US Findings of Extensor Hood Injury in Metacarpophalangeal Joint after Acute Trauma and Corresponding MRI Findings

ABSTRACT

Extensor hood is a structure that stabilizes the extensor tendon at the dorsal side of the metacarpophalangeal joints and keeps the tendon in place during extension and flexion of the joint. Diagnosis of Extensor hood injury of a metacarpophalangeal joint is difficult to diagnose because its clinical symptoms are nonspecific such as pain and swelling. And swelling can interfere with the accurate physical examination. So the imaging findings are important for diagnosis of extensor hood injury. Magnetic resonance image (MRI) and ultrasonography (US) are both good imaging tools. An advantage of ultrasonography is dynamic assessment of extensor tendon and extensor hood. Here, we describe a case of US findings of extensor hood injury with dynamic approach and corresponding MRI findings.