OTA 2012 Posters

Scientific Poster #22 Hip/Femur OTA-2012

Fate of Hip Stems After Operative Fixation of Periprosthetic Femoral Shaft Fractures

Mark J. Jo, MD; Jacob X. Didesch, MD; David S. Merriman;
Christopher M. McAndrew; Michael J. Gardner, MD; William M. Ricci, MD;
Washington University School of Medicine, Saint Louis, Missouri, USA

Purpose: The effect of periprosthetic fracture on the survivorship of hip arthroplasty stems is unknown. The objective of this study was to evaluate the long-term outcomes of patients who sustained a fracture about a hip arthroplasty stem and were treated with open reduction and internal fixation (ORIF). The focus was on revision rates of the femoral stem. Our null hypothesis was that a periprosthetic fracture about a femoral stem treated with ORIF would not lead to the need for revision arthroplasty.

Methods: 86 consecutive patients who underwent operative fixation following a periprosthetic fracture of the femoral shaft about a hip arthroplasty stem between 1998 and 2010 were studied retrospectively. Patients were excluded if they had previous surgery for infection, if their immediate postoperative course was complicated by infection, if the fracture was iatrogenic during their arthroplasty procedure, or if the stem was found to be loose at the time of fracture treatment and was treated with revision arthroplasty. 22 patients (average age at the time of injury 71.7 years; range, 23.6-95.5) with greater than 1-year follow-up (average 4.2 years; range, 1.2-9.7) remained after applying exclusion criteria. Of the 22 patients, 20 had fractures about a total hip arthroplasty and 2 were about a hemiarthroplasty. 13 patients had a press-fit stem and 9 were cemented. Using the Vancouver classification, there were 15 B1 and 7 C type fractures. 21 patients had a fracture about after a primary arthroplasty and one after a revision. All other patients were treated with a plate, screw, and cable construct and five patients also had bone grafts. All of these five cases included a strut allograft, cancellous allograft was added to one case, and one case added both cancellous allograft and bone morphogenetic protein–2 (BMP-2). Patients or their families were interviewed to obtain information regarding outcomes, complications, and subsequent surgical procedures relevant to their periprosthetic fractures.

Results: The average lifespan of the hip stems at the time of fracture was 8.6 years. Of the 22 patients, 20 patients’ fractures healed following the initial ORIF procedure. One patient had failure of fixation and was treated nonoperatively to union; one patient did not heal the fracture after three attempts and was treated with a proximal femoral replacement. Of the 20 patients who were treated to union, the average lifespan of the femoral component was 13.6 years with a range of 2.1 to 35.1 years. No patient with union of the fracture required revision of the stem for loosening.

Conclusion: Periprosthetic femur fracture about a hip stem does not appear to lead to premature stem loosening. In our series of 22 periprosthetic fractures, there was no need for revision arthroplasty after successful fracture treatment. Patients who did require revision of their femoral stem were those who had a postoperative courses complicated by nonunion.

• The FDA has not cleared this drug and/or medical device for the use described in this presentation   (i.e., the drug or medical device is being discussed for an “off label” use).  ◆FDA information not available at time of printing. Δ OTA Grant.