Luxation
COMPLETE dislocation of a joint
Subluxation
PARTIAL dislocation of a joint
Patellar luxation
DOGS & horses RARE in other species Can be an anatomical defect INHERITED = polygenic (multiple genes) = do NOT breed animals!
Medial patellar luxation
75% of cases
Common in SMALL dogs
Lateral patellar luxation
Common in LARGER dogs
Patellar luxation in horses
LESS common than in dogs
Usually LATERAL
Associated with a shortened lateral ridge of the femoral trochlea
Hip Dysplasia
Large DOGS & cattle RARE in other species Except Norwegian Dole horse INHERITED = polygenic (multi genes) Normal at BIRTH Certify dogs at 2 yr Acetabulum = shallow, wide, distorted Modification of the femoral NECK ULCERATION of femoral head Periarticular osteophytes
What is the official name for Hip Dysplasia?
Acetabular dysplasia
What can hip dysplasia be manifest from?
Osteochondrosis
What are periarticular osteophytes?
Boney projection along joint margins
Hip Dysplasia (cattle)
Only affects MALES
Esp. Herefords & beef breeds
Recessive & sex limited inheritance
Arthrogryposis
Persistent flexure of contracture of a joint
May be linked to defects in neural tube closure
LOSS OF MOTION of the fetus during development
Also = cleft palate, scoliosis
Joints & tissues are NORMAL
Osteoarthrosis
Degenerative disease WRONG name = osteoarthritis NOT driven by inflammation Injury to cartilage or subchondral bone Repetitive movemnt degeneration
In what species is osteoarthrosis common?
HUMANS!
Primary degenerative arthropathy
Cause = UNknown
MORE common in HUMANS
Secondary degenerative arthropathy
Cause = KNOWN
More common in ANIMALS
What joints are most affected in degenerative disease?
LARGE joints
Areas of cartilage that bear the most stress
What do the lesions in degenerative joints look like?
Loss of articular cartilage Eburnation = smoothing of bone surface Increase thickening of subchondral bone Presence of osteophytes Thickened joint capsule (fibrous) Villous proliferation of synovium Common in the MEDIAL aspect
What is eburnation?
Loss of articular cartilage
What does degenerative joint disease lead to?
Chronic osteoarthritis
Ringbone
HORSE = common
Interphalangeal joints
Osteophytes & loss of articular cartilage
Bone spavin
HORSE = common
Intertarsal joints
Osteophytes & loss of articular cartilage
Navicular disease
HORSE = common
Located on navicular bones
Osteophytes & loss of articular cartilage
Arthropathy of Canine Shoulder
VERY common = 80% older dogs Bilateral = both sides Typical pathology of joint degeneration Bad = dogs bear 70% of body weight on shoulders Osteochrondrosis = YOUNG dogs
Arthropathy of Bovine Stifle
DAIRY cattle
Esp. Holsteins & Jerseys
Lameness and muscle atrophy
Most common on medial aspect distal femur
Intervertebral disk degeneration
DOGS
Usually affects MALES
3-6 yr old
What is the anatomic structure nucleus pulposus?
Remnant of notochord
Gel in the middle of the disc
What is the anatomic structure annulus fibrosus?
Lamellated fibrous ring
Outer ring around the disc
What happens in a disk prolapse?
Complete rupture of the annulus fibrosus
What dogs are at risk for IDD at a young age?
Chondrodystrophic breeds
= Dachshund & Pekingese
Degeneration of NUCLEUS pulposus
Massive COMPLETE rupture
What dogs are at risk for IDD in old age?
Normally proportioned breeds
Fissures in the ANNULUS fibrosus
PARTIAL rupture and bulding of disk
Where is IDD more common & why?
Thoracolumber region
Less mobile than other regions of the spine
What direction do most displacements occur?
Dorsally
What is special about beagles and IDD?
Cervical protrusions are more common
Spondylosis
Osteophytes develop at intervertebral spaces
May form complete bridges
Bulls, pigs & dogs = abult SOWS
Usually seen first as FRACTURE of vertebral bodies
What is ankylosis?
Abnormal immobility and consolidation of a joint
Occurs with spondylosis