Page 232 - Equine Clinical Medicine, Surgery and Reproduction, 2nd Edition

Musculoskeletal system: 1.5 The hindlimb 207

VetBooks.ir 1.395 1.396

Figs. 1.395, 1.396 (1.395) Caudocranial
radiograph of the left stifle of a 6-year-old gelding that
had suffered diffuse chondromalacia of the medial
femoral condyle. The medial femoral condyle appears
flattened on this projection. (1.396) Arthroscopic
image of the left medial femoral condyle of the same
horse showing cracked and poorly adherent cartilage.

acetonide injected into the medial femorotibial joint; OSTEOARTHRITIS OF THE STIFLE JOINTS
avoid in animals where corticosteroids are contraindi-
cated), combined with a careful rest and rehabilitation Definition/overview
programme. Arthroscopic evaluation of the joint is Degeneration of the articular compartments that
indicated in cases where intra-articular medication has together form the stifle is not uncommon and even-
failed to resolve lameness or where more severe lame- tually will lead to overt OA. Such degeneration can
ness means that a concurrent soft-tissue lesion is sus- occur secondary to many of the other pathologies
pected. If abnormal cartilage is present, a decision has described in this chapter; in some cases, an inciting
to be made whether to remove the affected cartilage, cause of degeneration is not recognised. The medial
or not, as the scar that forms to repair any defect that is femorotibial joint is most frequently affected by OA,
created is often surprisingly poor. In most cases, loose, possibly as that is the joint most often affected by the
cracked and fibrillated cartilage is carefully removed other causes of joint disease.
to minimise the affected area as much as possible.
Where a cartilage defect has been created by debride- Aetiology/pathophysiology
ment, a considerable period of rest may be required. In the majority of cases, OA is recognised secondary
to long-standing joint disease such as chondromala-
Prognosis cia or as a primary lesion where an inciting cause is
Prognosis for future athletic function in horses affected not found.
by chondromalacia as a primary lesion is guarded.
Where concurrent soft-tissue injuries are present, the Clinical presentation
overall prognosis is reduced by the presence of the Horses affected by OA are older, active, working ani-
chondromalacia, such that there is a guarded to poor mals. In most cases, low-grade, bilateral lameness is
prognosis for a return to athletic soundness. present and often exacerbated by upper limb flexion.