Splint Padding Thickness: Temperature Effects and X-ray Visualization

The purpose of this study was to determine if the thickness of splint padding could be determined on X-rays, and whether increasing layers of splint padding have an effect on temperature at the skin after placement.

Both in vitro and in vivo testing was performed. Ten cadaveric lower extremities were used. A thermocouple was placed on the posterior calf for temperature determination. Cadavers were used with short leg posterior splints with sidebars placed using various thicknesses of padding: (1) 2 layers of Webril, (2) 4 layers of Webril, (3) 2 × 2 padding (Webril followed by kerlix, then repeated), and (4) bulky cotton padding. A splint with no padding was used as a control. Lateral X-rays of the ankle were obtained. The padding thickness was measured. The change in temperature at the level of the skin was measured throughout the process. The test was then repeated in vivo to correlate the cadaver findings with a live subject.

The mean thickness of the 5 padding types could be reliably determined on X-ray. Our cadaver temperature data shows that all padding thickness tested decreased temperature change after plaster curing, with no significant difference between wraps. Live subject testing showed similarities between the 2-layer Webril and 2 × 2 padding, and between the 4-layer Webril and bulky padding.

Padding thickness can be consistently determined on X-ray. We determined that at least 2 layers of Webril significantly decrease temperature change at the level of the skin caused by plaster curing. Two layers of Webril can be identified on X-ray by measuring at least 1 mm of padding.