Anconeal Process in Elbow Dysplasia
Berry Haven Veterinary Group Surgical Case
Max, a 4 year old German Shepherd, was quite lame in his right foreleg. On moving and examining the elbows, both joints were thickened and had some crunching (crepitus) in them. We suspected arthritic changes in both elbows, possibly due to a condition called un-united anconeal process.
In young animals, new bone formation occurs in the near the ends of each bone. Just below the end of each young bone is a thick layer of cartilage called the metaphysis. The top layer of the metaphysis is made up of new cartilage and the lowest layer is made of new bone. This is where new bone is made and the long bones grow.
This process continues until the pet matures. At this stage, the metaphysis turns to solid bone and joins the end of the bone (epiphysis) to the long shaft of the bone.
Its a bit like a chicken drumstick. You can break off the end of the drum stick (epiphysis) with your fingers. However, if you ate the same chicken leg when the chicken was a few years old, you would not be able to break off the end, It would be fused to the long bone.
In young animals, the elbow joint is made of of a few pieces of separate bone all growing by themselves. Eventually, when the animal matures, they fuse together to form a solid joint. Occasionally, one of the pieces of bone, the anconeal process, does not fuse to the underlying bone and is left floating around in the joint. This causes a lot of discomfort and can lead to arthritic changes.
Treatment is usually surgical to remove the united anconeal process from the joint. This is usually bets performed by a specialist surgeon to get the best results.
In Max's case, both of his elbows were affected but the right was causing him the most trouble. We referred Max to the Animal Referral Hospital (ARH) in Sydney where Dr David Simpson looked after him. A cat scan showed the presence of un-united anconeal processes in both elbow joints.
Dr Simpson operated on the right elbow and removed the un-united anconeal process (see picture). He decided the left elbow was not casing significant discomfort so it was
left alone. Max made a great recovery and is now using the right foreleg much better.