Hip and elbow dysplasia are a common cause of lameness in dogs. They sound like they should be the same thing, just involving different legs. Are they, though?
The word dysplasia has a rather broad meaning. It is from Greek, and it stands for malformation. In the context of veterinary medicine, dysplasia means abnormal development or growth.
Both hip and elbow dysplasia refer to abnormal development of the respective joints. Result? Pain, lameness, and progressive degenerative changes. So much they have in common.
The hip is a relatively simple joint where the thigh bone (femur) connects to the pelvis in a ball-and-socket joint.
In a healthy joint, the femoral head fits tightly into a deep and well-formed socket and moves smoothly. In a dysplastic hip, the ball and socket don’t fit together properly.
Often both the socket is too shallow, and the ball is misshapen. This makes the joint unstable, which leads to further degenerative changes. In severe cases, the two parts of the joint can pull apart completely!
Treatment for hip dysplasia depends on the individual situation. Non-surgical treatment consists of treating of resulting arthritis and supporting muscle strength.
There are a number of surgical treatments available, ranging from surgeries aimed at improving the fit between the ball and socket within the joint, to complete hip replacement. Check out Canine Hip Dysplasia at Veterinary Partner for more information.
In the elbow, three bones meet together to form the joint, and you can see that the structure is very different from the hip.
The elbow is composed of three bones: the humerus (the boney support of the upper limb from the shoulder to the elbow); the ulna (which runs from the elbow to the paw along the back of the limb); and the radius (which supports the major weight-bearing along the front of the lower limb).
(source: Veterinary Partner)
All parts of the joint need to develop properly and in sync with one another so they can fit together perfectly.
The more parts, the more things that can go wrong.
Complex issues in a complex joint
Elbow dysplasia is a blanket term that can cover multiple abnormalities, each of which even comes with its own name! These can occur individually or in combination.
- fragmented medial coronoid process (FMCP)
(malformed or fragmented bone and/or cartilage of the ulna)
- osteochondritis dissecans (OCD)
(damaged or abnormally formed cartilage cracks or separates from the bone surface; can even result in a piece of the cartilage breaking lose completely)
- ununited anconeal process (UAP)
(a part of the ulna involved in the joint fails to fuse with the rest of the bone, resulting in a fracture through the growth plate)
- elbow incongruity
(misalignment of the joint surfaces of the elbow)
Unlike in hip dysplasia, where the main problem is the joint’s instability, the abnormalities associated with elbow dysplasia often result in pieces of bone and/or cartilage breaking loose and irritating the joint tissues.
While mild cases can do well with medical treatment only, surgery is the treatment of choice for most dogs. Arthroscopy is minimally invasive, and it is preferred for both diagnosis and treatment of elbow dysplasia. Some cases might require open elbow surgery.
Further information: Elbow Dysplasia
Hip and elbow dysplasia – not really the same thing, are they?
What they do have in common is that the earlier the treatment the better the results. Understand the medical challenges your dog might be facing.