Journal of orthopaedic research : official publication of the Orthopaedic Research Society
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A biomechanical investigation on eight pairs of human cadaver proximal femurs was performed to evaluate the impact of a new augmentation method on the internal fixation of osteoporotic proximal femur fractures. The study focused on enhancing implant purchase to reduce the incidence of implant cut-out in osteoporotic bone. In a left-right comparison, a conventional hip screw fixation (control) was compared to the new cement augmentation method. ⋯ The displacement rate at the second load step was significantly higher (p=0.018) for the conventionally treated bones as compared to the augmented ones. All of the nonaugmented specimens failed during testing, where 50% of the augmented specimens did not fail. The promising results of these experiments suggest that this new standardized irrigation/augmentation method enhances the implant anchorage and offers a potential solution to the problem of implant cut-out in osteoporotic metaphyseal bone.
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The purpose of this work was to obtain kinematics data for the normal human patellofemoral joint in vitro. Eight fresh-frozen cadaver knees were used. The heads of the quadriceps were separated, and the knees mounted in a kinematics rig. ⋯ The patella tilted progressively to 7 degrees lateral by 90 degrees knee flexion, and patellar medial-lateral rotation was usually less than 3 degrees. This is believed to be the first set of patellar tracking data obtained in both flexion and extension motion while the patella was acted on by a full set of quadriceps muscle tensions acting in physiological directions. These data may be used in future studies of the effects of pathologies on patellar tracking.