Fixed bearing knee replacements have a fixed polyethylene tibial insert locked with the tibial tray.
Fixed- or mobile-bearing?
This is in comparison to knee replacements that are mobile-bearing, where the insert is free to move. Fixed bearing prostheses are recommended for the older patient who has less requirement for mobility.
Increased risk of aseptic loosening for 43,525 rotating-platform vs. fixed-bearing total knee replacements. Gothesen O, Lygre SHL, Lorimer M, Graves S and Furnes O. Acta Orthop. 2017 Nov; 88(6): 649–656.
Mobile bearing and fixed bearing total knee arthroplasty Capella M, Dolfin M and Saccia F. Ann Transl Med. 2016 Apr; 4(7): 127.
Fixed or mobile-bearing total knee arthroplasty. Huang C-H, Liau J-J and Cheng C-K. J Orthop Surg. 2007; 2: 1.