Congenital And Developmental Lesions

sihirlifil's version from 2017-09-05 03:01


Question Answer
What is a common sequel to developmental disorders?Osteoarthritis especially if primary lesion involves joint, produces limb deformity
We often see lameness and degenerative changes first... why?Secondary changes are often more pronounced/mask primary lesion
Ameila/hemimeila=Completely or partially missing limb
Ectrodactyly=Missing central digit(s) of manus or pes ('split hand,' 'lobster claw')
Polydactyly=Excess # of digits (mostly cats)
Syndactyly=2 or more digits fused together
What does panosteitis look like?New medullary bone, focal increased density (thumb print)
Can be solitary, polyostotic, or multiple lesions in 1 bone, symmetrical or not
Where is panosteitis most pronounced?Near nutrient foramen
Periosteal new bone pattern for panosteitis:Smooth
How does panosteitis present?Lameness (can be shifting), painful on palpation
Signalment usually young male dog
When is panosteitis often detected?Radiographing hips in young dogs (incidental finding)
Prognosis of panosteitisGood (self-limiting, usually just tx pain)
Hypertrophic osteodystrophy (HOD) looks like?Second, more fuzzy 'second growth plate' in metaphyses (bilat symm), adjacent sclerotic band
HOD lysis associated with?Neutrophilic inflammatory response --> necrosis, hge, increased osteoclasts
Progression of HODEarly lytic zone (2nd growth plate) --> widening of lytic zone in metaphyses (+/- sclerotic rim of collapsed necrotic trabecular bone) --> extracortical cuff of bone forms in adjacent soft tissues --> repair of lytic lesion w/ normal bone tissue --> resolution of periosteal cuff of new bone
Does HOD progress slowly or rapidly?Rapid
CS of HODFebrile (systemic dz), painful, lame, swelling
(Possible etiologies of HOD)(Distemper, vit & min imbalance, sterile suppurative infxn)
Osteopetrosis caused by?Deficient osteoclastic resorption
Osteopetrosis looks like?Generalized increased bone opacity (mainly BM cavities)
Osteopetrosis associated with ___ in catsFeLV
What does the distal humeral epiphysis look like w/ osseous/osteochondral dysplasia?(underdeveloped) Rounded w/ sclerotic centers of bone formation (Prox radial & olecranon eip-apophyses normal)
What does the ulnar metaphysis look like w/ chondrodysplasia?Flared ((wide growth plate, small carpal bones)
Congenital hypothyroidism can cause?Delayed mineralization of the epiphysis of long and cuboid carpal bones
Osteochondrodysplasia: inherited in who? what's going on?Scottish Fold cat (autosomal dominant). Defective cartilage maturation
SFC osteochondrodysplasia: which bones?Mainly distal limb joints (--> bilat symm carpal & tarsal ankylosis)
Osteochondroma/multiple cartilaginous exostosis (MCE) = ?Benign proliferative dz
T/F Osteochondromas/MCE can affect any type of boneF. Only ones that develop via enchondral ossification
Osteochondroma/MCE: what's happening?Chondrocytes don't differentiate into osteoblasts, proliferate --> cartilaginous islands form and ossify (stops at skeletal maturity)
How does osteochondroma/MCE present clinically?Non-painful. Insignificant bony protuberances remain
Retained cartilage core usually affects which bone(s)?Distal ulna (seldom lateral femoral condyle)
What does retained cartilage core look like?Cone-shaped lucency in metaphysis +/- narrow sclerotic zone
Secondary problems of retained cartilage core?Can delay ulnar growth if large
2ry angular limb deformity, osteoarthritis in elbow/carpal joints
Incomplete ossification of the humeral condyle looks like?Hard to see on radiograph b/c superimposed w/ olecranon process (CT better)
Lucent line on CdCr projection from subchondral bone to the supracondylar foramen of the humerus
Incomplete ossification of the humeral condyle hereditary inSpaniels
T/F Physeal disturbances are more common in dogsT
Physeal disturbances lead to what? What does that result in?Premature closure of the growth plate (partial or complete) --> angular limb deformity
Severity of physeal disturbances depends onAge of patient
Which physis
Potential for growth of the physis at time of injury
Distal ulnar physis contributes _________% of total ulnar growth85%
Distal radial physis contributes _________% of total radial growth70%
Normal growth of the antebrachium needs ____ growth of radius & ulnaSynchronous
Joint incongruency leads toOsteoarthritis
Most common injured physis in dogs:Distal ulnar physis
How does injury to the distal ulnar physis usually occur?Salter Harris type V (compression)
Radiographic changes of ulnar physeal disturbanceShorter ulna
Cranial bowing of radius w/ thickened caudal cortex
Widened humeroulnar joint space
Carpal valgus
Anconeal process fail to fuse
Special about the feline distal ulnar physes?Not conical (so radius & ulna traumatized equally)
Radiographic changes of radial physeal disturbanceShorter radius
Widened radiohumeral joint space, distal sublux of radial head
Widened humeroulnar joint space w/ prox sublux of ulnar notch
Carpal Varus, inward rotation of manus
T/F Premature closure of proximal radial physis occurs more commonly than distalF (often doesn't cause angular limb deformity either!)
Cats are less likely to have physeal disturbances b/cTheir growth plates are not as conical
Transitional LS vertebrae: whats going on?Abnormal shape of L7
Variation in fusion of L7 & S1, sacrum/ilium
Lumbarization of S1 or sacralization of L7 (trying to be hybrids)
What is Legg-Calve-Perthes dz?Osteonecrosis of the femoral head
Legg-Calve-Perthes: usually in who?Small breed dogs 3-11m.o.
How does Legg-Calve-Perthes dz happen?Ischemic, aseptic necrosis of subchondral bone of the femoral head. Compromised blood supply to femoral capital epiphysis (vascular disturbance at round ligament)
Legg-Calve-Perthes looks likeUsually unilateral, deformed femoral head w/ decreased opacity, flattening of acetabulum, +/-subluxation
Cavity forms within necrotic bone
+/- 2ry pathological fracture
Osteochondrosis/OCD common in?Young, fast-growing, large-breed dogs w/ CS btw 6-9m.o.
Osteochondrosis/OCD: what's going on?Cartilage necrosis --> failure of normal endochondral ossification, abnormal cartilage growth (prolifeate but don't mature or calcify)
Osteochondrosis/OCD is more clinically significant happens in epiphysis (articular surface)
Osteochondrosis looks likeIndentation & flattening of subchondral bone, wide/irregular joint space, cartilage flap (not visible on rads!)
OCD looks likeSubchondral defect w/ sclerosis, irregular joint space
Mineralized chondral flap formed and separated
Flap can be freely moving in joint space (joint mouse) or re-attach to synovial lining
OCD usually occurs where?Shoulder, stifle, elbow, tarsus (humeral head, medial humeral condyle, (L) femoral condyles, femoral trochlea, (M) trochlear ridges of talus)
Usually bilateral
What happens to the opposed articular surface in OCD?"Kissing lesion" i.e. subchondral bone defect
What do you need to diagnose loose cartilage flap?Contrast arthorgram
Caution for diagnosing OC in femur?Don't mistake extensor fossa on distolateral femur for lesion!
Best projection to see OC/OCD of elbowCraniolateral-caudomedial oblique
L or M humeral condyle most often affected by OC/OCD?M
L or M femoral condyle most often affected by OC/OCD?Both but usually L (& also femoral trochlea)
Secondary problems of OC/OCD?Joint effusion, 2ry osteoarthritis/DJD
Widening of joint space (talus)
L or M trochlear ridge of talus most often affected by OC/OCD?M (usually prox & plantar)
Lumbosacral osteochondrosis: mostly who? Whats going on?Young male german shepherds, boxers, rottweilers; CS >18m.o.
Fragmentation of craniodorsal margin of S1 (rarely caudodorsal L7), some sublux at joint

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