Osteomyelitis/Septic Arthritis Schoenwald (Exam 1)

Question 1

What is osteomyelitis?

Answer 1

Infection of bone

Question 2

What is the most common bacterial cause of osteomyelitis?

Answer 2

Staph aureus

Question 3

Patients with sickle cell anemia are prone to osteomyelitis caused by what bacteria?

Answer 3

Salmonella

Question 4

T/F? Nearly all patients with osteomyelitis present with fever.

Answer 4

False - fever is not a good indicator of osteomyelitis

Question 5

Why is diabetes a risk factor for osteomyelitis?

Answer 5

Diabetic foot ulcers are typically painless, and wounds can reach the bone before a patient notices the wound.

Question 6

T/F? Deep wounds are the only way bacteria can be introduced to the bone, causing osteomyelitis?

Answer 6

False - osteomyelitis can be due to hematogenous spread of bacteria.

Question 7

What labs would you expect to be elevated in a patient with osteomyelitis?

Answer 7

Acute phase reactants, such as ESR and CRP.

CBC may show elevated white count.

Question 8

Do bone fractures increase risk of osteomyelitis?

Answer 8

Yes

Question 9

Name some risk factors for osteomyelitis.

Answer 9

Any condition that weakness the immune system such as: diabetes, organ transplant, chemotherapy, AIDS, kidney failure, sickle cell anemia
IV drug use, joint replacement, peripheral neuropathy, Peripheral vascular disease

Question 10

You are seeing a patient with a diabetic foot ulcer that you can probe down to the bone. The patient states the ulcer has been present for 3 weeks. You order an XR of the foot. What do you expect to see on the XR?

Answer 10

Cortical bone erosion, periosteal reaction, and lucency or osteolysis.

Question 11

You highly suspect osteomyelitis in a patient whos symptoms began 5 days ago. The XR shows now acute abnormalities. What do you do next?

Answer 11

Order an MRI.

Remember that abnormalities may not be seen in plain films until 7-15 days after onset.

Question 12

What is the surgical treatment for osteomyelitis?

Answer 12

Surgical debridement of bone

Question 13

What is the preferred empiric antibiotic therapy for osteomyelitis?

Answer 13

Vancomycin 1g IV q12 hours +/- rifampin 300-450mg po bid
AND
Ceftriaxone 2g IV qd

Question 14

For what duration should osteomyelitis be treated with IV antibiotics?

Answer 14

6 weeks

Question 15

What is the preferred treatment for osteomyelitis caused by MSSA?

Answer 15

Nafcillin 2g IV q4 hours or Cefazolin 2g IV q8 hours

Question 16

Just for fun flashcard

Who is Brodie and why did he want an abscess named after him?

Answer 16

A Brodie’s abscess is named after Sir Benjamin Collins Brodie, who first described the condition in the 1830’s.
He is good friends with Dr. Witwer.

Question 17

What is a Brodie’s abscess

Answer 17

A bone abscess that is walled off by the bodies immune system.

Question 18

What is the most common bone to be affected by a Brodie’s abscess?

Answer 18

The tibia

Question 19

What is the most common organism to cause a Brodie’s abscess?

Answer 19

Staph aureus

Question 20

You started empiric tx of an osteomyelitis and cultures now come back showing an MRSA infection. What changes do you make to the patients antibiotic therapy?

Answer 20

You can stop the ceftriaxone and continue with the vancomycin +/- rifampin

Question 21

You are seeing a patient who stepped on a nail, which penetrated through the bottom of his shoe and punctured the bottom of his foot, what organism should you worry about and what should you treat it with?

Answer 21

Pseudomonas, because it can live in the bed of shoes.

Treat with a fluoroquinolone (Cipro)

Question 22

What is the most common organism isolated in septic arthritis?

Answer 22

Staph aureus

Question 23

What organism might you suspect in a 28 year old, sexually active patient with septic arthritis?

Answer 23

Neisseria gonorrhoeae

Question 24

T/F? Previously damaged joints are more susceptible to septic arthritis.

Answer 24

True

Question 25

What bacteria do you expect to be isolated from a joint aspiration in a patient with reactive arthritis?

Answer 25

No bacteria - Reactive arthritis is triggered by an infection, but the joint itself does not become infected.

Question 26

Reactive arthritis is more common in patients who are _________ positive.

Answer 26

HLAB27

Question 27

What are some common infections to trigger reactive arthritis?

Answer 27

Chlamydia and various GI bugs (salmonella, Yersinia, Campylobacter, C Diff.)

Question 28

Is fever a more common symptom in patients with septic arthritis or osteomyeltits?

Answer 28

Septic arthritis

Question 29

What are the 3 most common joints involved in septic arthritis?

Answer 29

Knee Hip Shoulder

Question 30

What differences might you see in a patient with Gonococcal arthritis vs a patient with non-gonococcal arthritis?

Answer 30

Gonococcal lesions | Arthralgias of multiple joints

Question 31

Treatment for septic arthritis that is non-gonococcal?

Answer 31

MRSA risk - vancomycin | No MRSA risk - cefazolin (Ancef) or keflex (cephalexin)

Question 32

Treatment for gonococcal arthritis?

Answer 32

IV ceftriaxone x 2 weeks +/- doxycycline

Question 33

Hematogenous spread: | Sickle cell pts susceptible to what?

Answer 33

Sickle salmonella (get it?)

Question 34

Osteomyelitis Hematogenous spread Elderly and IV drug users susceptible to what organism?

Answer 34

Staph aureus

Question 35

Osteomyelitis | Sx?

Answer 35

``` Fever Bone/joint pain Elevated CRP/ESR Bone can be swabbed Wound present greater than 6 weeks ```

Question 36

Osteomyelitis | Risk factors?

Answer 36

``` Bone fx Any condition that weakens immune system: Diabetes Organ transplant Chemo AIDS Kidney failure IV drug use Joint replacement Sickle cell anemia PAD/PVD ```

Question 37

Osteomyelitis | Minimum weeks you must give Abx?

Answer 37

6 weeks | Targeted to organism

Question 38

Osteomyelitis | Tx with what Abx?

Answer 38

Vanco for staph/MRSA Nafcillin for MSSA Ceftriaxone for gram Pos

Question 39

Osteomyelitis What is the name for the bone abscess that can be encapsulated by the body’s immune defenses for years, most commonly assoc. with S aureus, most commonly affects tibia?

Answer 39

Brodie’s abscess

Question 40

Nail through tennis shoe into foot What organism? Drug of choice for tx?

Answer 40

``` Pseudomonas Ciprofloxacin (covers pseudomonas) ```

Question 41

Osteomyelitis Infectious arthritis v Reactive arthritis Which one has bacteria at/in the joint?

Answer 41

Infectious | Reactive is postexposure after infection clears

Question 42

Osteomyelitis Infectious arthritis Most caused by what organism? Hint: same as osteomyelitis

Answer 42

S aureus | N gonorrhoeae in sexaully active younger folk

Question 43

Osteomyelitis Reactive arthritis More common in those pts who have which gene that also causes ankylosing spondylosis?

Answer 43

HLAB27

Question 44

Osteomyelitis Reactive arthritis Is commonly caused by what organism?

Answer 44

Chlamydia | Also GI bugs

Question 45

Osteomyelitis Gonococcal arthritis Arthralgias of?

Answer 45

Multiple joints

Question 46

Osteomyelitis Gonococcal arthritis Sx: Asymetric?

Answer 46

Tenosynovitis