What is canine elbow dysplasia?
The word “dysplasia” means “abnormality of development”. The elbow is a complex joint because it involves the articulation of three bones. If the three bones do not fit together absolutely perfectly as a result of abnormal development, the consequence is abnormal concentration of forces on a specific region of the elbow joint. The elbow joint is a complex hinge joint located in the forelimb of cats and dogs. Three bones meet at the elbow joint; the humerus of the upper limb and the radius and ulna of the lower limb.
Elbow dysplasia is generally a disease that affects rapidly growing, large breed puppies, however, some dogs do not develop symptoms until after adulthood. Breeds that have been noted to have higher incidence of occurrence are German Shepherds, Golden Retrievers, Labrador Retrievers, Newfoundland Dogs, Rottweilers, Mastiffs, Saint Bernards, and the Bernese Mountain Dogs. Typically the disease will be present in both elbows. Elbow dysplasia is a general term meaning arthritis of the elbow joint. This condition is one of the most common causes of front leg lameness in canines.
Forms of primary cartilage disease may also constitute abnormal development of the elbow joint resulting in significant clinical consequences. The term ‘developmental elbow diseases’ may be a more descriptive nomenclature for this condition since most people will have heard of ‘dysplasia’ only in reference to the hip joint. Elbow dysplasia describes the abnormal development of the elbow. The term includes a number of specific abnormalities, which affect different sites in the joint. These abnormalities cause problems by affecting the growth of the cartilage which forms the surface of the joint or the structures around it. These abnormalities are primary lesions, which then induce a secondary osteoarthritic process. Elbow dysplasia and hip dysplasia both mean that the conformation of the joint is abnormal. In hip dysplasia, the end result of the abnormality in all dogs will be osteoarthritis accompanied by pain and reduced range of motion. Osteoarthritis (OA) also known as degenerative arthritis or degenerative joint disease (DJD), is a group of mechanical abnormalities involving degradation of joints including articular cartilage and subchondral bone. Treatment mostly consists of management of the osteoarthritis or joint replacement. In elbow dysplasia, the forces concentrated on specific areas of the joint will not only result in osteoarthritis (as happens with hip dysplasia) but also in discrete pathological entities like fractures within the joint that may need to be managed separately and alongside the osteoarthritis.
How can I tell if my dog has elbow dysplasia?
Elbow dysplasia is the most common cause of forelimb lameness in young, large and giant breed dogs. Most dogs have a limp on one or both front legs. This can be seen as a nodding of the head when the good leg is placed and lifting of the head when the bad leg is placed. Some dogs that limp on both front legs will not have a limp, but will have an unusual “paddling” gait. Lameness is often triggered by prolonged rest and exercise. For this reason, many dogs will be lame when they wake up but after a warm up they will exercise freely and limp again afterwards. Although most dogs will be diagnosed before they are two years old, some dogs will not limp until they are older. Collectively, elbow dysplasia and elbow osteoarthritis are the commonest causes of forelimb lameness in dogs of any age. Small dogs can also be affected by elbow dysplasia and this problem should be suspected in any dog with forelimb lameness that has not been caused by trauma.
Although a limp is one of the most frequent indicators of elbow dysplasia, your dog may also hold his leg out from his body while walking, or even go so far as to put no weight on it at all. Symptoms of elbow dysplasia may be apparent as early as four months. However, most dogs affected by the condition will go through a period of about 6-12 months where the clinical signs are the worst. It should be noted that not all dogs will show signs or symptoms of elbow dysplasia when they are young. As your dog matures, you will most likely begin to recognize the signs of arthritis and other conditions associated with this problem. Unfortunately, this is a lifelong condition and as a pet owner, your primary goal is to make your pet as comfortable as possible.
Symptoms of Elbow Dysplasia in Dogs
- Limping after exercise
- Dog appears stiff when getting up from resting
- Joints may appear swollen
- Pet is reluctant to play or to go on walks
- Dog’s feet will rotate outward
- Decreased range of motion of one or both elbows
- Abnormal gait
- Pet shows pain upon manipulation of elbow joints
- Dog may hold his elbows out or tightly into their bodies
- A marked or diminished range of motion
- Advanced degenerative joint disease
- Displays signs of pain or discomfort when extending or flexing the elbow
- Dog may hold the affected limb away from the body
- Grating of bone and joint is often apparent in advanced degenerative joint disease
- Intermittent/persistent lameness that is agitated by exercise; progresses from stiffness, and noticed only after the dog has been resting
- Sudden (acute) episodes of elbow lameness is commonly seen in geriatric dogs
- There may be fluid build-up in the joints
What is the cause of elbow dysplasia?
