Bone and Its Types Classification on Basis of Shape Classification on Basis of Development Classification on the Basis of Region Classification on the Basis of Structure Types of Fractures De Quervain's Disease Jersey Finger Boxer's Finger Saturday night palsy Mallet Finger Carpal Tunnel Syndrome Student's Elbow

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Bone and Its Types
Definition:
Bone is a hard, rigid form of connective tissue constituting most the skeleton of vertebrates,composed
chiefly of calcium salts.
Types ofBone:
Bones are classified on the basis of:
1. Shape
2. Development
3. Region
4. Structure
a) Macroscopic Approach
b) Microscopic Approach
TYPE 1: Classification on Basis ofShape:
1- Long Bone:
- Definition: Long bones are hard, dense bones that provide strength, structure,and mobility.
A long bone has a shaft and two ends. There are also bones in the fingers that are classified as
"long bones," even though they are short in length.
- Examples:humerus,femur, radius, ulna, tibia and fibula. Metacarpals,metatarsals and
phalanges of both upper and lower limb. Clavicle and body of vertebrae.
2- Short Bone:
- Definition: Short bones are designated as those bones that are as wide as they are long. Their
primary function is to provide support and stability with little to no movement.
- Examples:Cuboid, cuneiform, scaphoid, trapezoid etc. In fact all the carpaland tarsal bones
are included in this category.
3- Flat Bone:
- Definition: Flat bones are bones whose principle function is either extensive protection or the
provision of broad surfaces for muscular attachment. These bones are expanded into broad,
flat plates.
- Examples:Scapula,ribs, sternum.
4- Irregular Bone:
- Definition: The irregular bones are bones which, from their peculiar form, cannot be grouped
as long bone, short bone, flat bone or sesamoid bone.
- Examples: Vertebrae,hip bone and bones in the base of skull.
5- Pneumatic Bone:
- Definition: Pneumatic Bones have air spaces within them which make them lighter than more
solid bone. They are only found in the skull.
- Examples: Sphenoid Bone, Ethmoid Bone and Maxilla.
6- Sesamoid Bone:
- Definition: A small independent bone or bony nodule developed in a tendon where it passes
over an angular structure, typically in the hands and feet.
- Examples:Patella,Pisiform and Fabella.

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TYPE 2: Classification on Basis ofDevelopment:
1. Membranous bones:
- Definition: These are also known as dermal bones and the process by which they ossify is
called intra-membranous ossification. These bones ossify from mesenchymal condensations
in the intrauterine life.
- Examples are bones of the skull and facial bones.

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2. Cartilaginous bones:
- Definition: These bones ossify from a cartilage model and this type of ossification is known
as intra-cartilaginous ossification. These bones do not form from mesenchymal condensations
but from preformed cartilage models.
- Examples of this type of bones include bones of limbs, vertebral column and thoracic cage.
3. Membrocartilaginous bones:
- Definition: These bones ossify partly from cartilage and partly from mesenchymal
condensations.
- Examples of this class of bones include clavicle, mandible, occipital, temporal and sphenoid
etc.

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TYPE 3: Classification on the Basis ofRegion:
1. Bones ofaxial skeleton:
- These bones form the axial skeleton of human body.
- Examples are bones of skull, vertebral column and thoracic cage.
2. Bones ofappendicular skeleton:
- These bones form the appendicular skeleton of the body.
- Examples of this type of bones are bones of the limbs and girdles of limbs.
TYPE 4: Classification on the Basis ofStructure:
The structural classification has two approaches that are macroscopic approach and microscopic
approach.
1. Macroscopic Approach divides the bones into two categories that are:
a) Compact bone:
- The part of a bone where bone substance to bone space ration is a bigger quantity is
called compact bone. This means that there is more bone tissue and less empty space.
a) Spongy bone:
- The part of a bone where bone substance to bone space ratio is a smaller quantity. This
means that there is more empty space and less bone tissue.
2. Microscopic approach divides the bones into following categories;
a) Lamellar bone:
- The type of bone which are composed of thin plates (lamellae) of bony tissue. Most
mature human bones are lamellar bones.
b) Fibrous bone:
- These have more fibers in them. In humans they are found only in fetus.

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Types of Fractures
A fracture is a partial or complete break in the bone. When a fracture occurs,it is classified as either open
or closed:
1- Open fracture (Also called compound fracture.) - The bone exits and is visible through the skin, or
a deep wound that exposes the bone through the skin.
2- Closed fracture (Also called simple fracture.) - The bone is broken, but the skin is intact.
Common Types of Fractures That May Occur:
 Greenstick Fracture - Incomplete fracture.
- A greenstick fracture occurs when a bone bends and cracks,instead of breaking
completely into separate pieces. This type of broken bone most commonly occurs in
children because their bones are softer and more flexible than are the bones of adults.
 Transverse Fracture:
- A transverse fracture,which is broken straight across the bone, is the result of a sharp,
direct blow or may be a stress fracture caused,for example, by prolonged running.
 Spiral Fracture:
- The break spirals around the bone; common in a twisting injury.
- A spiral fracture refers to a fracture caused by a twisting force that creates an oblique
fracture around and through the bone.

