Hip Dysplasia in DogsHip Dysplasia in Dogs

What is hip dysplasia? What is hip dysplasia?

Hip dysplasia is a common Hip dysplasia is a common developmental disease of the hip. developmental disease of the hip.

As a puppy grows the soft tissue As a puppy grows the soft tissue support for the hip may become support for the hip may become loose (lax) and this can allow the loose (lax) and this can allow the head of the femur (the ball) to slip in head of the femur (the ball) to slip in and out of the acetabulum (socket). and out of the acetabulum (socket).

DysplasiaDysplasia is an incomplete or arrested development of an organ or part

This abnormal laxity of the hip can This abnormal laxity of the hip can damage the tissues of the joint damage the tissues of the joint leading to osteoarthritis, leading to osteoarthritis, restricted restricted joint mobility, pain, and lameness are joint mobility, pain, and lameness are associated with it. associated with it.

Canine hip dysplasia, is a Canine hip dysplasia, is a developmental not a congenital developmental not a congenital disorder of the coxo-femoral joints. disorder of the coxo-femoral joints.

A similar disease occurs in humans, A similar disease occurs in humans, gorillas, bears, horses, cattle and cats. gorillas, bears, horses, cattle and cats.

EtiopathogenesisEtiopathogenesis::

The etiopathogenesis of hip The etiopathogenesis of hip dysplasia in dogs is not well dysplasia in dogs is not well understood. understood.

A genetic basis has been identified, A genetic basis has been identified, but the pattern of inheritance is but the pattern of inheritance is multifactorial not simple Mendelian multifactorial not simple Mendelian genetics.genetics.

SignsSigns::

These signs are often first observed These signs are often first observed between the ages of 4 months and 1 between the ages of 4 months and 1 year. year.

Young dogs can have a swaying and Young dogs can have a swaying and unsteady gait. unsteady gait.

Decreased activity and various Decreased activity and various degrees of joint pain are early degrees of joint pain are early manifestations. manifestations.

A dog standing with hind legs close together to compensate for hip dysplasia.

They may draw their hind limbs forward.

• Atrophy of thigh muscle after a two-year evolution of hip dysplasia

As the disease progresses, a As the disease progresses, a dog may have difficulty in dog may have difficulty in

rising from a sitting or lying rising from a sitting or lying position.position.

the femoral head has moved away from acetabulum.

an audible pop is heard as the femoral head slips back into the acetabulum.

In a dog suffering hip dysplasia,

DiagnosisDiagnosis::

Observation and physical examination Observation and physical examination can arouse suspicion of hip can arouse suspicion of hip dysplasia

however, the diagnosis of hip however, the diagnosis of hip dysplasia

is established by radiographic is established by radiographic examination with the dog under general examination with the dog under general anaesthesia or deep sedation to ensure anaesthesia or deep sedation to ensure

proper positioning.proper positioning.

RadiographyRadiography::

A ventrodorsal pelvic radiograph is A ventrodorsal pelvic radiograph is made with the dog’s hindlimbs made with the dog’s hindlimbs

extended to their maximum position, extended to their maximum position, with the femur parallel to each other with the femur parallel to each other

and the stifles rotated inward.and the stifles rotated inward.

1 2

The primary x-ray beam is centered on the pubis.

Grasp the hocks so the tibias are parallel to the table surface and each other. The stifles should be in approximately 90 degree flexion. The femur should be approximately perpendicular to the table surface. This is referred to as the stance phase position.

Another projection

The person holding the hocks rotates them slightly outward while moving the stifles laterally so that the stifles

are not superimposed over the hip.

Normal hips

Bilateral hip dysplasia in a cat

A radiograph showing severe hip dysplasianotice how the head of the femur is not fitting well in to the acetabulum

Normal Hip Joint

Severe Hip Dysplasia and Degenerative Joint Disease

The joint is considered dysplastic The joint is considered dysplastic when the femoral head conforms when the femoral head conforms poorly to the acetubulum. poorly to the acetubulum.

Increased joint space is commonly Increased joint space is commonly observed, and structural observed, and structural abnormalities can be detected in the abnormalities can be detected in the acetabula and femoral head.acetabula and femoral head.

