that some types of inter- and reversed trochanteric fractures develop a characteristic kind of nonunion at the level of the lesser trochanter. This condition causes pain while walking and includes the risk of implant failure due to material fatigue. In these cases dynamization may be blocked by the cortex of the distal fragment directly contacting the prominent lag screw or its sleeve. We describe a procedure we call “lateral notching”, which is needed to make distal conventional dynamization effective and to allow for bone healing.