Page 462 - The Veterinary Care of the Horse

• Flexion may be resented.

• The affected joint may be distended.
VetBooks.ir • Lameness is not always apparent, particularly with lesions deep in the bone such as those

seen in areas of the carpus (knee). Cyst-like lesions that are close to a joint surface are

more likely to be associated with lameness.

Diagnosis

Diagnosis usually requires regional or intra-articular analgesia in addition to radiography, but

not all bone cysts cause lameness. Lesions are sometimes seen as incidental findings on
radiographs of sound horses. Since the local anaesthetic takes some time to diffuse from the

joint into a subchondral bone cyst, it may be necessary to wait for up to one hour before the
full effect of the analgesia is seen. The lameness may be reduced rather than abolished.

Scintigraphy, computed tomography (CT) and magnetic resonance imaging (MRI) are
also used.

Treatment

Conservative treatment consisting of management changes and medication is normally tried

in the first instance, as surgery is not always successful. However, your vet will decide on the
best course of action depending on the location and severity of the lesion and the use and age

of the horse.

CONSERVATIVE TREATMENT

• Box or pasture rest to allow the bone the opportunity to remodel and heal.

• Non-steroidal anti-inflammatory drugs (NSAIDs) such as phenylbutazone.
• Intra-articular injection of hyaluronic acid.

• In selected cases intra-articular corticosteroids are used to reduce inflammation and

encourage healing.
• Corticosteroids may be injected into the lining of SBCs in the stifle.

SURGICAL TREATMENT

When the cyst-like lesion does not respond to conservative treatment or occupies a large area
of the joint surface, arthroscopic surgery may be indicated. This involves removing the lining

of the cyst cavity and all the debris from within the joint capsule. A screw may be placed
across the cyst; this is sometimes combined with the use of stem cells or platelet-rich plasma.