Transcript the PowerPoint associated with this video

What are we going to learn?
▪Today we will be covering:
▪ What is orthopedics?
▪ What are bones?
▪ How to classify bones
▪ Types of levers
▪ Muscle forces
▪ Fractures!
▪ How to repair a fracture
▪ A quick look at current research involving
bones
▪ All of this information is true for people and
pets!
Orthopedics Defined
That branch of medicine and surgery that is specially concerned with the
preservation and restoration of the function of the skeletal system, its
joints, and associated structures like ligaments and tendons
Associated Structures
▪ Joint – where two or more bones
come together
▪ Joint Cartilage – cartilage covering
the ends of bones that are in
contact with adjacent bones to
allow smooth movement and shock
absorption
▪ Tendon – connects muscle to bone
▪ Ligament – connects bone to bone
What Do Bones Do?
1. Support/protection for body’s vital organs (for example,
skull protects the brain, rib cage protects the heart &
lungs)
2. Serve as levers in conjunction with joints, tendons,
ligaments, and muscles for movement
3. Production of blood cells in bone marrow
4. Storage site for calcium & phosphorus
Anatomy of a Typical Bone
Two Types of Bone:
1.Compact Bone: bone’s outer layer, what we can see. It is
dense, strong, and heavy
2.Spongy Bone – bone’s inner layer; self- organizes in
response to the direction of weight put on it
Classification of Bones
▪
Long – long! Bones of
limbs
▪
Short – short! Small
bones of hands & feet
▪
Flat – flat! Bones on top
of skull
▪
Sesamoid – small
bones embedded in
tendon as it crosses a
bony prominence.
Found in digital
tendons.
▪
Irregular – jutting
processes give these
bones an irregular
shape. Found in pelvic
bone.
Quiz!
Can you identify what type of bones
these are?
❏ flat bones
❏ sesamoid bone
❏ short bones
❏ irregular bone
Quiz!
Can you identify what type of bones
these are?
❏ flat bones
❏ sesamoid bone
❏ short bones
❏ irregular bone
Quiz!
Can you identify what type of bones
these are?
❏ flat bones
❏ sesamoid bone
❏ short bones
❏ irregular bone
Quiz!
Can you identify what type of bones
these are?
❏ flat bones
❏ sesamoid bone
❏ short bones
❏ irregular bone
Living Tissue
 Your bones are living
tissue!
 They are continually
remodeling and changing shape
in response to the bodies needs.
Bone Remodeling
Osteo = bone, cyte = cell
Osteoblasts – secrete a matrix
made up of calcium phosphate
crystals. “Blasts Build up Bone”.
Osteocytes – retired
osteoblasts; found within bony
wall that they have deposited
around themselves.
Osteoclasts – break down bone;
release acids to dissolve crystals
and enzymes to break down
matrix. “Clasts Chew Bone”.
Bone Remodeling Fun Facts
▪ Goes on throughout life
▪ 10-30% of adult bone is re-built
every year
▪ Bones of femur completely rebuilt
every 6 months
▪ Bones in skull may take 10 years
to re-build
▪ Drink your milk (and sunshine for
vitamin D)
Bone Reacts to Stresses Put on It
Wolff’s Law: Greater
physical stress placed on a
bone at a particular site
results in more bone
deposition by osteoblasts at
that site
 Examples:
 Astronauts who spend a long
time in space will often
return to Earth with weaker
bones, since gravity hasn't
been exerting a load on their
bones. Their bodies have
reabsorbed much of the
mineral that was previously
in their bones
 Weightlifters often display
increases in bone density in
response to their training.
Levers in the Body
• Lever components
•Fulcrum- joint
•Resistance- weight
•Effort- muscle
E
• First class lever
•Fulcrum is between effort and resistance
R
F
• Second class lever
•Resistance is between effort and fulcrum
• Third class lever
•Effort is between the fulcrum and resistance
What type of lever?
 Biceps brachii muscles
Connects scapula to radius
Elbow joint is made of the
junction of humerus and radius
and ulna
Acts to flex the elbow joint
(reduce the flexion angle)
E
F
R
What type of lever?
 Gastrocnemius and other caudal leg
muscles
Connects femur to calcaneus bone of
foot
Fulcrum is the digital joints of the foot
Act to extend (increase the flexion
angle of) the tarsal (ankle) joint and flex
(decrease the flexion angle of) the
digital joints
E
R
F
What type of lever?
