An Innovative Weightbearing Device for Weightbearing 3-Dimensional Imaging for Foot and Ankle Surgery Preoperative Planning.

Three-dimensional preoperative planning has demonstrated multiple surgical advantages. Currently, we cannot carry out preoperative 3-dimensional planning of foot and ankle orthopedics in most hospitals due to the impossibility of performing weightbearing CT imaging. Our objective is to describe and evaluate an innovative accessible, simple, and effective device that simulates standing while in a supine position, to obtain 3-dimensional images supporting bodyweight load with a conventional CT machine. From a group of 30 volunteers, 10 patients were randomly selected and pressure and its distribution were analyzed while in a standing position in both feet. Differences between both feet were considered normal intrapersonal variability. Subsequently, the right footprint of the same 10 subjects was evaluated in the proposed loading device. Then, their pressures and distribution were compared with respect to standing and with respect to intrapersonal variability. The mean total standing pressure was 93 Kpa (standard deviation [SD] 14.32), which was reduced to 81.95 Kpa (SD 19.54) in the loading device. The load device reduced the pressure by a mean of16% (SD 22% (range -25% to -0.03%). At the hindfoot level, the loading device increased pressure by a mean of 20.59 Kpa, which expressed percentage implies an increase of 14% compared to standing. Due to its easy construction and effectiveness, this is the first device that opens the door of foot and ankle orthopedics in any hospital to 3D preoperative planning and the benefits derived from it.