What is canine hip dysplasia?

Hip dysplasia is an abnormality in the hip joint that affects the ‘ball and socket’ nature of the joint and makes the hip more lax.
It’s a common condition, particularly in larger dogs, but can also affect small dog breeds and cats. The condition is mostly genetic, although external factors like obesity in puppyhood may have an effect on its development in later years.


What are the symptoms?

Hip dysplasia in dogs tends to be noticeable in symptoms relating to their hind legs. These can include:

  • Hind limb stiffness
  • Trouble exercising
  • Difficulty rising
  • Swaying when walking
  • Restlessness
  • Limping on hind legs

These symptoms usually develop when the dog is young and growing (the first year of their life) or during early adulthood. Hip dysplasia will often lead to arthritis.

Hip dysplasia signs vary with the age of the animal. Those in the younger group often present with a sudden onset of unilateral disease. Owners often report a sudden reduction in activity associated with marked discomfort of the hindlimbs. Difficulty rising is often reported along with a decreased willingness to walk, run and climb stairs. At this age the femoral heads often appear normal on x-rays.

Most affected dogs between 12-14 months of age walk and run freely and are free of significant pain. Most exhibit a “bunny hopping” gait when running. Those dogs that present in the older group have different signs as they suffer from chronic degenerative joint disease and its associated pain.

Lameness may be unilateral but is more commonly bilateral and most commonly signs become apparent over a long period of time. Owners report lameness after prolonged or heavy exercise, a waddling gait and severe difficulty rising. The range of motion of the affected joints is restricted.

 

The diagnosis

Examination – The first step of diagnosis may be a clinical examination. Your vet might have noticed an unusual gait, and wish to examine your pet further.

Advanced imaging – Our specialists might suggest your pet undergoes an MRI or CT scan, where they’ll be looked after by our caring nursing team.

Consultation – You’ll then have a consultation with one of our orthopaedic clinicians, who will be able to effective diagnose hip dysplasia and offer a proposed treatment route.

How do we treat hip dysplasia?

There are a range of treatment options that will depend on the severity of the condition. Many dogs with hip dysplasia show no signs of pain while others only have mild intermittent signs. Approximately 75% of dogs in which hip dysplasia is diagnosed at an early age have minimal gait abnormalities 4-5 years later. A large number of these animals can be treated with conservative methods including minimising activity and the use of anti-inflammatory agents when required. Your specialist will be able to advise on the best course of action for your pet.

A large variety of surgical techniques have been introduced in an attempt to treat the clinical signs of hip dysplasia and arthrosis. The four most commonly employed are Juvenile Pubic Symphysiodesis (JPS), Triple Pelvic Osteotomy and Double Pelvic Osteotomy (TPO and DPO), Femoral Head and Neck Excision and Total Hip Replacement (THR). The operation most suitable for your dog will be discussed in detail in your consultation.

Juvenile Pubic Symphysiodesis

This is a procedure that may be performed in dogs with hip dysplasia if it is recognised at a very early age. It is a relatively minor procedure that may result in a more stable hip in the very young animal. For maximum effect the surgery should be performed at approximately 3-5 months of age while significant growth potential remains.

A small incision is made between the hindlimbs to expose the pubic bone of the pelvis and the area from which growth of this bone occurs, the growth plate, is cauterised to destroy all the growing cells. When growth from this centre stops and the remaining portions of the pelvis continue to grow, the sockets of the hips rotate over the femoral head. It is likely that your dog will be allowed home on the same day.

It is very unusual for hip dysplasia to be diagnosed sufficiently early for this procedure to be of benefit but in the unlikely case that this surgery is applicable for your pet, this will be discussed in more detail in your consultation.

