gms | German Medical Science

Objectives/Interrogation: The distal oblique bundle (DOB) is represented by obvious stretched fibers at the distal portion of the interosseous membrane (IOM) between the ulna and the radius below and on the outside.

It has been shown as an important stabilizer of the distal radioulnar articulation (DRUJ) and is however only present in 40% of cases according to studies on cadaverous studies.

Tolat described in 1996 four types of incisures of the DRUJ in the frontal plane, from most stable to least stable: S-shape, C-shape, Ski-slope, and Flat face (Figure 1 [Fig. 1]) [1].

The objective of this cadaverous study was to evaluate the existence of a correlation between the presence of a DOB and the type of DRUJ according to the classification of Tolat.

Methods: Twelve specimens (1 fresh frozen, 11 conserved) were dissected. The presence of a DOB was evaluated according to the description of Moritomo: the IOM was exposed in its distal portion to search for stretched fibers between the ulna and the radius below and on the outside.

The group of specimens was then evaluated by tomodensitometry to determine the type of DRUJ incisure according to Tolat's description on frontal cuts at one centimeter from the DRUJ (Figure 2 [Fig. 2]).

The statistical analysis was performed using the odds ratio.

Results and Conclusions: The DOB was found in 7 specimens, (58%). The presence of a DOB was more frequent in less stable incisures (4 flat face, 3 ski slope). They were never found in other more stable configurations according to Tolat's classification.

The less stables configurations (such as flat-face and ski-slope) should deserve a reconstruction according to the native anatomy like the DOB orientation such as proposed by De Vries et al. and Peter R. et al.