From the Department of Orthopaedic Surgery, Maimonides Medical Center, Brooklyn, NY (Weisberg, and Gordon), SUNY Downstate Medical School, Brooklyn, NY (Vingan), and Department of Orthopaedics, Connecticut Children's Medical Center, Hartford, CT (Lee).
J Am Acad Orthop Surg. 2022 Aug 1;30(15):e1025-e1032. doi: 10.5435/JAAOS-D-21-01272. Epub 2022 May 25.
Although regarded as conservative treatment, casting is not without risk. Injuries may be sustained during application, during cast valving, through the immobilization process, or during cast removal. We developed an experimental model to investigate safe parameters for the appropriate length of time between fiberglass cast application and bivalving for cast saw use.
A hospital sheet was rolled into a mock "arm" on which short-arm fiberglass casts were formed. An appropriate cast saw technique was used with complete withdrawal of the saw blade from the cast material between cuts. A total of 10 casts were made for control/no vacuum (N = 5) and study/vacuum (N = 5) groups. The temperature of the saw blade was measured at 1-minute increments beginning at 3 minutes after fiberglass submersion in water. A mixed factor analysis of variance assessed differences in temperature change over time between groups with a statistical threshold of P < 0.05.
Casts that set for 7 minutes were associated with lower blade temperatures compared with casts that set for 3, 4, 5, and 6 minutes. The average temperature increases for the 3- to 7-minute set times without the use of vacuum were 10.08 (± 1.42), 9.38 (±1.31), 9.32 (±1.85), 8.54 (±2.10), and 5.62°F (±2.42), respectively, and with the use of vacuum, they were 9.40 (±1.14), 8.36 (±1.64), 7.84 (±2.05), 7.30 (±3.14), and 4.82°F (±2.59), respectively. Independent of vacuum use, the change in temperature was significantly different from the maximum temperature (3 minutes) beginning at 7 minutes (all P < 0.043).
A minimum of 7 minutes of set time for a fiberglass cast before attempting to bivalve using segmented cuts is associated with the smallest increase in temperature of the saw blade. Blade temperature was not affected with the vacuum enabled. Clinicians can demonstrate best practices to minimize the risk of cast saw injuries.
尽管石膏固定被认为是一种保守的治疗方法，但它并非没有风险。在应用过程中、在打开石膏、在固定过程中或在拆除石膏时，可能会受伤。我们开发了一种实验模型，以研究在使用分段切割法对石膏进行双开之前，适当的石膏固定时间长度的安全参数。
将医院的床单卷成一个模拟“手臂”，在其上形成短臂玻璃纤维石膏。使用适当的石膏锯技术，在每次切割之间完全将锯片从石膏材料中抽出。总共制作了 10 个对照/无真空（N = 5）和研究/真空（N = 5）组的石膏。在玻璃纤维浸入水中 3 分钟后，以 1 分钟为增量测量锯片的温度。采用混合因子方差分析评估了两组之间随时间变化的温度变化差异，统计阈值为 P < 0.05。
与 3、4、5 和 6 分钟的设定时间相比，7 分钟的石膏设定时间与较低的锯片温度相关。在不使用真空的情况下，3 至 7 分钟的设定时间的平均温度升高分别为 10.08（±1.42）、9.38（±1.31）、9.32（±1.85）、8.54（±2.10）和 5.62°F（±2.42），而在使用真空的情况下，它们分别为 9.40（±1.14）、8.36（±1.64）、7.84（±2.05）、7.30（±3.14）和 4.82°F（±2.59）。无论是否使用真空，从 7 分钟开始，温度的变化与最大温度（3 分钟）显著不同（均 P < 0.043）。
在尝试使用分段切割法对石膏进行双开之前，至少要将玻璃纤维石膏固定 7 分钟，这与锯片温度升高最小有关。启用真空时，锯片温度不受影响。临床医生可以展示最佳实践，以最大程度地降低石膏锯伤的风险。
