Developmental Orthopedic Disease Flashcards
What is the most common signalment for panosteitis? What is the pathophysiology?
male young, large breed dogs of 5-14 months (and Basset Hounds)
inflammation and increased osteoblastic/fibroblastic activity results in fibrosis and mineralization in the medullary cavity
What is the most common imaging finding associated with panosteitis?
medullary cavity will have increased opacity usually by the nutrient foramen —> usually more lucent due to the presence of fat and trabeculae
What 3 species of dogs typically develop osteochondrosis (osteochondritis dissecans)?
- Labrador Retrievers
- GSD
- Rottweilers
(rapidly growing, medium/large breeds)
What is the pathophysiology of osteochondrosis (osteochondritis dissecans)?
failure of endochondral ossification causes the epiphyseal cartilage to become too thick, leading to decreased synovial fluid diffusion, avascular cartilage, and cartilage necrosis
- typically results in the development of clefts or fissures from subchondral bone to articular cartilage surface
How do patients with osteochondrosis (osteochondritis dissecans) present?
lamenss —> typically bilateral, so both limbs should be evaluated
What are the 3 imaging features of osteochondrosis (osteochondritis dissecans)? What 4 joints are most commonly affected?
- flattening of subchondral bone
- regional sclerosis
- mineralized osteochondral fragment (dissecans) dissected away from the articular surface
- humeral head
- humeral trochlea
- femoral condyles
- medial trochlear ridge of talus
What imaging features of osteochondrosis (osteochondritis dissecans) are present in this radiograph?
- flattened subchondral bone
- increased opacity of subchondral bone
- regional sclerosis
- flapping + thin mineral fragments
What patients most commonly present with hypertrophic osteodystrophy? What bones are most affected?
rapidly growing, large and giant breeds from 3-7 months of age
distal radius/ulna
What is thought to be the etiology of hypertrophic osteodystrophy? How do patients present?
viral etiology —> distemper (vaccine)
systemic disease - fever, lethargy, diarrhea, nasal discharge, lameness, swelling
How does hypertrophic osteodystrophy initially look on radiographs? How does it develop?
pseudophyseal lines = “double physis” (bilaterally symmetrical)
- collar of extra-cortical bone with surround the metaphysis toward the diaphysis, separated by a radiolucent line and superimposing over the distal metaphysis
- collar will eventually fuse with the cortex and remodel, becoming sclerotic
What is hypertrophic osteopathy? What is the most common radiographic sign?
osseous change that occurs secondary to a thoracic or abdominal mass
pallisading periosteal reactions starting distally and moving proximally, typically starting on the abaxial surfaces of metacarpal/metatarsal 2/5 (bilateral, spares joints)
What are the main differences between hypertrophic osteodystrophy and osteopathy?
OSTEODYSTROPHY - young, growth disruption/endochondral ossification, early lucencu in metaphysis with double physis, later periosteal bone, angular limb deformity
OSTEOPATHY - older, pulmonary or urinary bladder masses, always periosteal new bone with increased opacity
What dog breed most commonly develops retained cartilage cores? What is the pathophysiology?
giant breeds —> Irish Wolfhounds 4 months and older
temporary inadequate blood supply to metaphysis causes a central core of cartilage to not transform into bone, commonly resulting in angular limb deformity
What are the 2 most common imaging findings in patients with retained cartilage cored?
- triangular, “flame-like”, radiolucent wedge in distal metaphysis of ulna
- cranial bowing of the radius due to premature closing of the ulnar physis
What is the most common cause of angular limb deformities?
asynchronous growth of long bones or aberrant forced
- early physeal closure of one bone and not the other
(distal ulnar physis is responsible for 80% of lengthening)
What are the 3 most common causes of angular limb deformities?
- genetic in chondrodystrophic breeds, like Dachshunds and Lhasa Apsos
- traumatic injury to physes
- medial patellar luxation
What is the pathophysiology of angular limb deformities? What 2 deformations result?
injury or interruption of the physis results in the premature closure or asynchronous growth of long bones
- VALGUS = lateral deviation of digits and carpus/tarsus relative to the distal antebrachium/crus
- VARUS = medial deviation of the digits and carpus/tarsus relative to the distal antebrachium/crus
What are 2 imaging findings seen in this radiograph of an angular limb deformity?
- retained cartilage core (likely cause of premature physis closure)
- lateral deviation of carpus
What are 2 imaging findings seen in this radiograph of an angular limb deformity?
- premature closure of distal ulnar physis
- cranial bowing of radius
What is the congenital malformation, agenesis? What bones are most affected?
hypoplasia of bone, resulting in complete or partial absence of the bone or abnormal bones
radius, ulna, tibia
Classify the developmental orthopedic diseases seen in these radiographs:
- osteochondrosis
- panosteitis
- hypertrophic osteodystrophy
- angular limb deformity
