Finally , with use of a variety of vali date d measures , there was no difference between the two groups in terms of functional status at two , eight , and ten years , regardless of the measure used .
A less expensive all-polyethylene component as part of a total knee arthroplasty has results equivalent to those obtained with a cemented metal-backed tibial component .
BACKGROUND The cost of the implant as part of a total knee arthroplasty accounts for a substantial portion of the costs for the overall procedure : all-polyethylene tibial components cost considerably less than cemented metal-backed tibial components .
We performed a systematic review of the literature to determine whether the clinical results of lower-cost all-polyethylene tibial components were comparable with the results of a more expensive metal-backed tibial component .
Kinematics of Three Variations of the Freeman-Samuelson Total Knee Prosthesis
The effect of changes in the articulating surfaces on the kinematics of the Freeman-Samuelson total knee replacement was evaluated . Twenty-two patients ( 22 knees ) ( median age , 69 years ) were r and omized to a st and ard design with a fixed polyethylene bearing , a design with a mobile bearing , or a new design with a spherical medial femoral condyle with a fixed bearing . The patients were studied with radiostereometry and film-exchangers at 0 ° nonweightbearing and during active weightbearing extension from 45 ° to 15 ° . The center of the tibial tray with a mobile-bearing prosthesis occupied a more anterior position than observed in the design s with a fixed bearing . The medial femoral condyle center had a more posterior position in the st and ard design than in the design with a spherical medial condyle . From a distally displaced position at 45 ° , the medial condylar center displaced a mean of 1.8 mm proximally during extension in the st and ard design and had a constant position in the meniscal design . In the spherical design the medial condyle was displaced proximally at 45 ° and displaced a mean of 1.6 mm distally during extension . The reduced anteroposterior and proximodistal translations in the meniscal design are compatible with improved congruency between the components . The design with a spherical medial condyle stabilized anteroposterior motions , but showed more pronounced proximodistal displacement medially than did the other two design
Finally , with use of a variety of vali date d measures , there was no difference between the two groups in terms of functional status at two , eight , and ten years , regardless of the measure used .
A less expensive all-polyethylene component as part of a total knee arthroplasty has results equivalent to those obtained with a cemented metal-backed tibial component .
BACKGROUND The cost of the implant as part of a total knee arthroplasty accounts for a substantial portion of the costs for the overall procedure : all-polyethylene tibial components cost considerably less than cemented metal-backed tibial components .
We performed a systematic review of the literature to determine whether the clinical results of lower-cost all-polyethylene tibial components were comparable with the results of a more expensive metal-backed tibial component .