The Importance of the Deep Deltoid Ligament Repair in Treating Supination-External Rotation Stage IV Ankle Fracture: A Comparative Retrospective Cohort Study

BACKGROUND: The necessity of the deep deltoid ligament repair in the treatment of supination-external rotation (SER) ankle stage IV fracture with deltoid ligament rupture is highly debated. We conducted this retrospective research aimed at exploring the curative effect of the deep deltoid ligament repair in treating SER fracture. METHODS: Sixty-three patients with closed SER stage IV fractures received open reduction and internal fixation (ORIF), using either deep deltoid ligament repair (the DDLR group, 31 patients) or nondeep deltoid ligament repair (the NDDLR group, 32 patients). The radiographic parameters examined include the talocrural angle (TA), fibular length (FL), tibiomedial malleolar angle (TMMA), medial clear space (MCS), and tibiofibular clear space (TFCS). The functional performance parameters examined in the study were visual analog scale (VAS) pain score, American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scales, and range of motion of bilateral ankles (RMBA). Complications, including bone nonunion, infection, and fragment displacement, were also recorded and compared. RESULTS: Similar basic characteristics were found in both cohorts. All patients completed follow-up ranging from 12 to 22 months (mean time: 12.41 ± 4.21 months). The DDLR group had significantly reduced VAS score (p < 0.05), with markedly increased RMBA (p < 0.05) compared to the NDDLR group. The two cohorts showed similar follow-up performance at 3 months (p > 0.05), 6 months (p > 0.05), and 12 months (p > 0.05), in terms of parameters including TA, FL, TMMA, MCS, TCS, and AOFAS ankle-hindfoot scales. CONCLUSION: Although similar radiographic performances were achieved in both cohorts, the DDLR group displayed enhanced functional outcome postsurgery, indicating that DDLR may be a better potential for the treatment of SER stage IV fracture with deltoid ligament rupture.