Osteomyelitis: Cellulitis r/o Osteomyelitis

2nd INPATIENT, Clinic A/P, adults, Clinic A/P, Peds, Hospital A/P, Adults, Hospital A/P, Peds

#Cellulitis r/o Osteomyelitis, condition, stable.
The most common cause is strep or staph.
H&P performed.
Probed to bone? At ___cm?
Labs:
Imaging:  CXR shows _____; MRI ____
Admit to Med/Surg
Treatment
Vancomycin + Zosyn.
Elevate extremity.
F/u BCx.
Consult Podiatry/Wound Care for debridement, biopsy for cultures.
Consider consulting vascular surgery.
If diagnosis confirmed, will need 4-6 weeks of antibiotics.

–//END//–

Key Points

Diagnosis of Osteomyelitis

  • The gold standard for diagnosis of osteomyelitis a bone biopsy sample obtained via a sterile technique that grows bacteria PLUS with histologic findings of inflammation and osteonecrosis. However, you don’t have to meet this gold standard to diagnose osteomyelitis.
  • Positive results of a probe-to-bone test are sufficient for the diagnosis of osteomyelitis.
  • “If a diabetic foot ulcer is larger than 2 x 2 cm or bone is palpable, osteomyelitis is so likely that additional noninvasive evaluation may not be needed.”
  • If radiologic studies are consistent with osteomyelitis in a patient who also has positive blood cultures, a bone biopsy may not be needed.
  • The only culture that matters for osteomyelitis diagnosis is a bone biopsy, not a wound culture or even a wound debridement.
  • “Open biopsy is better than a needle biopsy. Bone samples should be obtained at the time of surgical debridement if performed. Percutaneous needle biopsy is an alternative to open biopsy; ideally, it should be performed via intact tissues and under radiographic guidance to optimize yield. Bone biopsy should be obtained prior to treatment with antimicrobial therapy whenever possible.”

Imaging studies:

  • Foot: If the patient has DM and osteomyelitis of the foot is suspected, MRI is the test of choice.
  • Spine: If the patient has symptoms referable to the spine, MRI is the test of choice to evaluate for vertebral osteomyelitis. If MRI is not available, CT is the alternative test of choice.
  • Metal Hardware: If metal hardware precludes MRI or CT, a nuclear study is the test of choice. There are two nuclear tests: 1) A Three-Phase Bone Scan, or 2) Indium White Blood Cell Scan (also called “indium leukocyte imaging,” “indium-111 scan,” or simply “indium scan,”

 

Case: I had a patient who was s/p ORIF of an ankle fx and had an infection in the surgical wound and we wanted to r/o osteomyelitis. However, radiology reminded us that we couldn’t do an MRI because of the metal hardware. The recommended a Three Phase Bone Scan or Indium WBC scan. The three-phase bone scan is usually used first at our institution.

print