Owner Fact Files: Hip Dysplasia
Welcome to the third instalment in the Owner Fact Files series, talking all about Hip Dysplasia (HD), the most commonly seen orthopaedic condition in dogs.
What is Hip Dysplasia?
The word dysplasia means the abnormal development of a tissue or organ. Therefore, in the case of HD, the hip joint develops abnormally. For the dog, this means that the joint becomes loose and unstable in the early stages of their life.
To understand the condition, it is important to recognise how a healthy hip joint should form, and how it functions. The hip works as a ball and socket joint, with the head of the femur (thigh bone), the ball, fitting into a part of the pelvis called the acetabulum, the socket. In a healthy hip, the ball fits perfectly into the socket, enabling a smooth, pain free, gliding movement at the joint.
In cases of HD, this perfect formation does not happen, read on to find out why, and how this effects the dog.
What causes Hip Dysplasia?
Although dogs will present with HD very early in life, the condition is NOT congenital, meaning affected dogs are born with normal hips. The changes in the anatomy begin in the first few weeks of life, with the soft tissues around the hip, which act to stabilise the joint, becoming loose. As the dog grows, the soft tissue does not keep up with the development of the bone, which causes a problem. Overall, these changes disrupt the perfect fit of the ball and socket.
There are several factors which are suggested to influence the development of HD in dogs. Genetics is a key player, because this condition is hereditary. It also more commonly occurs in larger breeds such as the Labrador, Great Dane, and German Shepherd. For this reason, 'hip scoring' is advised in certain breeds before breeding from them to try and prevent the passing on of the condition.
Another factor that plays a role is excessive growth rate, as stated previously, the soft tissue not keeping up with the bony development at the joint. High impact exercise at a young age, or excess body weight, also puts added strain on the hip during development, and is suggested to be an environmental factor. Finally, poor nutrition can also be linked to the development of HD, as certain breeds will require an appropriate diet to slow down excessive growth, giving the joints more time to develop correctly.
What is happening inside the hip joint? (the science bit)
When a poor fit occurs in the joint, the head of the femur (ball) and the acetabulum of the pelvis (socket) will rub and grind against each other, instead of producing the smooth sliding movement that they should. As the bones make contact, this impacts on their structure and shape - the head of the femur becomes flattened and deformed. The acetabulum also changes shape, becoming shallower and more saucer like, meaning it can no longer function as a socket, with nothing to catch the ball and hold it in place.
As the bones continue to grind against each other, the structures become more deformed and the poor fit worsens. This action also contributes to the development of osteoarthritis in the hips as a secondary problem. This is something that will need to be managed for life in dogs with HD.
You may start to see the signs of HD in your dog from the age of 4 months, and it is most commonly diagnosed between the age of 6 - 12 months.
The signs that you may notice are;
- Stiffness of the hindlimbs - Clicking of the hip
- Reluctance to exercise - Hunched lower back posture
- Difficulty getting up - Pottery gait of hindlimbs
- Difficulty lying down - Swaying of hips (waddling)
- Difficulty climbing stairs - Bunny hopping gait
- Lameness or limping on hindlimb - Pain in hip/pelvis area
If you see any of these symptoms in your dog and you have concerns, please speak to your vet for advice. HD can vary from mild - severe so you may not see all of these signs in your dog.
There are several treatment options available for HD, and the choice will be based on the severity of the condition at the time of diagnosis. In some cases where HD is discovered incidentally, and the dog is functioning well, conservative management is an option. This treatment involves body weight management, pain relief medication, changes to exercise, and additional physiotherapy/hydrotherapy to support the hip.
For dogs that are affected and suffer with hip pain, a surgical route will be chosen. One option is Juvenile Pubic Symphysiodesis, in which the pelvis is fused prematurely, to change the growth and improve the location of the head of the femur (ball) in the joint. This is best used in mild - moderate cases.
Triple Pelvic Osteotomy is a surgery which modifies the existing hip, allowing the better capture of the ball by the socket. The bone is cut, rotated, and fixed in place with plates and screws. This option is only suitable when there are no signs of secondary osteoarthritis in the joint.
A Total Hip Replacement, is an advanced surgery, with the whole diseased joint being removed, and replaced with implants. For dogs with secondary osteoarthritis this is a good choice, and the surgery is generally very successful.
Finally, a Femoral Head and Neck Excision, is a salvage procedure which is used when a hip replacement can not be done. In this surgery, the head of the femur (ball) and part of the neck of the femur are removed, and a false joint made of scar tissue forms in its place. The hip pain is relieved, as there is no longer any bony contact. In these cases function of the joint can be limited, which is why postoperative physiotherapy is essential to gain strength and maintain flexibility.
How can physiotherapy help?
I would always advocate physiotherapy as an important part of either conservative management or in rehabilitation following surgery for HD. As always, I begin by managing the pain in the joint, and in any muscles which have been working harder to compensate for the sore hips. The process then progresses to a steady return to exercise, to help build muscle in the hindlimbs to support the hips, and to maintain and increase the range of motion in the joints. The techniques I use also help to manage cases of secondary osteoarthritis in the hips, which is a lifelong condition that is benefited from ongoing maintenance sessions with a physio.
For more information on how physiotherapy could benefit a case of Hip Dysplasia, please get in touch - email@example.com // 07795163445.
Dogs can lead full and long lives if Hip Dysplasia is treated effectively. It is important to consider that osteoarthritis is likely to develop in the joint as a secondary problem, and this will need longer term management. Physiotherapy can be helpful to monitor your dog and keep them on track.
I hope you now feel informed about this condition, if you have any other questions feel free to contact me. Please come back to read next month's Owner Fact File and leave feedback if you liked this post.
If you think there is anything I can do to help your animals please drop me a message - Nancy
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