确定矫形外固定架锯片使用的安全参数。

Department of Orthopaedic Surgery, Queen Elizabeth II Health Sciences Centre.

Aberdeen Hospital, New Glasgow, NS, Canada.

J Pediatr Orthop. 2021;41(10):e884-e888. doi: 10.1097/BPO.0000000000001928.

BACKGROUND

The incidence of injuries from cast saws during cast removal ranges from 0.12% to 4.3%. With 1 second or less of exposure time, a temperature of 65°C can cause partial thickness burns. Despite numerous studies that recommend avoiding the use of a dull blade, there is no objective measure of what defines dullness.

METHODS

Plaster and fiberglass casts were collected and measured after removal from patients in the clinic. A series of slabs were constructed based on these measurements. To simulate our emergency department setting, a Stryker 940 cast saw without an attached vacuum was used to split plaster slabs. A thermocouple was used to directly measure the 940-23 ion-nitride saw blade temperature after each use. To simulate our orthopaedic clinic setting, a Stryker 940 cast saw with an attached vacuum was used to split fiberglass and plaster slabs. Three blades were tested in each setting, bivalving 50 slabs each.

RESULTS

For the plaster slabs split without a vacuum, average blade temperature of the 3 blades reached 65°C on the 42nd cast. However, the individual blades exceeded 65°C on the 33rd, 31st, and 38th casts, respectively. For the fiberglass and plaster slabs split with a vacuum, average blade temperature reached a maximum of 57.5°C in the first 50 trials. Extrapolating from this data, the blade is predicted to exceed 65°C on the 104th cast.

CONCLUSIONS

When a Stryker 940 cast saw without vacuum is used to cut plaster casts, the ion-nitride blade should be changed frequently, at minimum after 60 casts have been split, or 30 casts have been bivalved. When a Stryker 940 cast saw with vacuum is used to remove fiberglass and plaster casts, the ion-nitride blade should be changed after removing 103 casts. A cast saw with an attached vacuum should be used whenever possible to minimize the risk of burning patients.

CLINICAL RELEVANCE

Determine how often a cast saw blade should be changed to minimize risk of burning patients.

背景

在拆除石膏时，使用石膏锯导致受伤的发生率为 0.12%至 4.3%。暴露时间在 1 秒或更短时间内，温度达到 65°C 可能会造成部分厚度烧伤。尽管有许多研究建议避免使用钝刀片，但目前还没有客观的方法来定义什么是钝刀片。

方法

从诊所的患者身上取下石膏和玻璃纤维石膏后，对其进行测量并收集。根据这些测量结果制作了一系列平板。为了模拟我们的急诊室环境，使用 Stryker 940 无真空的石膏锯来切割石膏平板。使用热电偶直接测量每次使用后的 940-23 氮化离子锯片温度。为了模拟我们的骨科诊所环境，使用带有真空的 Stryker 940 石膏锯来切割玻璃纤维和石膏平板。在每种环境下测试了 3 个刀片，每个刀片分别切割 50 个平板。

结果

在没有真空的情况下切割石膏平板时，3 个刀片的平均刀片温度在第 42 个石膏时达到 65°C。然而，第 33、31 和 38 个石膏时，各个刀片的温度分别超过了 65°C。在有真空的情况下切割玻璃纤维和石膏平板时，平均刀片温度在前 50 次试验中达到了 57.5°C 的最大值。根据该数据推断，刀片预计在第 104 次切割时会超过 65°C。

结论

当使用不带真空的 Stryker 940 石膏锯切割石膏模型时，应至少在切割 60 个石膏模型后或切割 30 个石膏模型后频繁更换氮化离子刀片。当使用带真空的 Stryker 940 石膏锯切除玻璃纤维和石膏模型时，应在切除 103 个模型后更换氮化离子刀片。在可能的情况下，应使用带有真空的石膏锯以最大程度地降低灼伤患者的风险。