The weight of the dog has some bearing on the outcome on this surgery. In the surgery, the ball portion of the hip joint (the femoral head) is removed and the bone
smoothed, if necessary, so that no bone to bone contact occurs between the pelvis, which contains the now empty socket and the remaining portion of the femur. The
joint is not stabilized, it is destroyed. While that sounds bad, in almost all dogs under 40 to 50 lbs in weight, this surgery will provide reasonable comfort. A "false
joint" forms, consisting of fibrous scar tissue around the bone end. This forms in the muscles over the hip, which fortunately are strong enough to provide some
stability. It is less painful than leaving the dislocated femoral head rubbing against the pelvic bone.
The shoulder joint is naturally constructed in a similar fashion, although it has more stabilization. In dogs over 50 pounds of body weight there is more concern that the
joint will not be functional due to the need for more weight bearing capacity. Most of the time, there is still reasonable comfort even in big dogs but the outcome is
more questionable in these dogs.
1) Stabilization of the joint can be attempted. Many vets are reluctant to do these surgeries because some of them are technically difficult and all of them have a
moderate failure rate. It is disconcerting to do surgery, collect a large fee, have to explain the failure to the client and then have to go back and do a femoral head
ostectomy anyway. There are several possible stabilization procedures, including pinning the femoral head to the hip socket, moving the portion of the bone where
muscle attachment occurs to a different site on the femur to provide more stability, toggle pinning the femoral head and several other stabilization techniques. It may
be necessary to ask for referral to a surgical specialist for these procedures as many general practitioners are not comfortable doing them.
2) Total hip replacement. This is an option in some cases when hips can not be stabilized but it is necessary to consider this on a case by case basis. Again, this
surgery requires referral to a surgical specialist in most cases. Very few veterinary practices have the capability of doing hip replacement surgery.
If an alternative stabilization technique doesn't work, femoral head ostectomy remains an option. You do end up paying for two surgeries when one of the other
stabilization methods fail but if they work, the outcome is better for your dog. The success rates of the various surgeries would depend a lot on the individual
surgeon's experience and skill.
Hip dysplasia literally means an abnormality in the development of the hip joint. It is characterized by a shallow acetabulum (the "cup" of the hip joint) and changes in
the shape of the femoral head (the "ball" of the hip joint). These changes may occur due to excessive laxity in the hip joint. Hip dysplasia can exist with or without
clinical signs. When dogs exhibit clinical signs of this problem they usually are lame on one or both rear limbs. Severe arthritis can develop as a result of the
malformation of the hip joint and this results in pain as the disease progresses. Many young dogs exhibit pain during or shortly after the growth period, often before
arthritic changes appear to be present. It is not unusual for this pain to appear to disappear for several years and then to return when arthritic changes become
obvious.
Dogs with hip dysplasia appear to be born with normal hips and then to develop the disease later. This has led to a lot of speculation as to the contributing factors
which may be involved with this disease. This is an inherited condition, but not all dogs with the genetic tendency will develop clinical signs and the degree of hip
dysplasia which develops does not always seem to correlate well with expectations based on the parent's condition. Multiple genetic factors are involved and
environmental factors also play a role in determining the degree of hip dysplasia. Dogs with no genetic predisposition do not develop hip dysplasia.
At present, the strongest link to contributing factors other than genetic predisposition appears to be to rapid growth and weight gain. In a recent study done in
Labrador retrievers a significant reduction in the development of clinical hip dysplasia occurred in a group of puppies fed 25% less than a control group which was
allowed to eat free choice. It is likely that the laxity in the hip joints is aggravated by the rapid weight gain.
If feeding practices are altered to reduce hip dysplasia in a litter of puppies, it is probably best to use a puppy food and feed smaller quantities than to switch to an
adult dog food. The calcium/phosphorous to calorie ratios in adult dog food are such that the puppy will usually end up with higher than desired total calcium or
phosphorous intake by eating an adult food. This occurs because more of these foods are necessary to meet the caloric needs of puppies, even when feeding to keep
the puppy thin.
If clinical signs of hip dysplasia occur in young dogs, such as lameness, difficulty standing or walking after getting up, decreased activity or a bunny-hop gait, it is often
possible to help them medically or surgically. X-ray confirmation of the presence of hip dysplasia prior to treatment is necessary. There are two techniques currently
used to detect hip dysplasia, the standard view used in Orthopedic Foundation for Animals (OFA) testing and X-rays (radiographs) utilizing a device to exaggerate
joint laxity developed by the University of Pennsylvania Hip Improvement Program (PennHIP). The Penn Hip radiographs appear to be a better method for judging
hip dysplasia early in puppies, with one study showing good predictability for hip dysplasia in puppies exhibiting joint laxity at 4 months of age, based on PennHIP
radiographs.
Once a determination is made that hip dysplasia is present, a treatment plan is necessary. For dogs that exhibit clinical signs at less than a year of age, aggressive
treatment may help alleviate later suffering. In the past a surgery known as a pectineal myotomy was advocated but more recent evidence suggests that it is an
ineffective surgical procedure. However, administration of glycosaminoglycans (Adequan Rx) may help to decrease the severity of arthritis that develops later in life.
Surgical reconstruction of the hip joint (triple pelvic osteotomy) is helpful if done during the growth stages. For puppies with clinical signs at a young age, this surgery
should be strongly considered. It has a high success rate when done at the proper time.
Dogs that exhibit clinical signs after the growth phase require a different approach to treatment. It is necessary to determine if the disorder can be managed by
medical treatment enough to keep the dog comfortable. If so, aspirin is probably the best choice for initial medical treatment. Aspirin/codeine combinations,
phenylbutazone, glycosaminoglycosans and corticosteroids may be more beneficial or necessary for some dogs. It is important to use appropriate dosages and to
monitor the progress of any dog on non-steroidal or steroidal anti-inflammatory medications due to the increased risk of side effects to these medications in dogs. If
medical treatment is insufficient then surgical repair is possible.
The best surgical treatment for hip dypslasia is total hip replacement. By removing the damaged acetabulum and femoral head and replacing them with artificial joint components, pain is nearly eliminated. This procedure is expensive but it is very effective and should be the first choice for treatment of severe hip dyplasia whenever possible. In some cases, this surgery may be beyond a pet owner's financial resources. An alternative surgery is femoral head ostectomy. In this procedure, the femoral head (ball part of the hip joint) is simply removed. This eliminates most of the bone to bone contact and can reduce the pain substantially. Not all dogs do well following FHO surgery and it should be considered a clear "second choice".
Hip dysplasia may not ever be eliminated by programs designed to detect it early unless some effort is made to publish the results of diagnostic tests such as the OFA evaluation or PennHIP evaluations, openly. This is the only way that breeders will be able to tell for certain what the problems have been with hip dysplasia in a dog's ancestry.
When an older dog is exhibiting signs of pain associated with this condition it is often possible to help them dramatically through medication and simple steps like
providing a warm bed or warm spot to rest during the day. There is no advantage to pain and steps should be taken to ensure that the older dog is not in pain.
Regular exercise can be very helpful and weight loss can have dramatic effects on the amount of discomfort a dog experiences.
Working with your vet to come to the best solution for your dog and your situation will enable you and your dog to enjoy life to its fullest, despite the presence of hip
dysplasia.
