Hip dysplasia
Encyclopedia
Hip dysplasia is an abnormal formation of the hip socket that, in its more severe form, can eventually cause crippling lameness and painful arthritis
of the joints. It is a genetic (polygenic) trait that is affected by environmental factors. It can be found in many animals and occasionally in humans, but is most commonly associated with dog
s, and is common in many dog breeds, particularly the larger breeds.
Hip dysplasia is one of the most studied veterinary conditions in dogs, and the most common single cause of arthritis of the hips.
of the hip joint, the root
(the thigh bone) is connected to the pelvis
at the hip joint. The almost spherical end of the femur
head (the caput, or caput ossis femoris) fits into the acetabulum
(a concave socket located in the pelvis
). The bony surface of the femur head and of the acetabulum are covered by cartilage. While bones provide the strength necessary to support body weight, cartilage ensures a smooth fit and a wide range of motion. Normal hip function can be affected by congenital conditions such as dysplasia, discussed in this article, trauma, and by acquired diseases such as osteoarthritis
and rheumatoid arthritis
.
The body reacts to this in several ways. First, the joint itself is continually repairing itself and laying down new cartilage
. However cartilage repair is a relatively slow process, the tissue being avascular.
So the joint may suffer degradation due to the abnormal wear and tear, or may not support the body weight as intended. The joint becomes inflamed
and a cycle of cartilage damage, inflammation and pain commences. This is a self-fueling process, in that the more the joint becomes damaged, the less able it is to resist further damage. The inflammation causes further damage. The bones of the joint may also develop osteoarthritis
, visible on an X-ray
as small outcrops of bone, which further degrade the joint.
The underlying deformity of the joint may get worse over time, or may remain static. A dog may have good X-rays and yet be in pain, or may have very poor X-rays and apparently almost no problems. The hip condition is only one factor to determine the extent to which dysplasia is causing pain or affecting the quality of life. In mild to moderate dysplasia it is often the secondary effects of abnormal wear and tear or arthritis, rather than dysplasia itself, which is the direct causes of visible problems.
s are also known to suffer from it. Cats are also known to have this condition, especially Siamese.
To reduce pain, the animal will typically reduce its movement of that hip. This may be visible as "bunny hopping", where both legs move together, or less dynamic movement (running, jumping), or stiffness. Since the hip cannot move fully, the body compensates by adapting its use of the spine
, often causing spinal, stifle
(a dog's knee
joint), or soft tissue problems to arise.
The causes of hip dysplasia are considered heritable, but new research conclusively suggests that environment also plays a role. To what degree the causality is genetic and what portion environmental is a topic of current debate. Environmental influences would include overweight condition, injury at a young age, overexertion on hip joint at a young age, ligament tear at a young age, repetitive motion on forming joint (i.e. jogging with puppy under the age of 1 year). As current studies progress, greater information will help provide procedures to effectively reduce the occurrence of this condition.
In dogs, the problem almost always appears by the time the dog is 18 months old. The defect can be anywhere from mild to severely crippling, and can eventually cause severe osteoarthritis.
It is most common in medium-large pure bred dogs, such as Newfoundland Dogs, German Shepherd Dog
s, Labrador
or Golden retriever
s, rottweiler
s and mastiff
s, but also occurs in some smaller breeds such as spaniel
s and pug
s and occasionally (usually with minor symptoms) in cat
s.
(legs move more together when running rather than swinging alternately), lameness, pain, reluctance to stand on rear legs, jump up, or climb stairs, subluxation
or dislocation
of the hip joint, or wasting away of the muscle mass in the hip area. Radiographs (X-ray
s) often confirm the presence of hip dysplasia, but radiographic features may not be present until two years of age in some dogs. Moreover, many affected dogs do not show clinical signs, but some dogs manifest the problem before seven months of age, while others do not show it until well into adulthood.
In part this is because the underlying hip problem may be mild or severe, may be worsening or stable, and the body may be more or less able to keep the joint in repair well enough to cope. Also, different animals have different pain tolerances and different weights, and use their bodies differently, so a light dog who only walks, will have a different joint use than a more heavy or very active dog. Some dogs will have a problem early on, others may never have a real problem at all.
Each case must be treated on its own merits, and a range of treatment options exist.
for granted and have learned to live with it. Dogs suffering such pain do not usually exhibit acute signs of pain. Sometimes, they will suddenly and abnormally sit down when walking, or refuse to walk or climb objects which they usually would, but this can equally be a symptom of many other things, including a thorn in the paw, or a temporary muscle pain. So pain recognition is less common a means of detection than the visible gait and other abnormalities described above.
s and hip scoring
tests. These should be done at an appropriate age, and perhaps repeated at adulthood - if done too young they will not show anything. Since the condition is to a large degree inherited, the hip scores of parents should be professionally checked before buying a pup, and the hip scores of dogs should be checked before relying upon them for breeding
. Despite the fact that the condition is inherited, it can occasionally arise even to animals with impeccable hip scored parents.
