69. Misc Ortho Dz Flashcards
define osteochonrodysplasia
type of constitutive bone/cartilage diseaseoften heritable=abN endochondral and/or intramembranous ossificationdwarfism (disproportionate or proportionate)
T/F most osteochondrodysplasias are disproportionate dwarfism
TRUE osteochondrodysplasias and nutritional deficiencies are disproportionate dwarfismUSUALLY dwarfism w disproportional SHORT limbs
Hemimelia
APPENDICULAR DYSOSTOSEScongenital complete or partial absence of one of more BONESusually unilateralnot always heritable (except Chihuahuas, DSH, Siamese)usually non painfulterminal (transverse, longitudinal)intercalary (transverse, longitudinal)
Hemimelia classification
terminal (transverse, longitudinal)-absence of all or some of the bones of a limb distal to a certain point . intercalary (transverse, longitudinal)-absence of all or some of the middle bones of a limb with the proximal and distal bones still present (middle one is missing)transverse: complete absence across the limbs widthlongitudinal: absence along the medial or lateral side of a limb
radial hemimelia
usually pre-axial (medial) intercalary longitudinalusually unilateral, marked varus, unable to bear weight, flexure deformitysurgery: declaw (palliative), arthrodesis + reconstruct radial defect (graft, distraction osteogenesis), amputate
dimelia
APPENDICULAR DYSOSTOSEScongenital duplication of the whole or part of a limbdog (not seen in cat)figure out which is nonfunctional and amputate it
ectrodactyly
APPENDICULAR DYSOSTOSEScongenital digital cleft formation extending between metacarpal bonesmost btwn 1 and 2 metacarpal bonesunilateral usually of thoracic limbs
polydactyly
APPENDICULAR DYSOSTOSESpresence of one or more extra digitspreaxial (medial); post axial (lateral)normal autosomal recessive trait in St Bernards, Collies—medial pelvic limb
syndactyly
APPENDICULAR DYSOSTOSESlack of ddx btwn two or more digits simple vs complexcomplete vs incomplete
HOD signalment and presentation
2-6 months of ageLarge -giant breed dogs (Weimaraners)Males are 2.3 times more likelyMetaphyseal swelling (distal RU and tibia most common)Often bilateral+/- pyrexia, pain, warmth
List pediatric bone diseases
–Hypertrophic osteodystrophy HOD–Panosteitis–Craniomandibular osteopathy–Retained ulnar cartilagenous core–Legg calve perches disease–Femoral capital physeal dysplasia–Multiple cartilaginous exostoses
Possible etiologies for HOD
Vitamin D insufficiency (scurvy)Heritable (Weimaraners 0.68 inherited immunodeficiency w low Ig)Infection (blood culture)Canine distemper virus
Pathognomonic radio graphic sign of HOD
Lucent line in the metaphysis parallel to a narrow zone of increased radiodensity immediately immediately adjacent to the physiscan also see see metaphyseal “flare” or widening of the bone
Panosteitis signalment and disease progression
Self limiting Inflammatory disease of the bone marrow of long bonesShifting leg lameness w long bone pain5-12 months - up to 5 YO (older than HOD)Large-giant breed Males 4:1eosinophilic inflammation!
Radiographic diagnosis of panosteitis
Early (rare)- decreased radiodensity evident in medullary cavity near nutrient foramen (changes in intraosseous pressure to increase with vascular congestion–maybe from protein accumulation)Later- increase in medullary opacity w granular pattern or w loss of the normal trabecular pattern+/- Periosteal bone formation as it progresses the medullary canal becomes more diffuse and homogenous
Treatment of panosteitis
RestAnalgesicsSelf limiting Benzopyron (not available) proteolytic substance to decrease intraosseous pressure+/- recurrence
Craniomandibular osteopathy CMO
<6-12 months of ageWest highland white terriers, cairn, Scottish terriersSuggests heritable causeUnilateral or bilateral symmetric irregular osseous proliferation of mandibles and/or temporal bonesPain, dysphagia or inability to eat/drinkSalivation Self limiting at 11-13 mo of agemale = female
Retained ulnar cartilagenous core
Viable hypertrophic chondrocytes that project from the distal ulnar growth plate into the distal metaphysis with failure to convert to metaphyseal bone. Can lead to ALD from radial bowing, elbow incongruity, carpal valgusradiolucent core (triangle) of cartilage distal to metaphysis +/- surrounded by a zone of sclerosisMay need surgical correction if severe
Legg calve perthes
Avascular necrosis of femoral headNo inflammatory local ischemiaSmall breed dogs– toys & terriers1. necrosis2. fragmentation (apple core)3. collapse/thickening 4. revascularize/reossification
how many bilateral presence of Legg Calve Parthes
12-17%
treatment for legg calve perthes
only 25% resolve lameness with conservative mgmt–FHO–THRpx 84-100% with surgery
signalment for slipped capital femoral epiphysis
through the growth platenontraumatic ( NOT SH 1 fracture)CATS–male neutered young overweight (may be related to early neuter and hypotestosteronism)often BILATERAL
multiple cartilaginous exostoses
young dogsold cats (FeLV)may or may not have malignant transformationmay occur from secondary migration of chondrocytes from the physis into metaphysissingle (osteochondroma) or multiple well circumscribed calcified lesionsaffects vertebra, ribs. long bones
most common reason for surgical excision of cartilaginous exostosis
vertebral exostosis causing spinal cord compression
causes of metabolic bone disease
–primary HPT–nutritional or renal secondary HPT–vit D toxicoses–hypo vit D (ricketts)–hypo/hyper vit A–hypovit E**most often affect Ca metabolism/homeostasis—osteopenia and brittle bones seen
osteogenesis imperfecta
metabolic bone diseasedisruption in collagen I
hypertrophic osteopathy
HO—older dogsassociated with neoplasia (abdominal, thoracic) can also be nonneoplastic (spirocerca lupin, heart worm dz)periosteal reaction of DISTAL (diaphyseal) extremities due to peripheral blood flow changes stimulating an overgrowth of vascular connective tissue and periosteal proliferation radiographs appear aggressive or nonaggressive. look for palisade formation of bone
disseminated idiopathic skeletal hyperostosis
spinal and extraspinal manifestation of heavy bone formationlimited spinal ROM1. continuous flowing calcification > 3 vertebra2. relative preservation of disc space3. periarticular osteophytosis around zygapophyseal joint4. pseudoarthrosis btwn spinous processes5. periarticular osteophytosis and calcification of soft tissuesneed 4 out of 5 to make dx
T/Fbone cysts are lined by epithelium
FALSEbone cysts are lined by fibrous connective tissueyounger larger breed dogs (male 2:1), Dobiesradiographs reveal expansile, locally aggressive lucent lesion with minimal to no periosteal reaction, most are eccentrically located, most involve metaphysis and diaphysis
acute caudal myopathy
limber tailpointers and labradorspainful at base of tail and tail is flaccidusually after extreme exertionself limiting but can recur
swimmer syndrome
flat-pup, turtle-pupneonates affectedsternal with splayed legspectus excavatumneed physical rehab in first 3 weeks, prognosis can be good
puppy carpal laxity syndrom
carpal hyperextension >180 degrees (dropped hock)OR carpal hypo extension < 180 degrees uni or bilateral; self limited +/- splints/braces65% recover in two weeks
normal flexion in carpus vs hypoflexion
flexion 20-30 degreeshypoflexion (older dogs) >30 degrees
iliopsoas muscle injury
attaches to lesser trochancter of femurdiscomfort on extension and internal rotation of hipneed rehab and rest +/- NSAIDssevere cases—tenomyectomy
