Kohyama Sho, Tanaka Toshikazu, Okano Eriko, Naoyuki Ochiai
1 Department of Orthopedic Surgery, Kikkoman General Hospital, Noda, Chiba, Japan.
J Hand Surg Asian Pac Vol. 2017 Sep;22(3):281-285. doi: 10.1142/S0218810417500307.
This study aimed to develop a classification that precisely describes the extensor carpi ulnaris (ECU) groove morphology.
Reconstructed axial plane computed tomography scans of the wrists of 200 patients were reviewed. Three groups of groove shape were created based on the position of the deepest point: deviated to the ulnar side (Type U), in the middle of the groove (Type M), and deviated to the radial side (Type R). Groove depth, width, carrying angle, and radius of the curvature were measured using the Picture Archiving and Communication System in a slice in which the ulnar head was the largest.
Type U was present in 88 patients (44%), Type M in 74 patients (37%), and Type R in 38 patients (19%). The average depth, width, carrying angle, and radius of curvature were 2.2 mm, 9.2 mm, 135.8° and 7.0 mm, respectively. Depth, width, and carrying angle were normally distributed. Both depth and width were statistically correlated with the carrying angle; groove depth and width were not correlated. ECU groove shape and depth showed excellent intra- and inter-observer reliabilities; the reliabilities for the width were poor. Therefore, depth subgroups were defined using cutoffs of ±2 standard deviations (SD): d1 (≤-2 SD), ≤1.0 mm; d2 (±SD), 1.1-3.3 mm; and d3 (≥+2 SD), ≥3.4 mm. The 200 wrists were classified as follows: 0.5% Ud1, 40.2% Ud2, 1.3% Ud3, 0.8% Md1, 38.3% Md2, 0.8% Md3, 1.5% Rd1, 16.4% Rd2, and 0.2% Rd3.
The detailed morphology of the ECU groove was classified using three major types and depth subgroups. The Type R ECU groove, which lacks a medial bony buttress, might be more prone to ECU-related injuries. This classification helps to understand the ECU tendon-related injury pathologies and may provide valuable information for treatment decisions; however, further research is necessary.
本研究旨在开发一种能精确描述尺侧腕伸肌（ECU）沟形态的分类方法。
回顾了200例患者腕部的重建轴向平面计算机断层扫描图像。根据最深点的位置创建了三组沟形状：向尺侧偏斜（U型）、位于沟中间（M型）和向桡侧偏斜（R型）。在尺骨头最大的层面上，使用图像存档与通信系统测量沟的深度、宽度、提携角和曲率半径。
88例患者（44%）为U型，74例患者（37%）为M型，38例患者（19%）为R型。平均深度、宽度、提携角和曲率半径分别为2.2mm、9.2mm、135.8°和7.0mm。深度、宽度和提携角呈正态分布。深度和宽度均与提携角存在统计学相关性；沟深度和宽度无相关性。ECU沟形状和深度显示出极好的观察者内和观察者间可靠性；宽度的可靠性较差。因此，使用±2个标准差（SD）的临界值定义深度亚组：d1（≤-2 SD），≤1.0mm；d2（±SD），1.1 - 3.3mm；d3（≥+2 SD），≥3.4mm。200例腕部分类如下：0.5% Ud1，40.2% Ud2，1.3% Ud3，0.8% Md1，38.3% Md2，0.8% Md3，1.5% Rd1，16.4% Rd2，0.2% Rd3。
ECU沟的详细形态通过三种主要类型和深度亚组进行分类。缺乏内侧骨支撑的R型ECU沟可能更容易发生与ECU相关的损伤。这种分类有助于理解与ECU肌腱相关的损伤病理，并可能为治疗决策提供有价值的信息；然而，仍需进一步研究。
