metabolic bone disease

Question 1

What endocrine disorders can contribute to osteoporosis?

Answer 1

-hyperthyroid, high cortisol, low estrogen, hyperparathyroidism

Question 2

In addition to bisphosphonates, what treatments are available for osteoporosis?

Answer 2

selective estrogen receptor modulators like raloxifene or pulsatile teriparatide (recombinant parathyroid hormone) stimulate osteoblasts and bone remodeling. This can be used for up to 2 yrs
(possibly denosumab? monoclonal antibody against RANK-L)

Question 3

What is osteopetrosis?

Answer 3

increased bone density caused by impaired osteoclast activity

Question 4

What are clinical manifestations and labs seen with osteopetrosis?

Answer 4

pts have incr fracture risk, possible blindness or deafness, neuro sx from compression of nerves. they have decr Hgb and hct, incr acid phosphatase, and increased CK.

Question 5

What is the treatment for Paget’s disease of bone?

Answer 5

-bisphosphonates, calcitonin

Question 6

what are the lab findings in paget’s disease of bone?

Answer 6

normal calcium and phosphorus, incr ALP, incr hydroxyproline in the urine

Question 7

What are the findings from joint aspiration in patients with gout?

Answer 7

-needle-shaped negatively birefringent crystals and WBCs

Question 8

What are medical options for treating chronic gout?

Answer 8

allopurinol (inhibits uric acid formation) or probenecid (inhibits kidney uric acid resorption)

Question 9

What are the crystals made of in pseudogout?

Answer 9

CPPD: calcium pyrophosphate dihydrate deposition disease (these positively birefringent and look like rhomboids)

Question 10

What other disease are associated with pseudogout?

Answer 10

in familial cases, look for DM and hyperparathyroidism

Question 11

What is the most common cause of septic arthritis (pathogen-wise)? What about other pathogens?

Answer 11

S. aureus (but it coud be gonorrhea). Can also be gram negative rods if pts are immunosuppressed or otherwise ill

Question 12

What are complications of septic arthritis and what are risk factors that increase the likelihood of those complications?

Answer 12

• cartilage destruction due to body’s own inflammatory response
• even greater risk if pt has preexisting arthritis

Question 13

What are the lab findings for septic arthritis?

Answer 13

-incr WBCs (often >50,000), usually PMN predominant, decreased glucose, may or may not have positive gram stain and culture (gonorrhea in particular often has false negatives)

Question 14

How many leukocytes typically seen in inflammatory arthropathies (RA, gout, pseudogout)

Answer 14

-5,000 to 50,000

Note that for osteoarthritis or trauma usually less than 2,000 WBCs/mm3

Question 15

What is the tx for septic joint?

Answer 15

• incision and drainage (unless for gonorrhea, in which case not always needed)
• abx:
• penicillinase resistant penicillin for S aureus, ceftriaxone and doxycyline for gonorrhea, aminoglycoside for gram negative

Question 16

What is the most common pathogen of osteomyelitis?

Answer 16

S. aureus. This is even true for patients with sickle cell disease (when you should think about salmonella too) or IV drug abuse (when you should think about pseudomonas)
pseudomonas is the second most common pathogen

Question 17

When must I&D be performed for osteomyelitis?

Answer 17

abscess inside the bone or in surrounding tissue

Question 18

What are the 3 stages of lyme disease?

Answer 18

1. Early localized: fever, chills, erythema chronicum migrans
2. early disseminated stage: myocarditis (wks-months), cardiac arrhythmias and heart block, bell’s palsy, neuropathies, aseptic meningitis
3. late disseminated stage: months-yrs, see chronic synovitis, monoarthritis or oligoarthritis, polyneuropathies, subacute encephalitis