title: Mobile-bearing, congruent patellofemoral prosthesis: short-term results.
abstract: OBJECTIVE
  To report the short-term outcome of the low contact stress (LCS) patellofemoral prosthesis in 51 knees.
  
  
  METHODS
  12 men and 37 women aged 23 to 79 (mean, 53.4) years underwent 51 consecutive LCS patellofemoral replacements. All patients had symptomatic isolated arthritis in the patellofemoral joint with well-preserved tibiofemoral compartments. All knees were evaluated pre- and post-operatively. The new Oxford scoring system was used. Anteroposterior, lateral, and skyline weight-bearing radiographs were reviewed.
  
  
  RESULTS
  The mean follow-up period was 4.2 years; no patient was lost to follow-up. The mean new Oxford Knee score was 13.9 preoperatively and improved by 13.7 at 3 months (p<0.001) and by further 7.1 at 12 months (p<0.001). Any change after 12 months was not significant (p=0.73). 18 of the knees developed patellar maltracking and resulted in subluxation and lateral tilt of the patella with severe polyethylene wear. 10 (20%) of the knees were revised; 8 with patellar maltracking were revised to total knee arthroplasty (n=3) or patellofemoral arthroplasty with a different implant (n=5), whereas 2 with disease progression were revised to total knee arthroplasty. The estimated survival rate of the prosthesis was 73% at 4.5 years and 48% at 5.5 years.
  
  
  CONCLUSIONS
  The revision rate for the LCS patellofemoral prosthesis was high (20%).
authors.affiliation: Bradford Royal Infirmary, Duckworth lane, Bradford, United Kingdom.
authors.forename: Basavaraj
authors.initials: B
authors.lastname: Yadav
authors.forename: David
authors.initials: D
authors.lastname: Shaw
authors.forename: Graham
authors.initials: G
authors.lastname: Radcliffe
authors.forename: Sunil
authors.initials: S
authors.lastname: Dachepalli
authors.forename: Wolfram
authors.initials: W
authors.lastname: Kluge
mesh_terms: D000328:Adult; D000368:Aged; D001168:Arthritis / Q000601:surgery*; D019645:Arthroplasty, Replacement, Knee; D018450:Disease Progression; D005260:Female; D006801:Humans; D007595:Joint Prosthesis; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D057071:Patellofemoral Joint / Q000601:surgery*; D011474:Prosthesis Design; D012086:Reoperation; D016896:Treatment Outcome; D055815:Young Adult