title: Adjustable cutting blocks improve alignment and surgical time in computer-assisted total knee replacement.
abstract: OBJECTIVE
  Computer navigation increases accuracy and precision of component alignment in total knee arthroplasty (TKA) compared to the manual technique, but is often associated with increases in surgical time. In a previous cadaver study, we demonstrated a significant improvement in guide positioning precision, final bone cut precision, and procedure length when using adjustable cutting blocks (ACB) compared to conventional cutting blocks (CCB) in computer-navigated TKA. The aim of this study was to evaluate the use of ACB in vivo.
  
  
  METHODS
  We radiographically compared component alignment and mechanical leg alignment, as well as tourniquet time, in 94 patients who underwent TKA using either ACB (N = 30) or CCB (N = 64).
  
  
  RESULTS
  Postoperative mechanical alignment variability was significantly less in the ACB group (SD = 1.7°) than in the CCB group (SD = 2.7°). Tourniquet time was significantly reduced by 14.8 min in the ACB group compared to the CCB. Differences in component alignment were not significant.
  
  
  CONCLUSIONS
  ACB for TKA significantly reduced postoperative mechanical alignment variability and tourniquet time compared to conventional navigated instrumentation, while providing equal or better component alignment.
  
  
  METHODS
  III.
authors: Department of Orthopaedic Surgery, Hospital for Special Surgery, 535 E 70th St., New York, NY 10021, USA. SueroE@hss.edu
authors: Eduardo M
authors: EM
authors: Suero
authors: Christopher
authors: C
authors: Plaskos
authors: Peter L
authors: PL
authors: Dixon
authors: Andrew D
authors: AD
authors: Pearle
mesh_terms: D000368:Aged; D019645:Arthroplasty, Replacement, Knee; D005260:Female; D006801:Humans; D008297:Male; D061646:Operative Time; D020370:Osteoarthritis, Knee / Q000601:surgery*; D012189:Retrospective Studies; D013238:Stereotaxic Techniques; D025321:Surgery, Computer-Assisted / Q000295:instrumentation*