Total Hip Arthroplasty Templating: A Simple Method to Correct for Radiograph Magnification.

Several factors can cause magnification errors when templating. Parallax, distance from the plate, and printing or monitoring the radiographs can lead to errors. Steel balls, 25.

Stability of the posteromedial fragment in a tibial plateau fracture.

The posteromedial fragment in tibial plateau fractures is considered unstable and requires specific fixation. However, if not loaded by the femur, it may remain stable and not require additional fixation. Our purpose was to determine the size of the posteromedial fragment that would remain unloaded by the femoral-tibial contact area, as a function of fracture line orientation and knee flexion angle.

Preclinical evaluation method for total knees designed to restore normal knee mechanics.

The objective was to develop a simple, rapid, and low-cost method for evaluating proposed new total knee arthroplasty (TKA) models and then to evaluate 3 different TKA models with different kinematic characteristics. A "desktop" knee testing rig was used to apply forces and moments over a full flexion range, representing a spectrum of positions and activities; and the positions of the femur on the tibia were measured. The average neutral path of motion (for compressive force only) and the laxities about the neutral path (for superimposed shear and torque) were determined from 8 knee specimens to be used as a benchmark for the TKA evaluations.