Debnath Ujjwal K, Guha Abhijit R, Das Sreejib
Wrexham Maelor Hospital, Wrexham, North Wales, UK.
Indian J Orthop. 2011 Jul;45(4):341-6. doi: 10.4103/0019-5413.80322.
Displaced distal forearm fractures in children have been treated in above-elbow plaster casts since the last century. Cast index (CI) has been proposed as a measure to indicate how well the cast is molded to the contours of the forearm. In this study the CI in post-manipulation radiographs were analyzed to evaluate its relevance to re-angulation of distal forearm fractures in children in different age-groups.
Out of 174 consecutive cases treated during the study period, 156 patients (114 male and 42 female) with a mean age of 9.8 years (range: 2-15 years) were included in this retrospective radiographic analysis; 18 patients were excluded for various reasons. All patients were manipulated in the operation theater under general anesthesia and a molded above-elbow cast was applied. The CI was measured on immediate post-manipulation radiographs. Children were divided into three groups according to age: group 1: <5 years, group 2: 5-10 years, and group 3: >10 years.
Angulation of the fracture within the original plaster cast occurred in 30 patients (19.2%): 22/114 males and 8/42 females. The mean CI in these 30 patients who required a second procedure was 0.92±0.08, which was significantly more than the mean CI in the other children (0.77±0.07) (P<.001). The mean CI in children who underwent re-manipulation in the group 1 was 0.96, which was significantly higher than that of the other two groups, i.e., 0.90 in group 2 and 0.88 in group 3 (P<.05). A receiver operating characteristics (ROC) curve estimated the cutoff point for intraoperative CI of 0.84 when both the sensitivity and specificity of CI was high to predict re-manipulation for re-displaced fractures of the distal forearm in children in any age-group.
The CI is a valuable tool to assess the quality of molding of the cast following closed manipulation of forearm fractures in children. A high CI (≥0.84) in post-manipulation radiographs indicates increased risk of re-displacement of the fracture in children, especially in those under the age of 5 years and over the age of 10 years.
自上世纪以来，儿童桡骨远端移位骨折一直采用长臂石膏管型治疗。石膏指数（CI）已被提议作为一种衡量石膏贴合前臂轮廓程度的指标。在本研究中，对手法复位后X线片上的CI进行分析，以评估其与不同年龄组儿童桡骨远端骨折再成角的相关性。
在研究期间连续治疗的174例病例中，156例患者（男114例，女42例）纳入本回顾性影像学分析，平均年龄9.8岁（范围：2 - 15岁）；18例患者因各种原因被排除。所有患者均在手术室全身麻醉下进行手法复位，并应用塑形长臂石膏管型。在手法复位后即刻的X线片上测量CI。儿童根据年龄分为三组：1组：<5岁，2组：5 - 10岁，3组：>10岁。
30例患者（19.2%）在初次石膏管型固定后骨折发生再成角：男性22/114例，女性8/42例。这30例需要二次手术的患者的平均CI为0.92±0.08，显著高于其他儿童的平均CI（0.77±0.07）（P<0.001）。1组中接受再次手法复位的儿童的平均CI为0.96，显著高于其他两组，即2组为0.90，3组为0.88（P<0.05）。当CI的敏感性和特异性都较高时，受试者工作特征（ROC）曲线估计术中CI的截断点为0.84，以预测任何年龄组儿童桡骨远端骨折再移位的再次手法复位。
CI是评估儿童前臂骨折闭合复位后石膏塑形质量的有价值工具。手法复位后X线片上高CI（≥0.84）表明儿童骨折再移位风险增加，尤其是5岁以下和10岁以上儿童。
