2. Intramembranous Ossification:
Mesenchymal cells within embryonic connective
tissue
Proliferates
Early Mesenchymal condensations
Differentiate directly
Osteoblasts
3. Mesenchymal Condensation
Cartilage Anlage (Model)
Bone Collar
Mesenchymal Cells Differentiate Into
Prechondroblasts And Chondroblasts & Later In To
Chondrocytes
Calcification Of Bone Collar – Osteoclasts & Blood
Vessels, Enter Primary Ossification Center
4. Osteoclast Invasion And Wave Of Resorbing
Activity
Removal Of Calcified Cartilage
Woven Bone- The Primary Spongiosa
Further Remodeling -Woven Bone And The
Cartilaginous Remnants
Replaced With Lamellar Bone
The Mature Trabecular Bone- Secondary
Spongiosum
5. Growth in Bone Shape and Diameter
(Modeling)
During Longitudinal Growth Of A Long Bone,
Continuous Resorption By Osteoclasts Beneath
Periosteum
Progressively Destroys Lower Part Of Metaphysis
Transforming It Into Diaphysis
6. Dysplasias
Osteopetrosis
Pyknodysostosis
Craniotubular dysplasias
Craniotubular hyperostoses
Metabolic
Renal osteodystrophy
Poisoning
Chronic hypervitaminosis A
Idiopathic
Caffey's diesase (infantile cortical hyperostosis)
Idiopathic hypercalcemia of infancy
Lead
Fluorosis
Hypervitaminosis D
7. Dysplasias Of Endochondral Ossification
(Primary Spongiosa)
Failure In Resorption & Remodeling Of Primary
Immature Spongiosa By Osteoclasts
Accumulation Of Calcified Cartilage Matrix Packing The
Medullary Cavity
- Osteopetrosis
- Pyknodysostosis
Target sites: tubular & flat bones, vertebrae, skull
base, ethmoids, ends of clavicle
8. Defective Carbonic anhydrase function
Lack of alkaline environment for osteoclast
function
Defective osteoclast function
Types
Infantile autosomal recessive osteopetrosis
Benign adult autosomal dominant osteopetrosis
14. A lysosomal disorder due to genetic deficiency in
Cathepsin K
Short stature particularly limbs
Delayed closure of cranial sutures
Frontal and occipital bossing
Nasal beaking
Obtuse mandibular gonial angle with relative
prognathism
Segmentation defects
19. Hyperirritability
Soft tissue swelling
Cortical thickening
Bones commonly
affected mandible,
ribs, clavicle, ulna,
any long bone but not
spine
21. Diagnosed as an incidental finding
Monostotic, Monomelic, Or Polyostotic
Sclerotomal distribution
Dripping wax appearance or flowing candle wax
appearance
26. Group of diseases
Too many of certain types of cells made
in the bone marrow
Fibrosis of the bone marrow with
extramedullary hematopoiesis
27. Chronic myeloproliferative diseases e.g. essential
thrombocytopenia and polycythemia vera and
chronic neutrophilic, eosinophilic, and myeloid
leukemia
Acute myeloid leukemia & lymphocytic leukemia
Hodgkin's disease & non-hodgkin's lymphoma
Hairy cell leukemia
Multiple myeloma
28. Fatigue, Weight Loss
Easy Bruising And Bleeding
Fever, Night Sweats
Splenomegaly
Gout And Renal Colic Due
To Hyperuricemia
29. Replacement of the normal
marrow cavity with fibrous tissue
with no trabecular or cortical
disorganization
30.
31.
32.
33.
34. A superscan
appearance -
intense symmetric
activity in the
bones with
diminished renal
and soft tissue
activity on a Tc99m
diphosphonate
bone scan
35.
36. Musculoskeletal abnormalities secondary to
chronic renal failure, due to concurrent and
superimposed
Osteomalacia (adults) / rickets (children)
Secondary hyperparathyroidism (abnormal
calcium and phosphate metabolism)
◦ Bone resorption
◦ Osteosclerosis
◦ Soft tissue & vascular calcifications
◦ Brown tumours
Aluminum intoxication
37. Osteopaenia : Early, thinning of cortices
and trabeculae
Salt and pepper skull
Subperiosteal resorption : on radial aspects
of middle phalanges of index and long
fingers
Rugger-jersey spine
Demineralization
Soft tissue calcification
38. Renal failure - phosphate retention
Subsequent hyperplasia of parathyroid gland chief
cells
Decrease in serum calcium and an increase in
serum parathyroid hormone
Acts on kidneys
39. Increased osteoclast
activity - release of calcium from bone
Osteoblasts form an increased amount
of osteoid in response
to bone resorption
Excess osteoid does not contain
hydroxyapatite but appears
opaque on radiographs - Rugger jersey
Spine
42. Fluorosis
- Endemic areas (asia - india and china; rajasthan
and gujarat, andhra, punjab, haryana, M.P. And
maharashtra,t.N.,W.B.,U.P.,Bihar and assam)
- Increased osteoclastic response
- Cortical thickening encroachment upon
medullary cavity, ossification of ligamentous
attachments
43.
44. Metastatic disease
◦ Prostatic carcinoma
◦ Breast cancer
◦ Transitional cell carcinoma (TCC)
◦ Multiple myeloma
◦ Lymphoma
◦ Carcinoid
◦ Medulloblastoma
◦ Neuroblastoma
◦ Mucinous adenocarcinoma of the
gastrointestinal tract: , e.G. Colon carcinoma
◦ Lymphoma
45.
46. Hypercalcaemia, and
increase in periosteal new
bone with cortical
thickening
Pseudotumour cerebri
D/D
Infantile cortical
hyperostosis : > 1yrs of age