Bone structure and clinical importance
-
Upload
giridhar-boyapati -
Category
Education
-
view
987 -
download
1
description
Transcript of Bone structure and clinical importance
![Page 1: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/1.jpg)
BONE STRUCTURE AND ITS CLINICAL IMPORTANCE
Dr GIRIDHAR BOYAPATI P.G
![Page 2: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/2.jpg)
What is Bone? – Mineralized connective tissue
- constitute part of the endoskeleton of vertebrates
![Page 3: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/3.jpg)
Classification
REGION- Axial, Appendicular
SHAPE - Long bones, short bones, irregular, pneumatic, sesamoid, accessory
STRUCTURE Macroscopic – Compact
Spongy
Microscopic – Lamellar (Secondary Bone) Woven/fibrous(Primary Bone)
DEVELOPMENT – Membranous Cartilaginous
Membrano-cartilaginous
![Page 4: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/4.jpg)
ENDOCHONDRAL OSSIFICATION
MESENCHYMAL CELLS
CHONDROBLASTS
CHONDROCYTES
CARTILAGE MODEL OF FUTURE BONE
OSTEOBLASTS
![Page 5: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/5.jpg)
Endochondral Ossification
![Page 6: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/6.jpg)
Endochondral Ossification
![Page 7: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/7.jpg)
Endochondral Ossification Defects – AD Inheritance
• Achondroplasia
• Thanatophoric Dysplasia
• Hypochondroplasia
Mutation in FGFR 3 gene
![Page 8: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/8.jpg)
Intramembranous Ossification
![Page 9: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/9.jpg)
EXAMPLES OF INTRAMEMBRANOUS OSSIFICATION
1. EMBRYONIC FLAT BONES : SKULL, PELVIS, MAXILLA, MANDIBLE, CLAVICLE
2. DISTRACTION OSTEOGENESIS
3. FRACTURE HEALING WITH RIGID FIXATION
4.BLASTEM BONE
![Page 10: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/10.jpg)
PERIOSTEAL OSSIFICATION
OSTEOGENIC CELLS FROM PERIOSTEUM
LAY PARLLEL LAYERS OF COMPACT BONE
![Page 11: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/11.jpg)
Bone cells
Osteo progenitors(Pleuripotent stem cells)
Osteoblasts ("bone makers")
Osteocytes ("bone cells")
Osteoclasts (“bone breakers”) remodeling
MATRIXGround substance
ProteoglycansGlycoproteinsMineralsWater
Fibers
![Page 12: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/12.jpg)
Cells of Bone (Primary/Temporary)
Osteoprogenitor
Osteoclast
Osteoblast
Osteocyte
Osteoid
![Page 13: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/13.jpg)
PERIOSTEUM
MEMBRANE COVERING OUTER SURFACE OF BONE
LAYERS: 1. FIBROUS LAYER 2. CAMBIUM LAYER
![Page 14: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/14.jpg)
OSTEOGENIC CELLS
![Page 15: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/15.jpg)
OSTEOBLAST
![Page 16: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/16.jpg)
OSTEOCYTE
![Page 17: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/17.jpg)
OSTEOCLAST
![Page 18: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/18.jpg)
Osteoclast
![Page 19: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/19.jpg)
CANALICULI
![Page 20: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/20.jpg)
Bone cells -Function• Osteoblasts – Matrix synthesis – Osteoid,
Calcification
PTH receptors
• Osteocyte – Maintanace of Matrix by intercellular sickling systems
• Osteoclast – Digestion of collagen, dissolving hydroxyapatite
* Calcitonin receptors
![Page 21: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/21.jpg)
Bone cells- Medical applicationRate of bone apposition – Bone growth
Osteomalacia – Impaired mineralization
Osteitis fibrosa cystica – osteoclast activityOsteopetrosis – “Marble bones” – Bone resorption
defect due to osteoclastic activityOsteitis deformans (Paget’s disease) –Uncontrolled
osteoclast activity followed by osteoblastic activity (incomplete)- Stops at osteoid level
![Page 22: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/22.jpg)
BIOCHEMISTRY
1.INORGANIC 65 -70%2.ORGANIC 30-35%
ORGANIC: a. collagen 90-95% b. pps 4-5% c.Lipids 0.1% INORGANIC 90% Calcium and phosphate
![Page 23: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/23.jpg)
BONE COLLAGEN
1.AXIAL PERIODICITY OF 640 TO 700A
2.PROTIEN COMPOSITION WITH ONE THIRD GLYCINE
3.LARGE NO. OF ALANINE RESIDUES
4.CYSTEINE IS COMPLETELY ABSENT
![Page 24: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/24.jpg)
Matrix
• Fibers – Collagen Type I- Gene mutation in alfa 1or 2 OSTEOGENESIS IMPERFACTA
• Ground substance
Proteoglycans – Chondroitin Sulphate, Keratan Sulphate
Glycoproteins – Osteocalcin , Alkaline phosphatase
