Injury + Healing Flashcards
What are the 3 mechanisms of bone fracture?
- Trauma
- Stress
- Pathological
What are the 2 main types of trauma fractures?
- Low energy
* High energy
How does a stress fracture occur?
overuse ➡ stress exerted on bone is greater than bones capacity to remodel ➡ bone weakening ➡ stress fracture ➡ risk of complete fracture
What is a stress fracture?
fracture caused by abnormal stresses on normal bone
What is a pathological or insufficiency fracture?
fracture caused by normal stresses on abnormal bone
What are 6 causes of pathological fractures?
- osteoporosis
- paget’s disease
- osteogenesis imperfecta
- vitamin D deficiency
- osteomyelitis
- malignancy
What is the difference between osteopenia + osteoporosis?
- penia = not so severe bone loss, T-score of -1 to -2.5
* porosis = more severe bone loss, T-score of -2.5 or less
What is osteopenia + osteoporosis?
- OC activity > OB activity
- bone microarchitecture is disrupted
- more common in females (F : M , 4 : 1)
What is primary osteoporosis? What is it caused by?
- caused by natural age-related changes to bone
* e.g. postmenopausal or senile
What is secondary osteoporosis? What is it caused by?
- caused by other clinical disorders or conditions
- e.g. hypogonadism, glucocorticoid excess, alcoholism
- more common in males
What is congenital osteogenesis imperfecta?
- hereditary autosomal dominant or recessive disorder
- causes a reduction in Type I Collagen due to:
- Decreased secretion
- Production of abnormal collagen
- results in insufficient osteoid production
What is Paget’s disease?
• excessive bone break down + disorganised remodelling
• leading to deformity,
pain, fracture or arthritis
What are 4 examples of primary bone cancers?
- Osteosarcoma
- Chondrosarcoma
- Ewing sarcoma
- Chordoma
What is secondary bone cancer?
when tumours from other tissue metastasise to bone
What 5 most common tissues to cause secondary bone cancer?
- prostate (blastic)
- breast (blastic + lytic)
- kidney (lytic)
- thyroid (lytic)
- lung (lytic)
What 3 ways in which fractures are patterned or classified?
- soft tissue integrity
- bony fragments
- movement
What are the 2 types of soft tissue integrity fractures?
- open
* closed
What are the 3 types of bony fragment fractures?
- greenstick
- simple
- multifragmentary
What are the 2 types of movement fractures?
- displaced
* undisplaced
What are the general principles of tissue healing? What cells do they involve?
- bleeding (blood)
- inflammation (neutrophils + macrophages)
- new tissue formation (blasts)
- remodelling (macrophages, OCs + OBs)
What does the inflammation phase of fracture healing involve?
- haematoma formation
- release of cytokines
- granulation tissue + blood vessel formation
What does the repair phase of fracture healing involve?
- soft callus formation (Type II collagen - cartilage)
* converts to hard callus (Type I collagen - bone)
What does the remodelling phase of fracture healing involve?
- callus responds to activity, external forces, functional demands + growth
- excess bone is removed
What is Wolff’s Law?
bone grows and remodels in response to the forces that are placed on it
