title: Long-term results of cruciate-retaining total knee replacement in patients with rheumatoid arthritis: a minimum 15-year review.
abstract: BACKGROUND
  There is controversy about whether to retain or excise the posterior cruciate ligament in rheumatoid knees because attenuation of the ligament is often present in this subgroup of patients. We reviewed more than 15 years of results of cruciate-retaining total knee replacements (TKRs) in patients with rheumatoid arthritis.
  
  
  METHODS
  We reviewed patients' charts and radiographs to evaluate knee range of motion and flexion contractures, component loosening and osteolysis at the bone-cement interface. Our primary outcome was revision of a femoral or tibial component for any reason, and the secondary outcome was revision for any reason and periprosthetic fracture during the follow-up period.
  
  
  RESULTS
  Our study included 112 patients (7 men, 105 women, 176 knees). Their mean age was 49.3 (range 33-64) years. Twenty-one patients died and 16 were lost to follow-up, leaving 75 patients (119 knees) with a minimum follow-up of 15 (mean 16.1) years for our analysis. Of these, 61 patients (101 knees) were available for clinical and radiological evaluation at the final follow-up assessment. At a mean of 12.2 (range 6-16) years, revision was necessary in 14 patients (19 knees), including 1 patient with an infection. Eleven patients (11 knees) had periprosthetic fractures at a mean of 11.4 (range 5-14) years after the index operation. The survival rate, with the end point being revision of the femoral or tibial component for any reason, was 98.7% at 10 years and 83.6% at 17 years. The survival rate of revision and periprosthetic fracture was 97.6% at 10 years and 76.9% at 17 years.
  
  
  CONCLUSIONS
  Special attention should be paid to component loosening or periprosthetic fracture after more than 10 years of follow-up in this subgroup of patients.
authors.affiliation: The Department of Orthopaedic Surgery, Hanyang University Hospital, Seoul, South Korea.
authors.forename: Jin Kyu
authors.initials: JK
authors.lastname: Lee
authors.affiliation: The Department of Orthopaedic Surgery, Hanyang University Hospital, Seoul, South Korea.
authors.forename: Young Moon
authors.initials: YM
authors.lastname: Kee
authors.affiliation: The Department of Orthopaedic Surgery, Hanyang University Hospital, Seoul, South Korea.
authors.forename: Hyung Kee
authors.initials: HK
authors.lastname: Chung
authors.affiliation: The Department of Orthopaedic Surgery, Hanyang University Hospital, Seoul, South Korea.
authors.forename: Choong Hyeok
authors.initials: CH
authors.lastname: Choi
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000601:surgery*; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D053208:Kaplan-Meier Estimate; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D057068:Periprosthetic Fractures / Q000453:epidemiology / Q000209:etiology; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D011475:Prosthesis Failure; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D016896:Treatment Outcome