Real-Time Ultrasound Demonstration of (Psoriatic Arthritis-Related) Hand Extensor Tendon Ruptures

Psoriasis is a chronic immune-mediated inflammatory disease characterized by erythematous and scaly plaques, most commonly affecting extensor surfaces such as the elbows and knees, and may be associated with systemic manifestations, including psoriatic arthritis (PsA).[ 1 ] PsA is a type of spondyloarthropathy characterized by synovial joint inflammation, primarily affecting peripheral joints.[ 2 ] It can also involve hand and wrist tendons, more commonly the flexor ones.[ 3 ] Previous studies have examined patterns of joint and tendon involvement in PsA using musculoskeletal ultrasound (US), indicating common findings such as joint effusion and/or erosion, synovitis, synovial hypertrophy, and tenosynovitis of flexor/extensor tendons.[ 3 ] Herein, dynamic US examination videos demonstrate complete ruptures of the extensor digitorum communis (EDC) and extensor digiti minimi (EDM) tendons, attributed to PsA, in an 84-year-old female patient. On physical examination, there was marked weakness (1/5) in the extension of the left 3rd, 4th, and 5th fingers at the metacarpophalangeal joint level. Dactylitis was also present in the right 2nd digit. Subsequently, US examination revealed the absence of both EDC and EDM tendons in the distal one-third of the left forearm/wrist ([ Videos 1 ] and [ 2 ]). The patient had a longstanding diagnosis of psoriasis, with intermittent erythematous scaly plaques predominantly involving the elbows and knees, and rheumatoid factor was negative. Given the absence of trauma history, systemic inflammatory diseases other than PsA, crystal arthropathy, or medication use associated with tendon rupture, these tendon ruptures were attributed to PsA. As the patient declined reconstructive surgery, she is followed with conservative management. Download Video Video 1 Short-axis dynamic ultrasound imaging demonstrates extensor digitorum communis (EDC) tendons (white asterisks) along with the extensor indicis proprius (EIP) tendon at the proximal two-third of the forearm. The tendons are then traced distally toward the wrist/hand, revealing a widespread area with chronic inflammatory changes (white stars). In the distal one-third of the forearm, an anechoic region (black arrows), indicating absence/rupture of the EDC tendons, is noted. Note that the EIP tendon is preserved. EPL, extensor pollicis longus. Download Video Video 2 Short-axis dynamic ultrasound imaging demonstrates the extensor digiti minimi (EDM) tendon (yellow star). At the beginning of the video, its muscle (yellow dashed area) appears as hyperechoic, indicating atrophic/fibrotic changes. As the hypoechoic tendon is traced distally, it seems to disappear from view. At the wrist level, an anechoic zone indicating tendon rupture (white asterisk) is observed. With continued tracking into the hand, the most distal portion of the EDM tendon (yellow stars) with its splitting two branches is visible again. tri, triquetrum; mc 4, 4th metacarp; mc 5, 5th metacarp. To the best of our knowledge, complete ruptures of the EDC and EDM tendons due to PsA have not been previously/directly reported. Not to mention, in relevant cases, US serves as a quick, accessible, and dynamic examination tool that provides “seeing” and therefore “believing” as well.[ 4 ] Consent to Participate Informed consent was obtained from the patient. Consent to Publish The authors affirm that the patient provided informed consent for publication of [ Videos 1 ] and [ 2 ]. Authors' Contributions A.F.Ç.: investigation and writing-original draft. B.Y.: investigation and writing-original draft. L.Ö.: conceptualization, writing-review and editing, and supervision. Publication History Article published online: 26 June 2026 © 2026. Indian Radiological Association. This is an open access article published by Thieme under the terms of the Creative Commons Attribution-NonDerivative-NonCommercial License, permitting copying and reproduction so long as the original work is given appropriate credit. Contents may not be used for commercial purposes, or adapted, remixed, transformed or built upon. (https://creativecommons.org/licenses/by-nc-nd/4.0/) Thieme Medical and Scientific Publishers Private Limited A-13A, Graphix Tower 1, 6th floor, Sector 62, Noida 201309, Uttar Pradesh, India