Stevens Michael R E, Kirk Andrew M, Collofello Brandon S, Muffly Brian T, Prusick Vincent W
University of Kentucky Department of Orthopaedic Surgery and Sports Medicine, Lexington, KY.
Shriners Hospital for Children, Lexington, KY.
J Pediatr Orthop. 2024 Jan 1;44(1):63-67. doi: 10.1097/BPO.0000000000002531. Epub 2023 Oct 5.
Thermal injuries can occur during cast removal with an oscillating saw. The purpose of this study is to describe the effect of blade material, blade wear, and cast material on blade temperature.
Short arm plaster and fiberglass casts were cured overnight and bivalved with either new or worn stainless-steel or tungsten-disulfide coated blades. Blade use was defined as removing 1 short arm cast. Blades used to remove more than 20 casts were defined as worn. Ten trials were performed with each combination of blade material, blade wear, and cast material, except for the combination of fiberglass and a worn stainless-steel blade due to complete erosion of cutting teeth. Thirty casts were removed with stainless-steel blades, and 40 casts were removed with coated blades. Blade temperature was measured continuously at 5 Hz using a T-type thermocouple and microcontroller board. A Mann-Whitney U test was used to compare the mean maximum temperature between groups.
For plaster casts, new and worn stainless-steel blades produced mean maximum temperatures of 51.4°C and 63.7°C ( P =0.003), respectively. New stainless-steel blades produced significantly higher mean maximum temperatures on fiberglass casts than plaster casts (95.9°C vs. 51.4°C, P <.001). For plaster casts, new and worn coated blades produced mean maximum temperatures of 56.9°C and 53.8°C ( P =0.347). For fiberglass casts, new and worn coated blades produced mean maximum temperatures of 76.6°C and 77.7°C ( P =0.653). As with new stainless-steel blades, new coated blades produced significantly higher mean maximum temperatures on fiberglass than plaster (76.6°C vs. 56.9°C, P <0.001). Mean maximum temperatures between new stainless-steel and coated blades during removal of plaster casts were 51.4°C and 56.9°C ( P =0.131), respectively. However, new coated blades demonstrated significantly lower mean maximum temperatures during fiberglass cast removal compared to new stainless-steel blades (76.6°C vs. 95.9°C, P =0.016).
Coated blades outperformed stainless-steel in nearly all combinations. We recommend limited use of stainless-steel blades to minimize blade temperatures during cast removal.
Appropriate selection of blade material and monitoring blade wear minimizes blade temperature during cast removal.
使用摆动锯拆除石膏时可能会发生热损伤。本研究的目的是描述刀片材料、刀片磨损和石膏材料对刀片温度的影响。
短臂石膏和玻璃纤维石膏过夜固化，然后用新的或磨损的不锈钢或二硫化钨涂层刀片将其切成两半。刀片的使用定义为拆除1个短臂石膏。用于拆除超过20个石膏的刀片定义为磨损。除了玻璃纤维和磨损的不锈钢刀片组合（由于切割齿完全磨损）外，对刀片材料、刀片磨损和石膏材料的每种组合进行了10次试验。用不锈钢刀片拆除了30个石膏，用涂层刀片拆除了40个石膏。使用T型热电偶和微控制器板以5Hz的频率连续测量刀片温度。使用Mann-Whitney U检验比较各组之间的平均最高温度。
对于石膏，新的和磨损的不锈钢刀片产生的平均最高温度分别为51.4°C和63.7°C（P = 0.003）。新的不锈钢刀片在玻璃纤维石膏上产生的平均最高温度明显高于石膏（95.9°C对51.4°C，P <.001）。对于石膏，新的和磨损的涂层刀片产生的平均最高温度分别为56.9°C和53.8°C（P = 0.347）。对于玻璃纤维石膏，新的和磨损的涂层刀片产生的平均最高温度分别为76.6°C和77.7°C（P = 0.653）。与新的不锈钢刀片一样，新的涂层刀片在玻璃纤维上产生的平均最高温度明显高于石膏（76.6°C对56.9°C，P <0.001）。拆除石膏时，新的不锈钢刀片和涂层刀片之间的平均最高温度分别为51.4°C和56.9°C（P = 0.131）。然而，与新的不锈钢刀片相比，新的涂层刀片在拆除玻璃纤维石膏时的平均最高温度明显更低（76.6°C对95.9°C，P = 0.016）。
在几乎所有组合中，涂层刀片的性能都优于不锈钢刀片。我们建议限制使用不锈钢刀片，以在拆除石膏时将刀片温度降至最低。
适当选择刀片材料并监测刀片磨损可在拆除石膏时将刀片温度降至最低。
