Fractures and Bone Healing Flashcards
What is the most common fracture under the age of 75?
Colles fracture
What is the most common fracture over the age of 75?
Hip fracture
When are fractures most common in men and women?
In men = under 45
In women = over 45
What is a closed fracture?
Where the bone fragments don’t pierce the skin
What is an open fracture?
The bone fragments from fracture pierce the skin
What is a displaced fracture?
Where the fracture has moved the bone out of it’s anatomical position
What is a transverse fracture?
Usually caused by direct force to the fracture site, and is a horizontal fracture
What is a spiral/oblique fracture?
Caused by violence transmitted through the limb from a distance, often due to twisting movements. The fracture is a diagonal line.
What is a crush/compression fracture?
Where there is a fracture in the cancellous bone (trabecular) and is a result of compression, and is often seen in osteoporosis, especially in the vertebrae.
What is a burst fracture?
This is where strong direct pressure leads to impaction (of a vertebral disc) which leads to a burst appearance. This only occurs in the short bones such as the vertebrae.
Where are burst fractures most likely to occur?
Thoraco-lumbar vertebral junction.
What is an avulsion fracture?
Where the bone fragment is torn off by a tendon or ligament
What is a dislocation/subluxation fracture?
Where a fracture involves a joint and results in mal-alignment of the joint surfaces
What is an impacted fracture?
Where the bone fragments are forced into each other
What is a comminuted fracture?
Where there are two or more bony pieces affected; usually the result of high-energy trauma
What are the two types of stress fracture?
Fatigue and insufficiency
What is a fatigue fracture?
Where there is abnormal stress on a normal bone leading to fracture
What is an insufficiency fracture?
When there is normal stress on an abnormal bone leading to a fracture
What is a greenstick fracture?
Where there is a bend in the bone without a complete fracture; tend to occur in children where the bones are softer.
What are the four stages of fracture healing?
Haematoma formation, fibrocartilaginous callus formation, bony callus formation and bone remodelling
Describe haematoma formation in fracture healing
The blood released from the broken vessels clots within 6-8 hours after the injury followed by swelling and inflammation to remove the dead bone cells (osteocytes) at the fracture site
Describe fibrocartilaginous callous formation in fracture healing
New capillaries organise the fracture haematoma into a granulation tissue known as a ‘pro-callus’. Fibroblasts and osteogenic cells then invade the pro-callus and make collagen fibres to connect the ends together followed by the production of fibrocartilage by chondroblasts. Inflammatory cells then appear and organise and resorb the clots as new capillaries form. The fibroblasts then enter and differentiate as chondrocytes which then produce collagen which bridges the fracture site cartilage and the trabecular bone that has been laid down.
Describe bony callus formation in fracture healing
Osteoblasts make woven bone, and this lasts 3-4 months.
Describe bone remodelling in fracture healing
Osteoclasts remodel the woven bone into compact and trabecular bone, and thereafter there is often no trace of the fracture line on x-rays.
Outline the process of fracture healing
Blood capillaries are damaged and the leaked blood forms clots followed by inflammation to remove the dead osteocytes. New capillaries then reorganise the haematoma and collagen is produced from invading fibroblasts which connects the two ends. Osteoblasts then make woven bone and thereafter bone remodelling takes place (woven into compact and trabecular bone)
