Background: Medial cuneiform dorsal opening wedge (Cotton) osteotomy is often used for treating forefoot varus in patients undergoing surgery for stage II posterior tibialis tendon dysfunction. The goal of this study was to examine the radiographic outcomes of Cotton osteotomy with bioactive glass wedge to assess for both maintenance of correction and clinical results and complications. We hypothesized that bioactive glass wedges would maintain correction of the osteotomy with low complication rates.
View Article and Find Full Text PDFFull flexion is critical for total knee arthroplasty (TKA) patients in the Middle East, where daily activities require a high range of motion in the lower limb. This study aimed to increase understanding of the knee kinematics of normal Muslim subjects during high-flexion activities of daily living, such as kneeling, Muslim prayer, sitting cross-legged, and squatting. The early postoperative kinematics for a select group of Muslim, high-flexion TKA patients are also reported.
View Article and Find Full Text PDFJ Biomed Mater Res B Appl Biomater
November 2006
A series of in vitro patella damage tests were developed using a knee simulator to investigate electron-beam-irradiated and -melted ultra-high molecular weight polyethylene and conventional ultra-high molecular weight polyethylene at the patellofemoral articulation. Three different simulations were created: (i) normal gait with optimal component alignment, (ii) stair climbing with optimal component alignment, and (iii) stair climbing with 4 degrees of femoral component internal rotation to simulate a component malalignment condition. In the last two simulations, all patellae were artificially aged.
View Article and Find Full Text PDFAccurate in vivo measurement of tibiofemoral forces is important in total knee arthroplasty. These forces determine polyethylene stresses and cold-flow, stress distribution in the implant, and stress transfer to the underlying implant bone interface. Theoretic estimates of tibiofemoral forces have varied widely depending on the mathematical models used.
View Article and Find Full Text PDFThe moment arm of the knee-extensor mechanism is described by the moment arm of the patellar tendon calculated with respect to the screw axis of the tibia relative to the femur. The moment arm may be found once the line of action of the patellar tendon and the position and orientation of the screw axis are known. In this study, the orientation of the patellar tendon and the position and orientation of the finite screw axis of the tibia relative to the femur were calculated from measurements of the three-dimensional positions of the bones obtained from fresh cadaver specimens.
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