Common Types of Fractures
and Joints
Chapter 5: The Skeletal System
Comminuted Fracture
• Bone breaks into many fragments
• Common in older people whose bones are
more brittle.
Compression fracture
• Bone is crushed
• Common in porous bones.
• Common in older people with osteoporosis
Compression
fracture of C5
vertebra
Depression Fracture
• Broken bone portion is pressed inward
• Typical of skull fracture
Impacted Fracture
• Also known as an incomplete fracture
• Broken bone ends are forced into each other
• Commonly occurs when one attempts to
break a fall with outstretched arms.
Spiral Fracture
• Ragged break occurs when excessive twisting
forces are applied to a bone
• Common sports fracture
Greenstick Fracture
• Bone breaks incompletely, much in the way a
green twig breaks
• Common in children, because bones are more
flexible than adults.
Joints…aka..Articulations
• Every bone in the body forms a joint with at
least one other bone.
– Except for the hyoid bone of the neck.
• Function:
– holds bones together
– Give skeleton mobility
Fibrous Joints
• Held together by fibrous tissue
• Allows no movement
• Example: Sutures of the skull
Cartilaginous Joints
• Bone ends are connected by cartilage
• Slightly moveable
• Examples:
– Pubic symphysis
– Intervertebral joints
Synovial Joints
• Have 4 distinct features
1. Articular cartilage
covers the ends of
bones
2. Fibrous articular
capsules that is lined
with a smooth synovial
membrane
3. Joint cavity contains
lubricating synovial
fluid
4. Reinforcing ligaments
Types of Synovial Joints
• There are six types of synovial joints based on
shape
1.
2.
3.
4.
5.
6.
Plane joint
Hinge joint
Pivot joint
Condyloid joint
Saddle joint
Ball-and –socket joint
Plane joint…aka gliding joint
• Articular surface are flat
• Only allows short
movement
• Example:
– Intercarpal joints of the
wrist
Hinge joints
• Cylindrical end of one
bone fits into a troughshaped surface of
another bone.
• Angular movement in
one plane
• Examples:
– Elbow and ankle
Pivot joint
• The rounded end of one
bone fits into a sleeve
of another bone
Examples:
Neck (Joint between the
atlas and the dens of
the axis)
Ulna and Radius
Condyloid Joint..aka..Elipsoidal joint
• Egg shaped articular
surface fits into an oval
concave surface in
another bone.
• Have two axes
• Example: Knuckles
Saddle Joints
• Each articular surface
has both convex and
concave areas.
• Example:
– Twiddling your
thumbs
Ball-and –socket joint
• The spherical head of one bone fits into a
round socket in another
• Allows movement in all axes