21- Bone Disease Flashcards
What is osteoporosis?
It is a representation of low bone density. It is osteoclast activity that is more robust that of osteoblast activity.
How does osteoporosis appear on radiographs?
- Radiolucent
- Poorly demarcated
What is osteopenia?
It is a less severe level of low bone density that is sometimes considered as a precursor to osteoporosis.
What does osteoporosis look histologically?
1.) Thin cortex
2.) Fewer and thinner trabeculae
3.) Widely spaced trabecule
What does osteoporosis look clinically?
Like fragile bones
Susceptibility to fracture
What are some mediators involved with osteoporosis?
1.) TNF (tumour necrosis factor)
2.) RANK ligand is blocked
What are the three types of osteoporosis?
1.) Postmenopausal osteoporosis
2.) Aging osteoporosis
3.) Idiopathic osteoporosis
What are the treatments of osteoporosis?
1.) Bisphosphonates
2.) Estrogen replacement therapy
3.) Calcitonin
4.) Calcium
What is osteopetrosis?
It is known as Albers-Schonber Syndrome and Marble Bone Disease.
What are the causes of osteopetrosis?
It is the inherited failure of normal osteoclast function. May occur due to AD or AR inheritance.
What are the demographics of osteopetrosis?
- men = women
- onset is usually infancy
- affects all bones
What are the clinical features of osteopetrosis?
1.) Pathologic fracture
2.) Osteomyelitis
3.) Impingement of cranial nerves
4.) Delayed tooth eruption
What are the radiographic indications of osteopetrosis?
- Generalized increase in bone density (really radiopaque)
What is the histology of osteopetrosis?
1.) Thick, lamellar bone
2.) Small marrow spaces
3.) May see inflammatory cells if there is concurrent osteomyelitis
What is the treatment of osteopetrosis?
1.) Manage osteomyelitis with antibiotics. This is critical to prevent dental infection in these patients
What is Vitamin D? And what is its responsibility?
It is a fat-soluble steroid hormone that helps directly maintain calcium levels and indirectly affects phosphorus levels.
What does a deficiency of vitamin D result into?
It leads to rickets in children or osteomalacia in adults.
What are the clinical signs and symptoms of Vitamin D deficiency?
- Growth delay
- Defects at costochondral junction (rachitic rosary)
- Bowed legs
- Osteoporosis
- Cognitive problems
- Diffuse bone pain
- Increased risk of bone fracture
What are the head and neck signs and symptoms of Vitamin D?
Enamel Hypoplasia
Enamel hypocalcification
Frontal bossing
What is the treatment of Vitamin D deficiency?
Vitamin D and Calcium supplementation
What is hypoparathyroidism?
It is when there are low levels of parathyroid hormone due to:
- latrogenic damage to parathyroid gland
- autoimmune destruction of the gland
What are the key roles of PTH? (parathyroid hormones)
1.) Regulates calcium levels
2.) Decrease calcium -> Increase PTH -> Increase calcium levels
3.) Increase calcium resorption in kidneys
4.) Increase calcium release from bone
5.) Increase phosphate excretion from kidneys
6.) Increase Vitamin D production -> increase calcium absorption in the intestine/GI system
What are the clinical signs and symptoms of hypoparathyroidism?
- Problems related to low calcium (hypocalcemia)
- Tetany:
Trousseau’s sign
Chvostek’s sign - Tingling and numbness
- Arrythmia
- Seizures
What is Chvostek’s sign in Hypoparathyroidism?
When there is twitching of the upper lip when the facial nerve is hit.
What is hyperparathyroidism?
It is when there is an elevated level of PTH.
What occurs if there is an elevated of PTH?
- increase in calcium absorption
- increase calcium resorption from kidneys
- increase bone resorption
What are the causes of elevated PTH?
- an increase secretion from pituitary
- primary hyperparathyroidism
- renal disease
What are the main clinical signs and features of hyperparathyroidism?
