title: Correction of varus deformity during TKA with reduction osteotomy.
abstract: BACKGROUND
  Reduction osteotomy (removing the posteromedial tibial bony flare) is one step to aid in achieving deformity correction in varus arthritic knees during TKA. However, the amount of deformity correction achieved with reduction osteotomy during TKA is unclear.
  
  
  OBJECTIVE
  We therefore addressed the following questions: (1) What is the amount of deformity correction achieved with reduction osteotomy during TKA in varus knees? (2) What is the correlation of amount of deformity correction achieved to the amount of bone osteotomized and the degree of varus deformity?
  
  
  METHODS
  We prospectively collected and analyzed intraoperative data on the degree of varus deformity before and after reduction osteotomy (using computer navigation) and the amount of reduction osteotomy performed (using a measuring scale) in 71 primary, computer-assisted TKAs.
  
  
  RESULTS
  For a mean reduction osteotomy of 7.5 ± 2 mm, a mean correction of 3.5° ± 1° was achieved; a mean osteotomy of 2 mm was required (confidence interval, 1.7-2.6 mm) for every 1° correction of varus deformity. Degree of varus correction achieved correlated positively with the amount of osteotomy performed, especially in knees with preoperative varus deformity of < 15° (r = 0.77, p < 0.001) and the preosteotomy residual varus deformity correlated positively with the amount of correction achieved (r = 0.81, p < 0.001).
  
  
  CONCLUSIONS
  Reduction osteotomy can achieve deformity correction in a predictable 2 mm for 1° in most varus arthritic knees during TKA. Further studies are required to ascertain its effectiveness as a soft tissue-sparing step when performed early on during TKA to achieve deformity correction.
authors.affiliation: The Arthritis Clinic, 101, Cornelian, Kemp's Corner, Cumballa Hill, Mumbai, 400036, India, arunmullaji@gmail.com.
authors.forename: Arun B
authors.initials: AB
authors.lastname: Mullaji
authors.forename: Gautam M
authors.initials: GM
authors.lastname: Shetty
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D006801:Humans; D016916:Joint Deformities, Acquired / Q000503:physiopathology / Q000601:surgery*; D007719:Knee Joint / Q000503:physiopathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000503:physiopathology / Q000601:surgery*; D010027:Osteotomy / Q000379:methods*; D016059:Range of Motion, Articular / Q000502:physiology; D013977:Tibia / Q000601:surgery; D016896:Treatment Outcome