Misc. MSK Disorders Flashcards
(108 cards)
Essentials of Osteomyelitis Dx:
- Fever associated with bone pain and tenderness.
- Microbiologic dx often made from blood cx.
- Elevated ESR and CRP common.
- Early radiographs are typically negative.
causes of osteomyelitis
classification
- Hematogenous spread
- Spread from a contiguous site of infection / open wound
- Secondary infection in the setting of vascular insufficiency or concomitant neuropathy
duration of osteomyelitis
classification
- acute
- chronic
osteomyelitis: Hematogenous Spread Typically results from ?
bacteremia and begins in the medullary canal
osteomyelitis hematogenous spread - MC in what demographic?
- MC children
-
Male
- Infection is seen in the metaphysis of long bones
- Hemoglobinopathies, such as sickle cell increase the risk
RF for Hematogenous Spread in osteomyelitis
Complicated delivery, maternal infection at delivery, prematurity, indwelling catheters, urinary tract anomalies, sickle cell, immunodeficiency disorders
MC organism in children to cause osteomyelitis
S aureus (MC), Salmonellae (sickle cell), groups A and B Streptococcus, Strep. pneumo, E. coli, and Kingella kingae (other countries)
In adults, osteomyelitis often manifests in ?
risk increases with?
- vertebral column (LS>TS>CS)
- Risk increases with age and IVDU
RF for hematogenous spread of osteomyelitis in adults
Diabetes, IVs, and indwelling urinary catheters
MC organisms in adults for osteomyelitis
- S aureus (MC)
- Pseudomonas (IV drug use)
- gram - organisms (elderly)
Infection travels from a soft tissue site
what type of spread in osteomyelitis
Contiguous Spread
causes fo contiguous spread of osteomyelitis
- open fractures/trauma, prosthetic devices, neurosurgery, septic arthritis
- Symptoms often begin 1 month after inoculation
- Infection inoculates the bony cortex and migrates towards the medullary canal
contiguous spread is MC in who?
osteomyelitis
adults
MC organisms for contiguous spread in osteomyelitis
S aureus, Staph. epidermidis, Streptococcus
Polymicrobial infections MC for contiguous spread
- Often results from a chronic, progressively soft tissue infection of the foot or ankle
- Hip and sacrum can be involved (pressure injury)
- Most often related to diabetes/diabetic ulcers and vascular insufficiency
Secondary Infection due to Comorbid Conditions
MC pathogens for Secondary Infection due to Comorbid Conditions in osteomyelitis
- Polymicrobial infections common
- S. aureus and 𝛃-hemolytic strep MC
-
Gradual onset of sx over several days - wks
- Dull pain at the involved site - +/- worse with movement
- Fever and rigors - Tenderness, warmth, erythema and swelling on exam
presentation of what dx
Osteomyelitis
what type of condition may lees to less severe subjective complaints for osteomyelitis
DM
osteomyelitis: _____ should be performed when ulcer is present
Probing for bone
vertebral involvement presentation of osteomyelitis
- Slower progression → 3 weeks - 3 months
-
Localized pain and tenderness of involved vertebrae
- Often more than one vertebrae is involved including the intervertebral disks
- Pain is increased with percussion over affected area - (+) fever in ½ of patients
- +/- neurologic sx (present ⅓ of pts)
- Results from extension of infection leading to a spinal epidural abscess
other presentations of osteomyelitis
- Nonverbal patients/pediatrics - decreased use/movement, fussiness
- Hip, pelvis, vertebral involvement - predominantly pain with few other sx
lab dx osteomyelitis
-
Organism isolation → blood, bone, or contiguous focus
- Blood cx (+) in 60% of cases
- Cx from overlying wounds, ulcers are NOT reliable - CBC - Elevated WBC - left shift in acute infection
-
ESR and CRP - elevated
- Helpful to monitor throughout treatment course - BMP
- Assess renal and liver function before starting pharmacotherapeutics
imaging dx for osteomyelitis
X-ray - Abnormal findings may not be present early in course
- Children - 5-7 d+
- Adults - 10-14 d+
- Early changes → possible soft tissue swelling, loss of tissue planes, periarticular demineralization of bone
-
Later XR changes (>2 weeks after sx)
- Periosteal thickening or elevation
- Bone cortex irregularity - Osteolysis, endosteal scalloping, regional osteopenia - Chronic infection - New bone formation, sclerosis
CT/MRI - highly sensitive
1. Avoid with indwelling metal devices
2. MRI preferred for foot infections
nuclear studies
1. If MRI is CI
2. High sensitivity but a low specificity
indications for bone bx for osteomyelitis
- All pts with radiologic evidence of osteomyelitis without (+) blood cx
- Osteomyelitis by hematogenous spread doesn’t require bone bx - Do not delay biopsy due to abx use