Elbow Dysplasia

Diagnosis

Forelimb Lameness

The leading cause of canine forelimb lameness is elbow dysplasia, the abnormal development of the three bones of the elbow joint: radius, ulna and humerus. Elbow dysplasia is complex and influenced by genetic regulation and environmental influence on skeletal and cartilage growth.

When growth is normal, the bones of the joint match perfectly, smoothly guiding and supporting movement.

When growth is abnormal, the bones of the joint are incongruent and don’t match, resulting in irregular and high contact pressure. This leads to the following conditions, which can occur in combination:

• Sub-Trochlear Sclerosis (STS)
• Osteochondritis Dessicans (OCD)
• Ununited Anconeal Process (UAP)
• Fragmented Coronoid Process (FCP)
• Medial Compartment Disease (MCD)
• Elbow Incongruency

Because these conditions can occur in combination and varying degrees of severity, a complete evaluation, including Xray and in some instances, CT, should be performed. A veterinary orthopedic specialist will be able to recognize the full spectrum of contributing conditions and determine treatment strategies.

What are the signs?

Signs can be identified as early as four to five months of age by a clinical and radiographic exam, but the fast rate of growth and ability for our companions to hide the signs of lameness make early detection a challenge.

Signs:

• Pain
• Decreased range of motion
• Loss of muscle mass (muscle atrophy)
• Abnormal posture when standing, getting up, lying down or sitting
• Abnormal gait when walking, trotting, climbing stairs or turning
• Swelling and inflammation
• Grating or grinding joint movement

As with people, arthritis in a dog is painful, resulting in intermittent and persistent lameness, especially following physical activity.

The condition is more common and the consequences more debilitating in large breeds. German shepherds and Golden and Labrador retrievers are among the most commonly affected.

If you suspect that your companion is suffering from elbow dysplasia, contact your general practitioner to inquire about a physical and radiographic exam. Unique radiographs and evaluations of joint function will be performed to properly screen for disease and recommend treatment strategies.

Treatment Options

Prolong Active Life

While it is not possible to reverse the abnormal growth of the joint, there are a variety of strategies to minimize the pain, prolong active life and slow the progression of disease. 

Options for treatment vary by age, severity, arthritic change, degree of pain/discomfort, owner expectations and financial ability.

For many, diet/weight control, activity restriction, physical rehabilitation, non-steroidal anti-inflammatory drugs and oral supplements can manage and mitigate the symptoms of disease.

When the condition is more severe, surgical treatments are available and will vary, generally, by the age of the patient and the amount of arthritic changes that have occurred in the joint.

To keep it simple, we can think of these as: Early, Middle and Late stages of disease.

Early

Dogs that are screened and diagnosed as puppies at approximately four months of age, will have the most options. When the patient is still growing, up to approximately one year of age, surgical procedures can be performed to influence the growth of the radius and ulna so that the joint functions more normally, ideally avoiding future surgeries and progression to Fragmented Coronoid Process (FCP), Osteochondritis Dissecans (OCD) or Ununited Anconeal Process (UAP). These procedures are categorized as osteotomy or ostectomy procedures and include: Distal Ulna Osteotomy (DUO), Proximal Ulna Oblique Osteotomy (PUO) and proximal radius oblique/lengthening osteotomy. Osteotomy procedures involve cutting bone to alter the alignment of the limb. The objective is to normalize the loading of the joint during the growth phase. Deciding which procedure to perform will depend on the severity and combinations of conditions.

Middle

Once a patient is skeletally mature at one year and up, many patients will have developed one or several of the conditions associated with elbow dysplasia, for example Fragmented Coronoid Process (FCP). Fragment removal, the surgical intervention for FCP, will eliminate a consequence of elbow dysplasia, but will not address the underlying drivers of disease. For many patients, especially those with Medial Compartment Disease (MCD), the overloading of a compartment of the elbow joint, fragment removal will provide a temporary benefit, but lameness will return and progression of disease will persist.

In recent years, corrective osteotomies have been developed to normalize the loading of the joint, slow progression of disease and extend the active life of patients. These include: Sliding Humeral Osteotomy (SHO) and Proximal Abducting Ulnar Osteotomy (PAUL). Both procedures involve cutting and plating bone to shift weight bearing away from the most painful part of the joint. The PAUL procedure has been most effective in patients who receive treatment prior to advanced progression of disease, but older patients also see a benefit, typically an improvement of one to two grades of lameness. These procedures, considered palliative, seek to slow the progression of disease and reduce pain and lameness, but will not reverse the damage that has occurred or completely stop the progression of disease.

End

The end stage of disease occurs when major arthritic changes have occurred in the joint, causing severe lameness and pain that result in a major decline in quality of life. Medical management to control pain and swelling are at their limits, and limb function is significantly compromised. For these patients, elbow joint replacement has become a viable option thanks to the pioneering of surgeons and innovators.

With approximately 60% of a dog’s weight born by forelimbs and a complex joint that hinges and rotates, a sufficient joint replacement device is a challenge. While these devices are still in the relatively early stages of commercialization, implants and procedures have been developed with great care. A sufficient implant will not only replace the diseased and painful parts of the joint but allow normal limb function and last for the life of the patient.

Consider Your Companion

Dogs with elbow dysplasia will still wag their tails and, undiagnosed, are often considered “lazy.” But, inactivity, especially in young dogs, is often a result of chronic pain and discomfort. Our companions want and need to be active. We bring specific breeds into our lives because we want to share our active lives with them.

As guardians, it is our responsibility to evaluate what is practical and preferable for ourselves and our companions. When consulting with owners, Andy Torrington, BVMS CertSAO MRCVS, will often ask, “What treatment strategy do you think your companion would choose?” It’s an important question to consider.

When middle-aged dogs, who live for long hikes and racing alongside us, are diagnosed with elbow dysplasia, would they choose a lifetime of activity restriction and medication or a surgery and recovery that can put them back into action?

You know your companion best, and your veterinarian will help you evaluate the status of disease and relevant options.

References:
1. American College of Veterinary Surgeons. Osteoarthritis in dogs.
2. Daily Dog Stuff. US pet ownership statistics 2018/2019. https://www.dailydogstuff.com/us-pet-ownership-statistics
3. Bland SD. Canine osteoarthritis and treatments: a review. Veterinary Science Development. 2015;5(2):84-89. DOI: 10.4081/vsd.2015.5931.
4. Orthopedic Foundation for Animals. Examining elbow dysplasia. https://www.vin.com/apputil/content/defaultadv1.aspx?id=3853864&pid=11203&
5. American College of Veterinary Surgeons. Canine Elbow Dysplasia. https://www.acvs.org/small-animal/canine-elbow-dysplasia

Products & Solutions

In an effort to improve the treatments for patients who miss the window of early intervention and delay the need for joint replacement, Dr. Ingo Pfeil of Dresden, Germany, proposed a proximal ulna osteotomy aimed at unloading the medial compartment to reduce pain and improve limb function. KYON partnered with Dr. Pfeil to bring this vision to reality with the Proximal Abducting Ulnar Osteotomy (PAUL) System.