Mobile vs. fixed meniscal bearing in total knee replacement: a randomised radiostereometric study.
52 knees scheduled for a total knee arthroplasty were randomised to either a fixed or a mobile polyethylene bearing. The design was identical in all parts. The knee systems used were the Rotaglide Total Knee System (RTK) and the Nuffield Total Knee System (NTK), both from the same manufacturer (Corin Medical Ltd., UK). All knees implanted were uncemented. The patients were followed for 2 years clinically and with radiostereometric analyses to assess migration over time and inducible displacement of the tibial component. Separate analysis of the mobility of the tibial insert in the knees with a mobile bearing was also made. The migration measured with RSA between the 1st and 2nd year expressed as maximum total point motion (MTPM) might predict the risk of loosening of the implant. There were no differences between the groups regarding clinical outcome (HSS Knee score), migration or inducible displacement during the 2 years follow-up. The movement between the tibial tray and the mobile meniscal insert expressed as maximum total point motion (MTPM) was 6.8+/-3.3 mm at the 1st year follow-up.
Hansson
Ulrik
U
Department of Orthopedics, Lund University Hospital, S-221 85 Lund, Sweden. Ulrik.Hansson@ort.lu.se
Toksvig-Larsen
Sören
S
Jorn
Lars Peter
LP
Ryd
Leif
L
D000368:Aged; D000369:Aged, 80 and over; D001175:Arthrography; D019645:Arthroplasty, Replacement, Knee / Q000295:instrumentation* / Q000379:methods; D005260:Female; D005548:Foreign-Body Migration; D006801:Humans; D007720:Knee Prosthesis; D008297:Male; D008592:Menisci, Tibial / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D009984:Orthopedic Fixation Devices; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging / Q000601:surgery; D010780:Photogrammetry / Q000379:methods; D011183:Postoperative Complications; D011474:Prosthesis Design; D011475:Prosthesis Failure; D016059:Range of Motion, Articular; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery; D016896:Treatment Outcome; D016474:Weight-Bearing