title: Enthesiopathy of the flexor carpi ulnaris at the pisiform: findings of high-frequency sonography.
abstract: OBJECTIVE
  Acute or chronic pain at the pisiform may be due to tendinopathy of the flexor carpi ulnaris tendon (FCU) insertion, mechanical overuse, bony fractures, and osteoarthritis of the pisiform-triquetral joint. Enthesiopathy of the FCU at the pisiform might exhibit abnormalities assessable for sonographic characterization. This study aimed to determine the most relevant sonographic features of tendinopathy of the FCU insertion at the pisiform.
  
  
  METHODS
  We retrospectively analyzed radiological findings of 9 patients admitted for high-frequency sonographic evaluation of a painful pisiform FCU insertion. The FCU insertion was assessed for active enthesiopathy in terms of tendon thickening and hyperemia, peritendinous effusion, peritendinous hyperemia, peritendinous soft tissue thickening, cystic fluid collections, erosive cortical irregularities, and osteoproliferative alterations at the pisiform.
  
  
  RESULTS
  Of all patients, 5 had inflammatory rheumatic disorders and the remainder had a painful pisiform FCU insertion related to overuse. While peritendinous effusion, pisiform erosive cortical irregularities, and peritendinous soft tissue thickening at the FCU insertion were exclusively found in rheumatic patients, active enthesiopathy of the FCU tendon, pisiform osteoproliferative alterations, and hyperemia of the peritendinous soft tissue were inconsistent and found in both groups. Cystic fluid collections from the pisiform-triquetral joint were only seen in patients with overuse.
  
  
  CONCLUSIONS
  In this small case series of patients with pain at the pisiform FCU insertion, we could reveal several typical sonographic features for insertion tendinopathy. Further studies should prove if these sonographic features could impact on the management of patients with pain at the pisiform.
authors.affiliation: Department of Radiology, Innsbruck Medical University, Anichstrasse 35, A-6020 Innsbruck, Austria. marius.wick@i-med.ac.at
authors.forename: Marius C
authors.initials: MC
authors.lastname: Wick
authors.forename: Rüdiger J
authors.initials: RJ
authors.lastname: Weiss
authors.forename: Rohit
authors.initials: R
authors.lastname: Arora
authors.forename: Markus
authors.initials: M
authors.lastname: Gabl
authors.forename: Johann
authors.initials: J
authors.lastname: Gruber
authors.forename: Werner
authors.initials: W
authors.lastname: Jaschke
authors.forename: Andrea S
authors.initials: AS
authors.lastname: Klauser
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015203:Reproducibility of Results; D012216:Rheumatic Diseases / Q000000981:diagnostic imaging*; D012680:Sensitivity and Specificity; D052256:Tendinopathy / Q000000981:diagnostic imaging*; D013710:Tendons / Q000000981:diagnostic imaging*; D014463:Ultrasonography / Q000379:methods*; D014955:Wrist Joint / Q000000981:diagnostic imaging*