osteomyelitis

Question 1

how commonly do odontogenic infections spred via bone

Answer 1

less common than soft tissue

Question 2

Osteomyelitis - Definition
* Osteomyelitis def? tendency to?
* This process starts where in bone? spreads to?
* The disease if untreated progresses?
* In the oral region, it is usually a result of?

Answer 2

• Osteomyelitis is Inflammation and infection of the bone marrow with a tendency to progression.
• This process starts of in the medullary bone and then continues to involve adjacent cortical plates and often periosteum (More frequently seen in the Mandible)
• The disease if untreated progresses from inflammatory destruction of bone, to necrosis (sequestra).
• In the oral region, it is usually a result of bacterial infection secondary to odontogenic infections, trauma.

Question 3

Osteomyelitis - Incidence
* which arch? why?

Answer 3

• Much higher in the mandible due to the dense, poorly vascularized cortical plates.
• Maxillary bone is much less dense with excellent blood supply.

Question 4

Mandible blood supply/ bone

Answer 4

• Predominantly supplied by Inferior
  alveolar Neurovascular bundle
• Overlying cortical plate is thick

Question 5

Maxilla
* vascular supply
* density?

Answer 5

• Much more vascular than Mandible
  as it receives blood supply from
  several arteries.
• Less dense than Mandible

Question 6

sequestra

Answer 6

necrotic bone

Question 7

osteomyelitis course?

Answer 7

This pathologic entity usually follows an indolent, yet progressive and persistent

Question 8

Answer 8

osteomyelitis

Question 9

Microstructure of Bone

Answer 9

Question 10

Osteomyelitis – Predisposing factors

Answer 10

Immuno-compromised status
and Conditions that affect the Jaw vascularity

Question 11

Osteomyelitis - Pathogenesis
in mandible

Answer 11

Question 12

Osteomyelitis - Pathogenesis
Primarily a result of? allows?
Results in an? limiting?
With progression, the condition is considered?

Answer 12

• Primarily a result of odontogenic infections or trauma, which cause inoculation of bacteria into the jaws.
• Results in an inflammatory cascade that is usually self-limiting in the healthy patient.
• With progression, the condition is considered pathologic

Question 13

Osteomyelitis - Pathogenesis
* Infection and associated inflammation(edema) spreads into?
* Pus travel through? accumulates where?
* Ultimately, cortical bone will? result?
* Reduced blood supply causes?

Answer 13

• Infection and associated inflammation (edema) spreads into marrow spaces and causes compression of blood vessels and therefore causes severe compromise of blood supply.
• Pus travel through haversian & volkaman’s canal and accumulation beneath the periosteum & elevating it from cortex & there by reducing the blood supply.
• Ultimately, cortical bone perforates, compromising periosteal blood supply as well.
• Reduced blood supply causes necrosis of bone.

Question 14

Osteomyelitis - Pathogenesis
* Small section of necrotic bone may get completely? what if larger?
* The dead bone is surrounded by the new viable bone this is called?
* Then pus penentrate the?
* fistulas?

Answer 14

• Small section of necrotic bone may get completely lysed while large get localized and get separated from the shell of new bone by bed of granulation tissue.
• The dead bone is surrounded by the new viable bone this is called involucrum.
• Then pus penentrate the periosteum & mucosal & cuteneous fistulae develop and thereby discharging the purulent pus.
• Intraoral or extraoral fistulas usually develop.

Question 15

Osteomyelitis - Pathogenesis
* Bacteria then proliferates as what cannot reach site? spreads until?

Answer 15

• Bacteria then proliferates as normal blood-borne defenses do not reach the tissue and the osteomyelitis process spreads until it is stopped by surgery and medical treatment

Question 16

Osteomyelitis - Microbiology
Usually a?
Osteomyelitis of the long bones usually caused by?

Answer 16

Usually a mixed infection when involving the jaws.

Osteomyelitis of the long bones usually caused by Staphylococcus aureus

Question 17

Osteomyelitis - Classification
Many systems?
System developed by ? is the most practical today
This system divides osteomyelitis into what types based on?

Answer 17

Many systems have been developed in the past
System developed by Hudson is the most practical today
This system divides osteomyelitis into Acute and Chronic types based on presence for a 1 month duration

Question 18

Acute osteomyelitis - Classification
* Contiguous focus?
* Progressive?
* Hematogenous ?
* Suppurative vs. non-suppurative?

Answer 18

• Contiguous focus (It is the result of the spread of infection from an adjacent soft tissue
  focus such as wound, laceration, abscess, post-operative infection)
• Progressive
• Hematogenous (spread to the bone from a source through bloodstream)
• Suppurative vs. non-suppurative

Question 19

Chronic Osteomyelitis - Classification
* Recurrent multifocal?
* Garré’s?
* Suppurative or nonsuppurative?
* Chronic sclerosing?
* Chronic refractory osteomyelitis?

Answer 19

• Recurrent multifocal
• Garré’s – proliferative periostitis, periostitis ossificans
• Suppurative or nonsuppurative
• Chronic sclerosing
• Chronic refractory osteomyelitis

Question 20

Answer 20

garres osteomyelitis

Question 21

Osteomyelitis - Clinical presentation, which is highlighted?

Answer 21

– Pain
– Swelling and erythema of overlying tissues
– Adenopathy
– Fever
– Paresthesia of the inferior alveolar nerve
– Trismus
– Malaise
– Fistulas

Question 22

Osteomyelitis - Laboratory work-up
In the acute phase, common to see?

sensitive indicators of inflammation but non-specific?

Answer 22

In the acute phase, common to see leukocytosis, which is uncommon in the chronic phases.

Elevated ESR (erythrocyte sedimentation rate) and CRP (C-reactive protein) which are sensitive indicators of inflammation but non-specific.

