Elbow dysplasia is a common cause of front limb lameness in young large breed dogs. Dysplasia simply means abnormal growth or development; and although an injury can lead to elbow dysplasia, the disease that is discussed here is usually a heritable condition. The elbow functions as a hinge joint, located at the convergence of three bones: the humerus in the upper forelimb, and the radius and ulna that run parallel together through the lower forelimb. The elbow is formed in such a way as to allow flexion, extension and rotation of the limb. While a dog is young and growing, the radius and ulna must develop at proportional rates in order to form the joint properly and allow for a complete range of motion. Disproportionate bone growth stemming from genetic aberrations common to large breed dogs causes malformation of the joint and / or loose bone fragments whereby inflammation occurs and chronic arthritis develops.
Most young dogs affected by elbow dysplasia will begin to exhibit symptoms of pain, abnormal gait, and lameness in one or both front legs at 4 to 6 months of age. While walking, dogs may be reluctant to flex the limbs during forward motion, appearing as “paddling”, or swinging the extended painful leg out and forward. Standing, they may shift weight off of the affected limb, holding it gingerly away from the center of the body with the foot rotated outward.
When both elbows are dysplastic, symptoms may alternate from side to side. In the most severe bilateral cases, the dog may shift body weight to the rear in a squatting posture with both front legs pointed forward and outward. Swelling may be present over the elbows, and crepitation (grinding) may be felt when the joints are flexed manually. Exercise typically makes the symptoms more pronounced, and the dog may be stiff and slow to rise after rest.
As the dog ages and the disease progresses, secondary arthritis (inflammatory reactions) in the joints will develop. Avoidance of exercise can lead to muscle atrophy (wasting). Untreated elbow dysplasia can become quite crippling.
Observed symptoms, changes in gait, and a physical examination (palpation of the limbs) may lead the veterinarian to suspect elbow dysplasia, which is confirmed by taking x-rays of the joints of the front legs. (The shoulders are also x-rayed to rule out coincidental problems of a similar nature.) On x-ray, abnormal joint conformation should be evident, and arthritic change may be seen. While free-floating bone fragments are often difficult to visualize on the x-ray, the location of missing bone pieces is usually typical and easy to identify.
The treatment for elbow dysplasia is targeted at three objectives: to relieve pain, restore joint function as much as possible, and slow degenerative change. This will require surgical correction and medical management of the disease. Surgery may be performed by arthroscopy or in a standard “open incision” technique depending on the surgeon’s recommendation and the classification / severity of the abnormality. Medical management involves weight control, pain medications, nutraceutical joint supplements, and physical therapy (controlled exercise).
Unfortunately, elbow dysplasia is progressive. A complete “cure” may not be possible, and success in treatment may be measured in small degrees of improvement. Early detection of the disease is vital to the dog’s long-term prognosis.