Bone Fractures (Breaks)
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Transcript of Bone Fractures (Breaks)
Bone Fractures (Breaks) Bone fractures are classified by:
The position of the bone ends after fracture (displaced vs. nondisplaced)
The completeness of the break (complete vs. incomplete)
The orientation of the bone to the long axis (linear vs. transverse)
Whether or not the bones ends penetrate the skin (compound vs. simple)
As well as…
Common Types of Fractures
Table 6.2.1
Common Types of Fractures
Table 6.2.2
Common Types of Fractures
Table 6.2.3
Stages in the Healing of a Bone Fracture1. Hematoma formation
(immediate – 1st day or 2) Torn blood vessels
hemorrhage
A mass of clotted blood (hematoma) forms at the fracture site
Site becomes swollen, painful, and inflamed
Figure 6.13.1
Stages in the Healing of a Bone Fracture2. Fibrocartilaginous callus
forms (few days – week or 2) Granulation tissue (soft callus)
forms a few days after the fracture
Capillaries grow into the tissue and phagocytic cells begin cleaning debris
Figure 6.13.2
Stages in the Healing of a Bone Fracture Fibrocartilaginous callus forms when:
Osteoblasts and fibroblasts migrate to fracture
Fibroblasts secrete collagen fibers to connect bone (some become chondroblasts = cartilage)
Osteoblasts begin forming spongy bone
Osteoblasts furthest from capillaries secrete cartilaginous matrix that later calcifies
Stages in the Healing of a Bone Fracture3. Bony callus formation (few
weeks – 2 to 3 months) More bone trabeculae
appear in fibrocartilaginous callus
Fibrocartilaginous callus converts into a bony (hard) callus = firm union
Figure 6.13.3
Stages in the Healing of a Bone Fracture4. Bone remodeling (up to
several months after bony callus)
Excess material on bone shaft exterior and in medullary canal removed
Compact bone laid down to reconstruct shaft walls
Figure 6.13.4
Homeostatic Imbalances Osteomalacia - inadequately mineralized bones (soft
and weak) in adults
Main symptom = pain when weight is put on affected bone
Insufficient calcium in diet, or vitamin D deficiency Rickets – inadequately mineralized bones of
children
Bowed legs and deformities of the pelvis, skull, and rib cage
Insufficient calcium in the diet, or vitamin D deficiency
Example: Infants of breastfeeding mothers deficient in Vitamin D will also be Vitamin D deficient and develop rickets
Osteoporosis – bone-thinning disease (reabsorption outpaces deposition)
30% of women over age 60-70 (70% by 80); 20% men over 70 Makes bones fragile and fracture-prone (even a sneeze
can cause fracture) Often results in vertebral collapse (broken hips)
Osteoporosis: Treatment Calcium and vitamin D supplements
Increased weight-bearing exercise
Hormone (estrogen) replacement therapy (HRT) slows bone loss
Increased risk of cancer and cardiovascular disease, yikes!
Statins increase bone mineral density
Paget’s Disease – haphazard and excessive bone deposit and resorption
High ratio of spongy to compact bone
Can cause spotty weakening of bone, pain, deformity (spine, pelvis, femur, skull)
Osteoclast activity wanes, but osteoblast activity continues
Possibly viral, 3% of Americans over 40
Treated with drugs, calcitonin