An Unusual Presentation of Gout Involving the Ankle Ligaments

Gout is the most common inflammatory arthritis due to deposition of monosodium urate (MSU) crystals in joints and connective tissues. In contrast to joint disease, the majority of extra-articular involvement remains asymptomatic in patients with gout. Achilles tendon is the most common site of involvement and the inflammation elicited by MSU crystals can be falsely attributed to injury or overuse. In addition, tendon or ligament damage secondary to MSU crystal deposition can lead to ligament tear or tendon rupture. However, the diagnosis of gout in patients with extra-articular involvement is often delayed or even missed because tissue sampling is not feasible in routine clinical practice. Advanced imaging techniques using ultrasound and dual-energy computer tomography (DECT) can detect MSU crystal deposition in a non-invasive manner and confirm the diagnosis of gout in patients with extra-articular involvement. The following case demonstrates an atypical presentation of gout causing multiple ligament tears in the ankle and highlights the role of DECT in the diagnosis of gout with extra-articular involvement.