Scott Richard D
Department of Orthopedic Surgery, Brigham and Womens Hospital and New England Baptist Hospital, Boston, MA, USA.
Orthopedics. 2006 Sep;29(9 Suppl):S64-7.
Rotating-platform mobile-bearing knee arthroplasties have potential advantages over fixed-bearing knee prostheses that may lead to better long-term wear of the polyethylene articulation. Their potential disadvantages include bearing spin-out that is usually the result of a tight posterior cruciate ligament in need of release. The "slide-back test" can help determine this need during placement of the trial components. Clearing polymerized cement from the back of the knee can be difficult during rotating-platform knee arthroplasty unless cementing is completed using a trial tibial insert without a stem. Exchanging a rotating-platform insert at a future arthrotomy can be facilitated by the use of a shim that provides exposure to the polyethylene tibial post that articulates within the stem of the tibial tray. Severing the post allows extraction of the polyethylene plateau and access to the post within the tray.