Osteomyelitis, osteonecrosis and Osteoradionecrosis Flashcards
Give the pathological definition for osteomyelitis
Inflammation of bone marrow
What is osteomyelitis
A spectrum of inflammatory and reactive changes in the bone and periosteum
What can osteomyelitis result in
Due to the indicative disease of bone it can result in necrosis of the affected bone
Which area is almost always affected in osteomyelitis
in almost all cases the infection extends to involve the cortical bone and periosteum of the affected area.
Name the different types of osteomyelitis
- Acute
- Chronic
- Subperiosteal
- Sclerosing
What can acute and chronic osteomyelitis also be called
Suppurative and Non-suppurative
What is acute osteomyelitis
When a clinical picture of acute infection is seen
Systemic effects seen
What can chronic osteomyelitis be split into
Primary and secondary
What is primary chronic osteomyelitis
When there is no acute episode present
What is secondary chronic osteomyelitis
When a prolonged inflammatory process is seen
Talk through the aetiology of osteomyelitis
- Odontogenic infection
- Underlying disorders
- Infected cysts
- Infected tumour
- Surgical wounds
What are the risk factors fro osteomyelitis
- Fibrous dysplasia
- Previous radiation bone exposure
- Osteoporosis
- Osteopetrosis
- Paget’s disease
- Bone tumours
- Immunocompromised patients
Talk through how osteomyelitis can lead to bone necrosis
- Bacteria infects bone marrow space
- This increases vascular collapse, venous stasis and thrombosis and ischaemia
- This increases inter medullary pressure and compromises blood supply
- Necrosis of bone
- Sequestration of new bone and increased resorption
List some bacteria that can lead to osteomyelitis
- Bacteroides
- Anaerobic strep
- Staph
What can lacteal infection in marrow space lead to
Increased intramedullary pressure and compromised blood supply
Is the mandible or maxilla more susceptible to osteomyelitis
Mandible
Why is the mandible most sensitive to infection that the maxilla
- As mandible is cancellous bone which is more likely to become ischaemic
- Blood supply to mandible is less oxygenates than maxilla
- Dense ovelying cortical bone of mandible prevents penetration of periosteal blood vessels in comparison to maxilla
Describe the microbiology of osteomyelitis
- Viridans streptococcus
- Strict anaerobes
- Staph aureus
Name some strict anaerobes that can lead to osteomyelitis
prevotella,
fusobacterium,
peptostreptococcus
Describe the how osteomyelitis of the mandible may present
- Deep intense pain with high intermittent fever
- Identifiable causable tooth
- Patient may have malaise, headache and reduced appetite
- Minimal swelling
- No fistulae
- Infection usually well localised
How long does the initial event for mandibular osteomyelitis last
1-2 weeks
What can happen if osteomyelitis of the mandible is not treated
Can spread and more toxic symptoms can develop
Talk through the signs of mandibular osteomyelitis
- Purulent discharge eroding bone
- Puss
- Extensive firm swelling
- Possible trismus
- Throbbing jaw pain
- Severe tenderness
- Extrusion of teeth
- Nerve involvement
Give some signs of mandible inflammation
- Leukocytosis
- Elevated CRP
- Local lymphadenopathy
Talk through the presentation of chronic osteomyelitis
- Normothermic
- Symptoms resolve/ disappear
- Teeth locally are tender
- Sequestra maybe expelled through mucosa
How do we diagnose acute osteomyelitis
Through clinical findings such as deep intense pain, paraesthesia etc
How do we diagnose chronic osteomyelitis
Through clinical findings AND imaging
When is osteomyelitis detectable on a plain film
1-2 weeks after onset
What are the characteristic features of osteomyelitis
- Increased radiolucency
- Moth eaten island of bones
- sequestra
What gives us a better imagine than plain oil,
CT scans and MRIS
What will a CT/ MRI of osteomyelitis show
- Increased attenuation in medullary cavity
- Destruction of cortical bone
- Proliferation of bony tissue
- Sequetra
How can we treat osteomyelitis
- Antibiotics
- Surgery
- Hyperbaric oxygen
Which antibiotics do we prescribe for osteomyelitis
- High dose penicillin with or without Metronidazole
2. Clindamycin
When might we prescribe penicillin for osteomyelitis treatment
When blood flow is compromised
How does clindamycin help treat osteomyelitis
Penetrates vascular tissue
What are the benefits of surgically treating osteomyelitis
Removes cause / eliminates source
Is important for micro sampling
How can hyperbaric oxygen aid osteomyelitis treatment
- Increase in oxygen result sin augmentation of angiogenesis
- Improvement in osteogenesis
- Increase in leukocyte activity
- Stimulates growth factors
How can hyperbaric oxygen aid osteomyelitis treatment
- Increase in oxygen result sin augmentation of angiogenesis
- Improvement in osteogenesis
- Increase in leukocyte activity
- Stimulates growth factors
How is osteomyelitis different to alveolar osteitis
Osteomyelitis:
- Spreads through bone
- Is not self limiting
- Much more chronic
- Represents failure of normal defence
Define Osteoradionecrosis
Bone necrosis in previously irradiated tissue in the absence of tumour persistent or recurrence
Talk thorough how bone is necroses in Osteoradionecrosis
- Irradiation of bone leads to osteocytes and fibroblast death
- Bone is hypo-cellular as a result
- This reduced vitality and inability to prepare
- Trauma may occur
- Bone necrosis occurs
What are the clinical features of Osteoradionecrosis
- Follows radiotherapy
- Exposed bone (often small asymptomatic site)
- Severe pain
- Oro facial fistulas
- Foul smelling necrosis of jaw
- Suppuration
- Pathological fracture
How do we diagnose Osteoradionecrosis
Through signs and symptoms
Imagining
What signs and symptoms do we see in Osteoradionecrosis
- Severe pain
- Non healing exposed bone
- Incidents of recurrent infection
What does a plain radiograph of Osteoradionecrosis show
Reduced bone density and sometimes fracture
What does MRONJ stand for
Medication Related Osteonecrosis of the Jaws
Patients on what medication have a higher risk of developing MRONJ
Bisphosphonates
What do Bisphosphonates do
- They attach to hydroxyapatite binding sites particularly on surfaces that are actively resorbing
- They impair osteoclastic ability to bind to the bony surface and inhibit resorption
- Reduces osteoclast activity by promoting osteoclast apoptosis and inhibiting development of new osteoclasts
Why are Bisphosphonates prescribed
- Metastasising solid cancers
- Multiple myeloma
- Hypercalcaemia of malignancy
- Post menopausal osteoporosis
- Steroid induced osteoporosis
- Paget’s disease
Define MRONJ
Exposed bone the can be proved through an intra oral or extra oral fistula in the maxillofacial region which has persisted more than 8 weeks in patients with a history of treatment on Bisphosphonates and where there has been no history of radiation therapy
Describe the pathopsyiology of MRONJ
- Inhibition of osteoclastic bone resorption and re modelling
- Inflammation of infection
- Inhibition of angiogenesis
Name some Bisphosphonates
- Alendronic acid
- Risedronate sodium
- Zoledronic acid
- Ibandronic acid
Talk through how MRONJ develops
- Extraction or mucosal trauma preceded osteolytic lesion
- Patients develop exposed bone in the jaw
- Exposed bone may worsen or heal slowly
Is MRONJ more common in the maxilla or mandible
Mandible
What increases the risk of developing MRONJ
- Previous MRONJ diagnosis
- If patietn is on anti resorptive or anti angiogenic drugs
- If patient has been taking Bisphosphonates for more than 5 years
- If the patietn is being treated with systemic glucorticosteroid
