Hand and Upper Limb Centre, St. Joseph's Health Care, University of Western Ontario, London, ON, Canada.
J Shoulder Elbow Surg. 2012 Dec;21(12):1669-73. doi: 10.1016/j.jse.2012.07.002. Epub 2012 Sep 21.
Fractures of the radial head are common with most partial articular fractures resulting in an anterolateral fragment. The exact mechanism of radial head fracture is unknown; however, forces transmitted and variations in local bone density are believed important. This study quantifies the regional variations in bone density and volume of the radial head to better understand the pathomechanics of fracture patterns.
Computer tomography scan data of 18 cadaver elbows were imported into imaging analysis software. The radial head was divided into quadrants based on neutral forearm rotation. Bone density and volume were calculated and compared between quadrants.
The regional densities of bone expressed in Hounsfield units (HU) were posteromedial quadrant (PM) 496 ± 87 HU, anteromedial quadrant (AM) 443 ± 72 HU, anterolateral quadrant (AL) 409 ± 60 HU, and posterolateral quadrant (PL) 406 ± 57 HU. The volume of bone in descending order was PM 1138 ± 179 mm(3), PL 1013 ± 213 mm(3), AM 1010 ± 210 mm(3), and AL 938 ± 175 mm(3). The PM quadrant was significantly denser than the AM, AL, and PL quadrants, (P = .001) and the AM quadrant was significantly denser than the AL and PL quadrants (P = .006 and .009). The PM quadrant had significantly more bone volume when compared to the AM, AL, and PL (P = .001). The AM and PL quadrants had significantly greater bone volume compared to AL quadrant (P = .023 and .018, respectively).
Radial head bone volume and density is highest in the posteromedial quadrant and lowest in the anterolateral quadrant where fractures occur more frequently.
桡骨头骨折很常见，大多数部分关节骨折导致前外侧碎片。桡骨头骨折的确切机制尚不清楚；然而，所传递的力和局部骨密度的变化被认为是重要的。本研究量化了桡骨头的骨密度和体积的区域变化，以更好地了解骨折模式的病理机制。
将 18 例尸体肘部的计算机断层扫描数据导入成像分析软件。根据中立前臂旋转将桡骨头分为四个象限。计算并比较了象限之间的骨密度和体积。
以亨氏单位（HU）表示的区域骨密度为后内侧象限（PM）496±87 HU、前内侧象限（AM）443±72 HU、前外侧象限（AL）409±60 HU 和后外侧象限（PL）406±57 HU。按降序排列的骨体积为 PM 1138±179 mm（3）、PL 1013±213 mm（3）、AM 1010±210 mm（3）和 AL 938±175 mm（3）。PM 象限明显比 AM、AL 和 PL 象限致密（P =.001），AM 象限明显比 AL 和 PL 象限致密（P =.006 和.009）。PM 象限的骨体积明显大于 AM、AL 和 PL（P =.001）。AM 和 PL 象限的骨体积明显大于 AL 象限（P =.023 和.018）。
桡骨头骨体积和密度在后内侧象限最高，在前外侧象限最低，骨折更常发生。
