Bone Repair and Bone Disorders Study Guide Flashcards
If they are so strong, why can bones break?
During youth trauma breaks bone, during elderly years fractures and breaks result from thinner and weaker bones
What is the 1st step in fracture repair? What are the 2 ways this can be achieved?
Reduction
- Closed: clinician manipulates bone ends back into position
- Open: surgeon utilizes pins and wires to re secure bone ends
What determines the necessary time of immobilization for fracture healing?
- Fracture severity
- Which bone is fractured
- The patients age
Write out the 4 steps of fracture healing – include the relevant details of each step.
- Hematoma formation
Torn blood vessels hemorrhage
A mass of clotted blood, called a hematoma, is formed
Site is swollen, painful, and inflamed - Fibrocartilaginous formation
Capillaries grow into hematoma
Phagocytic cells clear debris
Fibroblasts secrete collagen fibers to span break and connect broken ends
Fibroblasts, cartilage, and osteogenic cells begin reconstruction of the bone
Create a cartilage matrix of repair tissue
Osteoblasts form spongy bone within matrix
Mass of repair tissue - Bony callus formation
Within a week, new trabeculae appear within the fibrocartilaginous callus
Fibrocartilaginous callus is converted into bony callus of spongy
Bony callus continues for about about 2 months - until a firm union forms - Bone remodeling
Begins during bony callus formation and continues for several months
Excess material on the diaphysis exterior and within the medullary cavity is removed
Compact bone is laid down to reconstruct shaft walls
Final structure resembles original structure - it responds to the same mechanical stressors
What is the blood clot that surrounds the fracture called?
Hematoma
What types of fibers are secreted to connect broken bones? What type of cell secretes these fibers?
Fibroblasts secrete collagen fibers to connect broken bone ends
During fracture repair, what type of bone is formed within the cartilage matrix?
Spongy bone
What is the name for the 1st type of callus formed during fracture repair? This type of callus becomes a __________ callus.
- fibrocartilaginous
- bony callus
What is necessary for the final remodeling of the bone?
Excess material on the diaphysis exterior and within medullary cavity is removed, compact bone is laid down to reconstruct shaft walls
Bone disorders are caused by what?
Imbalances between bone deposition and resorption
Define osteomalacia, rickets, osteoporosis, and Paget’s disease.
- Osteomalacia
Bones are poorly mineralized
Osteoid is secreted, but calcium salts are not adequately deposited
Result: soft/weak bones + pain with weight bearing - Rickets
Osteomalacia in children
Cause: deficiency in vitamin D or insufficient dietary calcium
Result: bowed legs or other bone deformities - Osteoporosis
Group of diseases in which bone resorption > bone deposition
Bone matrix remains normal, but bone mass declines
Bones become porous and light - very likely to fracture under minimal stresses
Bones most susceptible to fracture are the neck of the femur and the vertebrae - Paget’s disease
Excessive or haphazard bone deposit and resorption - causes bone to grow quickly and poorly
High ratio of spongy to compact bone with reduced mineralization
Typically occurs in the spine, pelvic, femur, or skull
Rarely occurs before age 40
Affects about 3% of elderly people in North America
Cause is unknown - possibly triggered by a viral infection
treatment : bisphosphonates and calcitonin
What are some risk factors for developing osteoporosis? At what age do most people reach their maximal bone density?
- Older, post menopausal women are most affected
- 30% of women aged 60+, 70% of women aged 80%
- Men are less affected - testosterone plays a protective role
- Insufficient exercise
- Diet poor in calcium + protein
- Smoking and alcohol use
- Genetic
- Hormone - related conditions
- Hyperthyroidism
- Diabetes mellitus
- Use of certain medications - especially steroids
Why are women more affected by osteoporosis than men?
Because of the decrease in estrogen which stimulates bone growth
What are some things that you would suggest to a patient for treating osteoporosis? How about preventing it?
- treatment
Calcium and vitamin d supplements
Regular weight bearing exercise
Hormone replacement therapy - can slow bone loss but can increase risk of heart attack, stroke, and cancer - Prevention
Plenty of dietary calcium in early adulthood
Reduced consumption of carbonated beverages and alcohol
Plenty of weight bearing exercise
Anatomically speaking, what do you see with Paget’s Disease? What bones are most likely to be affected?
- Typically occurs in femur, spine, pelvis, skull
- Excessive or haphazard bone deposit and resorption - causes bone to grow quickly and poorly