Subluxation, or partial displacement Subluxation, or partial displacement of the femoral heads from the of the femoral heads from the acetabulla is the hallmark of canine acetabulla is the hallmark of canine hip dysplasia. hip dysplasia.

If the heads are dislocated further, If the heads are dislocated further, the hip dysplasia is rated severe.the hip dysplasia is rated severe.

Osteophytes are observed in Osteophytes are observed in advanced cases. advanced cases.

The radiographic changes (at 2 years The radiographic changes (at 2 years old) often are subtle and can be old) often are subtle and can be detected only by an experienced detected only by an experienced radiologist.radiologist.

Conditions which can mimic or replicate the symptoms of hip dysplasia

The following conditions can give symptoms very similar to hip dysplasia, and should be ruled out during diagnosis:

•Cauda equina syndrome (i.e. lower back problems)

•Cranial (anterior) cruciate ligament tears

•Other rear limb arthritic conditions

TreatmentTreatment:: The available treatments for hip dysplasia vary The available treatments for hip dysplasia vary

widely and depend on the age of the animals, widely and depend on the age of the animals, desired function, pathological condition of the desired function, pathological condition of the joint and financial resources of the owner.joint and financial resources of the owner.

Conservative therapy:Conservative therapy: ((Non surgical interventions)

The primary goals of therapy are to alleviate The primary goals of therapy are to alleviate discomfort and maintain function. discomfort and maintain function.

Non-surgical interventions include three elementsNon-surgical interventions include three elements : : weight controlweight control , ,

exercise controlexercise control , , and medicationand medication . .

If an animal is overweight, recommendation If an animal is overweight, recommendation include weight loss to decrease the load include weight loss to decrease the load across the hip joints.across the hip joints.

AA-Reasonable (-Reasonable (nonconcussivenonconcussive ) ) exercise exercise such as swimming may such as swimming may help maintain muscle mass and help maintain muscle mass and joint function without joint function without overstressing the hip jointoverstressing the hip joint,, Stimulates cartilageStimulates cartilage growth and reduces growth and reduces degenerationdegeneration

((though excessive exercisethough excessive exercise can do harm toocan do harm too.).)

Hydrotherapy (swimming)swimming)

Also regular long walks in early or mild Also regular long walks in early or mild dysplasia can help prevent loss of muscle dysplasia can help prevent loss of muscle mass to the hipsmass to the hips..

Regular long walksRegular long walks

BB--Medication can reduce pain and Medication can reduce pain and discomfort, and also reduce discomfort, and also reduce damaging inflammation.damaging inflammation.

Nonsteroidal anti-inflammatory drugs Nonsteroidal anti-inflammatory drugs (NSAIDs) are the most widely (NSAIDs) are the most widely recommended analgesics in the recommended analgesics in the treatment of dysplagia which treatment of dysplagia which alleviate pain, but do not alter the alleviate pain, but do not alter the degenerative changes in the joint.degenerative changes in the joint.

Typical NSAID's used for hip Typical NSAID's used for hip dysplasia include dysplasia include carprofencarprofen and and meloxicammeloxicam (often sold as (often sold as RimadylRimadyl and and MetacamMetacam respectively), both used to respectively), both used to treat arthritis resulting from treat arthritis resulting from dysplasia, although other NSAIDs dysplasia, although other NSAIDs such as such as tepoxalintepoxalin ( (ZubrinZubrin) ) , , acetylsalicylic acid acetylsalicylic acid and and phenylbutazone phenylbutazone are also sometimes are also sometimes tried. tried.

NSAIDs vary dramatically between NSAIDs vary dramatically between species as to effect - a safe NSAID in species as to effect - a safe NSAID in one species may be unsafe in one species may be unsafe in another. another.

It is also common, if necessary, to try It is also common, if necessary, to try multiple anti-inflammatories over a multiple anti-inflammatories over a further 4-6 week period. further 4-6 week period.

This is since an animal will often respond This is since an animal will often respond to one type, but will fail to respond to to one type, but will fail to respond to another. another.

If one anti-inflammatory does not work, a If one anti-inflammatory does not work, a Vet will often try one or two other brands Vet will often try one or two other brands for 2–3 weeks each, also in conjunction for 2–3 weeks each, also in conjunction with ongoing glucosamine, before with ongoing glucosamine, before necessarily concluding that the condition necessarily concluding that the condition does not seem responsive to medication.does not seem responsive to medication.