Triple pelvic osteotomy and double pelvic osteotomy (TPO/ DPO)

TPO/DPO is an effective method of treating dysplasia if carried out early. This operation is most commonly carried out between 4 and 7 months of age. The most important criterion determining success of TPO is not age but the condition of the joint surfaces. If the acetabulum is filled with bone or fibrous tissue or the socket has been worn away or the cartilage on the head of the femur is damaged then TPO will fail. This analysis is made on standard radiography and using a test, performed under anaesthesia, to assess the condition of the socket via the sensations felt when the hip joint is manually dislocated and popped back into place.

The operation involves two or three cuts being made in the pelvis allowing the socket to be rotated to provide adequate stabilisation for the head of the femur. A plate is then used to maintain the new positioning of the bones. Recovery involves 6 weeks of restricted exercise with lead only walking. In many cases this operation will be required bilaterally, and the second operation will normally be carried out 4-6 weeks following the first. Cases must be selected carefully as many patients will not benefit from this surgery.

One further factor to consider is that total hip replacement is significantly more difficult to perform in an animal which has already undergone TPO.

Femoral head and neck excision

This operation is only normally considered in cases where THR is not a financially viable option. This is a non- reversible procedure and must be considered a salvage option. However, it is a valuable method for improving the quality of life of patients with hip dysplasia by elimination of pain.

In this technique, the femoral head and neck are completely removed allowing a false joint to form. Pain is relieved by elimination of bony contact between the femur and the pelvis as scar tissue interposes. Some abnormality of gait persists due to limb shortening and a slightly reduced range of motion but the animal is pain free. This procedure can be performed bilaterally if required. Recovery involves early active use of the limb. Exercises are performed known as “passive range of motion exercises” which are started immediately following the operation and lead walking is encouraged for two weeks. After stitches have been removed, swimming is encouraged. This operation is much more successful in animals which have maintained an appropriate body weight with smaller animals experiencing significantly less severe gait abnormality following surgery, however, pain relief is readily accomplished with this technique even in larger patients.

As for TPO, THR becomes much more complicated following femoral head and neck excision.

Total Hip Replacement

What is total hip replacement?

Total hip replacement (THR) is an advanced surgical procedure that removes the ball and socket parts of the hip joint and replaces them with metal and plastic implants. Often recommended for animals with advanced osteoarthritis or hip dysplasia, the goal of hip replacement surgery is to improve your pet’s quality of life, offering them pain relief and allowing them to maintain an active lifestyle.

When is total hip replacement needed?

Total hip replacement is offered for animals that struggle with painful hip conditions, and will only be recommended if other surgical techniques or rehabilitation methods have failed to manage your pet’s pain. Because hip dysplasia is most common in large dog breeds, total hip replacement (THR) is most commonly performed in these breeds. However, the condition can also affect cats and small dogs who can also benefit greatly from hip replacement.

Not all patients with hip dysplasia are candidates for a THR. Those with mild pain and lameness may be managed with conservative management. A total hip replacement would only be suggested and performed in the benefits outweighed the risks, as with all major procedures, it doesn’t come without possible risks and complications. THR can be performed in patients from around 10 months of age and there is no upper age limit.
Other indications for THR include dislocated (luxated) hips, hip fractures and avascular necrosis of the femoral head (Legge Perthe’s disease).

Collie on a lead

 

What are the types of total hip replacement?

THR surgery replaces a dysfunctional, painful hip joint with an artificial prosthesis, to provide a fully functional, pain-free joint. The prosthesis replaces both the ball and socket of the joint and there are a variety of options of implants available.

The surgery is performed through a small incision directly over the hip, and involves removing the degenerated femoral head (ball) and acetabulum (socket), replacing them with artificial components. The implants can be attached to the bone using cement or through a cementless system, depending on which best suits your pet. The cementless system relies on bone ingrowth into the implant for permanent fixation: the prostheses are secured by a “press-fit”, meaning that the bone in contact with the prostheses can grow into the small pores in their surface. Cementless THRs are not made for medium and small dogs or cats.

 

What does hip replacement surgery involve?

