Elbow dysplasia is an inherited developmental disease primarily impacting young growing dogs. The majority of dogs will have changes in both elbows.
The elbow is where the radius, ulna and humerus meet. Growth abnormalities of any of these 3 bones may cause joint incongruency (poor fit), resulting in atypical pressure points leading to cartilage wear or bone/cartilage fragmentation. These changes ultimately result in inflammation, osteoarthritis, and associated pain/lameness. Dogs with elbow dysplasia are typically reluctant to walk or play for long periods, or if they do exercise for extended periods, will be very sore afterwards.
While elbow dysplasia can impact a number of breeds, the most commonly seen dogs are Labrador Retrievers, German Shepherds, Rottweilers, Golden Retrievers, Bernese Mountain Dogs, and other giant breed dogs.
Despite being classified together, elbow dysplasia is actually comprised of multiple pathologies that can occur in combination or singularly: fragmented medial coronoid process (FMCP), osteochondritis dissecans (OCD), and ununited anconeal process (UAP).
Diagnosis
- Orthopedic Examination & Gait Evaluation
- Radiographs (also known as X-rays) highlight the bones comprising the elbow joint and can reveal the current extent of osteoarthritis. Larger distinct FMCP can be visible on radiographs, while smaller ones may be obscured by overlapping bone in the images. While incongruency can sometimes be seen on radiographs, it is often underestimated due to the limitations of the imaging. Overall, the joint remodeling secondary elbow dysplasia is more commonly seen on radiographs than the specific dysplastic component(s) contributing.
- CT Scan provides a more sensitive 3D reconstruction of the joint. It is the best non-invasive method to evaluate joint congruency and potential FMCP and OCD.
- Arthroscopy is useful as both a diagnostic method and to facilitate treatment. Arthroscopy involves the introduction of a miniature video camera through small incisions to visualize joint structures on a magnified scale. After camera-assisted visualization, an additional small incision can be made for specialized instruments to surgically address damaged tissues, such as FMCP or OCD.
Components of Elbow Dysplasia
Fragmented medial coronoid process (FMCP) describes a portion of the ulna (medial coronoid process) within the elbow that can develop a fissure, or crack, leading to fracture of the process away from the remainder of the ulna. Since joints must have smooth gliding surfaces to function properly, this FMCP and associated joint incongruency lead to abnormal cartilage wear, inflammation, and pain/lameness. The FMCP acts like a rock in your shoe and can irritate multiple sections of the joint while being trapped within the joint capsule.
Osteochondritis Dissecans (OCD) can occur in a number of joints, including the elbow. As dogs grows, their bones lengthen, and portions of cartilage transition into bone. With abnormalities in this process, a section of cartilage may not complete this transition and instead becomes thickened. This atypical section of thick cartilage does not have adequate blood supply to survive. As the cartilage piece dies off, cracks develop from the deeper layers to the joint surface. Eventually, a flap of cartilage forms that may detach from the rest of the joint surface. Since joints must have smooth gliding surfaces to function properly, this OCD flap leads to inflammation and pain/lameness.
Ununited anconeal process (UAP) describes the failure of a growth plate within the elbow (called the anconeal process of the ulna) to close normally during the maturation process. This failure ultimately leads to instability of the anconeal process, inflammation, and pain/lameness.
Prognosis
Unfortunately, as a hereditary condition, a dog born with elbow dysplasia will always have elbow dysplasia. However, there are treatment options to slow the progression of osteoarthritis by addressing the underlying components. The decision to pursue non-surgical versus surgical options depends on the definitive diagnosis, extent of osteoarthritis, and pet’s age and clinical signs. Case-by-case decisions will be made after meeting with one of our surgeons.
Non-surgical options
These methods do not correct the elbow dysplasia components causing issues within the joint. However, they can minimize their effects and increase comfort. Also known as medical management, options include: physical therapy/rehabilitation, maintaining a lean body weight, modifying exercise (low-impact), anti-inflammatory medications, joint supplements, and joint injections.
Surgery
Surgical options are meant to address the underlying dysplasia components such as FMCP, OCD, etc.
- Arthroscopy allows visualization of potential FMCP or OCD and removal of these abnormal pieces, preventing further abnormal cartilage wear.
- Osteotomy (cutting of the bone) of the ulna to improve elbow alignment/congruency.
- Stabilization or removal of UAPs.
These procedures can be performed individually or in combination depending on your dog’s diagnosis.
Recovery
Recovery can vary depending on the procedures pursued and can range from days to months. Throughout the recovery process, activity restriction is vital. Over the long term, maintenance of a lean body weight and administration of joint supplements is highly recommended. For more information, see our Osteoarthritis page. Further details will be discussed during your appointment with the surgeon.