title: Predictors of range of motion in patients undergoing manipulation after TKA.
abstract: BACKGROUND
  Knee stiffness or limited range of motion (ROM) after total knee arthroplasty (TKA) may compromise patient function. Patients with stiffness are usually managed with manipulation under anesthesia (MUA) to improve ROM. However, the final ROM obtained is multifactorial and may depend on factors such as comorbidities, implant type, or the timing of MUA.
  
  
  OBJECTIVE
  We asked whether diabetes mellitus, implant type, and the interval between TKA and MUA influenced post-MUA ROM.
  
  
  METHODS
  From a group of 2462 patients with 3224 TKAs performed between 1999 and 2007 we retrospectively reviewed 96 patients with 119 TKAs (4.3%) who underwent MUA. We determined the presence of diabetes mellitus, implant type, and the interval between TKA and MUA.
  
  
  RESULTS
  The average increase in ROM after MUA was 34°. Patients with diabetes mellitus experienced lower final ROM after MUA (87.5° versus 100.3°) as did patients with cruciate-retaining (CR) prostheses versus posterior-stabilized (92.3° versus 101.6°). The interval between TKA and MUA inversely correlated with final ROM with a decrease after 75 days.
  
  
  CONCLUSIONS
  Most patients experience improvements in ROM after MUA. Patients with diabetes mellitus or CR prostheses are at risk for lower final ROM after MUA. Manipulation within 75 days of TKA is associated with better ROM.
authors.affiliation: Department of Orthopaedic Surgery, Case Western Reserve University, University Hospitals Case Medical Center, 11100 Euclid Avenue, Cleveland, OH 44106, USA. harpreetbawa@gmail.com
authors.forename: Harpreet S
authors.initials: HS
authors.lastname: Bawa
authors.forename: Glenn D
authors.initials: GD
authors.lastname: Wera
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Kraay
authors.forename: Randall E
authors.initials: RE
authors.lastname: Marcus
authors.forename: Victor M
authors.initials: VM
authors.lastname: Goldberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee; D003920:Diabetes Mellitus / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D016059:Range of Motion, Articular / Q000502:physiology*; D012189:Retrospective Studies; D016896:Treatment Outcome