Complications of an Expandable Hip Nail

Abstract

Currently, the most common treatment of peritrochanteric fractures is surgical stabilization with use of either a compression hip screw or an intramedullary hip screw and early mobilization of the patient1-3. The compression hip screw provides secure fixation and controlled impaction of the fracture, but use of this device in the treatment of fractures with posteromedial comminution and subtrochanteric extension can be problematic4,5. Cephalomedullary nails combine the advantages of intramedullary fixation with those of a sliding screw. Such devices are load-sharing and offer a decreased bending strain, because the moment arm is reduced. These devices may also offer a biological advantage by combining a closed surgical technique with limited periosteal disruption6. Some of the problems encountered with intramedullary devices have been fracture propagation, difficulties with interlocking, stress mismatch, and jamming of the compression screw within the nail. If there is no sliding, the implant essentially functions as a fixed-angle device. This may result in screw migration, cutout, or failure2,7. Fig. 1 A photograph of the damage to the nail after the errant passing of the reamer. It could not be noted intraoperatively that the guide pin was anterior to the nail, and the nature of the instrumentation made it hard to tell that reaming was not progressing properly. Recently, a new device that allows a metal rod to expand inside the bone has been developed. This device is purported to provide rotational stability with use of rails that act as flutes. Because it is a thin-walled implant and is inserted at a diameter that is smaller than the medullary canal, it is also purported to be less likely to cause fracture propagation. Furthermore, it eliminates the need for screws and interlocking8. The use of this technology in …