Lecture 2 - finished Flashcards
What is the main complication of osteoporosis?
Fracture
How is bone lost in osteoporosis?
Resorption of bone is greater than formation of bone
Causes of generalised osteoporosis
GDNEIM
Genetic (congenital)
Deficiency states
- scurvy
- malnutrition
- protein deficiency
- alcoholism
Neoplastic
- myeloma
- lymphoma
- leukaemia
Iatrogenic
- Heparin induced
- Dilantin induced
Miscellaneous
- involutional
- postmenopausal
- Amyloidosis
- paraplegia
Risk factors for osteoporosis type 1
Female Premature menopause/postmenopausal Caucasian >65 Thin/small bone structure Family history of osteoporosis Sedentary lifestyle Cigarette smoking Alcohol abuse Low calcium intake High caffeine consumption
Is osteoporosis the most common metabolic disease of bone? If not, what is?
Yes it is.
What is the histology of osteoporosis?
Reduced cortical thickness Reduced number of trabeculae Reduced size of trabeculae Normal chemical composition Normal mineralisation
What are the main manifestations of type 2 osteoporosis?
Femoral neck # Proximal humerus # Proximal tibial # Pelvic # Vertebral #
What serum results would you find in osteomalacia/rickets?
25(OH)D3 = extremely low 1,25(OH)sD3 = extremely low Phosphate = low Alkaline phosphatase = increased Ca2+= decreased/normal PTH = increased Urinary Ca2+ = Decreased
In terms of patterns of bone loss, what does:
- normal matrix
- deficient mineralisation
usually mean?
Osteomalacia
What radiological findings can be expected with osteoporotic bone?
Decreased radiodensity (needs more that 30% bone loss)
Prominence of cortical end plates
Loss of horizontally oriented trabeculae
Wedge fractures
What radiological findings would you expect to see with osteomalacia?
Demineralisation especially in the spine, pelvis and lower extremities
Incomplete ribbon-like demineralisation of the cortex (pseudofractures)
Bone softening manifesting as:
- bowing of long bones
- vertical shortening of vertebrae
- flattening of pelvic bones
In terms of patterns of bone loss, what does:
- normal matrix and normal mineralisation
- increased resorption
usually mean?
Hyperparathyroidism
What are the ssx of osteoporosis?
Usually asymptomatic, may manifest as aching bone pain esp in the back.
What radiological findings would you expect with a patient with rickets?
Cup shaped diaphyseal ends
Spotty rarefaction at diaphyseal ends
Distance between the end of the radius and the metacarpal bones seems increased because the bone ends are not mineralised
Bending of bones
How would you diagnose rickets/osteomalacia?
Hx of inadequate vit D intake
Xray
Clinical picture
What are some DD’s for rickets/ostemalacia?
Hyperparathyroidism
Hyperthyroidism
Postmenopausal osteoporosis
Cushing syndrome
What are some causes of Vit D deficiency?
Dietary lack Increased intake of phytates Increased phosphate intake Decreased exposure to sunlight Malabsorption syndromes
What is the epidemiology of type 2 osteoporosis?
Greater than 70 years of age
2 times more common in females
Gradual onset
Age related
What are the ssx of rickets in 1-4 year olds?
Enlargement of the epiphyseal cartilages at the distal end of the radius, ulna, tibia, and fibula
Kyphoscoliosis
Bowleg
Delayed walking
What type of bone is lost in type 2 osteoporosis?
Both trabeculae and cortical bone
What are the clinical manifestations of crush fractures?
Acute, non radiating pain
Aggravation of pain by weightbearing
+/- local tenderness
Subsides within days to weeks
What is the aetiology of type 2 osteoporosis?
Possible:
- age related decreased in Vit D synthesis
- age related resistance to Vit D activity
Is osteoporosis a disease?
No, it is an outcome secondary to a number of pathological processes. It is caused by a group of diseases which have a final common pathway
What are the pathological events of osteomalacia in adults?
Defective calcification of growing bone
Hypertrophy of epiphyseal cartilage
Cessation of diaphyseal calcification
Bone resorption in diaphyses
….same as children.. however pathological changes are not confined to the ends of long bones.
What are the main manifestations of type 1 osteoporosis?
Vertebral crush fractures
Distal radius fractures (colles fractures)
What are the ssx of rickets in older infants?
Delayed sitting/crawling
Bossing of the skull bones
Costochondral beading (rachitic rosary)
Delayed fontanelle closure
What are the classifications of osteoporosis?
Generalised (diffuse)
Localised (regional)
What are the pathological events of rickets in children?
Defective calcification of growing bone
Hypertrophy of epiphyseal cartilage
Cessation of diaphyseal calcification
Bone resorption in diaphyses
Define involutional
A progressive degeneration occurring naturally with age resulting in shrivelling of organs or tissues
What are the ssx of rickets in children over the age of 4?
Pain on walking
Bow legs
Knock knees
What laboratory manifestations can be seen in primary and secondary osteoporosis?
Serum calcium: normal in primary
Serum P: normal in primary
ESR: normal in primary
Serum alk phosphatase: increased in #’s
PTH: Decreased in type 1, increased in type 2
Hypercalciuria: occurs in 20% of postemenopausal osteoporotic women.
Define frontal bossing. What causes it?
Definition: Abnormal prominence of the forehead
Cause: Due to the premature closure of the anterior portion of the sagittal suture resulting in compensatory expansion of the frontal diploe.
What are the main function of vitamin D?
Increased intestinal absorption of Ca2+ Promotion of normal bone formation Promotion of normal bone mineralisation Decreased renal loss of Ca2+ Removal of Ca2+ from bone
In terms of patterns of bone loss, what does:
- deficient matrix
- normal mineralisation
usually mean?
Osteoporosis
What are osteomalacia and rickets? How do they differ?
They are conditions that develop when people are Vit D deficient.
Rickets occurs in children, osteomalacia occurs in adults.
At what ages does type 1 osteoporosis usually occur?
51-75 years of age
What are the classifications of generalised osteoporosis?
Primary:
- Type 1: (postmenopausal)
- Type 2: (involutional)
- Idiopathic
Secondary:
- Endocrine
- Drug induced
- Miscellaneous
What causes delayed fontanelle closure in rickets?
Thickening of the skull develops with delays the closure of the anterior fontanelle
Where are the typical fractures that occur in osteoporosis?
Vertebral crush fracture
Fracture occurs with minimal trauma or no trauma
Usually occurs at T8 or below.
What are the ssx of rickets in neonates?
Restlessness
Poor sleep
Decreased skull mineralisation (craniotabes = thin soft skull bones)
What type of bone is lost in type 1 osteoporosis?
Spongy/cancellous bone
Define osteoporosis
Generalised progressive diminution in bone tissue mass per unit volume of bone (ie density)
The ratio of mineral to organic elements remains unchanged in the remaining morphologically normal bone.
What are the main causes of secondary osteoporosis?
Endocrine:
= glucocorticoid excess
= hyperthyroidism
= DM
Drug induced:
= Cortisone’s
= Ethanol
= Tobacco
Miscellaneous causes:
= prolonged immobilisation
= chronic renal failure
= R.A
Causes of localised osteoporosis
Localised (regional)
- immobilisation
- disuse
- pain
- infection
