title: Treatment of interprosthetic fractures of the femur.
abstract: BACKGROUND
  The treatment of interprosthetic femoral fractures is challenging because of several factors. Poor bone stock, advanced age, potential prosthetic instability, and limited fracture fixation options both proximally and distally can complicate standard femur fracture treatment procedures. The purpose of this report was to describe our experience treating interprosthetic femoral fractures, providing an emphasis on treatment principles and specific intraoperative management.
  
  
  METHODS
  All patients with fractures occurring between ipsilateral hip and knee prostheses between 2004 and 2010 were identified from a comprehensive database and included in this study. Patients had been treated using principles adapted from two isolated periprosthetic fracture classification systems, the Vancouver and Su classifications. The electronic medical record (including inpatient medical records, operative notes, outpatient medical records, and all radiographs) was reviewed for each patient and demographic and treatment-related variables as well as complications and outcomes were recorded.
  
  
  RESULTS
  Thirteen consecutive patients with interprosthetic fractures were included. Four fractures occurred around a clearly loose prosthesis, which were subsequently treated with long-stemmed revisions. The remaining 12 fractures were treated with a locked-plate construct. Two of nine patients (22.2%) died before fracture union. Follow-up averaged 28 months ± 4 months, with fracture union achieved at an average of 4.7 months ± 0.3 months. All patients returned to their self-reported preoperative ambulatory status except one who developed a loose hip prosthesis at 3-year follow-up after fracture union.
  
  
  CONCLUSIONS
  The principles for treatment of isolated periprosthetic fractures are useful to guide the fixation of interprosthetic fractures. Locked plating is an effective method for the treatment of interprosthetic femoral fractures. Bypassing the adjacent prosthesis by a minimum of two femoral diameters is a necessary technique to prevent a stress riser.
authors.affiliation: Department of Orthopaedic Surgery, Third Hospital of Hebei Medical University, Shijiazhuang, Hebei, China. hzy707@yahoo.com.cn
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Hou
authors.forename: Blake
authors.initials: B
authors.lastname: Moore
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Bowen
authors.forename: Kaan
authors.initials: K
authors.lastname: Irgit
authors.forename: Michelle E
authors.initials: ME
authors.lastname: Matzko
authors.forename: Kent A
authors.initials: KA
authors.lastname: Strohecker
authors.forename: Wade R
authors.initials: WR
authors.lastname: Smith
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip / Q000009:adverse effects* / Q000379:methods; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects* / Q000379:methods; D015331:Cohort Studies; D005260:Female; D005264:Femoral Fractures / Q000000981:diagnostic imaging / Q000453:epidemiology / Q000601:surgery*; D005500:Follow-Up Studies; D005593:Fracture Fixation, Internal / Q000379:methods*; D017102:Fracture Healing / Q000502:physiology; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D057068:Periprosthetic Fractures / Q000000981:diagnostic imaging / Q000601:surgery*; D011859:Radiography; D020127:Recovery of Function; D012042:Registries; D012086:Reoperation / Q000379:methods; D012189:Retrospective Studies; D018570:Risk Assessment; D013314:Stress, Mechanical; D016896:Treatment Outcome