A A glucosamineglucosamine based nutritional based nutritional supplement may possibly be supplement may possibly be suggested to give the body suggested to give the body additional raw materials used in joint additional raw materials used in joint repair. repair.

GlucosamineGlucosamine can take 3–4 weeks to can take 3–4 weeks to start showing its effects, since it can start showing its effects, since it can take up to 6 weeks to reach full take up to 6 weeks to reach full therapeutic effect in the body. therapeutic effect in the body.

Surgical therapySurgical therapy (interventions) ::

If medications fail to maintain an adequate quality of life, surgical options may need to be considered.

These may attempt to modify or repair the hip joint, in order to allow pain free usage, or may in some cases completely replace it.

Hip modification surgeries such as these usually result

in reduction of hip function in return for improved quality of

life, pain control, and a reduction in future risk.

Some types of surgical Some types of surgical interventionsinterventions

a- Femoral head and neck excisiona- Femoral head and neck excision

b- Total hip replacementb- Total hip replacement

c- c- DARthroplastyDARthroplasty

d- Juvenile Pubic Symphysiodesisd- Juvenile Pubic Symphysiodesis

Femoral Head/Neck Ostectomy

This surgery is best used for smaller dogs (50 lbs or less) or very active dogs.

Here, the femoral head is cut off and removed, allowing the joint to heal as a “false joint”.

If the dog is not carrying too much weight, a false joint is strong enough.

If the dog is very active, a false joint will form quickly.

The pet typically does not want to use the leg for the first 2 weeks but should at least be partially using the leg after 4-6 weeks.

The leg should be used nearly normally after a couple of months.

Total Hip ReplacementThis procedure is for dogs with

degenerative hip changes already established.

For these dogs, the best choice may be to simply replace the hip (or hips) with a prosthetic hip.

This procedure may sound radical but it has been commonly performed for nearly 20 years in dog with great success.

Usually only one hip receives surgery at a time.

Often only one replacement is needed and the pet does well enough not to need surgery on the other side.

Conventional cemented total hip system.  Different sizes of modular

implants are assembled and fixed in bones using cement (arrows).

Cemented (right side) and cementless (left side) total hip system.  Implants can be either stabilized with cement (arrows) or with tight fit “press-fit” cementless mechanism (left).  With this cementless system, bone can grow into the implants overtime to further stabilize the implants .

Cemented total hip system for small dogs and cats micro hip system.

Cementless total hip system. Implants are stabilized with screws.

Cementless total hip system.  Implants are secured to bones by the screw-in design.

DARthroplasty“DAR” stands for “Dorsal Acetabular

Rim.”

In this procedure bone grafts taken from other areas of the pelvis are used to build a longer rim on the acetabulum so that the femoral head will have a deeper socket in which to fit.

This procedure is best done in dogs that are too old for Triple Pelvic Osteotomy or have just started developing degenerative arthritis.

This is a fairly new procedure in the hip dysplasia.

Long term success (i.e. how patients do when they are old) is not really known as the procedure has not been performed long enough to collect results from a large number of patients. A specialist is needed for this surgery.

Juvenile Pubic Symphysiodesis

This surgery is performed on young puppies before age 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 seem 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 permaturely seals the symphysis which in turn results in rotation of the developing hip sockets into a more normal alignment.

The technique is basically, by stopping growth at the pubic symphysis with electrocautery, continued growth of the remainder of the pelvis and sacrum will force the acetabulae into a more ventral facing position (ventroversion). 

Stopping growth of the pubic symphysis is done by cauterizing this fibrous joint, taking care to protect the soft tissue structures in the pelvis.

Juvenile Pubic Symphysiodesis

Alternative treaments for hip Alternative treaments for hip dysplasiadysplasia

Acupressure points for hip dysplasiaAcupressure points for hip dysplasia

Spastic Paresis in Young Spastic Paresis in Young CattleCattle

Spastic is a neuromuscular Spastic is a neuromuscular contracture disorder causes a contracture disorder causes a progressive unilateral or bilateral progressive unilateral or bilateral hyper-extended posture and gait of hyper-extended posture and gait of the hock and stifle joints. the hock and stifle joints.

