Scapholunate Ligament Reconstruction with Suture Augmentation: a Biomechanical Analysis.

Abstract

To evaluate the biomechanical performance of the modified Brunelli scapholunate interosseous ligament (SLIL) reconstruction with and without suture augmentation, using a cadaveric model under cyclic loading conditions. Eight matched pairs of fresh-frozen cadaveric wrists underwent sequential sectioning of the SLIL, dorsal intercarpal ligament, long radiolunate ligament, and scaphotrapeziotrapezoid ligament to induce dorsal intercalated segment instability (DISI). Each wrist was reconstructed using the modified Brunelli technique; one in each pair received augmentation with 2 mm suture tape. Fluoroscopic imaging assessed the scapholunate angle (SLA), radiolunate angle (RLA), scapholunate gap (SLG), and dorsal scaphoid translation (DST) at baseline, post-injury, and post-reconstruction following cyclic loading. Generalized estimating equations were used to compare conditions. The DISI induction led to worsened alignment compared to baseline. Both reconstruction techniques significantly improved alignment versus the DISI condition. No significant differences were found between the baseline, graft only, and graft/tape conditions for SLG, SLA, or RLA, indicating equivalent restoration. The DST values did not differ significantly across conditions or when comparing the final reconstructed state; however, when subtracting each specimen's baseline or injured state, the graft/tape group showed greater DST reduction compared to the graft only group. Suture augmentation in modified Brunelli SLIL reconstruction did not enhance restoration of SLG, SLA, or RLA but did provide a greater reduction in DST compared to graft alone. Both techniques were biomechanically effective in restoring and maintaining alignment. Although suture augmentation does not significantly improve most radiographic outcomes, it may offer biomechanical advantages in stabilizing the scaphoid. Further investigation is warranted to determine if this finding translates to improved clinical durability and outcomes.