Bone Pathology And Soft Tissue Pathology Flashcards
What are the regions in the long bone
Epiphysis
Diaphysis
What is the epiphysis
Ends of the bone
What is the diaphysis
Shaft of the bone
What does an osteon unit have
Haverian canal
What are the haversian canal linked by
Volksmann canal
What are the 3 main functions of the bone
Mechanical: function for muscles
Endocrine regulation
Haemopoiesis (red bone marrow)
What is bone composed of
Water
Anorganic part
Organic part
What is the anorganic part
Calcium in the form of hydroxyapatite crystals
Inorganic salts
Fluorids
Trace elements
What is the organic part
Collagen fibres
Proteoglycans
What cells are involved in bone remodelling
Osteoprogenitor cells
Osteoblasts
Osteocytes
Osteoclasts
What cells does osteoprogenitor cells give rise to
Osteoblast and osteoclasts
What are osteocytes
Inactive form of osteoblasts
What are the types of bone that belong to the lamellar bone
Compact and cancellous
What is woven bone
Physiological bone in fertile development
When we see woven bone in adults is that normal
No it is pathological
What is achondroplasia
Autosomal dominant bone disease caused by FGFR3 mutation that inhibits chondrocyte proliferation
What happens when you block chrondrocyte proliferation in long bones
The epihyseal plate chrondrocyte proliferation decreases so you have shortening of the the long bones
What is brittle bone disease (osteogenesis imperfecta)
Autosomal dominant genetic disorder that affects type 1 collagen synthesis
Which cell decreases in activtiy in brittle bone disese
Osteoblast
What other parts of the body does the collagen disorder synthesis affect
Skin
Joints
Sclera
What is osteopetrosis (marble bone disease)
Autosomal recessive disorder
What occurs in osteopetrosis
- Carbonic anhydrase 2 deficiency (enzymes required for acidification and excretion of hydrogen ions)
- Acidification is required for a space that osteoclast sit in called howship lucunae
- There is therefore reduced osteoblast bone resorption
- This causes a systemic sclerosis
- Bone becomes prone to fracture
Which hormones are involved in regulating bone homeostasis
Parathormone (PTH) Calcitonin STH Oestrogen and androgen Steroid hormone Vitamin d and c
What happens to the boen when there is a disrupted hormonal homeostasis
Decreased or increased bone mass
What is a common disease of the bone that is associated with decreased bone mass
Osteoporosis
What is primary osteoporosis due to
Post menopausal
Senile
What is secondary osteoporosis due to
Hyperparathyroidism
Hypothyroidism
Multiple myeloma
Drugs: corticosteroids, anticoagulants, chemotherapy
How can vitamin d deficiency alao cause osteoporosis
Vitamin d deficiency leads to poor bone mineralisation this mobilises calcium and phosphoate ions from the bone leading to osteoporosis
What happens to the osteoblast activity in osteoporosis
Decreases
What is osteomalacia
Poor calcification that causes a delay of bone mineralisation usually due to vitamin d deficiency
Who does osteomalacia occur in
Adults
What is rickets
Osteomalacia occuring in children
What are the clinical features of rickets
Wide sutures in head Delayed closure of frontanelles Bowing of legs Pectus carinatum Swelling in wrist and ankle
What can hyperparathyroidism be
Primary
Secondary
What is primary hyperparathyroidism
Tumour (adenoma or carcinoma) or hyperplasia of the parathyroid gland
What is secondary hyperparathyroidism
Compensatory overactive parathyroid glands due to chronic renal failure
What role does pth have
Calcium homeostasis
What will hyperparathyroidism lead to
Osteoporosis of bone
What cells does PTH activate in the bone
Osteoclast
What is pagets disease
Disease of osteoclast dysfunction
What are the phases of pagets disease
- Osteolytic phase: increased osteoclast activity
- Mixed phase: bone tries to compensate to osteoblast activity is on
- Osteosclerotic phase
What is osteomyelitis
Infectious process of the bone
Wat is the route of entry of infection
- Contigous spread of adjoining soft tissue infection
- Direct inoculation secondary to trauma or surgery
- Haemtegenous bacterial emboli lodging in the bone
What are the features of ostemyelitis
Pain
Fever
Incresed WBC
Edema, erythema and tenderness of site of infections
What is potts disease
A type of osteomyelitis and is tuberuculosis of the spine due to haematogenous spread
What is the prefix for benign bone tumours
-oma
What is the prefix for malignant bone tumours
-sarcoma
What is a primary bone tumour in the osteocytes
Osteosarcoma
What is a primary bone tumour in the cartilage
Chondrosarcoma
What is osteoid osteoma
Benign tumour
Where does osteoid osteoma occur
Intracortical of long bones, small bone and vertebra
What are the symptoms of osteoid osteoma
Nocturnal pain relieved by aspirin and NSAIDs
What is echondroma
Benign cartilagenous tumour
What are the common sites of echondroma
Small bones of hands and feet
What are the background diseases that can occur in echondroma
Maffucis syndrome
Olliers disease
What is the treatment of echondroma
excision of the tumour
What is giant cell tumour of the bone
Locally agressive neoplasmis composed of neoplastic opiod mononuclear cells
What is the common site for giant cell tumour of the bone
End of long bone (epiphyseal)
What is the treatment of giant cell tumour of the bone
Denosumab
What is the action of denosumab
Blocks osteoclast acitvity and stops osteolytic part of tumour manifestation
What is high grade osteosarcoma
Malignant tumour that produces osteoid from tumour cells
What is the characteristic finding of osteosarcoma
Codmans trianlge
What is ewing sarcoma
Common bone sarcoma in children
Symptoms of ewing sarcoma
Fever
Weightloss
Leukocytosis
Mimicks osteomyelitis
What are the common cancers that can metastase to bone
Breast Prostate Lung Thryoid Kidney Neuroendocrne Colorectal Squamous cell carcinoma
