Efficacy of DIY Cast Covers: An In Vivo Study

Casting is routinely used in orthopaedics. Preventing a wet cast is crucial for maintaining structural integrity and reducing unwanted complications like unnecessary skin irritation/ulceration, bacterial overgrowth, and unnecessary emergency department visits. Using experimental models, studies have tested various contemporary methods to prevent a wet cast. One such study found that in comparison the most effective and cost-conscious approach was to use a Do-It-Yourself cast cover using a double-bag technique sealed with tape. There is a paucity of literature on the utility of this technique in vivo. The purpose of this study was to investigate the efficacy of the Do-It-Yourself cast cover on human test subjects.

Ten volunteers for the study were obtained. Each received one short arm cast and one short leg cast. Each cast was removed after they were deemed dry. These casts were subsequently weighed until they achieved a stable weight. Each cast was then reapplied to the subject's arm and held together with Scotch tape. A trash bag was then applied around the cast and then secured with Duct tape to the skin. This was repeated to create a double seal. These covered, reapplied casts were submerged under water for 2 minutes. After submersion, the cover was removed, and the cast was reweighed. The casts were then submerged completely without any protection for 2 minutes and their fully saturated weight was recorded. Efficacy was determined by comparing the postsubmersion and full-submersion weights. Data was analyzed using the Mann-Whitney test.

The percentage of water absorption prevention ranged from 96.8% to 99.9%, with an average of 99.6% across the entire study sample ( P <0.0001). No adverse effects were reported.

Our findings conclude that the double-bag with Duct-tape method is effective at preventing external water absorption. This in vivo study demonstrates that almost all external water absorption can be prevented using this simple and inexpensive technique.

Level II, prospective comparative study.