Human Anatomy: Joints and Fractures

Study Notes

Joints are where two bones meet.
Joints can be immovable, partially movable, or freely movable.
Immovable joints are found in the skull and pelvis.
Partially movable joints are found in the vertebrae and ribs.
Freely movable joints include ball and socket, hinge, pivot, and gliding joints.
Ball and socket joints allow for movement in any direction, examples include the shoulder and hip.
Hinge joints allow for back and forth movement like a door, examples include the elbow, knee, fingers and toes.
Pivot joints allow for rotation around another bone, examples include the forearm and neck.
Gliding joints allow bones to slide over each other, examples include the wrist and ankle.

A fracture is a break in a bone.
There are three main types of fractures: greenstick, simple, and compound.
Greenstick fractures are common in children and occur when a bone bends and cracks or partially breaks.
Simple fractures are clean breaks where the bone breaks into two pieces.
Compound fractures occur when a broken bone pierces the skin.

When a fracture occurs, tissues around the break swell and blood rushes to the area.
A sticky material forms to glue the bones together.
Cells and minerals gradually cement the bones together.
Healing typically takes 6-8 weeks.
A cast holds the bones together while they repair themselves.
A healed bone is typically stronger than before due to mineral deposits.
Steel pins are used surgically to repair crushed or fragmented bones.

Sprains are the most common joint injury.
Sprains occur when ligaments are stretched or torn due to a sudden twist or excessive pressure.
Severe sprains can involve torn ligaments.
Swelling around an injury is caused by broken capillaries (small blood vessels).
A high ankle sprain is a sprain of the ligaments connecting the tibia and fibula, above the ankle.
Stable high ankle sprains can heal with rehabilitation.
Unstable high ankle sprains require surgery and possibly screws for healing.

The healing process for sprains depends on the ligament involved.
Rest and weight-bearing restrictions can help heal some sprains.
RICE (Rest, Ice, Compression, Elevation) treatment is recommended for sprains.
Light rehabilitation exercises are used to strengthen the injured area for 2-3 weeks.
Minor surgery, such as arthroscopic surgery, may be needed if light rehab is ineffective.

Dislocation occurs when bones are pulled out of joint.
Ligaments are severely stretched or torn during a dislocation.
Dislocated bones must be put back in place and held in place with a bandage.
Torn cartilage may require surgery to remove all or part of it.
Arthroscopic surgery is often needed for cartilage repair.
A ruptured disc is damage to the cartilage between two vertebrae. It can press on nerves, leading to numbness and pain.