radiocapitellar line
Projectional
radiograph of a normal elbow, demonstrating the radiocapitellar line (black arrow). It should pass through the capitulum of the humerus. A line outside this area indicates a dislocation of the humeroradial joint.
Projectional
radiograph of an elbow, with the black line being the the radiocapitellar line. It should normally pass through the capitulum of the humerus, but is outside the area on this image, indicating a dislocation of the humeroradial joint.
The elbow:
review of anatomy and common collateral ligament complex pathology using MRI. Axial FS PD-weighted MRI (a) showing the measurement of normal ulnohumeral incongruity: the distance between the trochlear joint surface and olecranon joint surface (D1, D2, D3, and D4). Sagittal FS PD-weighted MRI (b) showing the measurement of normal radiocapitellar incongruity (RCI): the distance between CAP and R. Axial FS PD-weighted MRI showing an ulnohumeral incongruity of more 1 mm (c). Sagittal FS PD-weight MRI showing a radiocapitellar incongruity of more 2 mm (d)
The radiocapitellar line is one of the key lines used to assess alignment on the elbow radiograph. It is particularly useful in the pediatric setting.
The rule
A line drawn down the neck of the radius should intersect the capitellum. It is important to ensure that you draw the line down the radial neck and not along the shaft because of the slight angulation at the neck of the radius.
If the line does not intersect the capitellum, there is radial head dislocation. This usually occurs in pediatric patients as a result of trauma and the dislocation is usually anterior. If the radial head is rounded, consider congenital radial head dislocation.
Video tutorial
See also
Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Radius-Capitulum-humeri-Linie:
