So What is Hip Dysplasia?

The term dysplasia means abnormal growth, thus hip dysplasia means abnormal growth or development of the hips. Hip dysplasia occurs during the growing phase of a puppy, usually a large breed puppy, and essentially refers to a poor fit of the ball and socket nature of the hip. The normal hip consists of the femoral head (which is round like a ball and connects the femur to the pelvis), the acetabulum (the socket of the pelvis), and the fibrous joint capsule and lubricating fluid that make up the joint. The bones (femoral head and acetabulum) are coated with smooth cartilage so that motion is nearly frictionless and the bones glide smoothly across each other’s surface.

When a dog has hip dysplasia, the ball and socket do not fit smoothly. The socket is flattened and the ball is not held tightly in place, thus allowing for some slipping. This makes for an unstable joint and the body’s attempts to stabilize the joint only end up yielding arthritis.

How Can I Find out if My Pup is likely to develop Hip Dysplasia?

Checking hip looseness (laxity) is done under sedation or general anaesthetic.

The first test under sedation is to assess how much the ball is able to move out of the socket. This is called a hip distraction assessment. The other test normally done involves having the dog lie on its back with a hind leg perpendicular to the body. As the leg is moved away from perpendicular to the body, a loose hip will generate a pop as the femoral head slips to the center of the acetabulum. This pop, which can be felt if one’s hand is resting on the hip during the exercise, is called the Ortalani sign.

Another step is to take radiographs (xrays). These are useful to rule out deformed hips or other congenital conditions.
There are 2 main types of views:

• The classical view is called a VD pelvic view where the dog is held on its back with its legs straight out. This shows the seating of the two femoral heads as well as any bony changes indicating arthritis.
• The distracted view, showing how much the balls can come out of the sockets.

What are the consequences if my pup has loose hips?

Studies by Pennsylvania University researchers (who created the PennHip hip grading system) have shown a clear correlation between the looseness (laxity) of the hip ball in the socket and the likehood of developing hip dysplasia (Hip arthritis). Not all dogs with loose hips get HD, but the looser the hips are the more likely a dog will develop HD.

If my pup is found to have loose hips should I be worried, and can anything be done?

As mentioned above, loose hips can lead to Hip Dysplasia. If a hip check has shown that your dog has significant laxity, you should discuss with your vet what options you have. One option is a Juvenile Pubic Symphysiodesis.

Juvenile Pubic Symphysiodesis (JPS)

This surgery is performed on young puppies up to the age of 5 months, so it is generally done as a preventive procedure before it is known if the puppy will indeed have dysplastic hips. The pubic symphysis is the cartilage seen connecting the right side of the pelvis to the left side. As an individual matures, this cartilage converts to bone and the two halves of the pelvis fuse permanently. This surgery prematurely seals the symphysis, which in turn results in rotation of the developing hip sockets into a more normal alignment.

JPS is able to be performed at the same time as desexing. It is a relatively straight forward procedure, inexpensive with a good recovery and a low risk of complications.

Triple Pelvic Osteotomy (TPO)

A TPO is normally done at the age of 10-12 months if a dog is showing signs of hip soreness.  A TPO is where the pelvis is cut in 3 places, and the socket part of the hip joint is rotated to sit more on top of the hip rather than to the side. The cut pelvis is secured by a stainless steel plate. This procedure is usually the domain of a specialist surgeon.

Lifestyle

As with any arthritis, it’s advisable to keep your pets weight in the correct range, and give him/her regular exercise, but avoid excessive exercise.