Dealing with Elbow Dysplasia

Canine Elbow Dysplasia (ED) is a generic term encompassing several conditions of the elbow joint including fragmentation of the medial coronoid process (FCP), ununited anconeal process (UAP), osteochondrosis dissecans (OCD) and incongruity of the elbow joint (INC). There are strong breed associations with each of these diseases suggesting a significant underlying genetic aetiology. Estimates of its heritability vary between 20% and 30%.

Fragmented Medial Coronoid Process (FCP)

A FCP is the most common dysplastic lesion of the elbow occurring in 65% of patients. This condition is characterised by fissuring and fragmentation of the subchondral bone and cartilage on the apex or the lateral aspect of the medial coronoid process and erosion of cartilage (from chondromalacia to exposure the subchondral bone). They are often accompanied by so called ‘kissing lesions’ on the opposing medial humeral condyle. It is unclear whether the FCP is an osteochondrosis lesion or a primary osteochondral fracture.
Diagnostic tests for ED include radiography, arthrocentesis, arthroscopy, computed tomography (CT), magnetic resonance imaging (MRI) and nuclear scintigraphy. MRI and CT appear to offer a high sensitivity and specificity (about 90%). Arthroscopy is sometimes unable to detect subchondral lesions that do not disrupt the articular surface. CT assessment should therefore ideally be combined with arthroscopic evaluation to maximise the chance of diagnosing medial coronoid pathology.
Conservative treatment should always be implemented regardless whether surgery is performed. The details of this will be outlined in the presentation on osteoarthritis. Surgical treatment with fragment removal may be achieved by either an open medial arthrotomy or arthroscopically. Arthroscopy allows a greater appreciation of the variety of lesions that occur with FCP, greatly improves visualisation and is a minimally invasive technique. The convalescence period following arthroscopy is also shorter. Although many authors would advocate simple removal of the fragmented coronoid process, others advocate a subtotal coronoidectomy, based on the view that more extensive pathology than that readily observed FCP is frequently present.
Following arthroscopic fragment removal, approximately 60% of cases may show no obvious lameness, 30% show intermittent lameness and 10% may continue to show persistent lameness. Neither arthroscopy nor arthrotomy can avoid the inevitable progression of osteoarthritis in all patients. [...]