Metabolic bone disease Flashcards
1
Q
Vitamin or nutritional deficiencies causes of osteporosis (4)
A
- Osteomalacia (Looser zone).
- Alcoholism.
- Hypophosphatemia.
- Scurvy (Wimberger sign).
2
Q
Endocrine causes of osteoporosis (2)
A
- Hyperparathyroidism.
- Cushing disease or increase in endogenous/exogenous steroids.
3
Q
Diffuse malignancy cause of osteoporosis
A
Mylomatosis
4
Q
Genetic causes of osteoporosis (3)
A
- Osteogenesis imperfecta.
- Gaucher disease.
- Anemia (Sickle cell and thalassemia).
5
Q
Causes of focal osteopenia (3)
A
- Immobility / Disuse.
- Sudeck’s atrophy.
- Transient regional osteoporosis of the hip.
6
Q
Scurvy
A
- Hypovitaminosis C.
- Generalized osteopenia as osteoblast require vitamin C to form mature osteoid tissue.
- Manifestations: Subperiosteal hemorrage, hemarthrosis, retrobulbar and intracraneal bleeding.
- Pediatric signs:
- Wimberger ring sign: Increased epiphyseal sclerosis due to disorganized epiphyseal ossification.
- Pelkin’s fracture: Metaphyseal corner fracture.
- Frankel line: Dense metaphyseal line.
- Trümmerfeld zone: Underlying lucent band.
7
Q
Osteomalacia
A
- Faulty mineralization of bone matrix due to vitamin D deficiency.
- It is called rickets in children.
- Manifests as diffuse osteopenia.
- Looser zone: Cortical stress fracture filled with abnormal, poorly mineralized osteoid, appears as a radiolucency through the cortex.
- Common zones: Medial proximal femurs, distal scapulae and pubic bones.
- May be complicated by insufficiency fracture.
8
Q
Acromegaly
A
- Excress growth hormone.
- If physes are open it will cause gigantism.
- If they are closed it will cause acral (distal) growth and widening.
- Head: Enlargement of frontal sinuses, thickening of cranial bones, enlarged jaw.
- Hands: Beak-like osteophytes of metacarpal heads and spade-like overgrowth of the distal phalanges.
- Feet: Increased heel-pad thickness.
9
Q
Hyperparathyroidism
A
- Recklinghausen disease of bone.
- Excess of PTH.
- Primary (ex. PT adenoma), secondary (ex. renal failure), or tertiary (prolonged secondary HPT).
- Primary: CPPD deposition may occur.
- Secondary: Soft-tissue calcification, periosteal reaction and sclerosis.
- Complications: Insufficiency fracture and increased propensity for ligaments and tendons to rupture.
10
Q
Hyperparathroidism RX findings (7)
A
- Skull: Salt-and-pepper skull.
- Hands: Subperiosteal resorption of the radial aspects of the 2° and 3° middle phalanges.
- Clavicle: Subperiosteal resorption of the distal aspect.
- Knee: Subperiosteal resorption of the medial proximal tibial metaphysis.
- Teeth: Loss of lamina dura of the tooth socket.
- Brown tumors.
- Diffuse osteopenia.
11
Q
renal osteodysthrophy
A
- Combined effect of vitamin D deficiency and secondary HPT from prolonged renal failure.
- Increased risk of osteomyelitis, avascular necrosis (if on steroids) and amyloidosis (from chronic dialysis).
- Rugged jersey spine: Sclerotic striping of the vertebral bodies endplates.
- Soft tissue and vascular calcifications are frequent.
12
Q
Hypoparathyroidism
A
Produces Metastatic deposition of calcium, in particular in subcutaneous tissues and basal ganglia.
13
Q
Pseudo-hypoparathyroidism
A
- PHP is due to an defect in the PTH recector.
- Pseudo PHP PTH levels and receptor are normal but the phenotype is identical of PHP.
- Obesity, round facies, short stature and brachydactyly.
- Short metacarpal of the 4° or 5°.
14
Q
Tyroid acropachy
A
Rare cause of diaphyseal periosteal reaction of multiple bones including the metacarapals, metatarsals and phalanges, seen in the setting of treated hyperthyroidism.
15
Q
Paget disease
A
- Progressive disturbance of osteoclastic and osteoblastic regulation seen in older adults.
- Paramyxovirus may be involved.
- May cause OA, pathologic fracture and malignant degeneration to osteosarcoma.
- Commonly affects: Skull, spine, pelvis.
- Followed by: articular end of femur, proximal tibia and proximal humerus.
- Rare: Ribs and scapula.
- Three sequential phases: Osteolytic, mixed lytic and sclerotic, and sclerotic.
- Chronic paget shows thickening of the cortex, coarse irregular pattern and expansion of bone (Caricature appearance).
- Paget of the skull, vertebral bodies and pelvis (each with their own card).
16
Q
Paget of the skull
A
- Osteolytic phase (phase I): Sharply marginated geographyc lytic region called osteoporosis circumscripta.
- Mixed phase (Phase II): Cotton wool skull (picture).
17
Q
Paget of the vertebral bone
A
- Mixed phase (Phase II): Picture frame or an ivory vertebral body.
18
Q
Paget of the pelvis
A
- Assymetric coarsened trabecular thickening, with thickening of the iliopectineal and ilioischial lines.
- Acetabular protusio may occur.
19
Q
Paget of the long bones
A
- Lytic phase (Phase I): Progresses fro the proximal articular end of bone into the diaphysis with a sharply marginated border (Blade of grass or flame-shaped margin).
- May cause coxa vara deformity of the proximal femur.
21
Q
Osteopetrosis
A
- Deficiency of osteoclastic carbonic anhydrase, leads to inability of osteoclasts to resorb bone.
- Diffuse, marked sclerosis of the entire skeleton.
- Bones are brittle, leads to multiple fractures.
- Vertebral bodies may have a sandwich or rugged jersey (similar to osteodystrophy), but with greater bone sclerosis.
22
Q
Gaucher disease
A
- Autosomal recessive defect in glucocerebrosidase, leading to abnormal cerebroside deposition in altered macrophages called gaucher cells.
- Gaucher cells cause: Bone infarctions, medullary expansion and hepatosplenomegaly.
- Erlenmeyer flask deformity of long bones (result of abnormal modeling).
- H-Shaped vertebral bodies due to endplate avascular necrosis (also present in sickle cell disease).
24
Q
Myelofibrosis
A
- Progressive fibrosis of bone marrow in older patients.
- Anemia and splenomegaly.
- Bone marrow fibrosis leads to diffusely sclerotic bones.
25
Q
Mastocytosis
A
- Proliferation of mast cells.
- Result in either diffuse or patchy sclerosis from the reaction of the marrow to the infiltrating mast cells.
