Augmentation of proximal femoral nail in unstable trochanteric fractures

Biomechanically proximal femoral nail (PFN) is a better choice of implant, still it is associated with screw breakage, cut out of screw through femoral head, Z effect, reverse Z effect, and lateral migration of screws. The purpose of this study is to evaluate the results of augmented PFN in terms of prevention of postoperative complications and failure rates in unstable trochanteric fractures.

We carried out a prospective study of 82 cases with unstable trochanteric femoral fractures from April 2010 to December 2015. Forty-two females and 40 males in the age group between 58 and 81 years were included in this study. There were 45 cases of AO 31 A2 (2.2, 2.3) and 37 cases of AO 31 A3 (3.1, 3.2, 3.3). Fractures were fixed by PFN with augmentation by an additional screw from trochanter to inferior quadrant of femoral head or cerclage wire to strengthen the lateral trochanteric wall.

The bone healing is observed in all the cases in the mean period of 14.2 weeks. Nine patients developed complications, including lateral migration of neck screws (n = 5), Z effect (n = 1), infection (n = 2), and breakage of distal interlocking bolt in one case. Removal of screws was required in five cases. Patients were followed up for a mean of 8.4 months. At the end of follow-up the Salvati and Wilson hip function was 32 (out of 40) in 88% of patients.

The stabilization of lateral trochanteric wall with additional screw or cerclage wire increases the stability of construct.