title: Distal femur and proximal tibia replacement with megaprosthesis in revision knee arthroplasty: a limb-saving procedure.
abstract: OBJECTIVE
  The aim of the present study was to assess whether using megaprostheses in revision knee arthroplasty procedures allows limb salvage with an acceptable outcome and complication rate, in comparison with other limb-saving procedures.
  
  
  METHODS
  Between 2000 and 2010, megaprosthesis implantation was required for non-oncologic indications in 20 patients (21 knees) (average age 73 years). Reconstructions involved the distal femur (n = 15), proximal tibia (n = 4), and both femur and tibia (n = 2). The indications, type, and numbers of previous operations and implants, as well as complications associated with megaprosthesis implantation, were reviewed, and the clinical and radiographic outcomes after an average follow-up period of 34 months (range 10-84 months) were evaluated.
  
  
  RESULTS
  The indications for megaprosthesis implantation were periprosthetic infection (n = 5), fracture (n = 9), nonunion (n = 5), and aseptic loosening (n = 2). The types of implant placed before the megaprosthetic reconstruction were a cemented rotating-hinge arthroplasty (n = 16) and a primary total knee arthroplasty (n = 5). Six patients had an additional osteosynthesis of the distal femur. An average of 3.8 operations (range 1-7) had been carried out before megaprosthesis implantation. Complications developed in 11 patients. The Knee Society Score improved significantly, from 43 (± 15) to 68 (± 16.8); P < 0.05.
  
  
  CONCLUSIONS
  Megaprosthesis implantation in revision knee arthroplasty is an exceptional indication. Despite the high complication rate, the patients can be spared amputation in most cases, and rapid mobilization with full weight-bearing is possible.
authors.affiliation: Department of General Orthopedics and Tumor Orthopedics, Münster University Hospital, Albert Schweitzer-Campus 1, 48149 Münster, Germany. Steffen.hoell@ukmuenster.de
authors.forename: Steffen
authors.initials: S
authors.lastname: Höll
authors.forename: Annabel
authors.initials: A
authors.lastname: Schlomberg
authors.forename: Georg
authors.initials: G
authors.lastname: Gosheger
authors.forename: Ralf
authors.initials: R
authors.lastname: Dieckmann
authors.forename: Arne
authors.initials: A
authors.lastname: Streitbuerger
authors.forename: Dino
authors.initials: D
authors.lastname: Schulz
authors.forename: Jendrik
authors.initials: J
authors.lastname: Hardes
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000379:methods*; D005260:Female; D005269:Femur / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D007720:Knee Prosthesis; D023821:Limb Salvage / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology*; D012086:Reoperation; D013977:Tibia / Q000601:surgery*; D016896:Treatment Outcome