A Biomechanical Evaluation of the DRUJ After Distal Oblique Bundle Reconstruction.

Purpose: Distal oblique bundle (DOB) reconstruction for distal radioulnar joint (DRUJ) instability is an alternative to the Adams 2-incision distal radioulnar ligament reconstruction. The DOB reconstruction offers a single incision and is a technically less demanding procedure requiring a shorter tendon autograft. The DOB and Adams reconstruction may provide similar stability. This study sought to compare the biomechanical stability of the 2 DRUJ reconstructions. We hypothesized that DOB reconstruction would result in equivalent DRUJ translation, cyclic loading to failure, and maximal load to failure compared with the Adams reconstruction.

Methods: Ten fresh-frozen cadaver arms underwent DOB or Adams reconstructions. Volar, dorsal, and total translation of the radius relative to the ulna at the DRUJ were measured before and after each reconstruction. Translation was measured with a 20-N force in neutral position and 60° in pronation and supination. Measurements were obtained using a custom jig and electromagnetic motion-tracking system sensors. Total cycles and maximal load to failure of each reconstruction were measured and recorded using an electromechanical testing machine.

Results: There was a DOB incidence of 70%. Distal radioulnar joint translation, total cycles, and failure load were similar for the 2 reconstructions. On average, the DOB reconstruction had less dorsal translation than did the Adams in supination. Translation in the DOB reconstruction was similar to that of native DRUJs. In supination, on average, the Adams reconstruction had greater total, volar, and dorsal translation compared with native DRUJs.

Conclusions: In terms of translation, cyclical loading, and maximal load to failure, the DOB reconstruction for DRUJ instability is similar to the Adams reconstruction.

Clinical Relevance: This pilot study supports the DOB reconstruction as a possible alternative to the Adams reconstruction for DRUJ instability. The DOB reconstruction may theoretically reduce patient morbidity because it requires only one incision and a shorter tendon graft. However, further clinical and cadaveric studies are required to determine biomechanical equivalence and impact on patient morbidity.