Developmental Bone Diseases (27) Flashcards
Dr. Gilley
Which bone diseases discussed are primarily inflammatory?
paneosteitis
hypertrophic osteodystrophy (HOD)
What is the definition of panosteitis?
disease of young dogs causing lameness, bone pain, endosteal bone production, and occasional periosteal bone production
What kind of inflammatory response is canine panosteitis?
eosinophilic
What can potentially cause canine panosteitis?
“osseous compartment syndrome” - protein rich, high calorie diet
What is the pathophysiology of panosteitis?
excessive protein = intraosseous edema
secondary increased medullary pressure and ischemia
endosteal bone formed as marrow invaded by bone trabeculae
What is the signalment of canine panosteitis?
- male large breed dogs
- young dogs < 2
What clinical signs does a dog have with panosteitis?
- shifting leg lameness
- pain on deep bone palpation
Upon physical examination, what would you see with canine panosteitis?
single leg or multiple leg involvement
severity of lameness varies
pain on direct palpation of affected bones
What should you do if you don’t see panosteitis on radiographs?
clinical signs may precede radiographic changes by up to 10 days
repeat radiographs in 7 to 10 days
What are radiographic findings with panosteitis?
- widening of nutrient foramen
- intramedullary opacity - radiopaque patchy or mottled bone
- endosteal thickening
- periosteal new bone
Disease?
canine panosteitis
What is treatment for canine panosteitis?
- NSAIDs
- exercise restriction
- warn owner of recurrences
self-limiting
What is the definition of hypertrophic osteodystrophy?
disease causing disruption of metaphyseal trabeculae
long bones of young rapidly growing dogs
What can HOD have an association with?
- recent GI/respiratory problem
- possibly relationship with distemper virus vaccination
What is the pathophysiology of hypertrophic osteodystrophy?
- disturbance of metaphyseal blood supply
- no bone formed on calcified cartilage
- osteoclastic resorption of recently formed metaphyseal trabecular bone
How does the disturbance of metaphyseal blood supply happen with HOD?
- changes in physis and adjacent metaphyseal bone
- delayed ossification of physeal hypertrophic zone
- widening of physis + hypertrophied chondrocyte zone
What kind of inflammatory response is HOD?
neutrophils and mononuclear cells
What is the signalment for those with HOD?
- young rapidly growing large breed dogs
- males affected over female
- 3 to 4 months old, early as 2 months
- Weimaraners
What are clinical signs of HOD?
- acute onset of lameness
- may be severely affected
- diarrhea
- inappetence and lethargy
What might you see upon physical examination of a dog with hypertrophic osteodystrophy?
- mild to severe lameness on all four limbs
- long bone metastases swollen warm and painful on palpation
- swelling on all four limbs
- forelimb swelling may be more obvious
What are radiographic findings of a dog with HOD?
irregular radiolucent line metaphyseal side of physis
“double physis”
Identify the growth plate and osteolysis for this hypertrophic osteodystrophy case
A = active physis
B = osteolysis in metaphyseal side attributed to neutrophils and monocytes with cytokine production
What is treatment for HOD - mild cases?
self-limiting - focus on supportive treatment
analgesics to control pain - NSAIDs +/- opioids in mild cases
What is treatment for HOD - severe cases?
require I.V. fluid support
- corticosteroids, antibiotics, vitamin C
not proven to shorten disease course of severity
rule out bacteremia beforehand!
What is the prognosis for HOD?
most recover fully in 7 to 10 days; relapses may occur
severe debilitation or multiple severe relapses - euthanasia
What is a retained ulnar cartilaginous core?
- cones of growth plate cartilage
- project from distal ulnar growth plate into distal metaphysis
aka retained endochondral cartilage core
retained hypertrophic chondrocytes
If a retained ulnar cartilaginous core is associated with reduced ulnar length growth, what can occur?
carpal valgus - may be identical to premature closure of distal ulnar and radial growth plates
What disease can this be attributed to?
retained ulnar cartilaginous core
What is the signalment of someone with retained ulnar cartilaginous core?
large to giant immature canines
What do you see on radiograph with retained ulnar cartilaginous core?
radiolucent core (triangle) of cartilage in distal ulnar metaphysis +/- sclerotic zone
core can extend 3-4 cm into metaphysis
What is treatment of retained ulnar cartilaginous core - no deformity?
no treatment, usually resolves with a well-balanced diet
What is treatment for retained ulnar cartilaginous core - moderate to marked forelimb deformities?
surgical correction of deformity
well-balanced diet
What is Legg-Calve-Perthes Disease?
noninflammatory aseptic necrosis of femoral head - “avascular necrosis of femoral head”
What is the signalment of someone with Legg-Calve-Perthes Disease?
young patient - before capital femoral physis closure
What is the pathophysiology of Legg-Calve-Perthes Disease?
collapse of femoral epiphysis - caused by interruption of blood flow
How does collapse of femoral epiphysis caused by interruption of blood flow happen with Legg-Calve-Perthes Disease?
- vascular supply to femoral head comes from epiphyseal vessels - (metaphyseal vessels do not cross physis to contribute to femoral head vascularity)
synovitis or sustained abnormal limb position can increase intra-articular pressure and collapse the fragile veins which inhibits blood flow
What is the function of epiphyseal vessels?
course along femoral neck surface, cross growth plate, and penetrate bone
supplies nourishment to femoral epiphysis
What can cause Legg-Calve-Perthes Disease?
synovitis or sustained abnormal limb position
What happens with Legg-Calve-Perthes Disease when there is a hypoxic event?
cell death and reparative process begins
bone substance weakened during revascularization
What is the signalment for Legg-Calve-Perthes Disease?
- young, small breed dogs
- 6 to 7 months old
- males AND females
- sometimes bilateral
What is the clinical presentation for Legg-Calve-Perthes Disease?
slow onset of weight bearing lameness worsens over 6 to 8 weeks, may progress to NWB
may present as acute onset of lameness due to the sudden collapse of the epiphysis
chewing at skin over hip
What can you find with Legg-Calve-Perthes Disease upon physical examination of someone who has it?
- hip joint pain
- limited range of motion, crepitus
small dogs may have concurrent bilateral medial patella luxations
What do you see with radiographs and Legg-Calve-Perthes Disease?
femoral head deformity
femoral neck shortening and/or lysis
foci of decreased bone opacity within femoral epiphysis
How do you treat Legg-Calve-Perthes Disease - early stages before collapse of femoral head?
limited weight bearing on limb during revascularization to prevent collapse of femoral head
conservative treatment NSAIDs
How do you treat Legg-Calve-Perthes Disease - after collapse of femoral head?
surgery - excision of femoral head and neck (FHO)
What is post-operative care for someone who had a surgery to correct Legg-Calve-Perthes Disease?
- limb usage immediately after surgery
- NSAIDs to reduce pain and encourage early function
- passive flexion-extension of hip 2x daily
- physical therapy
What is the prognosis for someone with Legg-Calve-Perthes Disease?
good after FHO
slight intermittent lameness
can have complications
