title: Safety of Osseointegrated Implants for Transfemoral Amputees: A Two-Center Prospective Cohort Study.
abstract: BACKGROUND
  Osseointegrated implants are an alternative for prosthetic attachment for individuals unable to wear a socket following an amputation. The concept of an integrated metal implant communicating with the external environment raises substantial concern about the risk of ascending infection. We report on the safety of press-fit osseointegrated implants currently used in Australia and the Netherlands.
  
  
  METHODS
  We prospectively recorded all adverse events in all patients with transfemoral amputation who were managed with an osseointegration implant system between 2009 and 2013 at two centers. The procedure was performed in two stages. A customized porous-coated implant was placed in the first stage, and a stoma was created in the second. Adverse events were categorized according to type (infection or "other") and severity. Infections were classified according to four grades of severity based on clinical and radiographic findings: (1) low-grade soft-tissue infection, (2) high-grade soft-tissue infection, (3) bone infection, and (4) septic implant failure.
  
  
  RESULTS
  Eighty-six patients (ninety-one implants), twenty-five to eighty-one years of age, were included in the study and followed for a median of thirty-four months (range, twenty-four to seventy-one months). Thirty-one patients had an uneventful course with no complications; twenty-nine developed infection (all grade 1 or 2); and twenty-six did not develop infection but had one or more other complications requiring intervention, including stoma hypergranulation (seventeen patients), soft-tissue redundancy (fourteen), proximal femoral fracture (three), inadequate osseointegration leading to implant replacement (one), implant breakage (two), and breakage of the pin used as a fail-safe mechanism (twenty-five).
  
  
  CONCLUSIONS
  Mild infection and irritation of the soft tissue in the skin-penetration area are common in transfemoral amputees who have an osseointegrated implant. These complications were successfully managed with simple measures. Severe infections resulting in septic implant loosening are rare.
  
  
  METHODS
  Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
authors.affiliation: School of Medicine, University of Notre Dame Australia, Auburn, Australia Norwest Private Hospital, Bella Vista, Australia Macquarie University Hospital, Macquarie, Australia The Australian School of Advanced Medicine, Macquarie University, Macquarie, Australia munjed@me.com.
authors.forename: Munjed
authors.initials: M
authors.lastname: Al Muderis
authors.affiliation: School of Medicine, University of Notre Dame Australia, Auburn, Australia Norwest Private Hospital, Bella Vista, Australia aditya.khemka1@my.nd.edu.au.
authors.forename: Aditya
authors.initials: A
authors.lastname: Khemka
authors.affiliation: School of Medicine, University of Notre Dame Australia, Auburn, Australia National Health and Medical Research Council (NHMRC) Clinical Trials Centre, The University of Sydney, Sydney, Australia sally.lord@nd.edu.au.
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Lord
authors.affiliation: Radboud University Medical Centre, Nijmegen, the Netherlands Henk.vandeMeent@radboudumc.nl.
authors.forename: Henk
authors.initials: H
authors.lastname: Van de Meent
authors.affiliation: Radboud University Medical Centre, Nijmegen, the Netherlands JanPaul.Frolke@radboudumc.nl.
authors.forename: Jan Paul M
authors.initials: JP
authors.lastname: Frölke
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000674:Amputees; D001186:Artificial Limbs / Q000009:adverse effects*; D005260:Female; D005269:Femur / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016348:Osseointegration; D011474:Prosthesis Design; D019919:Prosthesis Implantation / Q000009:adverse effects* / Q000379:methods; D016896:Treatment Outcome