Abstract
Background The effects of dorsal angulation deformity on in vitro distal radioulnar joint (DRUJ)
contact patterns are not well understood.
Purpose The purpose of this study was to utilize intercartilage distance to examine the effects
of forearm rotation angle, distal radius deformity, and triangular fibrocartilage
complex (TFCC) sectioning on DRUJ contact area and centroid position.
Methods An adjustable implant permitted the creation of simulated intact state and dorsal
angulation deformities of 10, 20, and 30 degrees. Three-dimensional cartilage models
of the distal radius and ulna were created using computed tomography data. Using optically
tracked motion data, the relative position of the cartilage models was rendered and
used to measure DRUJ cartilage contact mechanics.
Results DRUJ contact area was highest between 10 and 30 degrees of supination. TFCC sectioning
caused a significant decrease in contact area with a mean reduction of 11 ± 7 mm2 between the TFCC intact and sectioned conditions across all variables. The position
of the contact centroid moved volarly and proximally with supination for all variables.
Deformity had a significant effect on the location of the contact centroid along the
volar–dorsal plane.
Conclusion Contact area in the DRUJ was maximal between 10 and 30 degrees of supination during
the conditions tested. There was a significant effect of simulated TFCC rupture on
contact area in the DRUJ, with a mean contact reduction of 11 ± 7 mm2 after sectioning. Increasing dorsal angulation caused the contact centroid to move
progressively more volar in the sigmoid notch.
Keywords
arthrokinematics - contact - distal radioulnar joint - intercartilage distance - triangular
fibrocartilage complex