In diagnosing suspected dysplasia, the x-ray to evaluate the internal state of the joints is usually combined with a study of the animal and how it moves, to confirm whether its quality of life is being affected. Evidence of lameness or abnormal hip or spine use, difficulty or reduced movement when running or navigating steps, are all evidence of a problem. Both aspects have to be taken into account since there can be serious pain with little X-ray evidence.
It is also common to X-ray the spine and legs, as well as the hips, where dysplasia is suspected, since soft tissue
s can be affected by the extra strain of a dysplastic hip, or there may be other undetected factors such as neurological
issues (e.g. nerve
damage) involved.
There are several standardized systems for categorising dysplasia, set out by respective reputable bodies (Orthopedic Foundation for Animals/OFA
, PennHIP
, British Veterinary Association/BVA
). Some of these tests require manipulation of the hip joint into standard positions, in order to reveal their condition on an X-ray.
It is also worth noting that a dog may misuse its rear legs, or adapt its gait, to compensate for pain in the forelimbs, notably osteoarthritis
, osteochondritis
(OCD) or shoulder or elbow dysplasia
, as well as pain in the hocks and stifles or spinal issues. It is important to rule out other joint and bodily issues before concluding that only hip dysplasia is present. Even if some hip dysplasia is present, it is possible for other conditions to co-exist or be masked by it.
If the problem is relatively mild, then sometimes all that is needed to bring the symptoms under control are suitable medications to help the body deal better with inflammation, pain and joint wear. In many cases this is all that is needed for a long time.
If the problem cannot be controlled with medications, then often surgery is considered. There are traditionally two types of surgery - those which reshape the joint to reduce pain or help movement, and hip replacement for animals
which completely replaces the damaged hip with an artificial joint, similar to human hip replacements
.
Non-surgical intervention is usually via a suitable non-steroidal anti-inflammatory drug
(NSAID) which doubles as an anti-inflammatory and painkiller. Typical NSAIDs used for hip dysplasia include carprofen
and meloxicam
(often sold as Rimadyl and Metacam respectively), both used to treat arthritis resulting from dysplasia, although other NSAIDs such as tepoxalin
(Zubrin) and prednoleucotropin ("PLT", a combination of cinchophen
and prednisolone
) are sometimes tried. NSAIDs vary dramatically between species as to effect: a safe NSAID in one species may be unsafe in another. It is important to follow veterinary advice.
A glucosamine
-based nutritional supplement may give the body additional raw materials used in joint repair. Glucosamine can take 3–4 weeks to start showing its effects, so the trial period for medication is usually at least 3–5 weeks. In vitro, glucosamine has been shown to have negative effects on cartilage cells.
It is also common to try multiple anti-inflammatories over a further 4–6 week period, if necessary, since an animal will often respond to one type but fail to respond to another. If one anti-inflammatory does not work, a vet will often try one or two other brands for 2–3 weeks each, also in conjunction with ongoing glucosamine, before concluding that the condition does not seem responsive to medication.
Carprofen
, and other anti-inflammatories in general, whilst very safe for most animals, can sometimes cause problems for some animals, and (in a few rare cases) sudden death through liver toxicity. This is most commonly discussed with carprofen but may be equally relevant with other anti-inflammatories. As a result it is often recommended to perform monthly (or at least, twice-annually) blood tests to confirm that the animal is not reacting adversely to the medications. Such side effects are rare but worth being aware of, especially if long-term use is anticipated.
This regime can usually be maintained for the long term, as long as it is effective in keeping the symptoms of dysplasia at bay.
Some attempts have been made to treat the pain caused by arthritic changes through the use of "laser therapy", in particular "class IV laser therapy". Well-controlled clinical trials are unfortunately lacking, and much of the evidence for these procedures remains anecdotal.
Hip modification surgeries include excision arthroplasty
, in which the head of the femur is removed and reshaped or replaced, and pelvic rotation (also known as triple pelvic osteotomy
, or pubic symphodesis) in which the hip socket is realigned, may be appropriate if done early enough. These treatments can be very effective, but as a rule tend to become less effective for heavier animals - their ability to treat the problem becomes reduced if the joint has to handle more pressure in daily life. Pelvic rotation is also not as effective if arthritis has developed to the point of being visible on X-rays.
Femoral head ostectomy
(FHO), sometimes appropriate for smaller dogs and cats, is when the head of the femur is removed but not replaced. Instead, the resulting scar tissue from the operation takes the place of the hip joint. In such surgeries, the weight of the animal must be kept down throughout its life in order to maintain mobility. FHO surgery is sometimes done when other methods have failed, but is also done initially when the joint connection is particularly troublesome or when arthritis is severe.
