A Cost Effective Cast Saw Simulation-based Educational Module to Improve Cast Saw Removal Safety
Grant Recipient: Teresa Cappello, MD
- Loyola University Medical Center
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- This is a pilot study aimed at validating a simulation-based educational module to reduce morbidity related to cast removal in children. The module uses a low-cost , reproducible, forearm length wax block that is castable and melts at the same temperature at which skin has been shown to burn (66 C). The wax models were casted using three to four layers of 3" Webril cast padding followed by three to four layers of 3" Delta-Lite Plus fiberglass casts. All models were casted by one person in a uniform manner.
The first data collection session included an untrained inexperienced cohort of 15 medical students with no cast-saw experience who then removed the fiberglass cast from our wax-based model. Each person was asked to make four longitudinal cuts in the cast covered wax model using a Stryker 940 Cast Cutter oscillating saw with a new Synthes 2.5 inch Ion Nitrided Cast Cutter Blade. The second cohort was comprised of 15 professionals with cast saw training and experience , ranging from a minimum of 5 years to over 20 years of experience. A new Synthes 2.5 inch Ion Nitrided Cast Cutter Blade was used. Identical measurements of cast saw indentation length, maximum depth and maximum width were made.
Heat-indentations created by the oscillation of the cast saw were measured using a digital measuring tool, "iGAGING OriginCal, Digital Caliper", which uses high accuracy ABSOLUTE encoder technology shown to have an accuracy within 0.001 +/- 0.02mm. The length, maximum depth, and maximum width of each individual error was measured. The length of combined cast saw indentations was calculated for each of the 4 cutting lanes. The total length of the cast saw indentations per cast saw user was then calculated.
For the untrained inexperienced cast saw users, the total length of cast saw indentations for the combined 4 cutting lanes ranged from 224.8 - 868.7mm. The average length was 527.5mm. The average maximum depth was 1.31mm. The average maximum width was 2.66mm.
For the trained experienced cast saw users, the total length of cast saw indentations for the combined 4 cutting lanes was 0- 479.7mm. When a cast saw indentation was observed, the average length was 152.5mm. The averagemaximum depth when a cast saw indentation was made was 0.42mm, and the average maximum width when a cast saw indentation was made was 1.56mm.
Comparison is planned between the two cohorts to determine if statistical significance is reached between the length, maximum depth and maximum width of cast saw indentations in the wax and to confirm that this particular casted wax model could differentiate between untrained inexperienced cast saw users and trained experienced cast saw users. However, we were unable to have the institution's statisticians review the data collection in the time frame allowed. We are currently on a waiting list for a statistician. We predict we will have adequate access to a statistician in the next 1-2 months in order to evaluate the data appropriately.
We have reviewed the data ourselves, and we predict statistical significance will be reached and that this model will be shown to have the ability to distinguish between inexperienced untrained cast saw users and experienced trained cast saw users.
The primary outcome measures of the study were reached. We were able order the wax models, cast the wax models and then to successfully have both inexperienced and experienced cast saw users remove the casts from the wax models. However, due to lack of statistical analysis support at our institution, we were unable to prove the differences measured reached statistical significance.
We predict it will do so, but we cannot conclude that as of yet.
Once we have access to statistical review and our conclusions are demons trated, we will submit this study fore-poster presentation at the 2020 POSNA Annual Meeting as well as for publication.
We plan on utilizing this cast model to teach orthopaedic residents at our institution how to properly remove fiberglass casts. Our next step is to develop a cast removal instruction module and then implement it. We plan on studying the efficacy of the cast removal instruction session for orthopaedic residents by measuring the length, maximum depth and maximum width of cast saw indentations in the wax model before and after a cast saw removal instruction session.