Question 23

Osteomyelitis - Imaging
Radiographic images lag? why?
Acute osteomyelitis often appears?
Till at least ?% destruction of mineralized portion of bone takes place – this destruction is not visible on radiograph?
Chronic osteomyelitis app?

Answer 23

Radiographic images lag behind the clinical presentation since cortical involvement is required for any change to be evident.
Acute osteomyelitis often appears normal radiographically
Till at least 30-60% destruction of mineralized portion of bone takes place – this destruction is not visible on radiograph.
Chronic osteomyelitis – moth eaten appearance

Question 24

Osteomyelitis - Imaging
– what is recommended initially?
– Gives information of?

Answer 24

– Orthopanoramic view is recommended initially
– Easily obtainable
– Gives information of possible sources and progression.

Question 25

Answer 25

chronic osteomyelitis-moth eaten

Question 26

Osteomyelitis - Imaging * what have become standard? – Provide detailed? – Require ?% demineralization before changes are seen. – Allow assessment of ?

Answer 26

* C.T scans have become standard – Provide detailed 3 dimensional views. – Require 30-50% demineralization before changes are seen. – Allow assessment of the cortices

Question 27

Osteomyelitis - MRI * It can assist in? how? * what are seen more accurately in MRI when compared to a CT scan?

Answer 27

* It can assist in early diagnosis by detection of bone marrow changes prior to cortical involvement. * Bone marrow changes and soft tissue changes are seen more accurately in MRI when compared to a CT scan.

Question 28

Osteomyelitis - Nuclear medicine highlights areas of? A technetium bone scan is more sensitive than? in detecting? However, bone scans in general are sensitive for? but not? There is a high incidence of false positive?

Answer 28

Nuclear medicine -Technetium 99 highlights areas of increased bone turnover. A technetium bone scan is more sensitive than plain film imaging in detecting early infections and may be positive as early as three days. However, bone scans in general are sensitive for bone turnover, but are generally not specific for osteomyelitis. There is a high incidence of false positive osteomyelitis nuclear medicine studies. of soft tissue infections

Question 29

Osteomyelitis - Treatment Both what interventions are required? Medical therapy alone? Tissues from the affected site should be sent for? Immunocompromised states should be?

Answer 29

Both medical and surgical interventions are required. Medical therapy alone will not suffice, and will only delay appropriate treatment. Tissues from the affected site should be sent for microbiological exam, culture and sensitivity, and histopathological examination. Immunocompromised states should be controlled medically to achieve optimum response to therapy

Question 30

Osteomyelitis – Medical Treatment * Begin abx based on? * Best choice of antibiotic can be determined following?

Answer 30

* Begin empiric antibiotic treatment based on Gram stain(microbiological exam) results. * Best choice of antibiotic can be determined following C & S results, which can take several days

Question 31

Osteomyelitis – Medical Treatment IV antibiotic therapy? Treatment may include what agents? Infectious disease consult? HBO therapy for?

Answer 31

* IV antibiotic therapy for 6 weeks is routinely used * Treatment may include carbapenems, cephalosporins, fluoroquinolones, Clindamycin, Metronidazole, or combination therapy. * Infectious disease consult may be considered * HBO therapy for chronic refractory osteomyelitis may be considered

Question 32

Hyperbaric Oxygen Therapy (HBOT) Chronic refractory osteomyelitis is?

Answer 32

* Hyperbaric oxygen is indicated in treatment of “Chronic Refractory osteomyelitis" * Chronic refractory osteomyelitis is a persistent or recurrent bone infection lasting longer than six months despite appropriate surgical and medical treatment.

Question 33

Hyperbaric Oxygen Therapy(HBOT) * HBOT involves placing a patient in a chamber where they breathe ?% oxygen at ? atmospheric pressure. * A typical course of treatment for Chronic refractory osteomyelitis consists of a ? minute session for ? days per week for ? to ? treatments based on their condition

Answer 33

* HBOT involves placing a patient in a chamber where they breathe 100% oxygen at increased atmospheric pressure. * A typical course of treatment for Chronic refractory osteomyelitis consists of a 90 minute session for five days per week for 20 to 60 treatments based on their condition

Question 34

Hyperbaric oxygen treatment – Mechanism of action - Enhanced? - Angiogenesis? - Osteo? - Synergistic?

Answer 34

- Enhanced leukocyte oxidative killing - Neo-Angiogenesis - Osteogenesis - Synergistic antibiotic activity

Question 35

Osteomyelitis – Surgical Treatment Sequestrectomy

Answer 35

* Sequestrectomy is the removal of infected and avascular pieces of bone. * Since the sequestrum is avascular, antibiotics will not be able to penetrate into it.

Question 36

Osteomyelitis – Surgical Treatment Saucerization * removal of? * permit healing by? * defect shape and clot?

Answer 36

Saucerization involves: * the removal of the adjacent bony cortices and open packing * permit healing by secondary intention after the infected bone has been removed. Here the margins of the bone which lodge the sequestra are trimmed down. This create a saucer shaped defect instead of a deep hollow cavity. This saucer shaped defect can’t accumulate a large clot

Question 37

Osteomyelitis – Surgical Treatment: Decortication * removal of? * periosteum role? * key element?

Answer 37

involves removal of the dense, chronically infected, and poorly vascularized bony cortex and placement of the vascular periosteum adjacent to the medullary bone to allow increased blood flow and healing in the affected area. * Key element is cutting back to healthy bleeding bone – clinical judgement

Question 38

Osteomyelitis – Surgical Treatment Additional considerations * May support weakened mandible using? * Segmental resection usually a?

Answer 38

* May support weakened mandible using external fixation, reconstruction plate, or MMF. * Segmental resection usually a last resort following multiple attempts at more conservative debridement