Bone Flashcards
How many days between osteoid formation and mineralization?
12-15 days
What are the main functions of the skeletal system?
Support Protection Movement facilitation Mineral storage Storage of hematopoietic tissue Lipid storage for energy
Physis
growth center for diaphysis
What disease has a predilection for the Epiphysis?
Osteochondrosis
Osteophytes
What disease has a predilection for the Physis?
Fractures
Premature Closure
What disease has a predilection for the Metaphysis?
Osteosarcoma
Hematogenous infection
Hypertrophic Osteodystrophy
What disease has a predilection for the Diaphysis?
Panosteitis
Fractire
What cells are found in the endosteum and periosteum?
Osteoprogenitor cells
What is the function of the Osteoprogenitor cells?
Remodeling and growth of bone cortex
Responisible for Osteogenesis during fracture repair
Where does intramembranous ossification take place?
Flat bones of skull
Metatarsal sequestrum
causes by disruption of periosteal bone supply with subsequent necrosis due to poor communication with endosteal blood supply
What develops from a sequestration that is not absorbed by the body?
Fistulous tracts
Wolff’s Law
Bone will respond to the stresses or strains placed or not placed on it
OC
Osteochondrosis
OCD
Osteochondrosis Dissecans
Osteochondrosis and Osteochondrosis dissecans
failure of endochondral ossification
Where is the predication site for Osteochondrosis and Osteochondrosis dissecans in dogs?
Caudal Humeral head
Medial humeral condyle
Lateral and medial femoral condyle
Lateral and medial trochlea of talus
What are the radiographic signs for Osteochondrosis and Osteochondrosis dissecans?
Flattening or concavity of subchondral bone
Adjacent sclerosis
+/- mineralized flap
Joint Fragments (Mice)
Necrotic cartilage breaks free and attaches to synovium and becomes vascularized
Dysplasia
Failure to develop properly
What are the triad of developmental lesions of the elbow?
Ununited anconeal process
Fragmented medial coronoid
Osteochrondrosis of humeral condyle
What are the three types of Incongruity?
Radioulnar length mismatch
Humeroulnar incongruity
Radioulnar incisure incongruity
What is more accurate than radiographs in measuring incongruity?
CT and arthroscopy
What is the treatment for Ununited Anconeal process?
Removal
Fixation + Ulnar osteotomy
What are the radiographic signs of a fractured Medial Coronoid Process?
New bone formation on proximal aspect of anconeal process
Poor definition of cranial margin of medial coronoid process on lateral view
Medial coronoid process is blunted or rounded
Joint incongruity
Subchondral sclerosis of ulna trochlear notch
Secondary DJD
What are the radiographic signs of Panosteitis?
Increased Medullary opacity
Lesion begins at nutrient foramen
Smooth continuous periosteal new bone occurs in a minority of patients
Cortical thickening can persist - remodeling
What are the clinical signs of Hypertrophic Osteodystrophy?
Pyrexia
Malaise
Pain + swelling over metaphyseal region
Lameness
What are the radiographic signs of Hypertrophic Osteodystrophy?
“Double Physis” Sign
Begins in metaphysis of tubular bones
irregular periosteal new bone formation along metaphysis
Physeal closure or retarded growth
What breeds do you see Aseptic Necrosis of Femoral Head?
Adolescent Toy and Small breed dogs
Aseptic Necrosis of Femoral Head (Legg-Calve-Perthes)
Compromised blood supply of femoral head causes bone necrosis while overlying cartilage continues to grow
Phagocytosis of necrotic bone during healing results in decreased opacity
Incomplete removal of necrotic bone and invasion of granulation tissues interferes with healing
Bone is weak and subject to microfracture
What are the Radiographic signs of Aseptic Necrosis of the Femoral Head?
Lysis of femoral head/neck
Widening of joint space due to hyperplastic cartilage
Microfracture and deformation of femoral head
Secondary DJD and muscle atrophy