Elbow dysplasia in canines is considered to be primarily a genetic developmental disease. Other possible contributing factors may be growth rate, high protein diet, trauma, hormonal imbalances, poor nutrition, rapid weight gain and level of exercise. A canine’s elbow is made up of three bones, the ulna, the radius and the humerus. These three bones are meant to fit together to form the elbow joint. In ED there is an abnormal developmental problem which results in impaired joint formation.
Understanding the Canine Skeletal Structure
To better understand this condition, you must first take a look at the physical structure of your dog’s skeletal system with a focus on his elbow. There are three bones that make up your dog’s elbow – the radius, the humerus, and the ulna.
In a healthy dog, these bones are supposed to grow together and fit seamlessly to form the elbow joint. However, if your dog is suffering from a form of elbow dysplasia, it is actually the result of a malformation and/or deterioration of the bone structure, cartilage, or joint itself.
Types of elbow dysplasia in dogs
Below is a breakdown of the types of canine developmental problems. Dogs with elbow dysplasia usually suffer from more than one of these diagnoses. There are four types of abnormal development that may appear in the canine’s elbow:
- Fragmented coronoid process (FCP) – A small or large fragment of the bone breaks off and moves around inside of the elbow joint. This small fragment of loose bone irritates the lining of the joint, wearing away the cartilage of the humerus.
- Osteochondritis dissecans (OCD) – OCD of the elbow usually occurs in young dogs, who show signs of lameness in one or both limbs. Osteochondritis dessicans is a condition where a piece of cartilage comes loose or completely pulls away from the surface of the joint, resulting in pain and inflammation. Once the inflammation or “itis” is gone, the condition is then referred to as osteochrondrosis dessicans.
- Growth rate incongruity – The radius bone and ulna bone grow at different rates. Growth Rate Incongruity or Elbow Incongruity is a term used to describe imperfect conformation of the joint, which causes the cartilage to wear away rapidly.
- Ununited anconeal process (UAP) – A bone outgrowth within the elbow becomes detached and causes irritation and degeneration. UAP is a condition noted by a bony protuberance within the elbow. This area becomes detached from the ulna, causing joint irritation and degeneration.
Arthroscopy, also called arthroscopic surgery, is a minimally invasive surgical procedure involving a joint in which an examination and sometimes treatment of an injury is performed using an arthroscope (a rigid endoscope that is inserted into the joint through a small incision). Arthroscopy can provide additional information regarding the joint surfaces which, in combination with the findings from radiography and CT, will allow efficacious treatment. Investigation of the joint with radiographs (x-rays) and/or CT and subsequent arthroscopy is considered the standard of care at the Animal Clinic of Billings and Animal Surgery Clinic.
The pattern of abnormal development is not the same in all affected elbow joints. In order to offer the optimal treatment for a dog with elbow dysplasia, it is essential that we identify and neutralise the abnormal forces acting on the affected elbow. These forces are summarised below:
Elbow incongruity due to a relatively short radius
Elbow incongruity can be transient or permanent. Subtle differences in the growth rate of the two bones that make up the forearm (the radius and ulna) can cause severe overloading of the prominent coronoid process of the ulna. In some dogs, it may be that this incongruity has resolved by the time the diagnosis of elbow dysplasia is made, but the consequence of this transient incongruity is stress fracturing of the coronoid process. Treatment of this problem is usually by arthroscopic fragment removal or subtotal coronoid ostectomy. With the latter, not only do we remove the fragmented coronoid process but also some of the unfragmented part which could still contribute to joint pathology due to its abnormal conformation and ongoing inflammation. In elbows, in which this type of incongruity is permanent, treatment is usually accompanied by proximal ulnar osteotomy in an effort to allow the longer bone (ulna) to find a more “convenient” place in the joint.
