title: Do High-Flexion Total Knee Designs Increase the Risk of Femoral Component Loosening?
abstract: The purpose of our prospective, randomized, long-term investigation is to compare the aseptic loosening rate of the femoral component of the total knee prosthesis and clinical and radiographic results of high-flexion posterior cruciate-substituting knee prosthesis or standard posterior cruciate-substituting knee prosthesis in the same patients.
  
  
  
  There were 960 patients (mean age 71.3 years). The mean follow-up period was 13.2 years (range 10-14). The patients were assessed clinically and radiographically with rating systems of the Knee Society. Furthermore, Western Ontario and McMaster Universities Osteoarthritis questionnaire and ranges of knee motion were determined in both groups.
  
  
  
  In the high-flexion knee group, 2 knees (0.2%) had aseptic loosening of both femoral and tibial components. In the standard knee group, 2 knees (0.2%) had aseptic loosening of the femoral component only. The mean postoperative knee scores (97 vs 97 points), Western Ontario and McMaster Universities Osteoarthritis scores (19 vs 19 points), and range of knee motion (128° vs 129°) were not significantly different between the 2 groups. Two knees (0.2%) in the high-flexion knee group underwent a revision of both femoral and tibial components and 2 knees (0.2%) in the standard knee group had a revision of the femoral component only.
  
  
  
  After a mean of 13.2 years of follow-up, this study did not show increased incidence of femoral component loosening in the high-flexion knee group. Furthermore, we found no significant differences between the 2 groups with regard to clinical or radiographic parameters or range of knee motion.
authors.affiliation: The Joint Replacement Center, Ewha Womans University, SeoNam Hospital, Seoul, Republic of Korea.
authors.forename: Young-Hoo
authors.initials: YH
authors.lastname: Kim
authors.affiliation: The Joint Replacement Center, Ewha Womans University, MokDong Hospital, Seoul, Republic of Korea.
authors.forename: Jang-Won
authors.initials: JW
authors.lastname: Park
authors.affiliation: The Joint Replacement Center, Ewha Womans University, MokDong Hospital, Seoul, Republic of Korea.
authors.forename: Jun-Shik
authors.initials: JS
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation*; D044466:Asian People; D005260:Female; D005269:Femur; D006801:Humans; D007719:Knee Joint; D007720:Knee Prosthesis / Q000009:adverse effects* / Q000706:statistics & numerical data; D008297:Male; D008875:Middle Aged; D009038:Motion; D010003:Osteoarthritis; D020370:Osteoarthritis, Knee / Q000208:ethnology / Q000601:surgery; D011184:Postoperative Period; D011446:Prospective Studies; D011474:Prosthesis Design; D011475:Prosthesis Failure / Q000209:etiology*; D016059:Range of Motion, Articular; D011795:Surveys and Questionnaires; D013977:Tibia
keywords: clinical results; complications; femoral component loosening; high-flexion total knee; posterior cruciate-substituting total knee; standard total knee