Musculo III

Question 1

Osteomyelitis: definition

Answer 1

acute or chronic infection or inflammation of the bone marrow and/or bone

“myelo”- spinal cord or bone marrow

Question 2

Osteomyelitis: cause of infection

Answer 2

direct from an open fraction or wound (exogenous)

seeding through blood (hematogenous)

spread from a contiguous site

vascular insufficiency (ex diabetic with cutaneous ulcers)

Question 3

Osteomyelitis: manifestations of acute

Answer 3

dull pain at the involved site, with or without movement

tenderness, warmth, erythema, and swelling may be present at site, and fever and chills may be present

Question 4

Osteomyelitis: chronic

Answer 4

usually secondary to an open wound

primary feature is sequestrum, an area of dead infected bone

Question 5

Osteomyelitis: diagnosis and treatment

Answer 5

radiography, MRI, CT scanning together with a bone biopsy

tx: often surgical debridement of necrotic material

Question 6

Neoplasms

Answer 6

most primary bone tumors are benign-most asymptomatic

osteochondroma most common benign tumor

osteoclastomas (giant cell tumor) can cause bone resorption and fractures

Question 7

Osteochondroma

Answer 7

is a cartilage capped bone spur on the external surface of a bone

typically persists as a painless mass near a joint or on axial skeleton

Question 8

Osteomyeitis: bone tumors

Answer 8

primary malignant tumors are rare, but one metastases are common

metastases from lung, breast, prostate cancers are especially rare-assoc with pain

osteosarcoma most common primary, malignant bone tumor-localized pain and show soft tissue mass large and tender to palpate

skeletal metastases are common

Question 9

Bone growth and maintenance: growth long bones

Answer 9

long bones lengthen at specialized cartilaginous structures (epiphyseal growth plates)

Chondrocytes in the plates multiply, hypertrophy, and ultimately calcify

Question 10

Bone growth and maintenance: maintenance

Answer 10

Once bones reach adult size, bone remodeling (resorption/formation) is critical for repair and maintenance

Question 11

Bone growth and maintenance: bone resorption

Answer 11

Osteoclasts are INDIRECTLY activated by factors such as parathyroid hormone (PTH) and vitamin D

Question 12

Bone growth and maintenance: bone formation

Answer 12

Activated osteoblasts synthesize osteoidthat includes type I collagen and calcium-binding proteins
(e.g., osteocalcin)

Osteocalcin often is used as a marker for bone resorption

Question 13

Osteoporosis: definition

Answer 13

Metabolic disease characterized by low bone mass, microarchitectural disruption, and skeletal fragility

Question 14

Osteoporosis: diagnosis T score

Answer 14

T-score

Standard deviation (SD) difference between a patient’s bone mineral density (BMD) and that of a young-adult reference population

T-score that is 2.5 SD or more below (i.e., -2.5) the young-adult mean BMD is defined as osteoporosis

T-score that is 1 to 2.5 SD below the young-adult mean is termed low bone mass (osteopenia)

Question 15

Osteoporosis: diagnosis Z score

Answer 15

Comparison of the patient’s BMD to an age matched population

Z-score of -2.0 or lower is considered below the expected range for age

T-and Z-scores assessment- usually determined by dual energy X-ray absorptiometry (DXA) of spine and hip

Question 16

Osteoporosis: secondary causes

Answer 16

–Advanced age, osteoblast activity decreases

–Sedentary lifestyle, exercise strengthens bone

–Poor nutrition, low calcium decreases bone mineralization and increases PTH secretion

–Drugs, e.g., corticosteroids stimulate bone resorption

–Hyperthyroidism, thyroid hormones increase bone resorption

–Low estrogen (menopause), estrogen decreases bone resorption

Question 17

Osteoporosis: treatment

Answer 17

General recommendations- adequate calcium, vitamin D, and exercise

Postmenopausal women:
General recommendations- Bisphosphonatesas first-line therapy
•Raloxifene(or hormone replacement therapy, HRT)
•PTH (teriparatide) for severe osteoporosis

Men:
•Similar to postmenopausal women (minus raloxifene and HRT)
•Testosteronetherapy considered for hypogonadal men

Question 18

Osteomalacia: definition

Answer 18

Decreased mineralization of newly formed osteoid at sites of bone turnover

Characterized by a gradual softening and bending of the bones; varying severity of pain

Question 19

Osteomalacia: primary causes

Answer 19

Insufficient calcium absorption from the intestine- low dietary calcium, a deficiency of vitamin D

Phosphate deficiency

Mineralization defects

Question 20

Rickets: definition

Answer 20

Defective mineralization of cartilage in the epiphyseal growth plates of children

•Ossification at the epiphyseal plates is delayed and new bone is undermineralized

Question 21

Paget disease

Answer 21

Focal disorder of bone metabolism characterized by an accelerated bone remodeling