Comparison Between Standard Screw and Internal Brace in Treatment of Subtle Lisfranc Injury.

Background: Subtle Lisfranc injuries are low-energy, purely ligamentous lesions increasingly recognized in active patients; although screw fixation is common, Internal Brace (IB) flexible fixation is an alternative. Methods: In this multicenter retrospective study (2014-2021), 65 patients with subtle ligamentous Lisfranc injury (C1-M2 diastasis < 5 mm) underwent standard screw (SS, n = 35) or IB fixation (n = 30). Outcomes included AOFAS and VAS, standing radiographs and weight-bearing CT (WBCT) diastasis, pedobarography (4-6 months), and complications. Results: Demographics and injury mechanisms were similar. Both groups improved from preoperative status to final follow-up (p < 0.05). At 6 months, IB had higher AOFAS and lower VAS than SS (p < 0.05). Final stability was comparable: standing C1-M2 diastasis 2.54 mm (IB) vs. 2.55 mm (SS); WBCT dorsal 1.26 vs. 1.21 mm and plantar 3.58 vs. 3.42 mm (all NS). Pedobarography showed no significant side-to-side differences in either group. Complications favored IB: SS had screw breakage 11.4% (4/35), recurrent diastasis 2.9% (1/35), and early arthritis 5.7% (2/35); IB had no implant breakage, no severe recurrent diastasis, and no early arthritis. Conclusions: In this Level III study, IB fixation was associated with better 6-month clinical outcomes with similar final radiographic stability and fewer hardware-related complications versus SS.