gms | German Medical Science

Objectives: Recent studies show that the distal oblique bundle (DOB) of the distal interosseous membrane (DIOM) contributes to the stability of the distal radio-ulnar joint. Its occurrence has been found in about 40% in a sample sizes less than 30 specimens. Therefore, the aim of our study was to prove its existence in a representative collective.

Method: 200 forearms (113 right and 87 left) of Thiel embalmed cadavers were investigated whereas 19 forearms had to be discharged due to defects in the DIOM.

After removal of the soft tissues, the DIOM was examined with regard to the existence of a DOB. This was evaluated using digital callipers.

The distance between the proximal (U1) and the distal (U2) attachment of the DOB at the ulna to the ulnar styloid process were evaluated. Further on, the proximal (R1) and the distal (R2) point of distal attachment at the radius to the radial styloid process were measured.

The width (W) was measured at its midpoint (M) and the DOB thickness (T) was defined.

Results: We found the DOB to be present in 53 specimens (29.3%). 41 were found in the right and 12 in the left forearm. From the ulnar styloid process the distance to U1 was 47.5 mm (mean value [mv]) and to U2 34.9 mm (mv). From the radial styloid process the distance to R1 was 34.8 mm (mv) and to R2 24.5 mm (mv). At the midpoint (M) the DOB's thickness (T) was 0.9 mm (mv) and the width was 8.4 mm (mv).

Conclusion: The presence of the DOB is believed to contribute to instabilities in distal radial translation fractures. Our results indicate a less frequent occurrence of a DOB in comparison to the recent literature.