Distal tibiofibular syndesmosis and its secrets

Abstract

The distal tibiofibular syndesmosis is a critical fibrous joint essential for ankle stability. Injuries to this complex, if misdiagnosed or improperly treated, can lead to chronic pain, instability, and premature osteoarthritis. This review covers the essential aspects of syndesmotic injuries, including anatomy, biomechanics, diagnosis, and current treatment strategies. The syndesmosis is stabilized by the anterior and posterior inferior tibiofibular ligaments and the interosseous ligament. These structures permit controlled motion during ankle movement. The typical injury mechanism involves excessive external rotation and dorsiflexion, leading to a sequential ligamentous rupture. Clinical diagnosis relies on the mechanism of injury and physical tests such as the squeeze and external rotation tests, although their reliability is debated. Imaging is crucial for confirmation. Weight-bearing radiographs are the first-line study, but computed tomography (CT), especially weight-bearing CT, offers greater accuracy for diagnosing instability. Magnetic resonance imaging (MRI) is excellent for assessing soft-tissue damage and associated injuries. Treatment is determined by joint stability. Stable, partial injuries are managed conservatively with immobilization and structured rehabilitation. Unstable injuries require surgical intervention to ensure anatomic reduction and restore stability. While rigid screw fixation was historically the standard, it impairs physiological motion and often necessitates a second surgery for hardware removal. Flexible fixation with suture-button devices has emerged as the modern standard of care. This technique provides dynamic stabilization, allows for natural joint micro-motion, and is associated with improved clinical outcomes and a lower rate of reoperation. Arthroscopy is a valuable tool for diagnosing and treating these injuries, enabling direct visualization and debridement to ensure accurate reduction. Proper management of syndesmotic injuries is paramount for optimizing patient recovery and preserving long-term ankle function. Level of evidence IV.