The Information Website for the Health & Welfare of the St Bernard

                                   Elbow Dysplasia

If your dog is Lame, you should seek Veterinary Advice. 

Elbow dysplasia is a multifactorial, polygenetic developmental condition affecting many large breeds including St bernards. The term elbow dysplasia refers to several conditions that affect the elbow joint: osteochondrosis of the medial humeral condyle, fragmented medial coronoid process, ununited anconeal process, and incongruent elbow. More than one of these conditions may be present, and this disease often affects both front legs. An affected dog may show forelimb lameness and elbow pain. These conditions may actually be different manifestations of a single disease process, osteochondritis dissecans (OCD) . OCD is abnormal maturation of cartilage (the specialized connective tissue from which bone develops). While this in an inherited defect, environmental factors such as diet, activity, and trauma also have a role in the development and progression of the disease.

Osteochondritis dissecans (OCD) A fragment of cartilage peels away from the bone, within the joint.

Osteochondrosis of medial humeral condyle  OCD develops on the elbow end of the humerus (the long bone in the front leg above the elbow).

Fragmented medial coronoid process and ununited anconeal process The coronoid and anconeal processes are small bones which fuse with the main part of the ulna as the animal matures. (The ulna and the radius are the two bones which make up the front leg between wrist and elbow). These terms describe the condition where those processes either break off from the ulna, or fail to fuse normally.

Incongruent Elbow The bones which form the elbow joint grow at different rates and do not fit together properly. Elbow dysplasia can be a problem in St Bernards.  It affects some dogs clinically but more dogs sub clinically (without showing sign of the disease).  However, when X-rayed the characteristic signs appear.

Lameness usually starts insidiously at  7 to 10 months of age. It is present every day, and may be most obvious when your dog first gets up, or starts to walk or run. The likely outcome depends on how far the disease has progressed when treatment begins. Good clinical results (ie. your dog will not be in pain) are usually seen if treatment starts early, before osteoarthritis (degenerative changes in the joint) has developed. If left untreated, your dog’s pain and lameness will gradually get worse.

Selection of Dogs for Breeding

To prevent Elbow Dysplacia in breed, breeders should look for animals least likely to carry genes which cause the problem into the next generation. This means identifying the dogs with clinical and sub-clinical disease. As both clinical and sub-clinical dogs will have changes in their elbow x-rays, this is the means of identifying affected dogs.

The BVA/KC have a scheme which scores the elbows upon submitting an identified x-ray. The scores are as follows:

Grade 0 No Lesions - clean, normal elbows
Grade 1

Minimal Arthrosis

Sclerosis of the ulna notch

Osteoarthritic change less than 2mm high at any site

Grade 2

Moderate Arthrosis

Osteoarthritic change 2 - 5mm high at any site

Grade 3

Severe Arthrosis

Osteoarthritic change over 5mm high at any site

The greater the degree of Elbow Dysplacia in the parents, the more likely they are to pass it on to their offspring.

Example

ParentsPercent Affected Offspring
Normal (0) x Normal (0) 31%
Normal (0) x Mild ED (1) 43%
Normal (0) x Moderate ED (2) 48%
ED (3) x ED (3) 56%

 

Elbow Dysplasia

  • Elbow dysplasia can cause lameness in young large-breed dogs and is commonly found in both elbows.
  • Elbow dysplasia is a generic term meaning arthritis in the elbow joint.
  • There are four developmental causes of elbow arthritis in dogs:
    • osteochondritis dessicans, ununited anconeal process, fragmented coronoid process, and elbow incongruency.
  •  Osteochondritis dissecans (OCD) - OCD is a condition in which a piece of cartilage becomes partially or fully detached from the surface of the elbow joint. This results in inflammation of the lining of the joint and pain.
  • Fragmented medial coronoid process - Fragmented medial coronoid process is a condition in which a small piece of bone on the inner side of the joint has broken off of the ulna bone. This piece of bone irritates the lining of the joint and grinds off the cartilage of the adjacent humerus (similar to having a pebble in your shoe)
  • Ununited anconeal process  - Ununited anconeal process is a condition in which a fragment of bone on the back side of the joint has failed to unite with the ulna bone during growth. Normally this bony process fuses with the ulna bone by 20 weeks of age.  The breeds most commonly affected include German Shepherds, Bassets, Mastiffs, and St. Bernards. 
  • Elbow incongruency  - Elbow incongruency is a condition in which the joint does not have perfect conformation, and the cartilage of the joint wears out rapidly. In simple terms the joint does not fit together well and the final result is progressive arthritis.

Diagnosis

  • X-rays of the elbow joint will allow us to make a diagnosis of ununited anconeal process and sometimes OCD and fragmented coronoid process.
  • CT scan is more accurate at arriving at a definitive diagnosis than plain x-rays, but has a 15% margin of error.
  • If we have an index of suspicion of a fragmented coronoid or OCD we usually recommend diagnostic arthroscopy as it is minimally invasive and these conditions can be then treated at the same time.

 Treatment

  • Arthroscopic surgery is used to treat OCD and fragmented coronoid processes. This technique allows us to treat the lesions more accurately and allows us to examine more of the joint. Because it is minimally invasive, the patients recover much quicker and have less pain.
  • Usually we can successfully remove the offending loose pieces from the joint using arthroscopic surgery, however if we are unsuccessful, a small incision is made on the inner side of the elbow. If your pet has an ununited anconeal process, arthroscopy of the joint is recommended to rule out a concurrent fragmented coronoid. Because an ununited anconeal process is fairly large, it is removed via a small incision made on the outer (lateral) side of the elbow joint.

 Convalescence period

  • If arthroscopic surgery is done, most pets will be using the limb on the day of surgery.
  • By 2 weeks after surgery the lameness is mild.
  • By 2 to 3 months after surgery, your pet should be using the limb well.
  • Recovery can be somewhat variable from one pet to another.

 Success rates

  • Most of the dogs with ununited anconeal process will be helped with surgery (about 60% return to normal function, 30% are improved, and 10% do not improve with surgery).
  • Approximately 75% of the dogs with having a fragmented coronoid process or OCD of the elbow will be helped with surgery. Unfortunately, surgery will not remove the arthritis that is already present in the joint. As a result, some pets may have some stiffness of the limb or lameness after very heavy exercise or during weather changes (cool damp conditions).
  • Dogs that have dramatically swollen elbows prior to surgery tend to be have a lower success rate.

 Complications

  • Anesthetic death is an uncommon complication.
  • One complication is infection of the surgical site, but this complication is uncommon.
  • Unresolved lameness may be due to elbow arthritis.

 Postop care

  • Monitor the stab incisions for signs of infection, which include signs of swelling, redness, pain, yellow or green discharge.
  • During the first 6 to 8 weeks after surgery, activity is restricted to short leash walks outside. Running, jumping, and rough play are forbidden.
  • After 8 weeks of rest, the activity can be gradually increased over the next two months

It is recommended that All St Bernards SHOULD BE ELBOW SCORED BEFORE BREEDING

KC/BVA Elbow Scheme

OFFA Elbow Information

OFFA Elbow Form (pdf)

Enigmas of the Canine Elbow (pdf)

What is Elbow Dysplsia?