12 year-old boy with a bone fracture injury
background
physiology
anantomy
type of bones
long bones
flat bones
Irregular bones
Sesamoid bones
Short bones
Wormian
greater in length than width
Elongated, cylindrical shaft ( diaphysis)
Most common bone shape,( all finger bones)
Length nearly equal to width.
carpal and tarsals
thin surfaces
surface for muscle attachment,
in top of skull, scapulae, sternum, ribs,
Protects underlying soft tissues
vertebrae, ossa coxae (hip bones), several bones in skull (ethmoid, sphenoid, temporal)
doesnt fit any other category
patella (kneecap)
bones that sometimes develop within tendons
used for leverage
stability and support
Regions
diaphysis
Elongated, usually cylindrical shaft (middle ),
Provides leverage and weight support,
Compact bone,
Medullary cavity (hallow)
within the diaphysis,
Contains red bone marrow in children,
Contains yellow bone marrow in adults,
(Epiphysis) each end of long bone
Proximal epiphysis (closest to body trunk),
Distal epiphysis (farthest from trunk),
Composed of
outer layer of compact bone
inner layer of spongy bone
Articular (hyaline)cartilage ( in the outer layer)
Covers the joint surface,
Reduces friction,
Absorbs shock in moveable joints,
outer layer compact
inner layer spongy
main two types of bones
compact bone
spongy bone
Trabeculae- network of matrix spikes,
Osteocytes (housed in lacuna) no concentric circles,
Trabecula form along lines of stress to provide strength to bone,
light so that mucles can move bone with ease
epithelial disk is here
usually has red bone marrow
composed of osteons
components
Canaliculi
Osteocytes
Concentric lamellae,
Central canal,
channel at center of osteon ,
Blood vessels and nerves enter through this central channel ,
Concentric rings of calcified matrix,
Surround central canal,
Mature bone cells,
Found in lacunae,
Maintain bone matrix,
Tiny, interconnecting channels that
travel through lamellae and connect from, lacunaes to the central canal,
Allow exchange between blood vessels and osteocytes,
Perforating canals( haversian canals)
Blood vessels and nerves travel through ,
connect osteons to osteons
covering and linings of bones
Periosteum is a tough membranous sheath that covers the outer surface of the bone, anchored to bone by collagen fibers
Endosteum covers the internals of the bone within the medullary cavity
types
Inner cellular layer
Outer fibrous layer of dense irregular CT
Protects bone from surrounding structures,
contains blood,lymph vessels,nerves that nourish compact bone,
Attachment site for ligaments and tendons,
Inner cellular layer
osteogenic cells
osteoblast ( bone builder)
osteoclast ( polisher)
contains osteogenic cells
osteoblasts
Covers all internal surfaces of bone within medullary cavity,
osteoclasts
–Stem cells from mesenchyme, will become an osteoblast
only bone cells that divides (One will be a stem cell (mesenchyme)and the other will be an osteoblast)
Makes and secretes goo : collagen matrix (organic) that attracts calcium salts (inorganic) to form a new bone
might become trapped within the matrix, and become osteocytes
osteocytes purpose is to maintain mineral concentration
big, multinuclear, phagocytic cells,
Derived from fused blood stem cells,
Involved in bone resorption ( sanding off wood),
types of fractures
Simple-closed,
Compound-open (through skin),
transverse fracture- straight across,
Spiral fracture- spiral often from a twisting action,
Comminuted fracture- more than 2 pieces,
impacted fracture-one fragment driven into another,
greenstick fracture- incomplete break with splintering,
incomplete – not all the way through,
complete- all the way through,
fissured fracture- Incomplete horizontal ( a crack),
healling
steps
Fibrocartilagenous: Internal and external callus forms
Fracture hematoma ( from clotted blood )
Cartilage replaced by trabecular bone ( spongy)
6-8 hrs
From chondrocytes in endosteum and periosteum,
secrete a fibrocartilaginous matrix between the two pieces
creates hyaline cartilage and the surrounding bone breaks off ( now stabile)
Osteoclasts resorb dead bone
Osteogenic cells become active and divide to make osteoblasts,
