Role of Lisfranc and First Cuneo metatarsal Ligaments in First Cuneo metatarsal Instability: A Cadaveric Study

Background Role of Lisfranc ligament maintaining midfoot stability is well established; however, specific contribution of the First Cuneo metatarsal (C1-M1) ligaments, in conjunction with the Lisfranc ligament, to the stability of the C1-M1 joint has not been thoroughly investigated. The aim of this study is to evaluate the importance of the Lisfranc and C1-M1 ligament in the stability of the C1-M1 joint. Methods Six cadaveric below-knee specimens were used in this study. Metal pins were placed dorsally and medially at the C1-M1 joint to measure displacement and angulation. The specimens were divided into two groups: Group 1 underwent progressive dissection of the C1-M1 ligaments, followed by dissection of the Lisfranc ligament. On the other hand, Group 2 started with Lisfranc ligament dissection, followed by progressive dissection of the C1-M1 ligaments. Axial and abduction stress was applied before and after each ligament section, with angulation and translation measured in both planes. Final measurements were taken after Lisfranc screw fixation. Results Sequential dissection of first C1-M1 and Lisfranc ligaments led to a progressive increase in angulation and translation of the C1-M1 joint. Instability was markedly higher when the Lisfranc ligament was sectioned. Lisfranc screw fixation achieve better stability of C1-M1 joint compared to the ligament-sectioned state, restoring values to near-native levels. Conclusions Lisfranc ligament is the principal stabilizer of the C1-M1 joint. Screw fixation confers greater stability compared to specimens with sectioned C1-M1 ligaments, supporting the potential for indirect stabilization. Level of evidence Not Applicable