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 Oblique Fracture:
- Diagonal break across the bone.
- The oblique fracture is broken at an angle across the bone and is usually the result of a
sharp angled blow to the bone.
 Compression Fracture:
- The bone is crushed, causing the broken bone to be wider or flatter in appearance.
- A compression fracture is a collapse of a vertebra. It may be due to trauma or due to a
weakening of the vertebra. This weakening is seen in patients with osteoporosis or
osteogenesis imperfecta, lytic lesions from metastatic or primary tumors, or infection.

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 Comminuted Fracture:
- The comminuted fracture which splinters and contains small bone particles that can
shatter into more than two pieces. This fracture is usually caused by severe force such as
in a car accident.
 Delayed Union Fracture:
- A delayed union fracture refers to a bone fracture that is taking an exceptionally long
amount of time to heal.
 Malunion Fracture:
- A malunion fracture refers to the healing of a fracture with incorrect anatomical
alignment.
 Nonunion Fracture:
- The nonunion of a fracture refers to the absence of healing in a fracture.

8. Be Confident..!!!
Symptoms of a Bone Fracture:
- Swelling or bruising over a bone
- Deformity of an arm or leg
- Pain in the injured area that gets worse when the area is moved or pressure is applied
- Loss of function in the injured area
- In compound fractures,bone protruding from the skin
Causes ofBone Fracture:
- Fractures are usually caused by a fall, blow or other traumatic event.
- Pathological fractures are those caused by disease that weakens the bones; they can occur with
little or no trauma.
Special Conditions
De Quervain's Disease:
 De Quervain's disease is a painful inflammation of tendons in the thumb that extend to the
wrist, also known as tenosynovitis.
 The swollen tendons and their coverings rub against the narrow tunnel through which they
pass.
 The result is pain at the base of the thumb and extending into the lower arm.

Jersey Finger:
 Jersey finger is a sports injury that can happen when one player grabs another's jersey and a
finger - usually the ring finger gets caught, and the tendon is pulled off the bone.

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Boxer's Finger:
 The head of the metacarpalbone connects the metacarpalbone to the bone of the finger.
 The head of the metacarpalbones form the knuckle of an enclosed fist.
 A boxer's fracture involves a break in the neck of the metacarpal.
Saturday night palsy:
 Saturday night palsy from falling asleep with one's arm hanging over the arm rest of a chair,
compressing the radial nerve at the spiral groove.
 Honeymoon palsy from another individual sleeping on and compressing one's arm overnight.

10. Be Confident..!!!
Mallet Finger:
 A mallet finger is a deformity of a finger caused when a certain tendon - the extensor tendon
is damaged.
 When a ball or other object strikes the tip of the finger or thumb, the force damages the thin
tendon that straightens the finger.
 The force of the blow may even pull away a piece of bone along with the tendon.
Carpal Tunnel Syndrome:
 CTS is a painful condition of the hand and fingers caused by compression of a major nerve
where it passes over the carpalbones through a passage at the front of the wrist.
 It may be caused by continual repetitive movements or by fluid retention.

11. Be Confident..!!!
Student's Elbow:
 Student’s elbow is a condition characterized by pain, redness and swelling around the
olecranon, caused by inflammation of the elbow's bursa.
 Student’s Elbow also informally known as:
 Olecranon bursitis
 Elbow bump
 Popeye's elbow
 Baker's elbow
References:
 http://www.webmd.boots.com/a-to-z-guides/bone-fractures-types-symptoms-prevention
 http://www.mayoclinic.org/diseases-conditions/greenstick-fractures/basics/symptoms/con-
20027302
 http://healthlibrary.brighamandwomens.org/RelatedItems/89,P07392
 http://www.innerbody.com/image_skel06/skel56.html
 en.wikipedia.org/wiki/Vertebral_compression_fracture
 umm.edu/health/medical/ency/articles/long-bones
 en.wikipedia.org/wiki/Short_bone
 en.wikipedia.org/wiki/Flat_bone
 en.wikipedia.org/wiki/Irregular_bone
 https://student.brighton.ac.uk/anatomy/pneumatic_bones.htm
 www.webmd.com/rheumatoid-arthritis/de-quervains-disease
 www.mymosh.com/services/hand/jersey-fingers/
 www.emedicinehealth.com/boxers_fracture/article_em.htm
 en.wikipedia.org/wiki/Radial_neuropathy
 orthoinfo.aaos.org/topic.cfm?topic=a00018
 en.wikipedia.org/wiki/Olecranon_bursitis
A broken bone can heal, but the wound a word opens can fester forever. - Jessamyn West