Stergios R. Metsovitis, MD and Avraam Ploumis, MD
Mobile-bearing knee designs, compared with fixed-bearing knees, have conforming geometry and minimum anteroposterior translation of both the medial and lateral femoral condyles over the polyethylene during gait. This leads to diminished surface stresses and minimizes stresses at the cement-bone interface distal to the tibial tray. Joint-simulator evaluations support the long-term efficacy of this design concept and are consistent with clinical reports. Mobile-bearing total knee prostheses can accommodate a wider range of axial rotation without creating excessive polyethylene stresses. Tibial rotational malalignment can be self-corrected, and both intraoperative adjustment of the joint space and postoperative replacement of the bearings can be done without disturbing prosthetic fixation.
Mobile-bearing knees differ from each other with regard to the extent of conformity during motion (which affects the kinematic advantage of the implant). The kinematic advantage depends on the amount of conformity of the articulating surfaces throughout the range of knee motion, and these prostheses should thus be distinguished in three categories, as follows: the gait congruent, the partial congruent, and the fully congruent mobile-bearing knee. Key characteristics of a mobile-bearing design are increased lubrication and a reduction in the amount of torque that is transferred to the tibial baseplate.
The purpose of the JBJS published study was to determine the clinical results of the Rotaglide mobile-bearing knee implant. The authors conclude this fully congruent, mobile-bearing total knee prosthesis had excellent survivorship during the ten to eighteen-year follow-up interval. This video supplement to the JBJS article demonstrates the authors’ surgical technique.
See the Corresponding JBJS Article:
- Stergios R. Metsovitis, MD, Avraam L. Ploumis, MD, Paraskevas T. Chantzidis, MD, Ioannis P. Terzidis, MD, Anastasios G. Christodoulou, MD, Christos G. Dimitriou, MD, Athanasios C. Tsakonas, MD
- Rotaglide Total Knee Arthroplasty: A Long-Term Follow-up Study
J. Bone Joint Surg. Am., May 2011; 93 (9); 878-884 [Article]
- Total Run Time: 32:18 minutes
- Catalog Number: 5113
- VJO Publication Date: June, 2011