Miscellaneous MSK Disorders - Exam 1 Flashcards
(96 cards)
Consider names xrays
https://www.radiologymasterclass.co.uk/tutorials/musculoskeletal/trauma/trauma_x-ray_page1
What is osteomyelitis?
osteo (bone)
myelitis (inflammation of the fatty tissues)
What are common s/s of osteomyelitis? What 2 labs should you order? What will the xray show early on?
fever associated with bone pain and tenderness. Tenderness, warmth, erythema and swelling on exam
blood cultures and ESR/CRP are commonly elevated
Early xray is usually negative
What are 3 major causes of osteomyelitis? **What is the highlighted way from lecture?These can be both _____ or _______
hematogenous
**spread from an previous infection or open wound (Jory said to think foot wounds and bed sores)
Secondary infection in the setting of vascular insufficiency or concomitant neuropathy
acute or chronic
In the hematogenous spread, where does it come from? What pt population? What gender? What part of the bone?
bacteremia and begins in the medullary canal
MC in children
MALE!!
metaphysis of long bones¹
What are risk factors for hematogenous osteomyelitis?
Complicated delivery
maternal infection at delivery
prematurity
indwelling catheters
urinary tract anomalies
sickle cell
immunodeficiency disorders
What is the MC organisms in children with hematogenous spread of osteomyelitis? What if sickle cell?
S aureus (MC)
Salmonellae (sickle cell)
Where is the MC bone location in adults for hematogenous spread of osteomyelitis? What are the 3 risk factors in adults? What are the 2 MC organisms?
In adults, often manifests in the vertebral column¹ (LS>TS>CS)
DM, IVs and indwelling urinary caths
S aureus (MC), Pseudomonas (IV drug use)
What are 4 causes of contiguous spread of osteomyelitis? When do symptoms typically start? How does it invade the bone?
open fractures/trauma, prosthetic devices, neurosurgery, septic arthritis
1 month after inoculation
Infection inoculates the bony cortex and migrates towards the medullary canal
What are the common organisms in contiguous spread osteomyelitis? MC in adults or children?
S aureus, Staph. epidermidis, Streptococcus
but really POLYmicrobial infections are more common
MC in adults
How is osteomyelitis from a secondary Infection due to Comorbid Conditions likely to occur? What type of microbes?
Often results from a chronic, progressively soft tissue infection of the foot or ankle, usually related to diabetes/diabetic ulcers and vascular insufficiency
Polymicrobial infections common, S. aureus and 𝛃-hemolytic strep
When should you probe the bone in osteomyelitis?
Probing for bone should be performed when ulcer is present
How will vertebral involvement osteomyelitis present?
slower progression 3 weeks to 3 months
Localized pain and tenderness of the involved vertebrae, pain increases with percussion over the affected area, may have fever (but not required), may have neurological symptoms
When getting blood cultures to test for osteomyelitis, must not pull from _______. How often are blood cultures positive? If negative, and suspicion is still high, what should you do next?
Cultures from overlying wounds, ulcers are NOT reliable
Blood cultures (+) in 60% of cases
bone bx
______: possible soft tissue swelling, loss of tissue planes, periarticular demineralization of bone
_______:
Periosteal thickening or elevation
Bone cortex irregularity
Osteolysis, endosteal scalloping², regional osteopenia
Early XR changes
Later XR changes greater than 2 weeks
Endosteal scalloping
periosteal reaction
osteolysis
moth sign
_______ is used to dx osteomyelitis. Which one is preferred for foot infections?
CT/MRI
MRI
What is the indication for a bone bx in osteomyelitis? Which type does NOT require it? Can you start abx before bone bx?
All patients with radiologic evidence of osteomyelitis without (+) blood cultures
Osteomyelitis by hematogenous spread doesn’t require bone bx
YES!! but often bone cultures are positive regardless of prior antibiotic therapy
What are the 2 different options for bone bx? Which one is preferred?
open** or percutaneous
percutaneous is used for vertebral osteomyelitis and must be collected through UNINFECTED soft tissue
What will the histology show of a pt with osteomyelitis?
Histology - shows necrotic bone with extensive resorption adjacent to an inflammatory exudate
What is the management plan for osteomyelitis?
consult ID and Ortho!
vancomycin + 3rd or 4th gen ceph (ceftriaxone, ceftazidime, or cefepime)
remove hardware involved
What organisms do you need to cover for in osteomyelitis? How long do you need to treat for?
MRSA and gram - organisms
Treatment for staphylococcal osteomyelitis should be at least 4 weeks in duration
Methicillin-sensitive isolates → IV cefazolin, nafcillin, or oxacillin
MRSA: vancomycin with goal trough level of 15-20mcg