Morphology of the articular surfaces of the distal radio-ulnar joint

Abstract

Background The two articular surfaces of the distal ulna get an important role in load transmission and stabilization of the distal radio‐ulnar joint. The present study describes the morphology of the distal radio‐ulnar joint surfaces in terms of the functional relationships between the shape of the ulnar articular facets and the predominant contact situation in this joint. Methods Besides macroscopic dissection and radiological investigation the model of the “inclined plane” has been used to simulate force transmission across the radio‐ulnar joint concerning the angle between the distal and the radial articular surfaces of the ulnar head. Results The presented morphological parameters of the radio‐ulnar joint surfaces verify that the transmitted forces are effective in both a radio‐ulnar and an axial direction. The protection and the captaincy of this joint are limited by its great mobility. The investigations show that signs of an increased load pressure are frequently found in the joints that also show degenerative changes. As a morphological sign of the force transmission, distinct spongious trabecles are formed perpendicularly to the articular circumference in those ulnar heads that show a stolid angle between their articular facets. Conclusions Because of the individuality of the morphological data only qualitative statements can be made both the predominant shapes of the ulnar head, in particular about the loading of its articular surfaces. The angle between its two articular facets influences the force transmission through the radio‐ulnar joint as well as the spongious architecture of the subchondral bone of the ulnar head. © Wiley‐Liss, Inc.

The Influence of Articular Morphology on Non-Traumatic Degenerative Changes of the Distal Radioulnar Joint. A Radiographic Study

“…The morphology of the ulnar head was statistically the most significant factor in the development of degenerative changes of the distal radioulnar joint in our study. This confirms the findings of Bade et al (1996), who stated that the angle between the two articular facets on the ulnar head influences the force transmission through the distal radioulnar head. When there is more inclination of the radial articular surface on the ulnar head force transmission is higher.…”

“…It is the angle between the long axis of the ulna and the surface on the ulnar head articulating with the radius (Fig 3). Bade et al (1996) measured the angle between the radial and distal articular facets on the ulnar head to study the morphology of the articular distal radioulnar joint surfaces. We used the long axis of the ulna instead of the articular surface on the ulnar head articulating with the carpus, because, on X-ray, it was difficult to determine this surface with one line and because the study was designed to examine the articular surface between the distal ulna and radius and not the ulnocarpal joint.…”

“…The morphology of the ulnar head can also vary. The angle between the radial and distal articular facets on the ulnar head ranged between 1111 and 1421 in a cadaveric study reported by Bade et al (1996). They concluded that force transmission through the distal radioulnar joint is higher when this angle is more obtuse and that this can, consequently, lead to degenerative changes.…”

A radiographic study of dorsovolar wrist axes and a database of angular measurements on axial computed tomography images

“…However, using the same principal axis, our mean sigmoid notch version angle with a mean of 1° was slightly less than that of the former,[ 12 ] greater than that of the latter. [ 11 ] The discrepancy may be because the former study performed the measurements photographically on the cadaveric radiocarpal joint surfaces,[ 12 ] and the latter performed digital measurement on three-dimensional CT images of cadaveric arms of elderly subjects. [ 11 ] Finally, Gupta et al[ 5 ] measured the sigmoid notch version angle with a mean of 7° (range –16 to +31) relative to the volar cortical axis, which is similar to our result (mean: 8°) with the same axis.…”

“…[ 11 ] The sigmoid notch axis was a line connecting the volar and dorsal rims of the sigmoid notch. [ 12 ] The scapholunate joint axis was the line passing through the midportion of the joint from dorsal to volar direction. [ 13 ] The lunotriquetral joint axis was the line passing through the midportion of the joint from dorsal to volar direction.…”