A Rare Facultative Anaerobe Causing Emphysematous Osteomyelitis of the Pubic Bone

Abstract

Emphysematous osteomyelitis is an uncommon and fatal disease that can only be confirmed with a contrast-enhanced CT scan showing characteristic features of air locules within the bone. It usually occurs in the setting of existing comorbidities and suppressed immune system resulting in widespread bacteremia which may be mono or poly-microbial. Presented here is a case of this disease caused by an unusual anaerobe affecting the pubic bone. This case emphasizes the importance of early imaging as it is crucial for the diagnosis and can facilitate early aggressive management. Moreover, it highlights the importance of early intravenous antibiotics and surgical intervention, which can be life-saving and result in a better outcome in the future.

Keywords: computed tomography imaging; diabetes mellitus; emphysematous osteomyelitis; morganella morganii; pubic bone.

Figure 1. CT abdomen and pelvis (coronal view, bone window) showing clusters of greater than three distinct foci of intramedullary gas with irregularly irregular sizes, giving the classic "Pumice Stone sign" of emphysematous osteomyelitis.

CT: Computed tomography

Figure 2. CT abdomen and pelvis with contrast (coronal images, soft tissue window) showing multiple loculated pockets of collection in the perineum, anterior and right hemi-pelvis surrounding the pubic bone. There are cortical erosions of bilateral pubic bones.

Figure 3. CT abdomen and pelvis (axial section, soft tissue window) showing intra-osseous pneumatosis of the pubic bone.

Figure 4. CT abdomen and pelvis (axial images soft tissue window) showing pockets of collections are seen in the right ishio-rectal fossa, extending into the right gluteal region and the superio-medial part of bilateral thighs. Most of these collections have enhancing walls and contain air foci.

Figure 5. CT abdomen and pelvis (axial section, bone window) showing intra-medullary gas with irregularly irregular sizes, consistent with emphysematous osteomyelitis.

Figure 6. CT thorax (coronal mediastinal window) showing a filling defect in the sub-segmental branch of the right pulmonary artery suggestive of pulmonary embolism.

Figure 7. CT thorax (coronal mediastinal window) showing a filling defect at the bifurcation of upper and lower segmental pulmonary branches indicating pulmonary embolism.