Page 187 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

162 CHAPTER 1

VetBooks.ir Aetiology/pathophysiology is deemed of some clinical significance. Surgical
debridement is described but can leave a large cloaca
OCLLs may be an incidental radiographic finding;
however, large cysts may communicate with the joint
substitute) has been undertaken in such cases.
and be a source of pain. Cystic changes in the ulnar in the bone and so packing (bone graft or other
carpal bone may occur secondarily to avulsion of the
lateral palmar intercarpal ligament. Prognosis
Prognosis for horses with OCLLs at present is
Clinical presentation unknown but is likely to depend on the presence of
Lameness localised to the carpus. other carpal joint disease.

Differential diagnosis CARPAL HYGROMA
Palmar intercarpal ligament injury.
Definition/overview
Diagnosis Carpal hygroma refers to a subcutaneous swelling
Diagnosis is made radiographically where a cystic over the dorsal aspect of the carpus.
lucency in the affected (usually ulnar) carpal bone
is present. Differentiation from avulsion fractures Aetiology/pathophysiology
of the lateral palmar intercarpal ligament is made Repetitive trauma to the dorsal aspect of the carpus
based on the location and appearance of the lucency. leads to chronic inflammation and a fluid-filled sub-
Evaluation for evidence of concurrent joint disease is cutaneous structure develops. Lameness is usually
important for prognostic purposes. minimal unless it becomes infected.

Management Clinical presentation
Most OCLLs are untreated. Medical management A fluid-filled, non-painful, fluctuant swelling over
for joint disease may assist in cases where the OCLL the dorsal aspect of the carpus is present (Fig. 1.304).

1.303 1.304

Fig. 1.303 Dorsopalmar
radiograph of the carpus of a
9-year-old riding horse with
lameness localised to the
antebrachiocarpal joint. Note
the osseous cyst-like lesion in
the distal medial radius, with
a wide entrance into the joint
and prominent pericyst bone
sclerosis. (Photo courtesy
Graham Munroe)

Fig. 1.304 This horse has
formed a carpal hygroma
over the dorsal aspect due
to persistent trauma. (Photo
courtesy Graham Munroe)