E1018. Eccentric Femoral Prosthesis Stem May Risk Fracture
  1. Wisam Witwit; St. Joseph Mercy Oakland Hospital
  2. Andrew Lukaszewicz; St. Joseph Mercy Oakland Hospital
  3. Harold Hayes; St. Joseph Mercy Oakland Hospital
  4. George Pappas; St. Joseph Mercy Oakland Hospital
Hip joint replacement is a very common procedure. It is indicated for displaced femoral neck fractures and advanced hip joint osteoarthrosis. Identifying an eccentrically-placed femoral prosthesis stem on postoperative radiographs is important to avoid potentially devastating complications, such as periprosthetic fracture. The risk factors like bone fragility, male gender and high activity are other important considerations.

Educational Goals / Teaching Points
1. Review the normal appearance of hip replacement on postoperative radiographs. 2. Identify the risks associated with an eccentric femoral prosthesis stem.

Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
A 60-year-old male, with recent history of right hip replacement procedure, presented to the Emergency Department two weeks after the procedure with pain and swelling in his right thigh. Radiographs of the femur demonstrated a periprosthetic fracture with significant angulation. Retrospective evaluation of the postoperative radiograph from two weeks earlier showed an eccentric prosthesis stem with associated lateral cortex thinning of the femur. There was no apparent osteopenia, history of smoking, or steroid treatment. This case illustrates the importance of identifying any significant prosthesis stem eccentricity to avoid, or at least anticipate future complications.

Hip joint prosthesis with eccentric femoral stem is a risk factor for periprosthetic fracture. Identifying this entity on the postoperative radiographs is important to anticipate future complications. The risk factors include older age, female gender, osteoporosis, trauma, and infection.