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.
Hip replacement
has the highest rate of success, especially in severe cases, since it completely replaces the faulty joint. It usually restores complete mobility if no other joint is affected, and also completely prevents recurrence. Hip replacement for dogs, can sometimes also be a preferred clinical option for serious dysplasia in animals over about 40–60 lb (18.1–27.2 kg), a weight that excludes certain other surgical treatments.
Other options under exploration include:
areas and reported up to 90-days of clinical improvement after a single implant. The bioscaffold has been shown to cause infiltrating cells to upregulate a variety of tissue repair factors including aggrecan
, connective tissue growth factor, bone morphogenetic protein
, transforming growth factors, and other tissue repair factors associated with osteoarthritis.
Arthritis
Arthritis is a form of joint disorder that involves inflammation of one or more joints....
of the joints. It is a genetic (polygenic) trait that is affected by environmental factors. It can be found in many animals and occasionally in humans, but is most commonly associated with dog
Dog
The domestic dog is a domesticated form of the gray wolf, a member of the Canidae family of the order Carnivora. The term is used for both feral and pet varieties. The dog may have been the first animal to be domesticated, and has been the most widely kept working, hunting, and companion animal in...
s, and is common in many dog breeds, particularly the larger breeds.
Hip dysplasia is one of the most studied veterinary conditions in dogs, and the most common single cause of arthritis of the hips.
Normal hip anatomy
In the normal anatomyAnatomy
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...
of the hip joint, the root
Root
In vascular plants, the root is the organ of a plant that typically lies below the surface of the soil. This is not always the case, however, since a root can also be aerial or aerating . Furthermore, a stem normally occurring below ground is not exceptional either...
(the thigh bone) is connected to the pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
at the hip joint. The almost spherical end of the femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
head (the caput, or caput ossis femoris) fits into the acetabulum
Acetabulum
The acetabulum is a concave surface of the pelvis. The head of the femur meets with the pelvis at the acetabulum, forming the hip joint.-Structure:...
(a concave socket located in the pelvis
Pelvis
In human anatomy, the pelvis is the lower part of the trunk, between the abdomen and the lower limbs .The pelvis includes several structures:...
). The bony surface of the femur head and of the acetabulum are covered by cartilage. While bones provide the strength necessary to support body weight, cartilage ensures a smooth fit and a wide range of motion. Normal hip function can be affected by congenital conditions such as dysplasia, discussed in this article, trauma, and by acquired diseases such as osteoarthritis
Osteoarthritis
Osteoarthritis also known as degenerative arthritis or degenerative joint disease, is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. Symptoms may include joint pain, tenderness, stiffness, locking, and sometimes an effusion...
and rheumatoid arthritis
Rheumatoid arthritis
Rheumatoid arthritis is a chronic, systemic inflammatory disorder that may affect many tissues and organs, but principally attacks synovial joints. The process produces an inflammatory response of the synovium secondary to hyperplasia of synovial cells, excess synovial fluid, and the development...
.
Dysplastic hip anatomy
In a hip suffering from dysplasia, two things are commonly abnormal. First, the caput is not deeply and tightly held by the acetabulum. Instead of being a snug fit, it is a loose fit, or a partial fit. Secondly, the caput or acetabulum are not smooth and round, but are misshapen, causing abnormal wear and tear or friction within the joint as it moves.The body reacts to this in several ways. First, the joint itself is continually repairing itself and laying down new cartilage
Cartilage
Cartilage is a flexible connective tissue found in many areas in the bodies of humans and other animals, including the joints between bones, the rib cage, the ear, the nose, the elbow, the knee, the ankle, the bronchial tubes and the intervertebral discs...
. However cartilage repair is a relatively slow process, the tissue being avascular.
So the joint may suffer degradation due to the abnormal wear and tear, or may not support the body weight as intended. The joint becomes inflamed
Inflammation
Inflammation is part of the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli and to initiate the healing process...
and a cycle of cartilage damage, inflammation and pain commences. This is a self-fueling process, in that the more the joint becomes damaged, the less able it is to resist further damage. The inflammation causes further damage. The bones of the joint may also develop osteoarthritis
Osteoarthritis
Osteoarthritis also known as degenerative arthritis or degenerative joint disease, is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. Symptoms may include joint pain, tenderness, stiffness, locking, and sometimes an effusion...
, visible on an X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
as small outcrops of bone, which further degrade the joint.
The underlying deformity of the joint may get worse over time, or may remain static. A dog may have good X-rays and yet be in pain, or may have very poor X-rays and apparently almost no problems. The hip condition is only one factor to determine the extent to which dysplasia is causing pain or affecting the quality of life. In mild to moderate dysplasia it is often the secondary effects of abnormal wear and tear or arthritis, rather than dysplasia itself, which is the direct causes of visible problems.
Causes and effects
In dogs, a femur that does not fit correctly into the pelvic socket, or poorly developed muscles in the pelvic area. Large and giant breeds are susceptible to hip dysplasia, and Cocker spaniels and Shetland sheepdogShetland Sheepdog
The Shetland Sheepdog, often known as the Sheltie, is a breed of herding dog.They are small to medium dogs, and come in a variety of colors, such as sable/white, tri-color, and blue merle. They are vocal, excitable, energetic dogs who are always willing to please and work hard...
s are also known to suffer from it. Cats are also known to have this condition, especially Siamese.
To reduce pain, the animal will typically reduce its movement of that hip. This may be visible as "bunny hopping", where both legs move together, or less dynamic movement (running, jumping), or stiffness. Since the hip cannot move fully, the body compensates by adapting its use of the spine
Vertebral column
In human anatomy, the vertebral column is a column usually consisting of 24 articulating vertebrae, and 9 fused vertebrae in the sacrum and the coccyx. It is situated in the dorsal aspect of the torso, separated by intervertebral discs...
, often causing spinal, stifle
Stifle joint
The stifle joint is a complex joint in the hind limbs of quadruped mammals such as the sheep, horse or dog. It is the equivalent joint to the human knee...
(a dog's knee
Knee
The knee joint joins the thigh with the leg and consists of two articulations: one between the fibula and tibia, and one between the femur and patella. It is the largest joint in the human body and is very complicated. The knee is a mobile trocho-ginglymus , which permits flexion and extension as...
joint), or soft tissue problems to arise.
The causes of hip dysplasia are considered heritable, but new research conclusively suggests that environment also plays a role. To what degree the causality is genetic and what portion environmental is a topic of current debate. Environmental influences would include overweight condition, injury at a young age, overexertion on hip joint at a young age, ligament tear at a young age, repetitive motion on forming joint (i.e. jogging with puppy under the age of 1 year). As current studies progress, greater information will help provide procedures to effectively reduce the occurrence of this condition.
In dogs, the problem almost always appears by the time the dog is 18 months old. The defect can be anywhere from mild to severely crippling, and can eventually cause severe osteoarthritis.
It is most common in medium-large pure bred dogs, such as Newfoundland Dogs, German Shepherd Dog
German Shepherd Dog
The German Shepherd Dog , also known as an Alsatian or just the German Shepherd, is a breed of large-sized dog that originated in Germany. The German Shepherd is a relatively new breed of dog, with its origin dating to 1899. As part of the Herding Group, the German Shepherd is a working dog...
s, Labrador
Labrador Retriever
The Labrador Retriever is one of several kinds of retriever, a type of gun dog. A breed characteristic is webbed paws for swimming, useful for the breed's original purpose of retrieving fishing nets. The Labrador is the most popular breed of dog by registered ownership in Canada, the United...
or Golden retriever
Golden Retriever
The Golden Retriever is a medium-sized breed of dog. They were historically developed as gundogs to retrieve shot waterfowl such as ducks and upland game birds during hunting and shooting parties. As such, they were bred to have a soft mouth to retrieve game undamaged and have an instinctive love...
s, rottweiler
Rottweiler
The Rottweiler is a medium to large size breed of domestic dog that originated in Rottweil, Germany. The dogs were known as "Rottweil butchers' dogs" because they were used to herd livestock and pull carts laden with butchered meat and other products to market...
s and mastiff
English Mastiff
The English Mastiff, referred to by virtually all Kennel Clubs simply as the Mastiff, is a breed of large dog perhaps descended from the ancient Alaunt through the Pugnaces Britanniae. Distinguishable by enormous size, massive head, and a limited range of colors, but always displaying a black mask,...
s, but also occurs in some smaller breeds such as spaniel
Spaniel
A spaniel is a type of gun dog. It is assumed spaniels originated from Spain as the word spaniel may be derived from Hispania or possibly from the French phrase "Chiens de l’Espagnol" . Spaniels were especially bred to flush game out of dense brush. By the late 17th century spaniels had become...
s and pug
Pug
The pug is a "toy" breed of dog with a wrinkly, short-muzzled face, and curled tail. The breed has a fine, glossy coat that comes in a variety of colors, and a compact square body with well-developed muscle. They have been described as multum in parvo , referring to the pug's personality and...
s and occasionally (usually with minor symptoms) in cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...
s.
Symptoms
Dogs might exhibit signs of stiffness or soreness after rising from rest, reluctance to exercise, bunny-hopping or other abnormal gaitGait
Gait is the pattern of movement of the limbs of animals, including humans, during locomotion over a solid substrate. Most animals use a variety of gaits, selecting gait based on speed, terrain, the need to maneuver, and energetic efficiency...
(legs move more together when running rather than swinging alternately), lameness, pain, reluctance to stand on rear legs, jump up, or climb stairs, subluxation
Subluxation
A subluxation may have different meanings, depending on the medical specialty involved. It implies the presence of an incomplete or partial dislocation of a joint or organ. The World Health Organization defines both the medical subluxation and the chiropractic subluxation...
or dislocation
Dislocation
In materials science, a dislocation is a crystallographic defect, or irregularity, within a crystal structure. The presence of dislocations strongly influences many of the properties of materials...
of the hip joint, or wasting away of the muscle mass in the hip area. Radiographs (X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s) often confirm the presence of hip dysplasia, but radiographic features may not be present until two years of age in some dogs. Moreover, many affected dogs do not show clinical signs, but some dogs manifest the problem before seven months of age, while others do not show it until well into adulthood.
In part this is because the underlying hip problem may be mild or severe, may be worsening or stable, and the body may be more or less able to keep the joint in repair well enough to cope. Also, different animals have different pain tolerances and different weights, and use their bodies differently, so a light dog who only walks, will have a different joint use than a more heavy or very active dog. Some dogs will have a problem early on, others may never have a real problem at all.
Each case must be treated on its own merits, and a range of treatment options exist.
Long term pain
A dysplastic animal has probably lived with the condition since it was only a few months old, and has therefore grown up taking the chronic painChronic pain
Chronic pain has several different meanings in medicine. Traditionally, the distinction between acute and chronic pain has relied upon an arbitrary interval of time from onset; the two most commonly used markers being 3 months and 6 months since the initiation of pain, though some theorists and...
for granted and have learned to live with it. Dogs suffering such pain do not usually exhibit acute signs of pain. Sometimes, they will suddenly and abnormally sit down when walking, or refuse to walk or climb objects which they usually would, but this can equally be a symptom of many other things, including a thorn in the paw, or a temporary muscle pain. So pain recognition is less common a means of detection than the visible gait and other abnormalities described above.
Diagnosis
The classic diagnostic technique is with appropriate x-RayX-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s and hip scoring
Hip score
Hip scoring is a procedure used to determine the degree of hip dysplasia in dogs and other animals and reporting the findings in a standard way.The hip score is the sum of the points awarded for each of nine radiographic tures of both hip joints....
tests. These should be done at an appropriate age, and perhaps repeated at adulthood - if done too young they will not show anything. Since the condition is to a large degree inherited, the hip scores of parents should be professionally checked before buying a pup, and the hip scores of dogs should be checked before relying upon them for breeding
Selective breeding
Selective breeding is the process of breeding plants and animals for particular genetic traits. Typically, strains that are selectively bred are domesticated, and the breeding is sometimes done by a professional breeder. Bred animals are known as breeds, while bred plants are known as varieties,...
. Despite the fact that the condition is inherited, it can occasionally arise even to animals with impeccable hip scored parents.
In diagnosing suspected dysplasia, the x-ray to evaluate the internal state of the joints is usually combined with a study of the animal and how it moves, to confirm whether its quality of life is being affected. Evidence of lameness or abnormal hip or spine use, difficulty or reduced movement when running or navigating steps, are all evidence of a problem. Both aspects have to be taken into account since there can be serious pain with little X-ray evidence.
It is also common to X-ray the spine and legs, as well as the hips, where dysplasia is suspected, since soft tissue
Soft tissue
In anatomy, the term soft tissue refers to tissues that connect, support, or surround other structures and organs of the body, not being bone. Soft tissue includes tendons, ligaments, fascia, skin, fibrous tissues, fat, and synovial membranes , and muscles, nerves and blood vessels .It is sometimes...
s can be affected by the extra strain of a dysplastic hip, or there may be other undetected factors such as neurological
Neurology
Neurology is a medical specialty dealing with disorders of the nervous system. Specifically, it deals with the diagnosis and treatment of all categories of disease involving the central, peripheral, and autonomic nervous systems, including their coverings, blood vessels, and all effector tissue,...
issues (e.g. nerve
Nerve
A peripheral nerve, or simply nerve, is an enclosed, cable-like bundle of peripheral axons . A nerve provides a common pathway for the electrochemical nerve impulses that are transmitted along each of the axons. Nerves are found only in the peripheral nervous system...
damage) involved.
There are several standardized systems for categorising dysplasia, set out by respective reputable bodies (Orthopedic Foundation for Animals/OFA
Orthopedic Foundation for Animals
The Orthopedic Foundation for Animals is a not-for-profit organization based in Columbia, Missouri that aims to research and prevent orthopedic and hereditary diseases in companion animals....
, PennHIP
PennHIP
PennHIP is a diagnostic technique for evaluating the hips of dogs for laxity. The acronym is also used for the network of veterinarians that use the PennHIP method of evaluation, and for the database of breed-specific hip dysplasia trends maintained at the University of Pennsylvania...
, British Veterinary Association/BVA
British Veterinary Association
The British Veterinary Association is the national body for veterinary surgeons in the United Kingdom and is a not-for-profit organisation. Its purpose is that of knowledge dissemination, and not professional validation or academic competence...
). Some of these tests require manipulation of the hip joint into standard positions, in order to reveal their condition on an X-ray.
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 syndromeCauda equina syndromeCauda equina syndrome ' is a serious neurologic condition in which there is acute loss of function of the lumbar plexus, neurologic elements of the spinal canal below the termination of the spinal cord.-Causes:...
(i.e. lower back problems) - Cranial (anterior) cruciate ligament tears
- Other rear limb arthritic conditions
- Osteochondritis dissecansOsteochondritis dissecansOsteochondritis dissecans , often abbreviated to OCD or OD, is a joint disorder in which cracks form in the articular cartilage and the underlying subchondral bone. OCD is caused by blood deprivation in the subchondral bone. This loss of blood flow causes the subchondral bone to die in a process...
and elbow dysplasiaElbow dysplasiaElbow dysplasia is a condition involving multiple developmental abnormalities of the elbow-joint in the dog, specifically the growth of cartilage or the structures surrounding it. These abnormalities, known as 'primary lesions', give rise to osteoarthritic processes...
in the forelimbs are difficult to diagnose as the animal may only exhibit an unusual gait, and may be masked by, or misdiagnosed as, hip dysplasia.
It is also worth noting that a dog may misuse its rear legs, or adapt its gait, to compensate for pain in the forelimbs, notably osteoarthritis
Osteoarthritis
Osteoarthritis also known as degenerative arthritis or degenerative joint disease, is a group of mechanical abnormalities involving degradation of joints, including articular cartilage and subchondral bone. Symptoms may include joint pain, tenderness, stiffness, locking, and sometimes an effusion...
, osteochondritis
Osteochondritis
Osteochondritis is a painful type of osteochondrosis where the cartilage or bone in a joint is inflamed.It often refers to osteochondritis dissecans...
(OCD) or shoulder or elbow dysplasia
Elbow dysplasia
Elbow dysplasia is a condition involving multiple developmental abnormalities of the elbow-joint in the dog, specifically the growth of cartilage or the structures surrounding it. These abnormalities, known as 'primary lesions', give rise to osteoarthritic processes...
, as well as pain in the hocks and stifles or spinal issues. It is important to rule out other joint and bodily issues before concluding that only hip dysplasia is present. Even if some hip dysplasia is present, it is possible for other conditions to co-exist or be masked by it.
Overview
There is no complete cure, although there are many options to alleviate the clinical signs. The aim of treatment is to enhance quality of life. Crucially, this is an inherited, degenerative condition and so will change during the life of an animal, so any treatment is subject to regular review or re-assessment if the symptoms appear to get worse or anything significantly changes.If the problem is relatively mild, then sometimes all that is needed to bring the symptoms under control are suitable medications to help the body deal better with inflammation, pain and joint wear. In many cases this is all that is needed for a long time.
If the problem cannot be controlled with medications, then often surgery is considered. There are traditionally two types of surgery - those which reshape the joint to reduce pain or help movement, and hip replacement for animals
Hip replacement (animal)
Hip replacement surgery can be performed on animals, as well as humans. This article discusses hip replacement surgery in animals.-Overview:...
which completely replaces the damaged hip with an artificial joint, similar to human hip replacements
Hip replacement
Hip replacement is a surgical procedure in which the hip joint is replaced by a prosthetic implant. Hip replacement surgery can be performed as a total replacement or a hemi replacement. Such joint replacement orthopaedic surgery generally is conducted to relieve arthritis pain or fix severe...
.
Non-surgical interventions
Non-surgical interventions include three elements: weight control, exercise control, and medication. Weight control is often "the single most important thing that we can do to help a dog with arthritis", and consequentially "reducing the dog's weight is enough to control all of the symptoms of arthritis in many dogs". Reasonable exercise stimulates cartilage growth and reduces degeneration (though excessive exercise can do harm too), and also regular long walks in early or mild dysplasia can help prevent loss of muscle mass to the hips. Medication can reduce pain and discomfort, and also reduce damaging inflammation.Non-surgical intervention is usually via a suitable non-steroidal anti-inflammatory drug
Non-steroidal anti-inflammatory drug
Nonsteroidal anti-inflammatory drugs, usually abbreviated to NSAIDs or NAIDs, but also referred to as nonsteroidal anti-inflammatory agents/analgesics or nonsteroidal Anti-inflammatory medicines , are drugs with analgesic and antipyretic effects and which have, in higher doses, anti-inflammatory...
(NSAID) which doubles as an anti-inflammatory and painkiller. Typical NSAIDs used for hip dysplasia include carprofen
Carprofen
Carprofen is a non-steroidal anti-inflammatory drug that is used by veterinarians as a supportive treatment for the relief of arthritic symptoms in geriatric dogs. It is also used for pain relief and to reduce swelling after spay or neuter...
and meloxicam
Meloxicam
Meloxicam is a nonsteroidal anti-inflammatory drug with analgesic and fever reducer effects. It is a derivative of oxicam, closely related to piroxicam, and falls in the enolic acid group of NSAIDs...
(often sold as Rimadyl and Metacam respectively), both used to treat arthritis resulting from dysplasia, although other NSAIDs such as tepoxalin
Tepoxalin
Tepoxalin is a nonsteroidal anti-inflammatory drug approved for veterinary use in the United States and the European Union. It is primarily used to reduce inflammation and relief of pain caused by musculoskeletal disorders such as hip dysplasia and arthritis.It is generally marketed under the...
(Zubrin) and prednoleucotropin ("PLT", a combination of cinchophen
Cinchophen
Cinchophen is an analgesic drug that was introduced in 1910 and frequently used to treat gout...
and prednisolone
Prednisolone
Prednisolone is the active metabolite of prednisone, which is also used as a drug.-Uses:Prednisolone is a corticosteroid drug with predominant glucocorticoid and low mineralocorticoid activity, making it useful for the treatment of a wide range of inflammatory and auto-immune conditions such as...
) are sometimes tried. NSAIDs vary dramatically between species as to effect: a safe NSAID in one species may be unsafe in another. It is important to follow veterinary advice.
A glucosamine
Glucosamine
Glucosamine is an amino sugar and a prominent precursor in the biochemical synthesis of glycosylated proteins and lipids. Glucosamine is part of the structure of the polysaccharides chitosan and chitin, which compose the exoskeletons of crustaceans and other arthropods, cell walls in fungi and...
-based nutritional supplement may give the body additional raw materials used in joint repair. Glucosamine can take 3–4 weeks to start showing its effects, so the trial period for medication is usually at least 3–5 weeks. In vitro, glucosamine has been shown to have negative effects on cartilage cells.
It is also common to try multiple anti-inflammatories over a further 4–6 week period, if necessary, since an animal will often respond to one type but fail to respond to another. If one anti-inflammatory does not work, a vet will often try one or two other brands for 2–3 weeks each, also in conjunction with ongoing glucosamine, before concluding that the condition does not seem responsive to medication.
Carprofen
Carprofen
Carprofen is a non-steroidal anti-inflammatory drug that is used by veterinarians as a supportive treatment for the relief of arthritic symptoms in geriatric dogs. It is also used for pain relief and to reduce swelling after spay or neuter...
, and other anti-inflammatories in general, whilst very safe for most animals, can sometimes cause problems for some animals, and (in a few rare cases) sudden death through liver toxicity. This is most commonly discussed with carprofen but may be equally relevant with other anti-inflammatories. As a result it is often recommended to perform monthly (or at least, twice-annually) blood tests to confirm that the animal is not reacting adversely to the medications. Such side effects are rare but worth being aware of, especially if long-term use is anticipated.
This regime can usually be maintained for the long term, as long as it is effective in keeping the symptoms of dysplasia at bay.
Some attempts have been made to treat the pain caused by arthritic changes through the use of "laser therapy", in particular "class IV laser therapy". Well-controlled clinical trials are unfortunately lacking, and much of the evidence for these procedures remains anecdotal.
Surgical 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 include excision arthroplasty
Arthroplasty
Arthroplasty is an operative procedure of orthopedic surgery performed, in which the arthritic or dysfunctional joint surface is replaced with something better or by remodeling or realigning the joint by osteotomy or some other procedure.-Background:Previously, a popular form of arthroplasty was...
, in which the head of the femur is removed and reshaped or replaced, and pelvic rotation (also known as triple pelvic osteotomy
Osteotomy
An osteotomy is a surgical operation whereby a bone is cut to shorten, lengthen, or change its alignment. It is sometimes performed to correct a hallux valgus, or to straighten a bone that has healed crookedly following a fracture. It is also used to correct a coxa vara, genu valgum, and genu varum...
, or pubic symphodesis) in which the hip socket is realigned, may be appropriate if done early enough. These treatments can be very effective, but as a rule tend to become less effective for heavier animals - their ability to treat the problem becomes reduced if the joint has to handle more pressure in daily life. Pelvic rotation is also not as effective if arthritis has developed to the point of being visible on X-rays.
Femoral head ostectomy
Femoral head ostectomy
Femoral Head Ostectomy is a surgical procedure that removes the femoral head and neck from the femur. FHO surgery is performed to alleviate pain. It is a salvage procedure, reserved for condition where pain can not be alleviated in any other way. It is common in veterinary surgery...
(FHO), sometimes appropriate for smaller dogs and cats, is when the head of the femur is removed but not replaced. Instead, the resulting scar tissue from the operation takes the place of the hip joint. In such surgeries, the weight of the animal must be kept down throughout its life in order to maintain mobility. FHO surgery is sometimes done when other methods have failed, but is also done initially when the joint connection is particularly troublesome or when arthritis is severe.
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.
Hip replacement
Hip replacement (animal)
Hip replacement surgery can be performed on animals, as well as humans. This article discusses hip replacement surgery in animals.-Overview:...
has the highest rate of success, especially in severe cases, since it completely replaces the faulty joint. It usually restores complete mobility if no other joint is affected, and also completely prevents recurrence. Hip replacement for dogs, can sometimes also be a preferred clinical option for serious dysplasia in animals over about 40–60 lb (18.1–27.2 kg), a weight that excludes certain other surgical treatments.
Other options under exploration include:
- DARthroplasty (Dorsal Acetabular Rim arthroplasty) is a technique developed by Dr. Barclay Slocum and Theresa Devine Slocum whereby cortico-cancellous bone strips, taken from the iliac crest, are contoured over the femoral head and sutured to the dorsal hip joint capsule and packed with additional cancellous bone graft dorsally to eventually anchor to drill holes in the original dorsal acetabulum. The new "shelf" eventually becomes an extension of the original acetabulum, thereby providing support and eliminating subluxation of the hip joint. The joint capsule becomes the new joint surface.
- Pubic symphysiodesis (also known as juvenile pubic symphysiodesis, or JPS), is a procedure for very young dogs that manipulates the way the pelvis grows to create a tighter hip. It involves cauterizingCauterizationThe medical practice or technique of cauterization is the burning of part of a body to remove or close off a part of it in a process called cautery, which destroys some tissue, in an attempt to mitigate damage, remove an undesired growth, or minimize other potential medical harmful possibilities...
the growth plates of the pelvis, in other words, the part of the pelvis which would usually grow and spread in puppyhood, no longer does so. To compensate, the rest of the pelvis grows outward, in a manner which enhances the "socket" of the hip and provides better support than that dog would have had naturally. Since it relies on growth in puppyhood, it has a very tight window for surgery – currently no sooner than about 4 months and no later than about 5 months. This is compatible with hip scoring of puppies at 4 months. - Capsular neurectomyNeurectomyNeurectomy is the surgical removal of a nerve or a section of a nerve. This procedure may be performed, for example, in cases of chronic pain where other treatments have failed. However the removal of the nerve can also cause negative effects, such as permanent numbness...
is a procedure in which the hip joint capsule is de-nerved to reduce pain in the hip. This allows the dog to exercise moderately with less pain, thus preventing the leg muscles from weakening from disuse and providing less support to the bad joint. Both hips can be done at one surgery. This surgery should not prevent a future hip replacement, if a more complete fix is desired.
BioScaffold Implant Procedure
In a recent comparative orthopedic study, a new bioscaffold having an embryonic-like structure has shown positive clinical outcomes in dogs with advanced, end stage osteoarthritis. The bioscaffold was implanted into intra-articularArticular
The articular bone is part of the lower jaw of most tetrapods, including amphibians, sauropsids and early synapsids. In these animals it is connected to two other lower jaw bones, the suprangular and the angular...
areas and reported up to 90-days of clinical improvement after a single implant. The bioscaffold has been shown to cause infiltrating cells to upregulate a variety of tissue repair factors including aggrecan
Aggrecan
Aggrecan also known as cartilage-specific proteoglycan core protein or chondroitin sulfate proteoglycan 1 is a protein that in humans is encoded by the ACAN gene. This gene is a member of the aggrecan/versican proteoglycan family...
, connective tissue growth factor, bone morphogenetic protein
Bone morphogenetic protein
Bone morphogenetic proteins are a group of growth factors also known as cytokines and as metabologens . Originally discovered by their ability to induce the formation of bone and cartilage, BMPs are now considered to constitute a group of pivotal morphogenetic signals, orchestrating tissue...
, transforming growth factors, and other tissue repair factors associated with osteoarthritis.