Interprosthetic femoral fractures treated with locking plate. 
Interprosthetic fractures are challenging to manage.  Although treatment of femoral fractures around a single implant has been described, there is little literature for treatment of interprosthetic femoral fractures.  This study analyses the management and outcomes of 15 patients with interprosthetic femoral fractures treated with locking plates.  A retrospective chart review was conducted of 17 patients with interprosthetic femur fracture treated with locking plates from 2002 to 2013.  Patient demographics and comorbidities were collected.  Preoperatively, patients were classified with the Vancouver or Su classification system.  Intraoperative use of bone graft and/or cerclage cables was also examined.  Clinical and radiographic outcomes were evaluated for union, time to full weight bearing, return to preinjury level of activity, and pain assessed with visual analog scale (VAS).  There were 15 patients with interprosthetic fractures meeting criteria for this study.  Average patient age was 80.53 (range, 61-92) years.  Bone grafting was used in 23.5% (four of 17) and cerclage cables in 29.4% (five of 17).  Patients achieved complete union and return to full weight bearing an average of 4.02 (range, two to six) months later.  Average VAS pain score was 1.00 (range, zero to six).  All patients returned to their preoperative ambulatory status.  Locking plates could achieve satisfactory results for interprosthetic fractures.  Considering an individual's fracture type, bone quality and protheses to determine the appropriate plate length and optional use of cerclage and/or bone graft was essential.  In this limited sample size, interprosthetic fractures occurred at similar rates at the supracondylar region and diaphysis.