What is a shortened radius?
Growth plates are responsible for longitudinal growth of many bones in the body, including those of the limbs. If there is an injury to a growth plate, the bone may fail to attain its normal length. If the growth plate located at the top or bottom of the radius bone fails to grow, the elbow joint may become incongruent (does not fit well together). With the top of the radius riding lower than normal, the humerus bone slides forward and downward, which puts excessive pressure on the coronoid process. This will cause the coronoid process to break or fragment off the ulna bone. This loose fragment of bone can cause damage to the elbow joint. In addition, the poorly fitting elbow joint will cause excessive wear of the cartilage within the joint. The result is arthritis within the elbow.
Signs and diagnosis
This condition typically affects young dogs. The primary clinical sign of this condition is lameness or stiffness on the affected limb. X-rays of the elbow joint are necessary to make a diagnosis of a shortened radius bone and elbow incongruity. In some cases, a diagnosis of a fragmented coronoid process can be made on the X-rays, yet many cases require additional testing. CT scan or arthroscopic surgery of the elbow joint is usually the best diagnostic tools used to diagnose fragmented coronoid processes.
Arthroscopic surgery is the recommended treatment for elbow conditions. Two very small incisions are needed to perform the surgery, which means less pain for your companion than traditional open surgery. The joint is examined with a very thin telescope to confirm the diagnosis. If your pet has a fragmented coronoid process it is removed with a combination of an arthroscopic shaver and small instruments. The second goal of surgery is to make the elbow fit together again. This can be accomplished by lengthening the short radius bone, or can be accomplished by shortening the ulna bone. The latter is a simpler technique that involves removing a segment of the ulna bone and placing a pin down the shaft of the ulna bone. With time, the gap in the ulna will heal together.
For more information on this subject, speak to the veterinarian who is treating your pet.