What is canine elbow dysplasia?
The elbow joint is a complex hinge joint located in the forelimb of cats and dogs. Three bones intersect at the elbow joint; the humerus of the upper limb and the radius and ulna of the lower limb. The word “dysplasia” means “abnormality of development”. If the three bones forming the elbow joint do not fit together properly as a result of abnormal development, the consequence is an abnormal concentration of forces producing a chronic strain on a specific portion of the elbow joint.
One of the most common causes of forelimb lameness in dogs, elbow dysplasia is a syndrome encompassing four inherited developmental abnormalities that most commonly affects rapidly growing large breed puppies and young adults. Breeds at elevated risk of developing elbow dysplasia include German Shepherds, Golden Retrievers, Labrador Retrievers, Newfoundlands, Rottweilers, Mastiffs, Great Danes, Saint Bernards, Bernese Mountain Dogs, and Weimaraners. Typically both elbows are affected. These developmental abnormalities result in arthritis of the elbow joint as well as discrete pathological entities such as fractures within the joint. Elbow dysplasia in canines is primarily a genetic developmental disease. Possible contributing factors may include growth rate, nutritional factors, rapid weight gain, trauma, hormonal imbalances, and level of physical activity.
How to tell if your dog has elbow dysplasia?
Elbow dysplasia is the most common cause of forelimb lameness in young large and giant breed dogs. Most affected dogs have a limp on one or both front legs. This can be seen as a head bob with the head being raised when the bad leg is placed. The painful limb may also be drawn out to the side with each step. Lameness may be more apparent following prolonged rest and exercise. Although most dogs with elbow dysplasia will be diagnosed before they are two years old, some puppies can start showing signs as young as four months old, and other dogs will not show obvious signs until they are older. Small dogs can often be affected by elbow dysplasia as well. This problem should be suspected whenever a dog suffers from forelimb lameness that hasn’t been caused by trauma. Symptoms include:
- Limping after exercise
- Stiff when getting up from resting
- Joints may appear swollen
- Feet appear to rotate outward
- Not wanting to play or to go on walks
- Decreased range of motion of one or both elbows
- Signs of pain upon or discomfort when extending or flexing the elbow
- Abnormal gait
- Holding elbows out or tightly against their bodies
- Holding the affected limb away from the body
- Grating or grinding sounds with movement
- Intermittent or persistent lameness that is agitated by exercise or by extended periods of rest
- Sudden (acute) episodes of elbow lameness are commonly seen in geriatric dogs
Understanding a Dog’s Skeletal Structure
In order to understand what elbow dysplasia is, we need to understand the physical structure of a dog’s skeletal system within and around the elbow. Three bones make up a dog’s elbow – the radius, the humerus, and the ulna.
In a normal healthy dog, these bones grow in a highly coordinated fashion and articulate precisely to form the elbow joint. However, if your dog is suffering from elbow dysplasia, one or more growth abnormalities interfere with the correct development of this complex structure.
Types of elbow dysplasia in dogs
There are four discrete entities that cause elbow dysplasia in dogs. While a dogs can be affected by just one of these conditions, it is not unusual to see multiple abnormalities present at the same time.
Fragmented coronoid process (FCP)
In this condition, one tip of the crescent-shaped ulnar notch (which accommodates the end of the upper arm bone, or humerus), breaks off and causes damage within the elbow joint. This results from excessive pressure against this spot due to the ulna bone being slightly longer than it should be relative to the length of the other bone of the forearm (the radius).
Osteochondrosis/Osteochondritis dissecans (OCD)
Osteochondrosis dessicans is a condition of abnormal development of joint cartilage and the underlying bone that may occur in the elbow joint as well as several other joints. This abnormality often results in an elevated flap of cartilage forming and potentially detaching from the surface of the joint, resulting in osteochondritis (pain and inflammation in the joint).
Elbow Joint Incongruity/Growth Rate Incongruity
In this condition, either the radius bone or the ulna bone grows at an abnormal rate. Because these two bones run parallel to each other and terminate together at the wrist joint and elbow joint, if one grows too rapidly or slowly relative to the other, this may result in the end of one bone becoming dislocated from the elbow joint or the cartilage surface becoming damaged.
Ununited anconeal process (UAP)
In this condition, the growth plate between the upper part of the ulnar notch within the elbow joint (called the anconeal process) fails to close at the normal time. This results in joint instability, inflammation, and pain.
What are the long-term consequences of elbow dysplasia?
Every dog that’s diagnosed with elbow dysplasia is affected by some degree of elbow osteoarthritis. This may be the consequence of a loose fragment within the joint, joint instability, or excessive strain causing one part of the joint to be overloaded.
Regardless of treatment, arthritis will occur and progress to some extent in all affected joints. In some dogs, lameness may be mild and intermittent, while in others, lameness may cause severe and permanent disability.
How is elbow dysplasia diagnosed?