Coronoid process overloading due to conflict with the radius
In some affected elbow joints, stress fractures of the coronoid process of the ulna could be the consequence of repetitive impact from the adjacent radial head. The anatomical structure with most contribution to this repetitive impact is a branch of the biceps tendon. This could be because every time the biceps muscle contracts it causes the radius to impact the ulna around an area known as radial incisure of the ulna (incisuar radialis ulnae). Treatment of this problem may be undertaken by a surgical procedure called “biceps ulnar release”.
Ulnar notch incongruity
In some cases, the notch of the ulna is excessively elliptical or simply the wrong shape relative to the humerus, resulting in severe overload of the extremities of the notch. In some dogs, this can cause severe cartilage erosion. When this happens, treatment options depend on the disease entities accompanying the developmental disorder and the extent of osteoarthritis present.
What is the long-term consequence of elbow dysplasia?
Every dog with elbow dysplasia is affected by some degree of elbow osteoarthritis at the time of diagnosis. This can be the consequence of a loose fragment acting like a “stone in a shoe” within the joint or of untreated elbow incongruity such as radio-ulnar or humero-ulnar conflict.
Surgical treatments for elbow dysplasia aim to treat the current source of pain and also to minimise the likelihood of osteoarthritis progression. Non-surgical treatments for elbow dysplasia aim to treat elbow pain and maintain mobility but do not have the potential to minimise osteoarthritis progression. Rehabilitation of elbow dysplasia can be provided through our rehabilitation service whereby your veterinarian and/or one of our physical rehabilitation practitioners will design a home care physiotherapy and exercise plan for you to follow at home between outpatient physiotherapy and hydrotherapy appointments.
The clinical impact of elbow osteoarthritis is unpredictable and, regardless of treatment, arthritis will progress to some extent for all affected joints. In some dogs, lameness can be mild and intermittent, whilst in others, lameness can cause severe and permanent disability. Where persistent cartilage erosion occurs, it is generally in the inner (medial) part of the elbow, constituting the joint between the humerus and the ulna (coronoid process). This could be the result of any form of elbow incongruity, such as a short radius, an abnormally shaped ulnar notch or just abnormal three-dimensional rotation conflict. In these situations, depending on the degree of poor fit, surgical treatment could include proximal ulnar osteotomy (PUO) or canine unicompartmental elbow replacement (CUE).
How is elbow dysplasia diagnosed?
One of our veterinary surgeons will take a thorough medical history of your pet. He will ask you when you first noticed the lameness and how it has progressed since. A physical examination will be performed; palpating each leg, checking for swollen joints. The veterinarian may ask to see your dog walk so he can see first-hand if there is limping, abduction of the elbows or an abnormal gait. Your veterinarian may want to take blood and a urine sample of your pet to get a baseline assessment of his overall health. The most common diagnostic test is to take x-rays of the elbows. X-rays will show if any bone fragments are present within the joint and whether or not arthritis has developed. Usually the dog will need to be sedated or anesthetized to obtain good x-rays. Other diagnostic tests your veterinarian may recommend are magnetic resonance imaging (MRI), the computed tomography (CT) scan and aspirating a sample of fluid from the joint.
Computed tomography (CT):
In addition to radiography, we use computed tomography (CT) and arthroscopy to facilitate diagnosis of elbow dysplasia. CT can be performed under sedation or general anaesthesia. It is a very sensitive method for the diagnosis of stress fracturing of the coronoid process of the ulna and for the assessment of elbow incongruity and the bone underneath the cartilage. CT gives us very useful information for planning the best treatment of elbow dysplasia in your dog. We offer CT to most cases when elbow dysplasia is suspected. The entire study can be completed in minutes and gives us a three-dimensional picture of the disease process.
Arthroscopy is the gold standard technique for diagnosis of problems within a joint. It is a keyhole surgical technique that is performed under general anaesthesia. Arthroscopy allows us to obtain a magnified panoramic view of the inside of a joint. In dogs requiring treatment of problems in both elbows, arthroscopy and surgery are performed as part of a single surgical procedure under the same general anaesthetic. When resolution of the problem can be arthroscopically achieved, your dog will generally be walking well the following day and recovery times are usually rapid.
How is elbow dysplasia treated?
