title: Cruciate-retaining TKA using a third-generation system with a four-pegged tibial component: a minimum 10-year followup note.
abstract: BACKGROUND
  A third-generation TKA system was designed to address problems encountered with earlier designs including a high rate of patellofemoral complications. At a minimum of 5 years, we previously reported survivorship of 98.7% using revision for any reason as the endpoint for a cohort that includes the patients described in this report. That cohort was unique in that a tibial component that uses four short pegs for fixation was used in a subset of patients undergoing cruciate-retaining TKA and the tibial and femoral components were precoated with polymethylmethacrylate.
  
  
  OBJECTIVE
  We now report the survival rate, postoperative function, complications, radiographic loosening, and osteolysis at a minimum of 10 years postoperatively.
  
  
  METHODS
  We retrospectively reviewed 161 patients who underwent 179 TKAs. The patella was resurfaced in all cases and all components were cemented. Patients were evaluated clinically and radiographically for evidence of component loosening and osteolysis. Forty of the 161 patients (with 44 TKAs) had died and eight patients (nine knees) were lost to followup. For the remaining 113 patients (126 knees), the minimum followup was 10 years (mean, 11.7 years; range, 10.0-13.9 years).
  
  
  RESULTS
  Survivorship at a minimum of 10 years postoperatively using revision for any reason and revision for aseptic loosening were 97.7% and 100%, respectively. Three knees were revised: one for infection, one for periprosthetic fracture, and one for postoperative arthrofibrosis. There were no reoperations for patellar component maltracking, wear or loosening, tibiofemoral polyethylene wear, osteolysis, or aseptic loosening. Hospital for Special Surgery scores improved from a mean of 47.7 (range, 23-78) preoperatively to 85.4 (range, 33-100).
  
  
  CONCLUSIONS
  This cruciate-retaining design had a low risk of implant failure or revision and the design changes eliminated the patellar failures seen with earlier iterations at up to 10 years.
  
  
  METHODS
  Level IV, therapeutic study. See the Guidelines for Authors for a complete description of levels of evidence.
authors.affiliation: Rush University Medical Center, 1725 W. Harrison Street, Suite 1063, Chicago, IL 60612, USA.
authors.forename: Adam J
authors.initials: AJ
authors.lastname: Schwartz
authors.forename: Craig J
authors.initials: CJ
authors.lastname: Della Valle
authors.forename: Aaron G
authors.initials: AG
authors.lastname: Rosenberg
authors.forename: Joshua J
authors.initials: JJ
authors.lastname: Jacobs
authors.forename: Richard A
authors.initials: RA
authors.lastname: Berger
authors.forename: Jorge O
authors.initials: JO
authors.lastname: Galante
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D002484:Cementation; D020099:Coated Materials, Biocompatible; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007087:Illinois / Q000453:epidemiology; D007720:Knee Prosthesis; D008297:Male; D008875:Middle Aged; D010014:Osteolysis / Q000453:epidemiology / Q000209:etiology; D057071:Patellofemoral Joint / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D011109:Polymethacrylic Acids; D016119:Posterior Cruciate Ligament / Q000601:surgery*; D011183:Postoperative Complications / Q000453:epidemiology* / Q000209:etiology; D011474:Prosthesis Design; D011475:Prosthesis Failure; D011859:Radiography; D012086:Reoperation / Q000706:statistics & numerical data; D012189:Retrospective Studies; D013977:Tibia / Q000601:surgery*
chemical_list: D020099:Coated Materials, Biocompatible; D011109:Polymethacrylic Acids; C030613:polymethacrylic acid