![Page 25: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/25.jpg)
Structural regions of long bone
![Page 26: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/26.jpg)
Gross structure of typical long bone Shaft – Thick compact bone+ medullary cavity Ends- Cancellous bone + thin compact layer Articular cartilage – No periosteum, avascular Periosteum – Fibrous + cellular
Shape, nutrition, attachment
fracture repair, sensitive Endosteum – Cellular -Repair
and remodelling Nutrient foramen – mid shaft Bone marrow – Red, Yellow
![Page 27: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/27.jpg)
Parts of a growing bone
Epiphysis
(Secondary) Epiphyseal
plate Metaphysis Diaphysis
(Primary)
![Page 28: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/28.jpg)
TYPES OF EPIPHYSIS
![Page 29: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/29.jpg)
PRESSURE
region of the long bone that forms the joint is called Pressure Epiphysis
ARTICULAR....WT TRANSMISSON
EX: HEAD OF FEMUR AND HUMERUS
TRACTIONNon-articularMuscle pullOssifies later than Pressure
.EX HUMERUS G.T AND L.T FEMUR G.T AND LT
![Page 30: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/30.jpg)
ATAVISTICCOROCOID PROCESS OF SCAPULAOS TRIGONUM
ABERRANTHEAD OF 1ST METACARPEL
Unusual
![Page 31: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/31.jpg)
Epiphyseal plate
![Page 32: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/32.jpg)
Growth Plate
![Page 33: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/33.jpg)
ZONE 1INJURY CAUSES CESSATION OF GROWTH
ZONE 2BONE LENGTH IS ADDED
ZONE 3WEAKEST PORTION OF GROWTH PLATE
![Page 34: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/34.jpg)
Metaphysis
Epiphyseal end of diaphysis
Active growth Before fusion
end arteries, hair pin bends
OSTEOMYELITIS
![Page 35: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/35.jpg)
Blood supply of bones
Long Bone Nutrient artery Metaphyseal arteries Epiphyseal arteries Periosteal arteries
Short Bone - Nutrient artery; Periosteal arteries
Vertebra- Body, Processes
Rib - Nutrient artery; Periosteal arteries
![Page 36: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/36.jpg)
Nutrient artery Mid shaft Tortuiosity 2/3rd inner compact bone Hair pin loops Direction – away from
growing end
.
“To the elbow I go. From the knee I flee.”
![Page 37: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/37.jpg)
Nutrient Artery
1.Enters into the diaphysis of long bones through an oblique canal
2.direction of canal is determined by relative amount of growth that has occurred at proximal and distal ends of the bone;
3.does not branch within the cortex, divides after reaching the medullary cavity,
4. direction of blood flow is centrifugal;
![Page 38: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/38.jpg)
Disruption of Nutrient Artery causes
1. In growing bone can result in necrosis of large portion of marrow & of inner two thirds of cortex
2. This cortical death does not occur in adult bone because combined epiphyseal-metaphyseal collateral circulation is developed enough to maintain these areas;
3.loss of circulation in terminal vessels of nutrient artery of growing bone will interfere with enchondral ossification;
![Page 39: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/39.jpg)
Epiphyseal arteries
In femoral and radial heads, which are almost entirely covered by cartilage vessels enter in region between articular cartilage & growth-plate cartilage
In other regions, the epiphysis has openings that permit passage of large number of vessels into and out of the ossification centers
![Page 40: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/40.jpg)
Obliteration of epiphyseal blood supplycauses
1.necrosis of epiphysis
2. longitudinal growth ceases
3. permanent closure of epiphyseal plate
![Page 41: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/41.jpg)
METAPHYSIAL ARTERIES
BRANCHES OF SYSTEMIC VESSELS
Epiphyseal vessels are responsible for permitting longitudinal growth to occur, whereas metaphyseal vessels nourish
osteoprogenitor cells, which lay down bone on cartilage matrix;
![Page 42: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/42.jpg)
PERIOSTEAL ARTERIES
Periosteal vessels send small branches thru minute channels in cortex to supply about outer 1/3 of cortex
Extensive network of vessels covers entire length of the bone shaft
Anastomoses with adjacent skeletal muscles so in cases in which the nutrient artery of muscle has been damaged, then periosteal vessels may temporarily serve as the primary blood supply;
