Acute osteomyelitis of the humerus mimicking malignancy: Streptococcus pneumoniae as exceptional pathogen in an immunocompetent adult

Osteomyelitis with abscess associated with acute closed upper humerus fracture in an adult: A case report

A 64-year-old female presented with malaise and fever 11 days after a closed, minimally displaced humerus surgical neck fracture. MR imaging revealed an abscess around the fracture, which is a very rare occurrence in adults. Two open debridements and IV antibiotics eradicated the infection. Reverse total shoulder arthroplasty was eventually performed for fracture nonunion.

Update on MRI findings of osteomyelitis of long bones in the adult population

OBJECTIVES

To evaluate the usefulness of new and established MRI signs of osteomyelitis in long bones in adults.

METHODS

All patient records over a 9-year period with clinical or MRI suspicion for osteomyelitis were retrospectively reviewed, using strict criteria for proof of infection. Two musculoskeletal radiologists independently reviewed the MRIs of proven osteomyelitis.

RESULTS

Out of 45 MRIs of confirmed osteomyelitis, 2 MRIs (4%) did not show confluent low-signal intensity on T1-weighted images, but all showed confluent high-signal intensity on T2-weighted images. Central hypoenhancing regions of marrow without abscess formation were found in 15-18/35 (43-51%) cases where gadolinium was given. We often found multiple foci of marrow replacement in the same bone. The areas of marrow involvement often had an irregular contour. Penumbra sign, marrow fat globules, and sequestra were uncommon.

CONCLUSION

Multiple foci of bone marrow signal abnormalities, an irregular contour of marrow abnormality, and central marrow hypoenhancement without abscess are common signs of osteomyelitis of long bones in adults. Confluent low T1-signal intensity is not always present.

[Austrian syndrome: A rare manifestation of invasive pneumococcal disease. A case report and bibliographic review]

The Austrian syndrome is a pathology caused by disseminated Streptococcus pneumoniae infection and characterized for the triad of pneumonia, endocarditis and meningitis. It has an estimated incidence of 0.9-7.8 cases per ten millions people each year, and a mortality of 32%. Alcohol abuse, as the main risk factor, appears only in four out of ten patients. Moreover, 14% of patientes do not have any risk factor. Two out of three patients are males and it occurs in the middle aged of life. It is more frequently on native valve, aortic valve is injured in the half of the cases. Severe regurgitation occurs in two per three patients. Appropriate antimicrobial treatment and early endocarditis surgery decrease mortality. It is possible that Austrian syndrome epidemiology is changing by the introduction of 13-valent pneumococcal conjugated vaccine in the children´s calendar.