title: Total knee arthroplasty after high tibial osteotomy. A systematic review.
abstract: BACKGROUND
  Previous osteotomy may compromise subsequent knee replacement, but no guidelines considering knee arthroplasty after prior osteotomy have been developed. We describe a systematic review of non-randomized studies to analyze the effect of high tibial osteotomy on total knee arthroplasty.
  
  
  METHODS
  A computerized search for relevant studies published up to September 2007 was performed in Medline and Embase using a search strategy that is highly sensitive to find nonrandomized studies. Included were observational studies in which patients had total knee arthroplasty performed after prior high tibial osteotomy. Studies that fulfilled these criteria, were assessed for methodologic quality by two independent reviewers using the critical appraisal of observational studies developed by Deeks and the MINORS instrument. The study characteristics and data on the intervention, follow-up, and outcome measures, were extracted using a pre-tested standardized form. Primary outcomes were: knee range of motion, knee clinical score, and revision surgery. The grade of evidence was determined using the guidelines of the GRADE working group.
  
  
  RESULTS
  Of the 458 articles identified using our search strategy, 17 met the inclusion criteria. Fifteen studies were cohort study with a concurrent control group, one was a historical cohort study and one a case-control study. Nine studies scored 50% or more on both methodological quality assessments. Pooling of the results was not possible due to the heterogeneity of the studies, and our analysis could not raise the overall low quality of evidence. No significant differences between primary total knee arthroplasty and total knee arthroplasty after osteotomy were found for knee range of motion in four out of six studies, knee clinical scores in eight out of nine studies, and revision surgery in eight out of eight studies after a median follow-up of 5 years.
  
  
  CONCLUSIONS
  Our analysis suggests that osteotomy does not compromise subsequent knee replacement. However, the low quality of evidence precludes solid clinical conclusions.
authors.affiliation: Department of Orthopaedics, Erasmus University Medical Center, Rotterdam, the Netherlands. t.m.vanraaij@mzh.nl
authors.forename: Tom M
authors.initials: TM
authors.lastname: van Raaij
authors.forename: Max
authors.initials: M
authors.lastname: Reijman
authors.forename: Andrea D
authors.initials: AD
authors.lastname: Furlan
authors.forename: Jan A N
authors.initials: JA
authors.lastname: Verhaar
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects; D019317:Evidence-Based Medicine; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D010027:Osteotomy / Q000009:adverse effects; D017410:Practice Guidelines as Topic; D016059:Range of Motion, Articular; D020127:Recovery of Function; D012086:Reoperation; D013977:Tibia / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome