Bone

Bone

1. cells

   • Osteoblast
     • Osteocyte
     • Receptors
       • Vit D, PTH, estrogen, cytokines and GF
     • RANK and OPG
       • RANK: stimulate osteoclast formation OPG: inhibit osteoclast function. 
   • Osteoclast
     • From macrophages effect bone resorption Have RANK and OPG receptors 

2. Bone dx

   • X-rays
     • Worm eaten lytic lesion sequestrum and involucrum
       • osteomyelitis
     • dense opaque and solid tubular bone
       • osteopetrosis
     • 30% bone loss
       • osteoporosis
     • "cotton wool" and thickening of cortices
       • Paget dx
     • Ground glass opacity; tapered expansion; blending borders; incorporates cortex
       • Fibrous dysplasia
     • Beaten copper skull
       • Hypophosphatasia
     • sunburst appearance
       • Expansile radiolucent/radiopaque mass that pushes out periosteum; 
       • osteosarcoma
     • lytic lesion; cortex onion skinning
       • Ewing Sarcoma
     • Moth eaten lytic radiolucencies
       • metastatic deposits
   • histology
     • Sequestrum and Involucrum w/ resorbing and necrotic bone masses ; pus marrow
     • Mosaic bone / prominent reversal lines and vascular marrow space w/ large osteoblast and class
     • cellular fibrous spindly storm and woven bone matrix w/ osteoblastic rimming. Trabeculae form w/o regard to physiologic demand "Chinese letter" or "animal crackers"
     • Malignant cells must produce bone and cartilage
     • osteoblasts producing bone
       • osteoid osteoma and osteoblasto
   • Dental sx
     • Extraction
       • Osteomyelitis
     • Dentinogenesis imperfect
       • osteogenesis imperfecta
     • Jaw osteonecrosis
       • aseptic necrosis
     • Maxilla expansion
       • Paget dx
     • Enamel hypoplasia
       • ricket
     • Elongated pulp horn at DEJ
       • Vit D resistant rickets
     • Widen pulp canals; early deciduous tooth loss b/c lack of cementum
       • hypophosphatasia
     • Brown tumor of jaw; loss of lamina dura
       • hyperparathyroidism
     • large tumor could occur in the jaw
       • osteoblastoma
     • Never occur in jaw
       • chondroma & chondrosarcoma & giant cell tumor
   • clinical sx
     • extraction, blood sickle cell anemia;TB, Gummas, and actinomycosis
       • Osteomyelitis
     • Blue Sclear and broken ribs
       • OSsteogenesis imperfecta
     • myelophthisic anemia; solid bone; deafness and blindness
     • elder, w/ decrease bone mass but normal collagen and mineralization
       • osteoporosis
     • Wedge shape infarct of medullary subchondral bone w/ pain on movement and unsupported articular cartilage
       • aseptic necrosis
     • increase thickness of weak bone; pain; increase hat size; maxilla expand; bowing legs; spinal compression fractures; deafness and blindness
       • Paget dx
     • firm, painless, slowly growing bony expansion in childhood and stop after puberty; fusiform expansion of bone; weak and deform bone; common in jaw, skull, long bone and ribs.
       • fibrous dysplasia
     • Bowed legs, pigeon breast
       • Rickets
     • deranged remodeling of already formed bone
       • osteomalacia
     • resemble Ricket
       • Vit D resistant rocket and Hypophosphatasia
     • Gardner sx
       • Osteoma
     • Pain can be relief by aspirin vs. Can't
       • osteoid osteoma and osteoblasto
     • deafness and blind
       • osteopetrosis
       • paget dx
   • genetic dx
     • osteogenesis imperfecta
     • paget dx (germline mutation
     • vit D resistant ricket (x-linked)
     • hypophosphatasia
   • weak bone/ thin trabeculae
     • osteoporosis
     • paget dx (increase weak bone
   • solid bone
     • osteopetrosis
   • bisphosphate
     • osteoporosis
     • breast cancer
     • myeloma
     • paget dx

3. knee

   • osteosarcoma