Elbow Dysplasia (ED)
Elbow dysplasia is more commonly seen in fast-growing large breed puppies, it is really a syndrome in which one or more of the following conditions are present:
Osteochondrosis
Fragmentation of the coronoid process
Ununited anconeal process
Elbow incongruity
Osteochondrosis
In osteochondrosis, there is an abnormality of the cartilage and the bone underneath it. In the elbow joint, this most commonly occurs on the medial condyle of the humerus. The cause of osteochondrosis may include genetic factors, trauma, and nutrition. The signs of this abnormal bone growth usually develop between 6 and 9 months of age, and generally appear as lameness. Osteochondrosisis is more common in rapidly growing, large breed puppies. In the condition termed osteochondrosis dessicans, a portion of cartilage loosens from the underlying bone. It may break loose and float free in the joint, or remain partially attached to the bone like a flap. In either case, this is an extremely painful situation.
Fragmentation of the medial coronoid process (FMCP)
Fragmentation means that the bone in this area of the ulna starts breaking up or degenerating. This occurs very early in the life of the dog, oftentimes before six months of age. It is mostly in the larger breeds such as the German Shepherd, Golden Retriever, Rottweiler, Doberman, and the giant breeds. Although the exact cause is unknown, it is thought to have strong genetic transmission, as it has been found to be passed from generation to generation in certain lines of several breeds. Osteochondrosis and a fragmented coronoid process frequently occur in the same joint.
Ununited anconeal process (UAP) Generally, by 20-24 weeks of age, the anconeal process should have fused with the ulna. In UAP, the hook, or anconeal process, never attaches correctly to the rest of the ulna as the puppy is developing, but rather floats loose. It is held fairly close to where it should be by ligaments between it and other portions of the bone, but it is not solid enough to remain exactly where it should. This leads to joint instability, preventing the humerus and ulna from interacting correctly. Additionally, the loose anconeal process is often caught abnormally between the ends of the ulna and humerus thus irritating and bruising the articular surfaces. An ununited anconeal process is commonly found by itself with the elbow dysplasia syndrome, although it larger breeds it is often seen with fragmentation of the medial coronoid process.
Elbow incongruity
If the radius and ulna do not grow at the same rate of speed, a condition called elbow incongruity can occur. This causes wear and tear on the cartilage as the humerus does not meet the appropriate surfaces on the radius and ulna. Thus some points of contact are overloaded and this can lead to fragmentation of the medial coronoid process and other abnormalities.
Symptoms of elbow dysplasia
Patients with elbow dysplasia will usually display an obvious limp, may hold the leg out from the body while walking, or even attempt to carry the front leg completely, putting no weight on it at all. Signs may be noted as early as four months of age. Many affected animals will go through a period between six and about twelve months of age, during which the clinical signs will be the worst. After this period, most will show some signs occasionally, but they will not be as severe. As these dogs continue to mature, there will probably be permanent arthritic changes occurring in the joint. This will cause many obvious problems and it may become necessary to utilize oral or injectable medications to make the animal more comfortable. Elbow dysplasia is therefore a lifelong problem for the affected animals. Some of these patients can be helped with surgery. In some, surgery can even eliminate the problem totally.
Prognosis
Usually, after the dog is 12 to 18 months of age, the lameness will have become less severe and some dogs will function very well. The long-term prognosis (outlook), however, is guarded. Usually, degenerative joint disease (arthritis) will occur as the animal ages, regardless of the type of treatment.
In recent years, a scheme to score elbows, rather like the hip scoring scheme, has been introduced by the BVA. Reputable breeders are now taking advantage of the scheme and making sure their breeding animals have elbow scores in addition to hip scores.
The scores range from 0-3 and are explained below:
0 = Normal Elbows
1 = Mild ED
2 = Moderate ED
3 = Severe ED
It is not advisable to breed from animals with scores higher than 0 or 1.
