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Appropriate management of radial head fractures is integral to prevent long-term consequences like chronic pain and loss of motion. Advanced imaging systems, like micro-computed tomography (μCT), are valuable for understanding radial head fracture patterns as they utilize micrometer scale resolution to define important parameters of bone health like cortical density and trabecular thickness. The purpose of this study was to identify and describe the structural morphology of the radial head utilizing μCT. Nine fresh-frozen cadaveric human radii were divided into four equal quadrants, based, and labeled as posteromedial, posterolateral, anteromedial, and anterolateral. Quadrants were scanned with a SCANCO MicroCT40 with both cortical and cancellous bone density measurements at a resolution of 36.0 μm. Bone density, direct trabecular number, and trabecular thickness were recorded as milligrams of hydroxyapatite/cm 3 . A one-way repeated measures ANOVA was performed to compare the bone densities, trabecular number, and trabecular thickness of each of the four quadrants (p < 0.05). The posteromedial quadrant contained substantially more bone than other quadrants. Significantly greater bone densities were found in the posteromedial quadrant (148.1 mg of HA/cm 3 ) compared to the anteromedial quadrant (54.6 mg of HA/cm 3 ), posterolateral quadrant (137.5 mg of HA/cm 3 ) compared to the anteromedial quadrant (54.6 mg of HA/cm 3 ), and posterolateral quadrant (137.5 mg of HA/cm 3 ) compared to the anterolateral quadrant (58.1 mg of HA/cm 3 ). The trabecular number was not significantly different between quadrants. Trabecular thickness was significantly lower in the anterolateral (0.1417 mg of HA/cm 3 ) and anteromedial (0.1416 mg of HA/cm 3 ) quadrants compared to the posteromedial (0.1809 mg of HA/cm 3 ) quadrant. The posterior half of the radial head was found to have a higher density of columns and arches compared to the anterior half. The microstructure of trabecular bone in the distal radius forms columns, struts, and arches, which allow for efficient transmission of stress through the bone. The microstructure of the radial head has similar microarchitecture to the distal radius with the present study identifying the presence of columns and arches in the radial head. These structures, along with trabecular density, in the posterior radial head may explain the lower incidence of fractures involving the posterior half of the radial head. Furthermore, our study supports the idea that the high incidence of fractures involving the anterolateral quadrant is due to microarchitecture characteristics and the relative lack of supportive structures compared to other areas. The novel insight gained from this study will aid in the development of advanced interventions for preventative measures and better treatment of radial head fractures like more satisfactory purchase when screws are directed towards the denser posteromedial quadrant., (© 2024 American Association of Clinical Anatomists and British Association of Clinical Anatomists.)

The posterior approach is a commonly employed exposure of the elbow that provides excellent visualization and efficacy for various orthopedic procedures, including total elbow arthroplasty (TEA) and fracture care. The posterior approach to the elbow has been associated with an increased rate of wound complications, including infection, skin necrosis, and wound dehiscence. Despite an association between these complications and decreased elbow perfusion, data regarding the intrinsic anatomic etiology for preferential complications in this area has been scarcely reported in the literature. This study characterizes the subdermal and cutaneous vascular perfusion about the elbow by describing the predominant direction of circulation, subdermal anastomoses, and volume of perfusion through cadaveric modeling using computed tomography angiography (CTA). Fifteen upper extremity cadaver specimens were prepared with injection of radiographic contrast directly into the axillary artery immediately preceding CTA imaging of each specimen. Sectra IDS7 software for Windows was used for analysis of all images to produce superimposed axial and 3-D reconstructions of each CTA series. From these images it was discerned that the predominant direction of flow in the posterior elbow integument is anterior medial to posterior lateral. Both the posterior medial and posterior lateral subdermal vascular networks emanate from proximally derived medial arterial sources with few anastomoses and minimal collateral perfusion from the anterolateral location. Consequently, it is important to preserve medial subdermal vascular structures to prevent ischemic wound complications. This is especially true in previously incised elbow integuments. Clin. Anat. 32:509-514, 2019. © 2019 Wiley Periodicals, Inc., (© 2019 Wiley Periodicals, Inc.)