Although there is no definitive cure for elbow dysplasia, there are steps you can take to maintain your four legged friend’s quality of life. Treatment of the condition varies upon the abnormalities present. There are incidents where your dog may be treated medically without surgery. For young dogs, a lifestyle change may be prescribed by your vet, including a low-impact exercise program (such as swimming) and a weight management regimen.
Depending on the severity of your dog’s condition, surgery may be performed to remove the fragmented process or cartilage flap in the affected limb. If your dog is a good candidate for corrective surgery, it’s imperative to follow up with appropriate care immediately afterwards.
In addition, range-of-motion exercises are highly recommended as a form of healing therapy until your pooch is able to bear his own weight again on the affected limbs. Your vet will demonstrate the types of exercises and movements to work on with your dog, based on the severity and location of the affected limb(s).
Non-steroidal anti-inflammatory drugs (NSAIDs) may be prescribed to help reduce pain and inflammation of the elbow joint. Long term use of NSAIDs is not recommended because these drugs have been linked with cartilage damage.
Non-surgical treatments for elbow dysplasia
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 the surgical expertise already in place. The traditional cornerstones of non-surgical treatment are body weight management, physiotherapy, exercise modification and medication (anti-inflammatory painkillers). We also offer regenerative medicine therapies such as stem cells and platelet-rich plasma to help combat the pain and inflammation 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, including those patients not surgically treatable and for postoperative rehabilitation of surgical patients. The protocols are custom-designed for your dog to optimize outcomes. Physiotherapy will not cure any arthritic changes in the joint or remove pain on its own, but it can significantly help mobility and improve function for arthritic joints, and it can significantly improve outcomes achieved after surgery.
Surgical treatments for elbow dysplasia
The treatment will depend on the severity of disease in the elbow joint.
Surgery can be performed to:
- Remove bone fragments or cartilage that are irritating the joint
- Help with alignment of bones
- Reattachment or removal of a bone within the elbow that is causing irritation and degeneration of the joint
Arthroscopic fragment removal:
In some cases, the problem at the time of diagnosis is confined to an isolated fragment of the coronoid process of the ulna. In dogs having arthroscopic fragment removal alone, the CT scan and arthroscopy will have shown no evidence of current elbow incongruity or radio-ulnar conflict, and any remaining coronoid process will have been assessed as having a low risk for stress microfracture. The majority of dogs will make a rapid clinical improvement after arthroscopic fragment removal, and in some cases this improvement will be maintained in the long-term. The long-term prognosis is dependent on the degree of osteoarthritis in the remainder of the elbow joint and this is discussed by your orthopaedic clinician on an individual basis.
Biceps ulnar release proceude (BURP):
In some cases, we recognise a specific pattern of stress fracturing of the coronoid process of the ulna typical of radio-ulnar conflict. This conflict is contributed to by excessive and repetitive forces imparted by one of the branches of the biceps muscle which attaches on the coronoid process itself. Although the tendon itself is not diseased, it exerts force on a badly fitting bone geometry which contributes to the micro-fractures and ultimate fragmentation. Arthroscopic surgical release of this branch allows neutralisation of these forces. The remaining biceps insertion on the radius is not affected, and because the biceps shares its function of flexing the elbow joint with another muscle (the brachialis), there is no deleterious mechanical consequence of biceps ulnar release.
Subtotal coronoid ostectomy (SCO):
In elbows where there is diffuse stress fracturing of the coronoid process of the ulna, the majority of the process should be removed using arthroscopy. In common with arthroscopic fragment removal, the majority of dogs will make a good clinical improvement after SCO and in many cases this improvement is maintained in the longer term. However, osteoarthritis is progressive for all forms of medial coronoid disease regardless of whether fragment removal alone or SCO is performed. In many cases however, this does not produce noticeable lameness and rehabilitation of osteoarthritis advice can be provided by our veterinarians or physical rehabilitation practitioners.
