The Contribution of the Distal Oblique Band to Distal Radioulnar Joint Stability

Abstract

The distal radioulnar joint (DRUJ) is supported by an array of dynamic and static stabilizers, of which the triangular fibrocartilage complex (TFCC) is the most important, and the distal interosseous ligament is next in importance. The distal oblique band (DOB) is an identifiable component of the distal interosseous ligament, found in a subset of the population. Our objective was to determine the contribution of the DOB to DRUJ stability in the presence of a disrupted TFCC. Twenty-three above-elbow specimens were prepared by removing the TFCC and the DRUJ joint capsule, preserving the distal interosseous ligament and the pronator quadratus. Cadavers were stratified into two groups-those with, and those without a DOB. A bone plate and screws were attached to the ulna; then, a transverse load was applied to failure, creating a diastasis between the radius and ulna. The group with a DOB had a mean load at failure of 160.7 ± 46.5 N. The group without a DOB had a mean load at failure of 148.0 ± 26.3 N. Stiffness prior to failure was 16.9 N/mm in the group with a DOB and 12.4 N/mm in the group without a DOB. The current results indicate that the DOB may not substantially contribute to DRUJ stability in the presence of a disrupted TFCC. Stability of the DRUJ after TFCC injury may not be substantially improved by the presence of a DOB. Thus, the clinical importance of DOB reconstruction remains unclear.