Osteomyelitis and osteosarcoma Flashcards
What is the difference between osteomyelitis and osteitis?
Osteomyelitis is the inflammation of all layers of the bone
Osteitis is the inflammation of just the cortex of the bone without the involvement of the bone marrow
Using DAMNITV which causes commonly cause disease in bone?
Developmental = common, Degenerative = typically joints Autoimmune = rare, Anomalous = possible Infectious = common, inflammatory = joints Metabolic = calcium disorders Neoplastic = common Traumatic = common Vascular = specifically affecting bone is uncommon
How do animals present with acute osteomyelitis?
Rapid onset, short duration single limb lameness often with a history of laceration or surgery
On clinical exam heat, pain and swelling on bone palpation are commonly found and joints can be normal and febrile
How do animals present with chronic osteomyelitis?
Moderate/intermittent lameness of days/weeks duration often with a history of laceration or surgery
On clinical exam it is possible to find heat, pain and swelling, normal joint structures, discharge and sinus tract formation and possibly a pathological fractre
What is a key diagnostic point for osteomyelitis?
Combination of the bone’s pathogenic process and the bone’s reaction results in bone loss and formation
How is osteomyelitis diagnosed?
Radiography, culture and sensitivity, biopsy and radionuclide scan
What is the treatment for osteomyelitis?
If early then broad spectrum antibiotics
Change on the basis of bacterial cultre
Consider local delivery, surgical debridement, immobilisation, lavage and rehabilitation of the entire limb
How does osteosarcoma present?
Typically older dog with unilateral few week long lameness that isn’t responsive to analgesia and rest
Pain on palpation and swelling
How do you investigate a case of osteomyelitis?
Clinical exam including LN palpation and degree of disability
Local and thoracic radiography
Swab tracts, culture and sensitivity to rule out osteomyelitis
Biopsy in a number of sites sing a Jamshidi needle
Definitive diagnosis based on biopsy or culture
Stage and evaluation of progression and prognosis
What are the decisions that need to be made in terms of treatment?
Analgesia doesn’t work so need to treat primary tumour whilst considering secondary spread as nearly all osteosarcomas have micro-metastases at the lungs at the time of diagnosis
What are the options for treatment of osteosarcoma and their prognoses?
Amputation (4 months) with chemo (12-14 months)
Limb sparing and chemo (12-14 months)
Euthanasia
Radiotherapy as a palliative treatment
