The effect of open reduction and internal fixation on concurrent scapholunate diastasis in acute distal radius fractures: A retrospective cohort study

Background Management of concomitant scapholunate (SL) injuries with distal radius fractures (DRFs) remains controversial. This study evaluates whether open reduction and internal fixation (ORIF) of DRF alone restores the SL relationship in moderate SL diastasis. Methods This retrospective multi-center study included DRF patients with moderate SL diastasis (> 2.50 mm). Scapholunate distance (SLD) and angle were measured post-injury, post-operatively, and at final follow-up. Data were analyzed using a linear mixed model. Results ORIF of the DRF alone significantly reduced mean SLD from 2.96 mm (post-injury) to 1.94 mm (post-operatively). The SL angle showed no significant variation, with no progression toward dorsal intercalated segmental instability. Conclusion Findings suggest moderate SL diastasis in DRF often representing carpal extrinsic ligament malalignment rather than SL interosseous ligamentous failure. ORIF is effective in restoring the SL relationship by anatomical bony reduction. Additional immediate ligamentous repair may not provide clinical advantages over primary osseous fixation alone.