Abstract: Knee arthroplasty trials, systems, and methods regarding the same. The knee arthroplasty trial system may include an expandable tibial tray trial having top and bottom plates, an actuation screw retained in the bottom plate, and an expansion ramp configured to slide along the bottom plate and lift the top plate as the ramp translates forward. The actuation screw may define a helical cut with step portions, and the expansion ramp includes a pin configured to engage the helical cut of the actuation screw. When the actuation screw is rotated, the pin rides along the helical cut and is configured to rest within one of the step portions, thereby ensuring that the expandable tibial tray trial expands only to discrete thicknesses.

Abstract: A vaporizer for air treatment and the like producing vapors which can be renewed to provide effective operation for an extended period of time. The vaporizer comprises an hourglass-shaped container having a pair of adjacent chambers communicating by means of a restrictive orifice. Each chamber has an opening in the end covered by a porous membrane. The container contains a supply of particulate fluid-like carrier material carrying a volatile vapor-producing treating material. A part of the treating agent is transferred by the carrier material to the membrane for producing air treating vapors by volatilization or evaporation of the treating agent. Inversion of the container, mixes and redistributes the treating agent among the carrier vehicle particles and exposes a freshly loaded vapor producing membrane.