Peritrochanteric fractures: choosing your weapon!

INTERTROCHANTERIC FRACTURES Approximately 50% of intertrochanteric fractures are stable and have minimal or no posteromedial comminution. The remaining 50% are unstable and have posteromedial instability and little resistance to varus deformity.1,4,5 Older rigid devices led to cutout or penetration of the nail as the fracture impacted. In the late 1960s, sliding devices were developed to allow impaction without cutout.1,6 The workhorse for intertrochanteric fractures in the new millennium is still the sliding hip screw. Intramedullary devices may also be used but these devices are most valuable in the combined intertrochanteric-subtrochanteric fracture. The single most important technical factor is proper placement of the guide pin that guides the screw into the center of the femoral head (Figure 1).3,5 On hip radiographs, the compression trabeculae and tension trabeculae that coalesce in the center of the head are clearly visualized (Figure 2).7,8 This means that no matter how osteoporotic the fracture, the best bone for placement of any screw will be at the confluence of the compression and tension trabeculae in the center of the head. That is the reason that center-head placement is critical in fixation of these fractures. The hip screw should be within 5 mm of subchondral bone to allow its deepest penetration with secure purchase in trabecular bone. In a recent study at Hennepin County Medical Center, 350 intertrochanteric fractures were evaluated and a new variant of intertrochanteric fracture was found. This variant is an intertrochanteric fracture with extension into the femoral neck region.9 This represented only 8% of intertrochanteric fractures in this series but it is the most problematic fracture, as it resulted in a 23% failure rate. Because this fracture pattern is unstable and routinely occurs in osteoporotic bone, special techniques in fixation may be necessary. A short barrel hip screw to allow impaction is essential. Bone substitutes, such as calcium phosphates and the Talon hip screw (Orthopaedic Designs Inc, St Petersburg, Fla), may be of value. This is the one intertrochanteric fracture where primary hip replacement may be used in healthy individuals. From the Department of Orthopedic Surgery, Hennepin County Medical Center, Minneapolis, Minn. Reprint requests: Richard F. Kyle, MD, Dept of Orthopedic Surgery, Hennepin County Medical Center, 701 Park Ave, Minneapolis, MN 55415. Peritrochanteric Fractures: Choosing Your Weapon!