Proximal ulnar osteotomy (PUO):
In some elbow joints, stress fracturing of the coronoid process of the ulna is caused by the presence of a relatively short radius, and this incongruity can be permanent. In these elbows, the incongruity is corrected in order to treat the current elbow pain and also to attempt to limit the future progression of osteoarthritis. This is achieved by cutting the ulna below the elbow joint. Cutting the bone at this point does not prevent the limb from being used normally and healing of the bone occurs in a new position that provides a more congruent elbow joint. The same technique may be employed to treat elbows affected by a poor fit between the humerus and the ulnar notch. Appropriate motion of the cut portion of the ulna and subsequent healing is facilitated by a specific angle of cut termed ‘dynamic oblique’.
Proximal abducting ulnar (PAUL) osteotomy:
PAUL surgery falls into the group of surgeries called load-altering osteotomies. An osteotomy involves a controlled surgical cut of a bone. The PAUL osteotomy procedure involves an ulnar osteotomy which is secured with a plate and screws to stabilise the bone while it heals in the new position. The surgery aims 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 or CUE surgery is an advanced and complex surgical approach that involves resurfacing the weight-bearing portion of the medial aspect of the elbow by placing an implant where the cartilage is now absent. The CUE procedure is offered by Dr. Sherburne at the Animal Clinic of Billings and Animal Surgery Clinic in selected mature dogs suffering from medial compartment disease (MCD).
When surgical treatment is deemed necessary, as is often the case, the Canine Unicompartmental Elbow (CUE) is a safe and effective option to consider. It was developed as a treatment for MCD in dogs when arthroscopic treatment and nonsurgical options either won’t work or have been tried and are no longer successful. By focusing on the specific area of disease (the medial compartment), the CUE implant provides a less invasive, bone-sparing option for resurfacing the bone-on-bone medial compartment while preserving the dog’s own “good” cartilage in the lateral compartment. This medial resurfacing procedure reduces or eliminates the pain and lameness that was caused by the bone-on-bone grinding.
Surgery for elbow dysplasia is usually successful in relieving pain and lameness in dogs. However, dogs that have several developmental abnormalities in their elbow joints may continue to have degenerative joint disease including arthritis. Therefore, life-long veterinary care will 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 maintain a healthy weight on your dog as it heals. Follow up visits with your veterinarian will be necessary to check on the incision and to monitor the use of any NSAIDs. In the years to follow surgery, it’s essential to schedule yearly examinations with your vet to assess the progression of your dog’s condition. Your vet will be able to determine the rate of deterioration of joint cartilage and asses if any additional treatments are necessary.
Although progression is anticipated with any type of degenerative joint disease, 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 elbow dysplasia surgery
Although activity is restricted for several weeks following your dog’s procedure, it’s important to encourage movement once he’s able to move around freely again. In order to avoid atrophy of the muscles and connective tissues, exercise is encouraged. However, be sure to follow the guidance and instruction of your vet when practicing any sort of physical therapy on your dog during his initial phases of recovery.
Weight Control: Weight management is essential for any dog affected by elbow dysplasia. Controlling your pup’s weight can help decrease the stress he’s putting on his affected joints and skeletal system. You may wish to discuss a specially-formulated diet for your pet with your vet, particularly if he is carrying extra weight or is struggling with obesity. There are a number of nutritionally-balanced dog foods for weight loss available on the market. As always, it’s best to ask your vet for professional recommendations if you’re uncertain.
Rehabilitation Therapy: There are a number of gentle forms of therapy that may benefit canines with elbow dysplasia. Most dogs usually respond well to therapies such as massage, underwater treadmill/swim therapy, joint mobilization, and therapeutic exercises. Discuss the possibilities with your veterinarian, who may refer you to a Certified Canine Rehabilitation Practitioner (CCRP) for treatment options.
Prevention of Canine Elbow Dysplasia
Although the majority of elbow dysplasia incidents can be accredited to genetics and breed type, there has also been a link to an excessive intake of nutrients during the early phases a dog’s life, resulting in rapid growth and the consequent development of the condition.
Therefore, maintaining your dog’s weight is crucial during his first year, particularly for high-risk breeds. By restricting weight gain, watching his diet, and ensuring your dog receives the proper nutrition, you may be able to assist in decreasing the incidence of elbow dysplasia.
Elbow dysplasia is a genetic trait. Therefore, it is recommended that animals who show signs of the condition are not bred. If your canine companion has been diagnosed, having your dog spayed or neutered is advised. You should also report findings to the breeder if you purchased your animal from a private source.