title: [Computer-assisted systems in total knee arthroplasty. Useful aid or only additional costs].
abstract: BACKGROUND
  The primary goal of computer-assisted surgery (CAS) in total knee arthroplasty is to increase the accuracy in terms of prosthesis positioning. In theory, this would lead to longer implant survival and a reduction of malpositioning. Thus, a better clinical outcome and lower revision rates would be expected. However, the necessary technical equipment represents significant additional effort and cost factors which are not included in the current diagnosis-related groups (DRG) system.
  
  
  OBJECTIVE
  The objective of this article is a critical review of the current literature to examine whether these costs are reasonable by taking the additional benefits of the technology into account.
  
  
  METHODS
  This review is based on a selective PubMed search on CAS and navigation in primary total knee arthroplasty.
  
  
  RESULTS
  The current evidence base on CAS suggests that at least the primary outcome parameter, the improvement of the radiological alignment, is achieved by the technique. However, the claimed secondary effects are not yet proven. In particular, an improvement of clinical outcome and patient satisfaction has not been demonstrated so far. Furthermore, there is some evidence of increased complication rates by the use of CAS.
  
  
  CONCLUSIONS
  Against this background and with respect to further cost-benefit analyses, the technology has to be reviewed critically. In particular, low-volume units do not seem to benefit from the use of CAS. However, the assessment of long-term effects is still pending.
authors.affiliation: Department Endoprothetik und Rekonstruktive Gelenkchirurgie, Orthopädische Klinik der Medizinischen Hochschule Hannover im Annastift, Anna-von-Borries-Str. 3, 30449, Hannover, Deutschland, Tilman.Calliess@ddh-gruppe.de.
authors.forename: T
authors.initials: T
authors.lastname: Calliess
authors.forename: M
authors.initials: M
authors.lastname: Ettinger
authors.forename: H
authors.initials: H
authors.lastname: Windhagen
mesh_terms: D019645:Arthroplasty, Replacement, Knee / Q000191:economics* / Q000706:statistics & numerical data; D003362:Cost-Benefit Analysis / Q000191:economics* / Q000706:statistics & numerical data; D017048:Health Care Costs / Q000706:statistics & numerical data*; D038622:Internationality; D011183:Postoperative Complications / Q000191:economics* / Q000453:epidemiology / Q000517:prevention & control*; D015995:Prevalence; D025321:Surgery, Computer-Assisted / Q000191:economics* / Q000706:statistics & numerical data; D016896:Treatment Outcome