Dogs and cats have to be evaluated to see if they are suitable for total hip replacement surgery. This is often done on a separate day, prior to the surgery, here at Swift Referrals. By obtaining very specific X-rays of the pelvis and (femur) and placing them against templates of the various sizes of prostheses available, we can measure the correct size of prostheses for the patient and order them if necessary.

On the day of surgery, a team of two Surgeons and Nurses will be involved in performing the joint replacement. The operation is performed through a relatively small incision directly over the hip. Careful preparation of the hip socket (acetabulum) and top of the femur is necessary prior to placement of the relevant cemented or cementless prostheses. The two artificial components are then brought together (reduced) and the stability of the hip checked. The thick capsule that surrounds the joint is carefully sutured prior to closure of the rest of the muscle and skin.
Radiographs are obtained at the end of the operation to check the position of the prostheses.

 

Postoperative care

It is likely your pet will stay in hospital for the first couple of days for intravenous pain relief and to ensure they are weight bearing on the operated leg. Post-op care and rehabilitation following THR surgery is very important and can take many months. Painkillers, antibiotics and an Elizabethan collar will be provided at discharge. The first check up is usually back at your own Vets around 10 days after surgery, at which point, any skin sutures can be removed.

Exercise must be restricted and your pet kept in a puppy crate or pen for the first few weeks until the joint capsule and surrounding soft tissues heal. They can only be taken out to the toilet on a lead or harness initially and you will be provided with an exercise regime to follow thereafter. It is imperative that your dog is not allowed to climb stairs or jump onto furniture.

After six weeks, your pet would revisit Swift Referrals for post-operative radiographs to ensure that the implants are stable and in the correct position. At this stage, further advice will be given with regards to exercise.

We then recommend a clinical examination and repeat X-rays one year after THR surgery, and annually thereafter. You must comply with this requirement to be eligible for the lifetime warranty.

 

What are the risks?

Fortunately, the success rate for total hip replacement surgery is very high, with over 95% of animals having excellent limb function after recovery. However, as with any major surgery, there are possible complications. The most common problem is dislocation of the prosthesis, which may require a second operation.

Although a long and complicated procedure, total hip replacement has the potential to provide your pet with a pain-free, normal hip joint, allowing them to return to a happy and active lifestyle.

The success rate of total hip replacement surgery in dogs and cats is high, and the majority do very well after their operation. It is a major undertaking and not a decision that would be taken lightly, but the procedure is one which our surgeons commonly perform. THR can be completely life changing for a dog or cat. They are radically transformed into happy, comfortable patients, able to exercise again and they have a vastly improved quality of life, for you to be able to enjoy with them.

 

Common Misconceptions About Total Hip Replacements

My dog is too young for a hip replacement

False. Dogs can have hip replacements from around 10 months of age, as long as the growth plates have closed and the bone density is strong enough.

My dog is too old and arthritic for a hip replacement

There is no upper age limit. Arthritic hips produce new bony growth, which actually provide a greater surface area and more solid bone for the implants to be inserted or cemented into.

My dog is too small or too large for a hip replacement

Nano hip replacement kits now allow surgeons to perform THR on miniature breeds of dogs, as low as 1kg, and also cats. Large breed dogs carry an increased risk of femoral fracture due to their bodyweight, but this is overcome by also placing a metal plate along the length of the femur for extra security.

My dog has hip dysplasia or arthritis in both hips so can’t be operated on

The worse affected limb causing the most lameness can be operated on first, followed by the second one, generally around 6 months later once everything has healed sufficiently.

My dog won’t be able to run around and play again
False. Assuming there are no complications, dogs can usually return to normal exercise and activity levels 12 weeks post surgery.

We would be happy to give you as much advice and support as possible to help you make an informed decision about a THR for your pet.

Please contact the surgery on 01937 374888 to arrange an initial consultation.

You can view further information about total hip replacement here.