Department of Orthopaedics, Marshall University School of Medicine Huntington, WV.
Shriners Hospitals for Children in Lexington, KY.
J Pediatr Orthop. 2021 Sep 1;41(8):e605-e609. doi: 10.1097/BPO.0000000000001877.
Supracondylar humerus (SCH) fractures are the most common elbow fractures in children. Historically, displaced (Gartland type 3) SCH fractures have been treated with closed reduction and percutaneous pinning. Fluoroscopic imaging is used intraoperatively in order to assess adequate reduction of the fracture fragments before pinning. On lateral fluoroscopic and radiographic images, a lateral rotation percentage (LRP) can be estimated in order to assess rotational deformity. The purpose of this study was to determine the true rotational deformity of distal humerus fracture fragments in SCH fractures based upon the LRP using a clinically relevant laterally based pinning technique.
In this study, a sawbones model was used to examine the correlation between calculated LRP and the true degree of rotational deformity with 3 of the most common extension-type SCH fracture types (low transverse, high transverse, and lateral oblique). Because fracture stability was not the focus of this study, a single pin was used to hold the construct and allow for fragment rotation along a fixed axis. In this study, 2 of the authors independently measured rotational deformity and compared this with LRP on fluoroscopic lateral imaging of a sawbones model at 0 to 45 degrees of rotational deformity.
The LRP of all 3 patterns demonstrated a near linear increase from 0 to 45 degrees with maximum LRP measured at 45 degrees for each of the 3 patterns. Univariate linear regression demonstrated an increase in LRP for the low transverse pattern of 2.02% for every degree of rotation deformity (R2=0.97), 2.29% for the lateral oblique pattern (R2=0.986), and 1.17% for the high transverse pattern (R2=0.971). Maximum LRP was measured at 45 degrees for all 3 patterns with a mean of 53.5% for the high transverse pattern, 93.5% for the low transverse pattern, and 111.2% for the lateral oblique pattern. A higher LRP was measured with increasing degrees of rotational displacement in the low transverse and lateral oblique patterns for all degrees of rotational deformity compared to the high transverse pattern.
There is a near linear correlation between the degree of malrotation and the LRP with more superior metaphyseal fracture patterns demonstrating a lower LRP than inferior fracture patterns.
Using our data one can estimate the degree of malrotation based on the LRP on radiographs in the clinical setting.
Not applicable (basic-science article).
肱骨髁上（SCH）骨折是儿童中最常见的肘部骨折。历史上，移位（Gartland 3 型）的 SCH 骨折采用闭合复位和经皮克氏针固定治疗。术中使用透视成像来评估固定前骨折碎片的充分复位。在侧位透视和 X 线图像上，可以估计外侧旋转百分比（LRP）以评估旋转畸形。本研究的目的是使用临床相关的外侧基于销钉技术，根据 LRP 确定 SCH 骨折中远端肱骨骨折碎片的真实旋转畸形。
在这项研究中，使用骨骼模型检查了 3 种最常见的伸展型 SCH 骨折类型（低横、高横和外侧斜）中计算的 LRP 与真实旋转畸形程度之间的相关性。因为骨折稳定性不是本研究的重点，所以使用单个销钉来固定结构，允许碎片沿固定轴旋转。在这项研究中，两位作者独立测量了旋转畸形，并将其与骨骼模型在 0 至 45 度旋转变形的侧位透视图像上的 LRP 进行比较。
所有 3 种模式的 LRP 均显示出从 0 度到 45 度的近线性增加，最大 LRP 在 3 种模式的 45 度时测量。单变量线性回归显示，低横骨折模式的 LRP 每增加 1 度旋转畸形增加 2.02%（R2=0.97），外侧斜骨折模式增加 2.29%（R2=0.986），高横骨折模式增加 1.17%（R2=0.971）。所有 3 种模式的最大 LRP 均在 45 度测量，高横骨折模式的平均值为 53.5%，低横骨折模式为 93.5%，外侧斜骨折模式为 111.2%。与高横骨折模式相比，低横和外侧斜骨折模式的旋转位移角度越大，LRP 测量值越高。
在旋转畸形程度和 LRP 之间存在近乎线性的相关性，较高的干骺端骨折模式比较低的干骺端骨折模式具有较低的 LRP。
根据临床实践中 X 线片上的 LRP，我们可以估计旋转不良的程度。
不适用（基础科学文章）。
