Juvenile musculoskeletal Disease Flashcards
Radiographic Opacities
Air → fat → ST and fluid → bone → metal
lucent to opaque
Degenerative Joint Disease (DJD)
Osteroarthritis/ osteoarthrosis
Common: intra-capsular ST, osteophytes, enthesophytes
Osteophytes
Physiologic attempt to stabilize joint
Outgrowth of the bone at the margin of the articular surface (within joint capsule)
Osteophytes pathophysiology
Abnormal joint cartilage loading → cartilage wear/loss → development of osteophytes
Enthesis
Origin or insertion of a tendon, ligament or joint capsule to bone
Enthesophytes
New bone formation at the enthesis
Secondary to chr. strain, trauma or previous avulsion
Juvenile musculoskeletal classifications
Osteochondrosis
Panosteitis
Hypertrophic osteodystrophy
Elbow/ hip dysplasia
Acquired musculoskeletal classifications
Fractures
Neoplasia
Osteochondrosis (OC)
Abnormal endochondral ossification → thickened cartilage that’s susceptible to injury
Commonly leads to DJD
Signalment of dogs with OC
Young rapidly growing large breed dogs
Radiographic findings of OC
Flattening of subchondral bone
Surrounding subchondral bone sclerosis
Mineralized cartilage flap (Joint mouse)
Kissing lesion
Joint effusion
Osteochondritis Dissecans (OCD)
Separation of the abnormal flap of cartilage from the subchondral bone
OC v OCD
OCD: usually cannot determine from survey rads and mineralized cartilage flaps ARE seen
Common sites for OC
Shoulder (cd femoral head)
Elbow (medial aspect of humeral condyle)
Stifle (Lateral femoral condyle)
Taurus (medial ridge of talus)
Panosteitis
Self-limiting dz
Affects the bones of young, large breed dogs (shepherds, danes, rotties, labs, retrievers)
Males most commonly affected
Early rad findings of panosteitis
↑ intramedullary opacity (diaphysis near nutrient foramen)
Blurring of trabecular pattern
Medullary opacities delineated (patchy sclerosis)
smooth periosteal reaction
Hypertrophic Osteodystrophy (HOD)
Long bones affected in large rapidly growing dogs
Self-limiting, if severe → premature physeal closure
Radiographic findings of HOD
Bilaterally symmetrical lesions
Commonly affects the metaphyses of the distal radius, ulna and tibia
Early stage of HOD
ST swelling adjacent to physis
Linear irregular lysis adjacent and parallel to physis (double physis signs)
Intermediate stage of HOD
Marked metaphyseal periosteal reaction due to sub-periosteal hemorrhage
Late stage of HOD
Periosteal new bone blends with cortex and remodels to normal shape
Retained Cartilage Core
Disruption of normal endochondral
Temporary inadequate blood supply to metaphysis → central core of cartilage not transformed to bone
Where is retained cartilage core most common?
Large breeds
Incidental finding (distal ulna metaphysis)
Radiographic findings of retained cartilage core
Cone-shaped radiolucent area
Narrow zone of adjacent sclerosis
What are the developmental conditions of elbow dysplasia
Ununited anconeal process (UAP)
Fragmented medial coronoid process
Osteochondrosis of the medial humeral condyle
Joint incongruity (asynchronous growth of radius/ ulna)
all 4 don’t have to be present, + DJD, usually bilat
Radiographic findings of Ununited anconeal process
Radiolucent between anconeal process and olecranon in dogs older than 5m
DJD present
Fragmented Medial Coronoid Process (FMCP)
Most common developmental disorder (bilat)
Degenerative changes and no evidence of UAP or OC
Difficult to visualize fragment on rads (CT needed)
Sometimes the cranially displaced fragment of FMCP is found on the __________ view
Lateral
Radius/ ulna normal growth
Ulna has only one physis distal to the elbow (predisposed to damage), radius has 2
Growth from ulna physis must equal the growth from both radial physes
Possible sequelae to premature closure of the ulnar physis
Humeroulnar subluxation
Radius curved (bowed radius)
Whys is the distal ulnar physis susceptible to trauma?
Conical shape
How do you tx the asynchronous growth of radius/ ulna
Ulnar osteotomy
cuts through ulna releasing pressure then IM pen placed → radius grows and straightens up
Hip dysplasia
Abnormal development of the coxofemoral joints → DJD
Large breeds, bilat and inherited
Normal femoral head
Articular margin between the acetabulum and femoral head should be parallel
50% of head covered by acetabulum
Femoral neck narrower than head with smooth margin
What are the big things found with hip dysplasia
Acetabular coverage
Congruity along cr. 1/3 of joint
DJD
Radiographic findings of hip dysplasia
Morgan line
Thickening of head and neck 2nd to osteophytosis
Osteophytosis of the cr. and cd. acetabular rim
Flattening/ Sclerosis of acetabulum
Subluxation of coxofemoral joint
Morgan line
Cd. curvilinear enthesophyte
Early indicator of osteoarthosis secondary to coxofemoral joint laxity
Other names for Avascular necrosis of the femoral head
Aseptic necrosis or legg-calve-perthes dz
Loss of blood supply to the proximal epiphysis
Signalment of avascular necrosis of the femoral head
Mini and toy breeds
4-11m
Bilat (less than 50% of the time)
Early rad findings of avascular necrosis of the femoral head
↑ radiolucency of the femoral head
Later rads findings of avascular necrosis of the femoral head
↑ joint space width
Flattening/ collapse of the femoral head
Shortening and widening of the femoral neck
Secondary DJD
Patellar luxation
Small breeds
Medial: congential/ developmental, small breeds
Lateral: rare
