Repair of Deltoid Ligament Disruption in Bimalleolar Equivalent Fractures: A Cadaveric Study

The effectiveness of deltoid ligament complex repair in bimalleolar equivalent fractures remains controversial. While direct repair of the superficial ligamentous structures is feasible, the necessity of primary repair for the deep component and the optimal approach for achieving this remain unclear. This study aimed to determine whether anterior deltoid ligament repair (ADLR; tibionavicular and tibiospring ligaments) can stabilize the ankle joint following a complete deltoid ligament rupture (cDLR).

Seventeen ankles from nine fresh-frozen cadavers were dissected from the knee downward and divided into 3 groups: normal (intact ankle ligaments), cDLR, and ADLR. The medial clear space and torque failure after ADLR were evaluated. Medial clear space was measured under non-weight-bearing conditions and during 8-lb (35 N) external rotation and gravity stress tests across the 3 groups. The medial clear space was measured using Adobe Photoshop's length measurement function.

Significant differences (p < 0.001) were observed in the medial clear space measurements across the normal, cDLR, and ADLR groups during all test conditions. Torque failure occurred after ADLR at a mean of 73.3 lb (standard deviation, 28.5).

The stability observed in stress tests following ADLR and the results of torque failure testing suggest that ADLR alone is sufficient to restore ankle stability. Initial stability was achieved using ADLR, which can be performed relatively easily even in cases of cDLR.