 Triceps muscle
Connects scapula to ulna
Elbow joint is made of the junction of humerus and
radius and ulna
Act to extend (increase the flexion angle of) the
elbow joint
E
F
R
Force and Torques
The weight lifting problem
How much force does your biceps have to
apply to keep the ball in place?
Force and Torques
∑𝑻𝒐 = 𝟎
Find the pivot point
Find the direction of the
forces
Find the distances from
each center of mass to the
pivot point
d3
d2
d1
Force and Torques
∑𝑇𝑜 = 0
M
W11 is
is the
the weight
weight of
of the
the ball
ball
M
W22 is
is the
the weight
weight of
of the
the forearm
forearm
𝑇 =𝐹∗𝑑
W2
W1
⊥
0 = 𝑀1 ∗ 𝑑1 + 𝑀2 ∗ 𝑑2 − 𝐹 ∗ 𝑑3
0 = 𝑇1 + 𝑇2 + 𝑇3
𝐹 ∗𝑊𝑑13∗=𝑑1𝑀+1 𝑊
∗ 𝑑21∗+𝑑2𝑀−2 ∗𝐹𝑑∗2𝑑3
0=
d3
d2
𝐹=
𝑑22)/𝑑
∗ 𝑑(𝑀
𝑊𝑑11∗+𝑑𝑀
∗ 𝑑23
1∗
2 ∗𝑊
3 =
1+
d1
𝐹 = (𝑊1 ∗ 𝑑1 + 𝑊2 ∗ 𝑑2)/𝑑3
Force and Torques
W2
W1
d3
d2
d1
W1= 20lb 𝑭 = 𝟐𝟓𝟖𝒍𝒃
d1= 30cm
W2= 3lb
d2= 30/2cm
Why does the bicepsd3work
= 2.5cm
so
hard to lift a combined 23lbs?
𝐹 = (𝑊1 ∗ 𝑑1 + 𝑊2 ∗ 𝑑2)/𝑑3
The biceps does not get much
𝐹 = (20𝑙𝑏
∗ 30𝑐𝑚
3𝑙𝑏 ∗ and
15𝑐𝑚)/2.5𝑐𝑚
benefit
from
the +lever
fulcrum
because its attachment is close to
How much force does the biceps exert to
the pivot
and the resistance is far
keep a 20lb ball in place?
from both pivot and biceps.
FRACTURES
A medical condition in
which there is a break in
the continuity of the bone.
What is a radiograph?
Radiographs are:
• The image produced on a film by X-rays or other forms of radiation.
X-Rays are:
• Electromagnetic radiation of short wavelength produced when high-speed electrons
strike a solid target.
X-Rays produced
here!
X-Rays travel here!
X-Ray film here!
Radiograph FAQ’s!
Does it hurt the animal?
• Not at all! They are totally painless, you cannot see or feel the X-Rays!
Are they safe?
• Yes, the dose of radiation used is the smallest possible to make a diagnostic image.
• Anyone regularly working around X-Rays must wear a dosimeter that tracks their total
exposure.
Name The Animal!
What Did the Snake Eat?
Human
Vs.
Dog
Normal Dog Images!
Can you name
the breed of
the dog?
Boxer
Closed Fracture
▪ A broken bone that
does not penetrate
the skin.
▪ Also known as a
simple fracture.
Open Fracture
▪ A broken bone that
penetrates the skin.
▪ Also known as a
compound fracture.
▪ Needs immediate
treatment, and an
operation is often
required to clean the
area of the fracture.
▪ Higher risk of infection
and more problems
associated with
healing.
Normal Fracture Healing
White zone is area of new bone deposit
Abnormal Fracture Healing
 Mal-union – a fracture that heals with
abnormal alignment
 Non-union – fracture healing has STOPPED
before the bone is completely healed
 elephant foot “hypertrophic non-union”
 tapered “atrophic non-union”
 Osteomyelitis – infection of bone
Malunion
In the wrist
 Mal-union – a fracture that
heals with abnormal alignment
In the elbow
Non-union
 Hypertrophic non-union is a bulging
appearance at the fracture site, which
results from a large amount of callus
formation. Usually caused by too much
mobility at fracture site, blood supply is
adequate.
 Atrophic non-union is
narrow, rounded ends of
bone at the level of the
fracture. This is caused
by a poor healing
response due to a lack
of blood supply.
Osteomyelitis
Osteomyelitis – infection of bone
What species is this?
Horse- it only has one toe
Fracture Reduction Goals
▪Get bones close enough
together to heal correctly
▪Proper alignment
▪ To Avoid:
▪
▪
▪
▪
▪
mal-union
loss of function
additional trauma
further fracture
infection
Treatment Options
Fracture Reduction
▪Closed fractures
▪
▪
Permanent (cast or splint)
Temporary (until surgery)
▪Open fractures (orthopedic surgery)
▪ Intramedullary Fixation (Pins)
▪ Cerclage (Wires)
▪ External Fixation Devices
Closed Fracture Reduction
Use of a bandage or
splint to heal the
fracture. Can be
temporary or
permanent.
Open Fracture Reduction
An open fracture
reduction involves
cutting through the
skin to realign the
bones. Normally this is
used if the bone is in
many pieces or is
difficult to reduce.
Intramedullary Fixation
Intramedullary fixation is the use of pins, they come in a variety of
sizes. You pick the pin based upon the bone itself, the animal, and
the location.
Cerclage
Cerclage: encircling
the bone with a wire
ring or loop, as for
fixation of fragments
in a fractured bone
External Fixators
The process of
installing temporary
repair supports
outside of the skin to
stabilize and align
bone while the body
heals.
External Fixators
Surgery Tools
▪
Animal Orthopedics
as a Human Model
▪
Animals are used as
human models in clinical
studies or experiments
in the development of
surgical procedures &
drugs in veterinary
medicine to be used in
human medicine.
▪
Example:
▪
The 1st hip replacement
surgery was developed
in military dogs (German
Shepherds have a
genetic problem with hip
joint being misaligned).
Protect Yourself
▪ Osteoporosis is a bone disease where the bone mineral
density is reduced.
▪ Bones become much more fragile. People with
osteoporosis are more likely to suffer fractures than
people with normal bone density.
▪ Reaching peak bone mass when young greatly reduces
your risk of developing the disease.
How to Strengthen Your Bones
▪Physicians recommend that
adolescents get 30 minutes of
exercise everyday of the week.
▪Be sure children and teens are
getting the recommended 1300
mg of calcium a day.
▪Eating a balanced diet and
exercising will keep you agile,
make you strong, and reduce your
risk of developing many serious
diseases later in your life.
Current NIH Research
Topic: Sustained-Release Drug Carrier for Treatment of Osteoarthritis
▪ Osteoarthritis is deterioration or
loss of the cartilage that acts as
a protective cushion between
bones, particularly in weightbearing joints such as the knees
and hips.
▪ Treatment: Injection of antiinflammatory drugs into arthritic
joints reduces inflammation and
pain.
▪ Problem?: Drug effect doesn’t
last, because drug diffuses out of
the joint quickly. Effect could last
longer if drug were held in the
joint.
Solution
▪Researcher Lori A. Setton at Duke
University designed a protein to
inject along with the drug.
▪This modified and injectable
arthritis drug remains at the site of
the injection and forms a “drug
depot”.
▪When studied in a rat knee joint
model, the delivered protein/drug
combination remained in the joint 25
times longer than the comparable
soluble drug on the current market.
What we have covered!
▪Today we learned:
▪ What is orthopedics?
▪ What are bones?
▪ How to classify bones
▪ Types of levers
▪ Muscle forces
▪ Fractures!
▪ How to repair a fracture
▪ A quick look at current research involving
bones
▪ All of this information is true for people and
pets!
Materials
 Good long bones to use include the
humerus, radius, femur, or tibia
 Choose bones from a mammal not a
bird
 Bones should be sawed into
transverse pieces small enough to fit
in your graduated cylinders
 Bones should be boiled before use
 Try asking a local slaughterhouse
or butcher for bones
 Use balances with decimal points
and graduated cylinders with 1 mL
marks for best accuracy
Main points
 Long bones are less dense at the
ends than in the middle
 Physeal plates where bone growth
occurs are near the ends of the bone
 More spongy bone is found at the
ends
 More compact bone is found near
the center
 Spongy bone is less dense than
compact bone
 Fractures are more likely to occur
near the ends of the bone than in
the middle
Charts and Graphs
Reminders for students
 Density=Mass/Volume
 Don’t round until the end
 Measure mass before volume so that
the bone specimens won’t be wet
 Record initial and final volume to
calculate water displacement volume