Stones, bones, abdominal groans, thrones and psychiatric overtones
What are head and neck findings of hyperparathyroidism?
1.) Ground glass bone
2.) Loss of lamina dura
3.) Cyst like radiolucencies
What are the treatment methods for hyperparathyroidism?
1.) Remove pituitary tumor
2.) Assess and treat kidney disease
3.) Remove parathyroid glands
What is Paget’s disease?
It is known as Osteitis Deformans, which is an increase in bone breakdown and formation. This occurs when the remodeling is disorganized, when there is more osteoblastic activity than osteoclastic.
What are the clinical signs and symptoms of paget’s disease?
1.) Weak, misshapen bones
2.) Increase in bones/joints
3.) Increase risk of osteosarcoma
What are the 3 distinct phases of Paget’s disease?
1.) Osteolytic phase (Bone breakdown)
2.) Mixed Phase (both bone breakdown and bone formation)
3.) Osteosclerotic phase (bone formation)
What are the clinical features of Paget’s Disease?
1.) Asymptomatic bone enlargement
2.) Bowing of legs
3.) Elevated alkaline phosphatase levels
4.) Normal calcium and phosphate levels
5.) Vision loss
6.) Anemia
7.) Increased infection risk
What is the radiographic presentation of Paget’s disease?
-Classic wool presentation of “Cotton wool”
- has a ressemblance to cemento-osseous dysplasia
What are the treatment methods of paget’s disease?
1.) Mild cases require no treatment
2.) Bisphosphonates
3.) Surgical reduction
4.) Be aware of risk of osteosarcoma
What is Fibrous dysplasia?
A developmental development of bone. Abnormality in the development of bone.
What is the cause of Fibrous Dysplasia?
- A mutation in the GNAS1 gene
Where does Fibrous Dysplasia typically present itself?
First present in children
In the posterior maxilla is the most common head and neck location.
What are the clinical features of Fibrous Dysplasia?
1.) Painless bone expansion
2.) Cortical expansion
3.) Ground glass radiopacity
4.) Poorly demarcated: blend with normal bone
5.) Lamina dura disrupted
6.) Teeth may become separate
What is the difference between the Monostotic fibrous dysplasia vs. Polyostotic Fibrous dysplasia?
Monostotic fibrous dysplasia (craniofacial fibrous dysplasia) involves one bone while the polyostotic fibrous dysplasia involves multiple bones.
What are the 2 major variants of Polyostotic Fibrous Dysplasia?
1.) Jaffe- Lichtenstein Syndrome
2.) McCune-Albright Syndrome
What are the feature of Jaffe-Lichenstein Syndrome?
- Cafe au lait spots
- Polyostotic fibrous dysplasia
What are the features of McCune-Albright Syndrome?
- Cafe au lait spots
- Polystotic fibrous dysplasia
- Endocrrinepathies: sexual precocity, hyperthyroidism, pituitary adenoma
What are the treatment and prognosis of Fibrous dysplasia?
1.) usually burns out and stops
2.) Tissue does not generally return to normal
3.) Bisphosphonates are often provided
4.) Surgical recontouring may be required
What is osteosarcoma?
It is a malignancy of osteoblasts, it is also known as the most common primary bone cancer.
What are the demographics of osteosarcoma?
Found in the second decade of life
Affects patients around the age of 10 years old than osteosarcoma of long bones
What are the 3 distinct histologic variants of osteosarcoma?
1.) Osteoblastic
2.) Fibroblastic
3.) Chondroblastic
What are the clinical and radiographic features of osteosarcoma?
1.) Aggressive growth
2.) Moth-eaten radiolucency
3.) Mixed radiolucency/radiopacity
4.) Sun-burst pattern
5.) Widened PDL space
6.) Painful
7.) Can metastasize
What is the treatment for osteosarcoma?
Radical surgery required
Adjunctive chemotherapy and radiation therapy
poor long term survival