One of our veterinary surgeons will take a thorough medical history of your pet. They will ask you when you first noticed the lameness and how it has progressed since. An orthopedic examination will be performed, and your dog’s gait will be observed. Your veterinarian may need to take a blood and urine sample from your pet to get a baseline assessment of their overall health. Definitive diagnosis is most commonly established with precisely positioned x-rays of the elbows. Typically, a dog will need to be sedated or anesthetized to obtain good x-rays.
Other diagnostic tests your veterinarian may recommend include magnetic resonance imaging (MRI), computed tomography (CT) scanning, joint fluid analysis, and arthroscopy. A CT scan can detect abnormalities that may not be visible on standard x-rays, such as stress fractures of the coronoid process of the ulna, and provides a more detailed view of joint structures to reveal subtle abnormalities. This type of imaging is particularly useful in elbow dysplasia because of the complex anatomy involved and the frequency of multiple abnormalities. Sedation or general anesthesia is necessary for a CT scan because the patient must remain perfectly still for several minutes. Arthroscopy is another highly useful procedure for diagnosing elbow dysplasia. In this procedure, the animal is placed under general anesthesia, a small incision is made into the joint, and a camera is inserted to directly view the inside of the joint. Oftentimes, a problem that is detected arthroscopically can also be treated at the same time (for example, removal of a cartilage flap in an elbow with OCD.)
How is Elbow Dysplasia Treated?
Even though elbow dysplasia isn’t entirely curable, there are steps we can take to provide your four legged friend with a near normal quality of life. Treatment of the condition varies depending upon the abnormalities present. There are circumstances in which your dog may be treated medically rather than surgically. For young dogs, lifestyle changes may be recommended by your vet, including a low-impact exercise program (such as swimming or hydro-therapy) and a weight management regimen. In other cases, surgery may be the best option for pain relief and improved function. Numerous different surgical procedures exist to address the various abnormalities that may be present.
Non-surgical therapies may be a preferable management option for some dogs with elbow dysplasia and osteoarthritis. We are proud to offer our Canine Physical Rehabilitation Therapy Center in Billings, which provides comprehensive non-surgical management of osteoarthritis and complements our surgical expertise. Non-surgical treatments include physiotherapy, weight management, exercise modification and medication (anti-inflammatory painkillers). At the Animal Clinic of Billings and Animal Surgery Clinic, we also offer regenerative medicine therapies such as stem cell and platelet-rich plasma (PRP) to help combat pain and inflammation that typically is associated with osteoarthritis.
At the Animal Clinic of Billings and Animal Surgery Clinic, we have canine physical rehabilitation practitioners providing physiotherapy and hydrotherapy protocols for treatment of all forms of joint disease, both for those patients who are not surgically treatable as well as for postoperative rehabilitation of surgical patients. A physical rehabilitation treatment plan is custom-designed for each of our patients to optimize individual outcomes. Physiotherapy will not reverse arthritic changes to the joints, but it can significantly improve mobility, function, and comfort, and it has been shown to significantly improve outcomes following orthopedic surgery.
Surgical Treatment Options
The method of surgical treatment depends on the severity of disease in the elbow joint.
Elbow dysplasia surgery can be performed to:
- Remove cartilage or bone fragments causing joint irritation
- Improve bone alignment
- Reattachment or removal of a bone or portion of bone within the elbow causing joint irritation and degeneration
Arthroscopic fragment removal:
This is often the treatment of choice in cases of a fragmented coronoid process of the ulna where there is no evidence of concurrent elbow incongruity or radio-ulnar conflict, and in which any remaining coronoid process has been assessed as having a low risk for stress microfracture. Most dogs show rapid improvement after arthroscopic fragment removal. The long-term prognosis of arthroscopic fragment removal is dependent on the degree of osteoarthritis already present in the elbow joint, which one of our veterinarians will discuss with you prior to surgery.
Biceps ulnar release procedure (BURP):
In some cases, a specific pattern of stress fracturing of the coronoid process of the ulna typical of radio-ulnar conflict occurs secondary to rotational instability. Stress on the coronoid process is exacerbated by the repetitive force imparted by the branch of the biceps tendon which attaches on the coronoid process. Arthroscopic surgical release of this tendon relieves these forces. The biceps tendon branch attached to the radius is not affected, so there is no deleterious mechanical consequence of biceps ulnar release.
Subtotal coronoid ostectomy (SCO):
In elbows where there is diffuse stress damage to the coronoid process of the ulna, the process should be surgically removed using arthroscopy. When combined with arthroscopic fragment removal, the majority of dogs will experience significant improvement after subtotal coronoid ostectomy surgery, and in many cases, this improvement is maintained long term. However, osteoarthritis is progressive in all forms of medial coronoid disease regardless of which surgery is performed. Long-term medications and physical rehabilitation therapy will often result in significant relief of any progressive arthritis that may develop.
