OSTEOMYELITIS & SEPTIC ARTHRITIS

Question 1

How the pathogen reach the bone ?

Answer 1

1- Hematogenous route 2- Contiguous soft tissue focus ( post operative infection, contaminated open fracture, soft tissue infection , puncture wounds)
3- In association with peripheral vascular disease (diabetes mellitus ,severe atherosclerosis, vasculitis)
• May have a short duration ( few days for hematogenous acquired
infection) or may last several weeks to months ( if secondary
to contiguous focus of infection).

Question 2

S. aureus, group B Streptococcus,Gram
negative rods (eg. E. coli,  Klebsiella ). 

Common in ?

Answer 2

Infants

Question 3

S. aureus, group A Streptococcus & H.
influenzae

Common in ?

Answer 3

Children

Question 4

S. aureus

Common in ?

Answer 4

Adults

Question 5

Salmonella species

Common in?

Answer 5

Sickle cell disease

Question 6

S. aureus, group A Streptococcus, Gram
negative rods, anaerobes.
Common in >

Answer 6

Infection after trauma ,injury or surgery

Question 7

Pseudomonas aeruginosa, S. aureus

Common in ?

Answer 7

Infection after puncture wound of foot.

Question 8

Mycobacterium tuberculosis or M. avium.

Answer 8

AIDS patients

Question 9

acute osteomyelitis

Clinically?

Answer 9

fever, localized pain , heat , swelling, tenderness of affected site ( one or more bones or joints affected in hematogenous spread). May be local tissue infection ( abscess or wound) .

Question 10

acute osteomyelitis

Blood tests:?

Answer 10

leukocytosis, high ESR and C-reactive

protein.

Question 11

acute osteomyelitis

• X-ray? Ultrasound? CT scan? MRI?

Answer 11

• X-ray : normal at early stages. Swelling of soft tissues
followed by elevation of periosteum , demineralization and
calcification of bone later on.

• Ultrasound: fluid collection (abscess) and surface
abnormalities of bone. • CT scan: reveal small areas of osteolysis in cortical bone. • MRI : early detection ,help in unclear situations. Defines
bone involvement in patients with negative bone scan.

Question 12

Diagnosis of acute osteomyelitis?

Answer 12

Blood culture: bacteremia common.
Biopsy of periosteum or bone or needle aspiration of
overlying abscess if blood culture is negative.
Blood test: complete blood and differential counts .
Erythrocyte sedimentation rate ( ESR) .
C-reactive protein
Imaging studies: X-RAY, MRI, CT-SCAN

Question 13

Complications of acute osteomyelitis include?

Answer 13

oSeptic arthritis
oChronic osteomyelitis
oMetastatic infection to other bones or organs
oPathological fractures

Question 14

Chronic Osteomyelitis

Infection due to?

Answer 14

hematological spread is rare.

Question 15

Chronic Osteomyelitis

Infection are ?

Answer 15

secondary to a contiguous focus or

peripheral vascular disease.

Question 16

Chronic Osteomyelitis

Most common pathogen ?

Answer 16

• S. aureus is the most common pathogen.

Question 17

? And ? clinically have
indolent “chronic” course
?

Answer 17

Tuberculosis and fungal osteomyelitis

Question 18

Chronic Osteomyelitis
? And ? may be the cause in
immunosuppressed patients.

Answer 18

Mycobacteria and fungi

Question 19

common in KSA. ?

Chronic Osteomyelitis

Answer 19

TB & Brucella

Question 20

Diagnosis of chronic osteomyelitis

?

Answer 20

• Blood culture is not very helpful because bacteremia is
rare.
• WBC usually normal, ESR elevated but not specific.
• Radiological changes are complicated by the presence of
bony abnormalities.
• MRI helpful for diagnosis and evaluation of the extent
of disease.

Question 21

Management & Treatment

Of chronic osteomyelitis

Answer 21

• Extensive surgical debridement with antibiotic therapy.
• IV antibiotics for 3-6 weeks followed by long term oral
suppressive therapy.
• Some patients may require life long antibiotic ,others for
acute exacerbations.

Question 22

 Is an acute inflammation of the joint space secondary to

infection. ?

Answer 22

Septic (Infectious) Arthritis:

Question 23

Generally affects a single joint and results in suppurative
inflammation.
?

Answer 23

Septic Arthritis

Question 24

Haematogenous seeding of joint is most common.

In ?

Answer 24

Septic Arthritis

Question 25

Septic Arthritis Common symptoms? Diagnosis by ? Management?

Answer 25

Common symptoms: pain, swelling, limitation of movement. Diagnosis by Arthrocentesis to obtain synovial fluid for analysis; Gram stain, culture & sensitivity. Drainage & antimicrobial therapy important management.

Question 26

Common causes of septic arthritis S. aureus, group B Streptococcus, Gram negative rods ( e.g. E. coli, Klebsiella, Proteus, Pseudomonas) . Common in ?

Answer 26

Neonates

Question 27

``` Common causes of septic arthritis S. aureus, group A Streptococcus, S. • Infants /children pneumoniae, H. influenzae type b Common in ? ```

Answer 27

Infants. Children

Question 28

S. aureus, Neisseria gonorrheae Common organism septic arthritis ?

Answer 28

Adults

Question 29

Salmonella species septic arthritis Common in ?

Answer 29

Sickle cell disease

Question 30

S. aureus Common in ? Septic arthritis

Answer 30

Trauma /surgical procedure

Question 31

septic arthritis Mycobacterium tuberculosis , Fungi Common in ?

Answer 31

Chronic arthritis

Question 32

Other causes of septic arthritis Reactive arthritis due to: ?

Answer 32

* Campylobacter jejuni * Yersinia enterocolitica * Some Salmonella species

Question 33

Other causes of septic arthritis Non-infectious causes of arthritis?

Answer 33

* Rheumatoid arthritis * Gout * Traumatic arthritis * Degenerative arthritis

Question 34

Risk factors Of septic arthritis ?

Answer 34

1. Gonococcal infection : • Most common cause in young, sexually active adults. • Caused by Neisseria gonorrheae . • Leads to disseminated infection secondary to urethritis/cervicitis . • Initially present with polyarthralgia, fever, skin lesions. 2. Non-gonococcal arthritis : • Occurs in older adults. • Results from introduction of organisms into joint space as a results of bacteremia or fungaemia from infection at other body sites. 3. Lyme disease due to tick bite in endemic areas. Uncommon in KSA.

Question 35

Diagnosis of Septic Arthritis | ?

Answer 35

1. History/examination to exclude systemic illness. Note history of tick exposure in endemic areas 2. Arthrocentesis should be done as soon as possible; 1- Synovial fluid is cloudy and purulent. 2- Leukocyte count generally > 25,000/mm3,with predominant neutrophils. 3- Gram stain and culture are positive in > 90% of cases. 4- Exclude crystal deposition arthritis or non-infectious inflammatory arthritis. 3. Blood cultures indicated • If Gonococcal infection suspected, take specimen from cervix, urethra, rectum for culture or DNA testing for N. gonorrheae. • Investigate for other sexually transmitted diseases. • Culture of joint fluid.

Question 36

Management & treatment | Of septic arthritis?

Answer 36

1. Arthrocentesis with drainage of infected synovial fluid. • Repeated therapeutic Arthrocentesis often needed. • Occasionally, surgical drainage/debridement • Antimicrobial therapy should be directed at the suspected organism and susceptibility results