Osteoblasts adjacent to callus makes trabeculae (spongy) via endochondral ossification,
remodeling
several weeks
Compact bone replaces spongy bone,
48 hrs
side note: on remodeling
Resorption of old bones
5-10% of skeleton replaced yearly,
Influenced by hormones and mechanical stress (exercise ( helps bone become stronger))
Forms by:
direct
indirect
flat bones
Intramembranous Ossification
Osteoblasts group into clusters, and ossification centers form,
Osteoblast secrets osteoid which traps osteoblasts which turns them into osteocytes,
Trabecular matrix and periosteum form,
Compact bone develops above trabeculae which crowds blood vessels and it condenses into red marrow,
long bones
endochondral ossification
Mesenchymal cells differentiate into chondrocytes,
The cartilage model and the perichondrium forms,
Capillaries penetrate cartilage. Perichondrium transforms into periosteum. (Periosteal collar develops) Primary ossification center develops,
Cartilage and chondrocytes continue to grow at ends of the bone,
Secondary ossification centers develop( at the ends of the bone )
Cartilage remains at epiphyseal (growth) plate and at joint surface as articular cartilage,
side note on epiphyseal plate
found in the middle of the Epiphysis and Diaphysis
On epiphyseal side the cartilage grows,
On diaphyseal side, bone grows ( bone grows in length),
area of hyaline cartilage in immature bone where ossification occurs
called Interstitial growth
once all the cartilage is replaced with bone it becomes the epiphyseal disc
side note : on growth
growth on diameter is appositional growth ( modeling)
Osteoclasts resorbs bone on the endosteum,
osteoblasts produce new bone tissue beneath the periosteum,
increased diameter of the medullary cavity, called modeling,
he was running and fell forward, landing on his right arm
only eats unhealthy food
lactose intolerant
hotdogs
spaghetti
burgers
junkfood etc
doesn't eat /drinks dairy
little calcium intake (or vitamin D)
low intake of
calcium
Vitamin K,
Fluoride,
Omega 3 fatty acids,
Magnesium
injury
fracture
humerus
comminuted
compound
raw material
helps in bone remodeling, growth, healing
Calcium,
Vitamin K,
Vitamin D,
Magnesium,
Flouride,
Omega 3 fatty acid,
regulator of calcium intake
helps bone be built and rebuilt
in conjuction with vitamin k stimulates the transformation of fracture site stem cells to bone building osteoblast
in conjuction with vitamin d stimulates the transformation of fracture site stem cells to bone building osteoblast
helps bind calcium to bone ( helps bone mineralization )
makes the bone have tensile strength
decrease inflammation that may interfere with osteoblast function.
in bones' structure. Strengthens bone and enamel of teeth
in structure of bones
aid in absorption and metabolism of calcium
treatment
surgery
upper arm
needs antiobiotics
post surgery
is going to need pain reliever
since it the humerus,to keep it place he is going to need an arm cast
Do to horrible diet he has a low income of calcium,magnesium,flouride,omega 3 fatty acid, vitamin D. and vitamin K his healing will be slower than most children
would need to change diet to more leafy greens, and certain fish such as salmon to bring his required nutrients/vitamins up ( additional examples include nuts and beans for magnesium, some OJ for vitamin D etc)
needed to put the bone back in place and close the wound to stop infections and antibodies from further entering the body
needs to clean out wound (remove the small fragments )
elbow
need fixation of the fracture fragments with plates, screws or pins.
need fixation of the fracture fragments with plates, screws or pins
although he has a horrible diet he is still a child and the bones are smaller and has a dense periosteum
means his bones will heal faster ( thicker periosteum = more chondrocytes ) ( with a proper nutritional diet his chondrocytes can attract calcium and other nutrients and form "new" bone
going to need rehablitaion to:
joint motion
flexibiity
restore muscle strength
well include excercising
for further info on the covering and lining as well as spongy and compact bone on long bones see upper branches.