title: [Extensor mechanism complications in revision total knee arthroplasty : Joint exposure and prevention of extensor mechanism complications].
abstract: BACKGROUND
  Revision total knee arthroplasty is complex surgery that has to be well planned from its indication to the actual surgical procedure.
  
  
  OBJECTIVE
  To review surgical techniques that allow a secure exposure of the joint in revision total knee arthroplasty.
  
  
  METHODS
  The authors summarize a review of the literature and present their own experience in knee joint exposure aiming to minimize extensor mechanism complications in revision TKA.
  
  
  RESULTS
  The choice of adequate skin incision, detailed scar removal and a systematic soft tissue release are inevitable prerequisites for an optimal joint exposure and the minimization of extensor mechanism complications. In most patients, a medial parapatellar arthrotomy is sufficient to expose the knee joint and, if necessary, allows a proximal extension using a quadriceps snip or VY-quadricepsplasty, or a distal extension via a tibial tubercle osteotomy. Whether the quick and easy quadriceps snip or a tibial tubercle osteotomy has to be performed depends in each case on the extent of scar formation, the extensor mechanism contracture and the preoperative position of the patella. In general, a parapatellar and lateral release has to be executed; therefore, a partial lateral facetectomy ensures a secure eversion of the patella. Alternative approaches to access the joint do not reveal significant advantages and play a minor role in revision total knee arthroplasty.
  
  
  CONCLUSIONS
  Revision total knee arthroplasty is a challenging surgical procedure. In addition to the regular soft tissue release techniques and joint approaches, the surgeon has to be aware of proximal and distal extension procedures to securely expose the joint and minimize the risk of extensor mechanism complications.
authors.affiliation: Klinik für Orthopädie und Unfallchirurgie, Evangelisches Waldkrankenhaus Spandau, Stadtrandstraße 555, 13589, Berlin, Deutschland. l.rackwitz@waldkrankenhaus.com.
authors.forename: L
authors.initials: L
authors.lastname: Rackwitz
authors.affiliation: Klinik für Orthopädie und Unfallchirurgie, Evangelisches Waldkrankenhaus Spandau, Stadtrandstraße 555, 13589, Berlin, Deutschland.
authors.forename: T
authors.initials: T
authors.lastname: Matz
authors.affiliation: Klinik für Orthopädie und Unfallchirurgie, Evangelisches Waldkrankenhaus Spandau, Stadtrandstraße 555, 13589, Berlin, Deutschland.
authors.forename: M
authors.initials: M
authors.lastname: Trojanowski
authors.affiliation: Klinik für Orthopädie und Unfallchirurgie, Evangelisches Waldkrankenhaus Spandau, Stadtrandstraße 555, 13589, Berlin, Deutschland.
authors.forename: U
authors.initials: U
authors.lastname: Nöth
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D019317:Evidence-Based Medicine; D006801:Humans; D007593:Joint Instability / Q000209:etiology* / Q000517:prevention & control; D007718:Knee Injuries / Q000209:etiology* / Q000517:prevention & control*; D017695:Soft Tissue Injuries / Q000209:etiology* / Q000517:prevention & control*; D016896:Treatment Outcome
keywords: Contracture; Knee arthroplasty, total; Patella; Quadriceps femoris; Revision, joint