Deltoid ligament injury: thinking beyond the ankle - an expert opinion.

Deltoid ligament (DL) injuries are common in ankle trauma, yet their optimal management remains debated. Most trauma literature considers DL injury as an isolated ankle problem, whereas foot-and-ankle specialists view the ankle and the foot as a complex. This disconnect leaves a critical knowledge gap that our work aims to address. As we know, every post-traumatic collapsing foot deformity involves a DL injury, but not every DL necessarily progresses to such a deformity. We introduce the concept of the DL as a tri-articular stabilizer within the medial ankle ligament complex, contributing to the stability of the tibio-talar, subtalar (ST), and talo-navicular (TN) joints. Neglecting this broader stabilizing role may lead to irreversible foot sequelae, such as post-traumatic plano-valgus or plano-abductus deformities. Therefore, DL injuries should be systematically recognized in both acute and chronic settings, whether treated conservatively or surgically. In this expert opinion, we synthesize current anatomical, biomechanical, and clinical evidence together with our experience to outline key diagnostic principles and therapeutic considerations for the management of DL injuries.