title: Revision total knee arthroplasty with varus-valgus constrained prosthesis versus posterior stabilized prosthesis.
abstract: OBJECTIVE
  The aims of this retrospective study were to provide the basis for the choice of prosthesis in revision total knee arthroplasty (TKA) and to evaluate the outcome with varus-valgus constrained prosthesis compared with posterior stabilized (PS) prosthesis.
  
  
  METHODS
  One hundred and five patients (121 knees) received revision TKA; of which thirty-seven patients (42 knees) received PS prosthesis and sixty-eight patients (79 knees) received varus-valgus constrained prosthesis. The mean follow-up duration was 64.8 ± 31.5 months and 63.2 ± 28.1 months in the PS and varus-valgus constrained groups, respectively. The criterion of prosthesis choice was a subjective laxity assessed by the surgeon intraoperatively. A multivariate analysis was performed to evaluate the preoperative factors in the choice of the prosthesis.
  
  
  RESULTS
  The grade of femoral bone defect was the only factor that affected the choice of prosthesis. Clinical results improved significantly in both groups after surgery. There were no significant differences in clinical results between the two groups. Complication rates were 9.5 % in the PS group and 10.1 % in the varus-valgus constrained group, and the Kaplan-Meier survivorship analysis revealed 8-year component survival rates of 83.1 and 93.0 % in the PS and varus-valgus constrained groups, respectively.
  
  
  CONCLUSIONS
  Femoral bone defect is an important factor to be considered in the choice of prosthesis for revision TKA. The varus-valgus constrained prosthesis showed an outcome similar to that of the PS prosthesis. For clinical relevance, varus-valgus constrained prosthesis is recommended in revision TKA when the PS prosthesis seems unsuitable for the management of instability.
  
  
  METHODS
  III.
authors.affiliation: Department of Orthopaedic Surgery, Seoul National University Hospital, 101 Daehak-ro, Jongno-gu, Seoul, 110-744, Korea.
authors.forename: Joon Kyu
authors.initials: JK
authors.lastname: Lee
authors.forename: Sahnghoon
authors.initials: S
authors.lastname: Lee
authors.forename: Dongwook
authors.initials: D
authors.lastname: Kim
authors.forename: Sang Min
authors.initials: SM
authors.lastname: Lee
authors.forename: Jak
authors.initials: J
authors.lastname: Jang
authors.forename: Sang Cheol
authors.initials: SC
authors.lastname: Seong
authors.forename: Myung Chul
authors.initials: MC
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000379:methods*; D005260:Female; D006801:Humans; D007592:Joint Diseases / Q000601:surgery*; D007719:Knee Joint / Q000601:surgery*; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies