Elbow dysplasia
Encyclopedia
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
. Elbow dysplasia is a common condition of certain breeds of dog
s.
Most primary lesions are related to osteochondrosis
, which is a disease of the joint cartilage
and specifically Osteochondritis dissecans
(OCD or OD), the separation of a flap of cartilage on the joint surface. Other common causes of elbow dysplasia included ununited anconeal process (UAP) and fractured or ununited medial coronoid process (FCP or FMCP).
Osteochondritis dissecans is difficult to diagnose clinically as the animal may only exhibit an unusual gait. Consequently, OCD may be masked by, or misdiagnosed as, other skeletal and joint conditions such as hip dysplasia. The problem develops in puppyhood although often subclinically, and there may be pain or stiffness, discomfort on extension, or other compensating characteristics. Diagnosis generally depends on X-rays, arthroscopy
, or MRI scans. While cases of OCD of the stifle go undetected and heal spontaneously, others are exhibited in acute lameness. Surgery is recommended once the animal has been deemed lame, before then non-surgical control is usually used.
hood and continuing for life. In elbow dysplasia, the complex elbow joint suffers from a structural defect, often related to its cartilage
. This initial condition, known as a "primary lesion", causes an abnormal level of wear and tear and gradual degradation of the joint, at times disabling
or with chronic pain
. Secondary processes such as inflammation
and osteoarthritis
can arise from this damage which increase the problem and add further problems of their own.
The most common cause is osteochondrosis
, which is a disease of the joint cartilage
, and specifically Osteochondritis dissecans
(OCD or OD), the separation of a flap of cartilage from the joint surface as a result of avascular necrosis
, which in turn arises from failed blood flow in the subchondral bone. Other common causes of elbow dysplasia included ununited anconeal process (UAP) and fractured or ununited medial coronoid process (FCP or FMCP).
In OCD, the normal change of cartilage to bone
in the development of the joint fails or is delayed. The cartilage continues to grow and may split or become necrotic
. The cause is uncertain, but possibly includes genetics
, trauma
, and nutrition (including excessive calcium
and decreased Vitamin C
intake). OCD lesions are found in the elbow at the medial epicondyle of the humerus
. Specific conditions related to OCD include fragmentation of the medial coronoid process of the ulna
(FMCP) and an ununited anconeal process of the ulna (UAP). All types of OCD of the elbow are most typically found in large breed dogs, with symptoms starting between the ages of 4 to 8 months. Males are affected twice as often as females. The disease often affects both elbows (30 to 70 percent of the time), and symptoms include intermittent lameness, joint swelling, and external rotation and abduction
of the paw. Osteoarthritis
will develop later in most cases.
UAP is caused by a separation from the ulna of the ossification center
of the anconeal process. FMCP is caused by a failure of the coronoid process
to unite with the ulna. OCD of the medial epicondyle of the humerus is caused by disturbed endochondral fusion of the epiphysis
of the medial epicondyle with the distal end of the humerus, which may in turn be caused by avulsion
of the epiphysis.
s, arthroscopy
or CT (computed tomography). In cases with significant lameness, surgery
is the best option, especially with UAP. However, conservative treatment is often enough for cases of FMCP and OCD of the medial humeral epicondyle. The dogs are exercised regularly and given pain medication, and between the ages of 12 to 18 months the lameness will often improve or disappear. Control of body weight is important in all cases of elbow dysplasia, and prevention of quick growth spurts in puppies may help to prevent the disease.
Surgery for FMCP consists of removal of cartilage and bone fragments and correction of any incongruity of the joint. Reattachment of UAP with a screw is usually attempted before the age of 24 weeks, and after that age the typical treatment is removal of the UAP. Without surgery, UAP rapidly progresses to osteoarthritis
, but with FMCP osteoarthritis typically occurs with or without surgery. Osteoarthritis is also a common sequela of OCD of the humerus despite medical or surgical treatment. Elbow replacement surgery has been developed and can be an option for treatment
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 http://www.trbio.com/Technical_information.html TR BioSurgical, LLC.
, rehabilitation can take significantly longer, and some degree of lameness will remain. The surgery is classified as of 2010 as a "salvage" operation - that is, a last resort for an otherwise viable animal. Success rates of around 80 - 85% (approximately 5 in 6) were being discussed by sources in 2005 and again in 2008.
There are also fewer options if the replacement fails, the main option being arthrodesis
(surgical fusion of the joint) which results in a pain-free but lame gait. However arthrodesis is itself a complex surgery with a long recovery time, and if arthrodesis is required, additional strain will be borne by other nearby joints, so other leg and shoulder conditions such as osteoarthritis may become more significant.
in the United States
will grade elbow X-rays of dogs intended for breeding.
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...
, specifically the growth of 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...
or the structures surrounding it. These abnormalities, known as 'primary lesions', give rise to osteoarthritic processes
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...
. Elbow dysplasia is a common condition of certain breeds of 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.
Most primary lesions are related to osteochondrosis
Osteochondrosis
Osteochondrosis is a family of orthopedic diseases of the joint that occur in children and adolescents and in rapidly growing animals, particularly pigs, horses, and dogs. They are characterized by interruption of the blood supply of a bone, in particular to the epiphysis, followed by localized...
, which is a disease of the joint 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...
and specifically Osteochondritis dissecans
Osteochondritis dissecans
Osteochondritis 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...
(OCD or OD), the separation of a flap of cartilage on the joint surface. Other common causes of elbow dysplasia included ununited anconeal process (UAP) and fractured or ununited medial coronoid process (FCP or FMCP).
Osteochondritis dissecans is difficult to diagnose clinically as the animal may only exhibit an unusual gait. Consequently, OCD may be masked by, or misdiagnosed as, other skeletal and joint conditions such as hip dysplasia. The problem develops in puppyhood although often subclinically, and there may be pain or stiffness, discomfort on extension, or other compensating characteristics. Diagnosis generally depends on X-rays, arthroscopy
Arthroscopy
Arthroscopy is a minimally invasive surgical procedure in which an examination and sometimes treatment of damage of the interior of a joint is performed using an arthroscope, a type of endoscope that is inserted into the joint through a small incision...
, or MRI scans. While cases of OCD of the stifle go undetected and heal spontaneously, others are exhibited in acute lameness. Surgery is recommended once the animal has been deemed lame, before then non-surgical control is usually used.
The disease
Elbow Dysplasia is a significant genetically determined problem in many breeds of dog, often manifesting from puppyPuppy
A puppy is a juvenile dog. Some puppies may weigh , while larger ones can weigh up to . All healthy puppies grow quickly after birth. A puppy's coat color may change as the puppy grows older, as is commonly seen in breeds such as the Yorkshire Terrier...
hood and continuing for life. In elbow dysplasia, the complex elbow joint suffers from a structural defect, often related to its 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...
. This initial condition, known as a "primary lesion", causes an abnormal level of wear and tear and gradual degradation of the joint, at times disabling
Disability
A disability may be physical, cognitive, mental, sensory, emotional, developmental or some combination of these.Many people would rather be referred to as a person with a disability instead of handicapped...
or with chronic pain
Chronic 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...
. Secondary processes such as inflammation
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 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...
can arise from this damage which increase the problem and add further problems of their own.
Causes
Osteochondrosis
Osteochondrosis is a family of orthopedic diseases of the joint that occur in children and adolescents and in rapidly growing animals, particularly pigs, horses, and dogs. They are characterized by interruption of the blood supply of a bone, in particular to the epiphysis, followed by localized...
, which is a disease of the joint 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...
, and specifically Osteochondritis dissecans
Osteochondritis dissecans
Osteochondritis 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...
(OCD or OD), the separation of a flap of cartilage from the joint surface as a result of avascular necrosis
Avascular necrosis
Avascular necrosis is a disease where there is cellular death of bone components due to interruption of the blood supply. Without blood, the bone tissue dies and the bone collapses...
, which in turn arises from failed blood flow in the subchondral bone. Other common causes of elbow dysplasia included ununited anconeal process (UAP) and fractured or ununited medial coronoid process (FCP or FMCP).
In OCD, the normal change of cartilage to bone
Bone
Bones are rigid organs that constitute part of the endoskeleton of vertebrates. They support, and protect the various organs of the body, produce red and white blood cells and store minerals. Bone tissue is a type of dense connective tissue...
in the development of the joint fails or is delayed. The cartilage continues to grow and may split or become necrotic
Necrosis
Necrosis is the premature death of cells in living tissue. Necrosis is caused by factors external to the cell or tissue, such as infection, toxins, or trauma. This is in contrast to apoptosis, which is a naturally occurring cause of cellular death...
. The cause is uncertain, but possibly includes genetics
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
, trauma
Physical trauma
Trauma refers to "a body wound or shock produced by sudden physical injury, as from violence or accident." It can also be described as "a physical wound or injury, such as a fracture or blow." Major trauma can result in secondary complications such as circulatory shock, respiratory failure and death...
, and nutrition (including excessive calcium
Calcium
Calcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
and decreased Vitamin C
Vitamin C
Vitamin C or L-ascorbic acid or L-ascorbate is an essential nutrient for humans and certain other animal species. In living organisms ascorbate acts as an antioxidant by protecting the body against oxidative stress...
intake). OCD lesions are found in the elbow at the medial epicondyle of the humerus
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
. Specific conditions related to OCD include fragmentation of the medial coronoid process of the ulna
Ulna
The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form and runs parallel to the radius, which is shorter and smaller. In anatomical position The ulna is one of the two long bones in the forearm, the other being the radius. It is prismatic in form...
(FMCP) and an ununited anconeal process of the ulna (UAP). All types of OCD of the elbow are most typically found in large breed dogs, with symptoms starting between the ages of 4 to 8 months. Males are affected twice as often as females. The disease often affects both elbows (30 to 70 percent of the time), and symptoms include intermittent lameness, joint swelling, and external rotation and abduction
Abduction (kinesiology)
Abduction, in functional anatomy, is a movement which draws a limb away from the median plane of the body. It is thus opposed to adduction.-Upper limb:* of arm at shoulder ** Supraspinatus** Deltoid* of hand at wrist...
of the paw. 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...
will develop later in most cases.
UAP is caused by a separation from the ulna of the ossification center
Ossification center
The first step in ossification of the cartilage is that the cartilage cells, at the point where ossification is commencing and which is termed an ossification center, enlarge and arrange themselves in rows....
of the anconeal process. FMCP is caused by a failure of the coronoid process
Coronoid process of the ulna
The coronoid process is a triangular eminence projecting forward from the upper and front part of the ulna.Its base is continuous with the body of the bone, and of considerable strength....
to unite with the ulna. OCD of the medial epicondyle of the humerus is caused by disturbed endochondral fusion of the epiphysis
Epiphysis
The epiphysis is the rounded end of a long bone, at its joint with adjacent bone. Between the epiphysis and diaphysis lies the metaphysis, including the epiphyseal plate...
of the medial epicondyle with the distal end of the humerus, which may in turn be caused by avulsion
Avulsion fracture
An avulsion fracture is a bone fracture which occurs when a fragment of bone tears away from the main mass of bone as a result of physical trauma. This can occur at the ligament due to the application forces external to the body or at the tendon due to a muscular contraction that is stronger than...
of the epiphysis.
Diagnosis and treatment
Diagnosis is through 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, arthroscopy
Arthroscopy
Arthroscopy is a minimally invasive surgical procedure in which an examination and sometimes treatment of damage of the interior of a joint is performed using an arthroscope, a type of endoscope that is inserted into the joint through a small incision...
or CT (computed tomography). In cases with significant lameness, surgery
Surgery
Surgery is an ancient medical specialty that uses operative manual and instrumental techniques on a patient to investigate and/or treat a pathological condition such as disease or injury, or to help improve bodily function or appearance.An act of performing surgery may be called a surgical...
is the best option, especially with UAP. However, conservative treatment is often enough for cases of FMCP and OCD of the medial humeral epicondyle. The dogs are exercised regularly and given pain medication, and between the ages of 12 to 18 months the lameness will often improve or disappear. Control of body weight is important in all cases of elbow dysplasia, and prevention of quick growth spurts in puppies may help to prevent the disease.
Surgery for FMCP consists of removal of cartilage and bone fragments and correction of any incongruity of the joint. Reattachment of UAP with a screw is usually attempted before the age of 24 weeks, and after that age the typical treatment is removal of the UAP. Without surgery, UAP rapidly progresses to 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...
, but with FMCP osteoarthritis typically occurs with or without surgery. Osteoarthritis is also a common sequela of OCD of the humerus despite medical or surgical treatment. Elbow replacement surgery has been developed and can be an option for treatment
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 http://www.trbio.com/Technical_information.html TR BioSurgical, LLC.
Total elbow replacement
The elbow is a complex joint, bears 60% of body load, and tolerates problems less well than the hips. As a result elbow replacement is more complex than hip replacementHip replacement (animal)
Hip replacement surgery can be performed on animals, as well as humans. This article discusses hip replacement surgery in animals.-Overview:...
, rehabilitation can take significantly longer, and some degree of lameness will remain. The surgery is classified as of 2010 as a "salvage" operation - that is, a last resort for an otherwise viable animal. Success rates of around 80 - 85% (approximately 5 in 6) were being discussed by sources in 2005 and again in 2008.
There are also fewer options if the replacement fails, the main option being arthrodesis
Arthrodesis
Arthrodesis, also known as artificial ankylosis or syndesis, is the artificial induction of joint ossification between two bones via surgery. This is done to relieve intractable pain in a joint which cannot be managed by pain medication, splints, or other normally-indicated treatments. The typical...
(surgical fusion of the joint) which results in a pain-free but lame gait. However arthrodesis is itself a complex surgery with a long recovery time, and if arthrodesis is required, additional strain will be borne by other nearby joints, so other leg and shoulder conditions such as osteoarthritis may become more significant.
Grading for breeding purposes
The Orthopedic Foundation for AnimalsOrthopedic 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....
in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
will grade elbow X-rays of dogs intended for breeding.