Proximal ulnar osteotomy (PUO):
Proximal ulnar osteotomy surgery can be implemented when stress fracturing of the coronoid process of the ulna is caused by the presence of a radius that is too short relative to the length of the ulna. In these cases, an angled (“dynamic oblique”) cut is made through the ulna just below the joint, enabling the two ends to slide along each other until ulnar length is congruent with the radius. As the ulna heals in its new configuration, pressure on the joint is relieved. The same technique can be employed to treat elbows affected by a poor fit between the humerus and the ulnar notch.
Proximal abducting ulnar (PAUL) osteotomy:
PAUL surgery falls into a group of surgeries called load-altering osteotomies. In this procedure, a precise cut is made through the ulna, and a special surgical plate is secured that changes the orientation of the two cut ends of the bone with respect to each other. The PAUL procedure helps to unload the medial compartment of the elbow, thus reducing pain and improving limb use and function.
Canine unicompartmental elbow replacement (CUE):
Canine unicompartmental elbow arthroplasty or CUE surgery is an advanced surgical approach that involves replacing the damaged joint surfaces of the inner (medial) portion of the elbow joint with metal and synthetic implants. The CUE procedure is offered by Dr. Sherburne at the Animal Clinic of Billings and Animal Surgery Clinic for mature dogs suffering from medial compartment disease (MCD).
When surgical treatment is necessary, the Canine Unicompartmental Elbow (CUE) is a safe and effective option to consider. It was developed as a treatment for MCD in dogs in whom arthroscopic treatment or nonsurgical options have proven unsuccessful. By focusing on the specific area of disease, the CUE implant provides relief of the pain caused by bone-on-bone grinding in this portion of the joint while preserving the dog’s own healthy cartilage in the lateral compartment.
Surgery for elbow dysplasia is usually successful in relieving pain and lameness in dogs. However, dogs that have been diagnosed with developmental abnormalities in their elbow joints often continue to have some degree of arthritis as they age (although much less than they would have developed without surgery). Therefore, life-long veterinary care will likely be needed to help slow the progression of arthritis in your dog’s elbow. Your veterinary surgeon will advise you of post-operative aftercare needed for your dog. Activity will be restricted for the first 8-12 weeks after CUE surgery and it will be important to help your dog maintain a lean body weight. Follow up visits with your veterinarian will be necessary to monitor healing and the physical rehabilitation process. In the years following surgery, it’s essential to schedule annual examinations with your vet to assess the progression of your dog’s condition. Your veterinarian will be able to determine the rate of deterioration of joint cartilage and assess if any additional treatments are necessary.
Although progression is generally anticipated with any type of degenerative joint disease in dogs, you can expect a fair to good prognosis from a CUE procedure if you follow your vet’s medical advice and create a plan for long-term care.
Recovery for Dogs After Surgery
Although activity must be restricted for several weeks following your dog’s procedure, it’s important to encourage movement once your dog is able to move around freely again. In order to avoid decreases in muscle mass and range of motion, controlled low-impact exercise (such as walking slowly on a short leash) is encouraged following surgery. However, be sure to follow the specific instructions provided by your veterinarian when incorporating physical therapy of any kind on your dog during his or her initial phase of recovery.
Weight Control: Weight management is imperative for any dog affected by canine elbow dysplasia. Controlling your pup’s weight will decrease the repetitive stress he’s putting on the affected joints. Ask your veterinarian about a specially-formulated diet with your vet, particularly if your dog is overweight or obese. There are many nutritionally-balanced dog foods scientifically designed for weight loss that can be very helpful in achieving a healthy weight in dogs who cannot exercise normally due to orthopedic problems. Remember, it’s always best to ask your veterinarian for professional recommendations if you’re uncertain.
Rehabilitation Therapy: There are a lot of gentle forms of therapy that have been shown to significantly benefit dogs as they recover from surgery for elbow dysplasia. Most dogs respond well to therapies such as ice/heat treatments, laser therapy, massage, stretches, underwater treadmill exercise, and other therapeutic exercises. Discuss the potential role of rehabilitation therapy in your dog’s recovery with your vet.
Prevention of Canine Elbow Dysplasia
Although the majority of cases of elbow dysplasia can be attributed to genetics, there is also a potential link to an excessive or unbalanced intake of nutrients in growing puppies that may impact growth rate and development, increasing the risk of developing elbow dysplasia. For all puppies, feeding an adequate but not excessive amount of a high quality nutritionally balanced puppy food is essential to healthy development. For large and giant breed puppies, it is important to select a puppy food specifically formulated for these breeds, as their requirements for minerals in particular differ from those of small and medium-sized breeds. It is especially important in large and giant breeds to avoid overfeeding.
Elbow dysplasia is hereditary. Therefore, it is highly recommended that pets who show signs of elbow dysplasia are not bred. If your dog has been diagnosed with elbow dysplasia, having your dog spayed or neutered is advised. If you bought your dog from a breeder, you should also notify them so they can take this condition into account in managing their breeding program.
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