Background: The use of intramedullary devices to treat intertrochanteric fractures continues to increase dramatically. The objective of this study was to determine the incidence and potential etiologies of iatrogenic displacement of minimally or nondisplaced intertrochanteric fractures treated with intramedullary devices and to evaluate the effect of such displacements on fracture union and complication rates.
Methods: Between 2002 and 2007, 303 patients with intertrochanteric fractures were treated with an intramedullary implant. Of these, 44 were minimally displaced (<5 mm of displacement on anteroposterior or lateral radiographs) or nondisplaced preoperatively. The average age was 71 (range, 42–94) years. There were 42 two-part (OTA 31-A1) and two three-part fractures (OTA 31-A2). All patients underwent intramedullary fixation of their intertrochanteric fractures under the supervision of fellowship trained orthopaedic trauma surgeons. Postoperative radiographs were evaluated for fracture reduction quality. Displacement was measured as a change in coronal or sagittal alignment of >5° when compared with the opposite hip, or fracture distraction of >5 mm. Clinical follow-up was available on 24 patients with a mean of 7 (range 3–18) months.
Results: Of the 44 fractures, 17 sustained an iatrogenic displacement after nailing (39%). Four patients sustained varus-producing displacements (average 6.25°; range 5–10°), and 13 sustained valgus-producing displacements (average 8.1°; range 5–10°). The valgus displacements demonstrated fracture distraction along the inferior medial calcar area, with a mean “calcar gapping” of 9.5 mm (range 6–16 mm). In the iatrogenically displaced group of 17 patients, all 10 patients with available follow-up healed uneventfully.
Conclusions: Iatrogenic displacements were common after intramedullary nailing of minimally or nondisplaced intertrochanteric fractures (39%); however, these minor displacements had no apparent effect on fracture union or complications.
Level of Evidence: Level III (Retrospective Study).