9 year-old, Intact Male, Husky

History: Painful and swollen right carpus.


Findings :

Mild smooth new bone proliferation on the craniodistal and medial aspect of the right radius associated with the groove of the abductoris digiti I longi tendon (previously termed abductor pollicis longus tendon).

Mild right carpal swelling.

Radiographic Diagnosis :

These changes are consistent with stenosing tenosynovitis of abductoris digiti I longi tendon.

Other etiologies, such as a carpal soft tissue malignancy in the groove of this tendon, are very unlikely.


Hittmair KM, Groessl V, Mayrhofer E. RADIOGRAPHIC AND ULTRASONOGRAPHIC DIAGNOSIS OF STENOSING TENOSYNOVITIS OF THE ABDUCTOR POLLICIS LONGUS MUSCLE IN DOGS: Stenosing Tenosynovitis Abductor Pollicis Longus Muscle. Veterinary Radiology & Ultrasound. 2012 Mar;53:135–140.


  1. Smooth periosteal proliferation along the dorsomedial aspect of the distal radius, along a mildly lytic cortical bone with an elongated lucent triangle seen on the lateral aspect. There is a small mineral fragment at the dorsal aspect of the intermedioradial carpal bone on the lateral projection. There is a thin, linear, soft tissue swelling along the lateral aspect of the carpus, coursing from the ulnar carpal bone to the 4th carpal bone, which may be a ligament or joint capsule. The joint spaces are unremarkable. There is extracapsular soft tissue swelling along the dorsomedial distal radius, surrounding the above described lesion, and a lesser amount surrounding the entire carpus.
    Primary differential is tenosynovitis of the abductor pollicus longus muscle, with monostotic neoplasia (ie, osteosarcoma, fibrosarcoma, chondrosarcoma or hemangiosarcoma) or fungal osteomyelitis is also possible.
    Recommend radiography of the contralateral carpus, and FNA or biopsy.

  2. There is mild soft tissue swelling along the dorsal and medial aspect of the distal antebrachium. A smooth periosteal reaction is also present along the dorsomedial aspect of the distal radius. Given the location, abductor pollicis longus tenosyvnovitis is considered most likely.

  3. Dorsopalmar and mediolateral views of the right antebrachiocarpal joint of a skeletally mature dog.
    There is no letter mark on the radiographs.

    Moderate minimally irregular, solid, tubular shaped new bone formation at the dorsomedial aspect of the distal radius, in the region of the radial styloid process, along the tendon sheat of the abductor pollicis longus muscle with associated moderate soft tissue swelling and deep distal radial sulcus.

    The radiographic findings are compatible with a moderate to severe, chronic, potentially stenosing tenosynovitis of the abductor pollicis muscle.

    Ultrasound of the affected front limb and orthogonal radiographs of the controlateral limb are advised.

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