Delayed Bone Healing Flashcards
What are the 4 major open fracture fixation types?
- external coaptation - no wound access
- IM pin/interlocking nail - spreads contamination
- external fixator - preserves blood supply, no implant at fracture site, access to wound
- bone plate
What are degloving injuries? What are the 2 types?
result of shearing forces that severe cutaneous vessels supplying the skin
- PHYSIOLOGIC - skin devitalized, but still in place
- ANATOMIC - skin avulsed from underlying tissue
Physiologic degloving:
- skin devitalized, but still in place
- if left untreated, the skin is a harbor of major contamination
Anatomic degloving:
- skin avulsed from underlying tissue
- want to support degranulation tissue for functional ankylosis to maintain ability to walk
What is the main concern with missile wounds?
increased soft tissue trauma underneath small entrance wound due to vibration of bullets
What is osteomyelitis?
inflammation of bone marrow, cortex, and periosteum, usually secondary to bacterial infection (also fungal or mixed infections)
- biopsy: fungal hyphae
- culture: bacteria
What are the most common monomicrobial, polymicrobial, and anaerobic infections isolated from osteomyelitis?
MONO - Staphylococcus intermedius or aureus
POLY - Streptococcus, Proteus, E. coli, Klebsiella
ANAEROBIC - Actinomyces, Clostridium, Bacteroides
What are the 4 causes of osteomyelitis?
- iatrogenic surgical inoculation/contamination
- open fracture
- hematogenous spread - septic translocation from GIT to the metaphyseal region (Parvo puppies)
- extension from adjacent soft tissue infection
What 4 factors are required for iatrogenic osteomyelitis development?
- inoculum of pathogenic bacterial in sufficient numbers, typically from FB that potentiate infection
- soft tissue damage - hematoma, lack of blood supply
- formation of biofilm (glycocalyx)
- unstable repair
What is bioflim?
combination of bacterial slime and host cellular debris that acts to promote bacterial adherence and protects bacteria from phagocytosis, host antibodies, and antibiotics
- reservoir for infection!
When is hematogenous osteomyelitis most common?
- immature dogs
- metaphysis of long bone
- fracture sites
What are the 5 most common acute findings on physical/laboratory exams with osteomyelitis?
- pain on palpation
- swollen and inflamed soft tissues
- pyrexia, anorexia, lethargy
- d/c from sinus tracts
- neutrophilia with left shift
What are the 2 most common radiographic findings in the acute phase of osteomyelitis?
- soft tissue swelling
- gas shadows if gas-producing bacteria present
What are the 6 most common physical exam findings in the chronic stage of osteomyelitis?
- lameness
- d/c from sinus tracts
- pain on deep palpation of bone
- disuse muscle atrophy
- intermittent soft tissue swelling
- instability at fracture site
What are the 2 types of draining tracts?
- SINUS - communication between mesothelial surface and skin, often associated with FB migration
- FISTULA - communication between 2 epithelial surfaces (e.g. tracheoesophageal fistula)