It occurs sporadically in both dairy and It occurs sporadically in both dairy and beef breeds, rarely in crossbred cattle.beef breeds, rarely in crossbred cattle.

EtiologyEtiology::

Most investigators believe its Most investigators believe its expression is multifactorial, expression is multifactorial, animals with straight-legged animals with straight-legged conformation of the pelvic limbs conformation of the pelvic limbs are more commonly affected.are more commonly affected.

The term spastic paresis is in The term spastic paresis is in appropriate in that no central or appropriate in that no central or peripheral nerve lesions are peripheral nerve lesions are consistently demonstrable. consistently demonstrable.

Most researchers of the disease Most researchers of the disease agree it is a primary muscular agree it is a primary muscular disorder. disorder.

Additional theories include Additional theories include imbalances of neurotransmitter imbalances of neurotransmitter activity in cerebrospinal fluid activity in cerebrospinal fluid and the role that magnesium and the role that magnesium and lithium may have in this and lithium may have in this disease.disease.

SignsSigns::

Signs can be noticed in calves aged a Signs can be noticed in calves aged a weeks to 10 months. weeks to 10 months.

Excessive tone and a spastic Excessive tone and a spastic contracture of one or both hind legs contracture of one or both hind legs primarily involving the primarily involving the gastrocnemius muscles lead to gastrocnemius muscles lead to progressive overextension of the progressive overextension of the hock joint and to a lesser extent the hock joint and to a lesser extent the stifle.stifle.

The insidious first signs are of stiff The insidious first signs are of stiff movement and a straight hock. movement and a straight hock.

Mild overextension of the hock Mild overextension of the hock causes the distal part of the limb causes the distal part of the limb occasionally to be placed caudally, occasionally to be placed caudally, and the limb is advanced in a and the limb is advanced in a swinging motion (pendulum fashion).swinging motion (pendulum fashion).

Later the claws may not contact the Later the claws may not contact the ground, and the animal may stand ground, and the animal may stand on three legs, the more affected hind on three legs, the more affected hind limb extended caudally. limb extended caudally.

The less affected contralateral limb The less affected contralateral limb tends to be placed a cross the tends to be placed a cross the median line for balance, and bowing median line for balance, and bowing of the limb medially.of the limb medially.

The tail head tends to be raised and The tail head tends to be raised and may move spasmodically up and may move spasmodically up and down. down.

The forelimbs tend to be placed The forelimbs tend to be placed caudally to transfere more weight caudally to transfere more weight bearing to the forequarters, bearing to the forequarters, resulting in an arched back.resulting in an arched back.

The gastrocnemius muscle group The gastrocnemius muscle group feels harder than normal as a result feels harder than normal as a result of the contracted state.of the contracted state.

DiagnosisDiagnosis::

The clinical signs and radiographic The clinical signs and radiographic changes in the hock joint reflect the changes in the hock joint reflect the effects of overextension are effects of overextension are diagnostic.diagnostic.

In very early stages, the condition In very early stages, the condition must be differentiated from infectious must be differentiated from infectious tarsitis and gonitis and upward tarsitis and gonitis and upward fixation of the patella. fixation of the patella.

In later stages, the stance and gait In later stages, the stance and gait are pathognomonic.are pathognomonic.

TreatmentTreatment::

No medical treatment has been No medical treatment has been successful. successful.

Breeding animals should be culled. Breeding animals should be culled.

Surgery can effectively alleviate the Surgery can effectively alleviate the condition by appropriate effects on condition by appropriate effects on the overextension produced by the the overextension produced by the gastrocnemius muscle and tendon gastrocnemius muscle and tendon several techniques have been used.several techniques have been used.

Complete tenotomy of the Complete tenotomy of the gastrocnemius tendon.gastrocnemius tendon.

Complete tibial neurectomy.Complete tibial neurectomy.

Partial tenectomy of the two Partial tenectomy of the two insertions of the gastrocnemius insertions of the gastrocnemius muscle on the calcaneus.muscle on the calcaneus.

Schematic representation of modified gastrocnemius tenectomy