MR imaging findings of trigger thumb

• Published in: Skeletal radiology Vol. 44; no. 8; pp. 1201 - 1207
• Main Authors: Chang, Eric Y., Chen, Karen C., Chung, Christine B.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-08-2015; Springer; Springer Nature B.V
• Subjects: Case Report; Diagnosis, Differential; Humans; Imaging; Magnetic resonance imaging; Magnetic Resonance Imaging - methods; Male; Medicine; Medicine & Public Health; Middle Aged; Nuclear Medicine; Orthopedics; Pathology; Radiology; Tendons - pathology; Thumb - pathology; Trigger Finger Disorder - pathology; Trigger finger; Sclerosing tenosynovitis; Magnetic resonance imaging; Trigger thumb; Pulley
• ISSN: 0364-2348; 1432-2161
• DOI: 10.1007/s00256-015-2172-y

Trigger finger (or trigger thumb), also known as sclerosing tenosynovitis, is a common clinical diagnosis that rarely presents for imaging. Because of this selection bias, many radiologists may not be familiar with the process. Furthermore, patients who do present for imaging frequently have misleading examination indications. To our knowledge, magnetic resonance (MR) imaging findings of trigger thumb have not been previously reported in the literature. In this article, we review the entity of trigger thumb, the anatomy involved, and associated imaging findings, which include flexor pollicis longus tendinosis with a distinct nodule, A1 pulley thickening, and tenosynovitis. In addition, in some cases, an abnormal Av pulley is apparent. In the rare cases of trigger finger that present for MR imaging, accurate diagnosis by the radiologist can allow initiation of treatment and avoid further unnecessary workup.