Ortho 1 Flashcards
what is the definition of primary osteoarthritis in cats? what is the most important risk factor?
caused by age, obesity (systemic factors), genetic predisposition.
age most important
what is the most common type of osteoarthritis in cats, primary or secondary?
primary
what is the definition of secondary OA in cats?
due to biomechanics factors affecting the joint (trauma, development abnormalities, instability, mechanical overload)
define primary OA in dogs.
due to genetics, age, systemic factors (obesity)
define secondary OA in dogs.
secondary to primary inciting cause.. a treatment needs to address primary cause
following injury or insult to affected joints (CCL rupture, articular fx or OC initiates biochemical cascade leading to arthritis)
which is more common in dogs, primary or secondary OA?
secondary
what are the most common C/S of OA in a dog?
lameness, reluctance to exercise, inactivity stiffness, pain, joint effusion, muscle atrophy, joint thickening, altered ROM, altered gait, altered behaviour
what are the most common C/S of OA in a cat?
most cats don’t show C/S recognized by owners!!!
more behaviour changes than clinical ones
changes in mobility, activity level, increased time spent resting, changes in social behaviour, increased vocalization, objection to being handled, changes in play and hunting, overall posture, pain on flexion and extension, crepitus upon manipulation of joint, muscle atrophy, joint thickening
client-based questionnaires or checklists regarding OA have been used in both research and clinical settings. What utility do these tools have?
provide a summative score that can assess severity of disease at outset and response to treatment
what PE findings are expected in a cat with OA?
gait changes (walking, jumping), pain on flexion and extension, joint effusion, crepitus, decreased ROM/ROM asymmetry, periarticular thickening/fibrosis, muscle atrophy
what PE findings are expected in a dog with OA?
gait abnormalities/changes, lameness, pain on flexion and extension, joint effusion, muscle atrophy, joint thickening, altered ROM
what are the radiographic signs of OA?
often nonspecific!
- osteophytosis/periarticular new bone formation
- enthesophytes
- subchondral bone sclerosis
- joint effusion
- ST swelling/thickening
- intra-articular mineralization/narrowed joint space
- cysts
- capsular or extra-articular mineralization
what are osteophytes?
outgrowth of bone at the margin of an articular surface
what are enthesophytes?
bone spurs forming at ligament or tendon insertion into bone; growing in natural direction of pull of ligament/tendon
what is the most valuable and cost-effective means to assess joint?
arthroscopy
do radiographic signs and C/S of OA always correlated? if no, then how do we interpret our findings?
no
complete systemic assessment is needed to rule out other metabolic abnormalities and provide a baseline before NSAID therapy
in cats with OA, treatment is often aimed at _______. why?
alleviating chronic pain
because arthritis is not dx in many cats until it’s advanced :(
tell me about the multimodal treatment options for feline OA
Pain relief:
- NSAIDs
- gabapentin, tramadol
- WEIGHT MGMT!!!
Joint supplements:
- essential fatty acids (DHA and EPA)
Chondroprotective agents:
- glucosamine and chrondroitin sulphate
Controlled exercise
Environmental mods
Rehab
Polysulfated glycosaminoglycans (PSGAG)
monoclonal antibodies (emerging)
surgery as a salvage procedure when medical mgmt doesn’t work
tell me about the multimodal medical treatment options for canine OA
WEIGHT LOSS!!!!
Exercise (low-impact)
nutrition (essential fatty acids = omega 3)
drugs:
- NSAIDs
- paracetamol/codeine (short term)
- oral opiates/tramadol (short term)
- gabapentin +amantadine
- corticosteroids
what is the most important therapy that all small animal owners can (and should!) offer their pets, regardless of financial situations, for OA?
WEIGHT MANAGEMENT!!!!!!!!!!
when is surgery considered in a dog with OA?
it is prolonged as long as possible until weight loss is maximized
what surgery do you do for a dog with OA?
total joint replacement
what is the typical signalment of panosteitis?
usually 5-12 mo, large breed dogs, males > females
possible <5mo to 5 years, possible in small dog breeds
how do you diagnose panosteitis?
PE: shifting leg lameness, pain on palpation of long bones
rads (diagnostic): circumscribed opacities in medullary canal (patchy opacities, “thumb prints”)
how do you treat panosteitis? what is the prognosis?
treatment does not influence outcome
pain mgmt (NSAIDs) and rest
feed complete and balanced diet (not too high in protein)
good to excellent
what is the typical signalment for hypertrophic osteodystrophy? (HOD)
2-6mo old, young rapidly growing Dogs, male>female, mostly large/giant breeds (but all can get it)
how do you diagnose HOD (hypertrophic osteodystrophy)? PE and diagnostic tests
PE: painful swelling of metaphysical long bones, often see systematic illness (fever, lethargy, inappetence, d+)
rads (diagnostic): Lucent line in metaphysial region parallel to physis = double physis
- periostea or endosteal reaction in physis region
- subperiosteal hemorrhage –> new bone formation, usually palisading along periosteum or bridging the physis
how do you differentiate between HOD and HO?
HO has deposition of periosteal new bone in distal extremities and long bones
how do you treat mild and severe cases of hypertrophic osteodystrophy (HOD)?
mild: supportive care + NSAIDs
severe: hospital, supportive care, opioids
basically, symptomatic therapy
typically improve in 7-10 days, bony changes improve over months
what is avascular necrosis of the femoral head? what is the typical signalment?
noninflammatory aseptic necrosis of the femoral head and neck in small breed dogs (toy breeds and terriers), 4-11mo
cause not well understood
how do you diagnose avascular necrosis of the femoral head? PE and tests
pe: mild to severe non-weight bearing lameness in pelvic limbs; mild cases may be subclinical; acute pelvic limb lameness in a small breed dog
rads (diagnostic):
- progressive radiopacity of lateral epiphyseal area of femoral head
- followed by lysis of femoral head (moth eaten, apple core appearance)
- flattening and lucency of the head
how do you treat avascular necrosis of the femoral head ?
this is a surgical disease… can help lameness with rest + NSAIDs, but ultimately they have to go to sx
femoral head and neck ostectomy or total hip arthroplasty (replacement)
what is the difference between multiple cartilaginous exostosis in cats and dogs?
dogs: young growing patients - exostosis appears + enlarges BEFORE skeleton matures (giant breed dogs)
cats: assoc w/ FeLV - exostosis appears AFTER skeleton matures
how do you diagnose multiple cartilaginous exostosis? PE and testing
PE: pain present if exostosis assoc with tendon, ligament, vessel, or spinal cord compression
rads (used as monitoring tool): single or multiple bony masses within cortex, medullary cavity confluent with host bone with distinct trabecular pattern
how do you treat multiple cartilaginous exostosis?
depends on size and location of lesions and C/S
non-sx: rest and NSAIDs
sx: indicated for single or large exostosis (esp w spinal cord compression)
what is the typical signalment for slipped capital femoral epiphysis?
cats > dogs
4.5-42 mo
maine coon, siamese
overweight neutered males
how do you diagnose slipped capital femoral epiphysis? PE and testing
PE: acute or chronic pelvic limb lameness, painful coxofemoral joint upon manipulation, inability to jump, 1/4 cases are bilateral
rads:
- widening and lateral displacement of capital femoral growth plate with progressive resorption and sclerosis of femoral neck
acute pelvic limb lameness in a cat
how do you treat slipped capital femoral epiphysis?
sx:
- if early: reduction with internal fixation
- if chronic: femoral head and neck ostectomy or total hip replacement
medical: rehab after hip replacement, sublingual buprenorphine or oral tramadol
what is osteochondrosis and what are the different types?
disorder of the ordered process of endochondral ossification. avascular necrosis of the developing epiphyseal cartilage
OC latens: early microscopic lesion
OC manifesta: subclinical lesions radiographically and clinically apparent
OC dissecans (OCD): if attached or loose cartilage flaps are present and typically causing C/S
what is the typical signalment of osteochondrosis dissecans? OCD
4-8 mo
males>females
large/giant breed dogs
can occur in small dogs and cats but not as common
how do you diagnose OCD? PE and testing
PE: consider in any young large/giant breed dog with lameness and swollen painful joints! Always look at contralateral joint bc often bilateral
rads (diagnostic):
- defects in subchondral bone
- flattening of contour
- sclerotic margins
- ± mineralization of cartilage flap
mainly at humeral head
how do you manage OCD non-surgically?
lean BCS, NSAIDs, exercise restriction, dietary supplements
how do you surgically manage OCD?
arthrotomy or arthroscopy
flap excision and joint mouse retrieval
palliative techniques: curettage, abrasion arthroplasty, Forage, micro fracture
restorative techniques: fragment reattachment, osteochondral translates (autografts)
what is the OCD prognosis based on location?
from best to worst:
shoulder
stifle, medial humeral condyle
talus
What is hypertrophic osteopathy? HO
periostea reaction of distal extremities
can be any bone and can be bilaterally symmetric
most often associated with primary or metastatic neoplasia
