Developmental Diseases—Ununited Anconeal Process (UAP)

Who is usually affected?
-Young German Shepherds

X-ray appearance of an ununited anconeal process Click to enlarge

What is happening?
-The 3 bones of the elbow joint fit poorly, causing abnormal pressure on the ulna
-A small piece of bone associated with the ulna in the back of the joint (anconeal process) fails to attach to or breaks off of the ulna
-Swelling and pain result from the altered joint mechanics and cartilage destruction
-Arthritis develops

Clinical signs you might notice in your pet
-Limping on a front leg after rest or exercise
-Tiring easily with play
-Resting more than other dogs of similar age and breed, "mellow" puppy
-Head bobbing during walking or running
-Sitting or standing crookedly with a front leg turned outward

Postoperative x-ray appearance of an ulnar ostectomy Click to enlarge

Diagnosis
-Careful orthopedic examination to determine which
joint(s) are affected
-X-rays are used to evaluate the condition of joint surfaces

Surgical treatment
-Depending on the specifics of each case, recommended surgical options may include:
-Removing the loose piece of bone
-Relieving the pressure on the ulna by cutting the bone (osteotomy) below the elbow joint, encouraging the previously loose piece of bone (anconeal process) to attach to the ulna

Special postoperative care
-Patient activity is generally limited for 4-6 weeks following surgery, allowing time for joint swelling to subside
-Patient activity may be limited for a longer period of time (6-12 weeks) with ulnar osteotomy, allowing time for the anconeal process to fuse with the ulna

Expected results after surgery
-Much initial improvement in the degree of pain and limping
-Ultimate outcome depends on the amount of joint damage present, prior to surgery and the degree of elbow misfit (incongruity)
-Moderate exercise, weight control and medication may be recommended for the long term management of optimal joint health