![Page 43: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/43.jpg)
![Page 44: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/44.jpg)
BLOOD SUPPLY OF GROWTH PLATE
growth plate itself is avascular & receives nutrition from 2 sources
1.epiphyseal vessels that supply germinal, proliferating, and upper hypertrophic cell layers by diffusion
2 .metaphyseal vessels that supply zone of provisional calcification
![Page 45: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/45.jpg)
In a young child, epiphyseal vessels are separated from metaphyseal vessels, but
following growth arrest of the cartilage plate, there is
an extensive anastomoses between epiphyseal vessels, metaphyseal vessels, &
terminal branches of Nutrient Artery;
![Page 46: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/46.jpg)
VENOUS DRAINAGE
TRANSVERSE VENOUS CHANNELS
CENTRAL VENOUS SINUS
NUTRIENT VEIN
-ONLY 5-10% OF VENOUS DRINAGE IS THROUGH NUTRIENT VEIN
-REMAINING IS THROUGH PERIOSTEAL VENOUS DRINAGE
![Page 47: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/47.jpg)
Circulatory disturbances
PHYSIS AND EPIPHYSIS1.Legg–Calve–Perthes Disease: Circulatory disturbance to the capital
femoral epiphysis 2.Physeal TraumaMETAPHYSIS1.Haematogenous Osteomyelitis2.Metastasis.DIAPHYSIS1.Intramedullary Reaming2.Fracture HealingPERIOSTEAL BLOOD SUPPLY1.Paralytic conditions
![Page 48: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/48.jpg)
Spongy bone
1. loose network of bone trabecule
2. interconnected
3. arranged along lines of maximum stress
![Page 49: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/49.jpg)
Spongy Bone
Superimposed lamllaeNo Haversian systemLamellated trabeculae Red marrow
![Page 50: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/50.jpg)
Spongy Bone- No HS
![Page 51: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/51.jpg)
Osteon (Haversian system) Central canal (Haversian
or osteonal canal) Transverse (Volkmann)
canals Lacuna Canaliculi ("tiny canals") Lamellae
Concentric,Intersititial,
Circumferential
![Page 52: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/52.jpg)
Compact bone
![Page 53: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/53.jpg)
COMPACT BONE
![Page 54: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/54.jpg)
Sharpey’s fibers
Connective tissue matrix
Bundles of collagen fibers Connect Perisoteum to Bone
Fibrous layer of Periosteum to outer circumferential and interstitial lamellae
![Page 55: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/55.jpg)
Growing Bone
BONE GROWTH1. Appositional
2. Endochondral
![Page 56: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/56.jpg)
Factors affecting growth of a bone
Nutritional Vit. A - Co-ordination of osteoblastic and
osteoclastic activity
Vit.C – Synthesis of organic matrix
Vit.D – Absorption of Ca, P
Rickets, Osteomalacia (Calcification deficiency)
Calcium – Decalcification of bone
![Page 57: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/57.jpg)
![Page 58: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/58.jpg)
Factors affecting growth of a bone
Hormonal – • Pituitary - GH- Dwarfism; Gigantism,
Acromegaly• Thyroid - Calcitonin
Parathyroid – PTH Decalcification
Sex Hormones - Androgens, estrogens - Stimulators Mechanical factors
Tensile forces – Bone formation
Compressive forces – Bone resorption
![Page 59: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/59.jpg)
Ossification Centre
![Page 60: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/60.jpg)
Rules of Ossification Primary centers - before birth
except carpal and tarsal (except calcaneus, talus, cuboid)
Secondary centers - after birth
except lower end of femur, upper end of tibia, humerus
Center which appears first unites last
except lower end of FIBULA
![Page 61: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/61.jpg)
Rules of Ossification Center which appears later unites first
except upper end of fibula Direction of nutrient artery - away from
growing end
except fibula Growing end is one where center
appears first and unites last
except fibula
![Page 62: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/62.jpg)
Fracture Healing1. Hematoma
formation Macrophages
Osteoclasts2. Fibrocartilaginous
callus formation Periosteum Endosteum 3. Bony callus
formation Ossification (EC & IM)4. Remodeling Sec.bone formation
![Page 63: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/63.jpg)
Bone remodeling cycle
![Page 64: Bone structure and clinical importance](https://reader033.fdocuments.us/reader033/viewer/2022052623/559b54051a28ab900c8b4569/html5/thumbnails/64.jpg)